**Shoulder**

**6**(2):



of osteochondral defects in the knee joint in young athletes. Arthroscopy. 2005;**21**(9):

141-149. DOI: 10.1007/s12178-013-9157-z. PubMed PMID: 23392780; PubMed Central

gous chondrocyte implantation: Prospective evaluation at average 4-year followup. The American Journal of Sports Medicine. 2009 Nov;**37**(Suppl 1):33S-41S. DOI:

cytes for the treatment of full-thickness cartilage defects of the knee joint. Arthroscopy.

[19] Biant LC, Simons M, Gillespie T, McNicholas MJ. Cell viability in arthroscopic versus open autologous chondrocyte implantation. The American Journal of Sports Medicine. 2017 Jan;**45**(1):77-81. DOI: 10.1177/0363546516664338. Epub 2016 Oct 1. PubMed PMID:

[20] Edwards PK, Ebert JR, Janes GC, Wood D, Fallon M, Ackland T. Arthroscopic versus open matrix-induced autologous chondrocyte implantation: Results and implications for rehabilitation. Journal of Sport Rehabilitation. 2014 Aug;**23**(3):203-215. DOI: 10.1123/

[21] Masri M, Lombardero G, Velasquillo C, Martinez V, Neru R, Villegas H, Ibarra C. Matrixencapsulation cell-seeding technique to prevent cell detachment during arthroscopic implantation of matrix-induced autologous chondrocyte implantation. Arthroscopy

[15] Strauss EJ, Galos DK. The evaluation and management of cartilage lesions affecting the patellofemoral joint. Current Reviews in Musculoskeletal Medicine. 2013 Jun;

[16] Pascual-Garrido C, Slabaugh MA, L'Heureux DR, Friel NA, Cole BJ. Recommendations and treatment outcomes for patellofemoral articular cartilage defects with autolo

[17] Brittberg MM, Peterson LL, Sjögren-Jansson EE, et al. Articular cartilage engineering with autologous chondrocyte transplantation. A review of recent developments. The Journal of Bone and Joint Surgery. American Volume. 2003;**85**(A Suppl 3):109-115 [18] Erggelet C, Sittinger M, Lahm A. The arthroscopic implantation of autologous chondro

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10-10

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76 Recent Advances in Arthroscopic Surgery

**Chapter 6**

Provisional chapter

**Subscapularis Tendon Tears: Classification, Diagnosis**

DOI: 10.5772/intechopen.77349

Rotator cuff tears include a panel of tendon lesions, and superior cuff tears are often combined with subscapularis lesions that are more difficult to repair. We propose in this chapter to describe the Lafosse subscapularis tears classification and to describe the arthroscopic repair that can be performed easily with a needle as shuttle. The advantages of these surgical techniques are simplicity, safety and quickness. The procedure is performed under general anaesthesia with the patient in beach chair position. A classic arthroscopic posterior portal is used to perform glenohumeral exploration, and cuff tendons are analysed. Once subscapularis tear is confirmed, the tendon must be released after repair with anterolateral portal. Then, a triple-loaded anchor is positioned at the edge of the bicipital groove to perform both

Keywords: subscapularis tendon, rotator cuff tear, Lafosse classification, needle shuttle,

The subscapularis (SSC) muscle is one of the four components of the rotator cuff along with the supraspinatus, infraspinatus and teres minor muscles. The first SSC tendon tears have been reported in 1834 by John Gregory Smith. In 1954, Hauser reported two cases of full-thickness tears repaired with an open approach using trans-osseous sutures [1]. In 1960, McLaughlin reported an SSC tear associated with recurrent anterior shoulder instability. More recently, the first major series with 16 patients including isolated SSC tears were described by Gerber in 1991 [2]. Early studies of rotator cuff tendon tears focused on the supraspinatus tendon. However, SCC tendon tears have garnered increasing attention over the last decade: clinical exam and

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Subscapularis Tendon Tears: Classification, Diagnosis

**and Repair**

and Repair

Laurent Baverel

Abstract

biceps tenodesis

1. Introduction

Laurent Baverel

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

biceps tenodesis and subscapularis repair.

http://dx.doi.org/10.5772/intechopen.77349

#### **Subscapularis Tendon Tears: Classification, Diagnosis and Repair** Subscapularis Tendon Tears: Classification, Diagnosis and Repair

DOI: 10.5772/intechopen.77349

#### Laurent Baverel Laurent Baverel

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.77349

#### Abstract

Rotator cuff tears include a panel of tendon lesions, and superior cuff tears are often combined with subscapularis lesions that are more difficult to repair. We propose in this chapter to describe the Lafosse subscapularis tears classification and to describe the arthroscopic repair that can be performed easily with a needle as shuttle. The advantages of these surgical techniques are simplicity, safety and quickness. The procedure is performed under general anaesthesia with the patient in beach chair position. A classic arthroscopic posterior portal is used to perform glenohumeral exploration, and cuff tendons are analysed. Once subscapularis tear is confirmed, the tendon must be released after repair with anterolateral portal. Then, a triple-loaded anchor is positioned at the edge of the bicipital groove to perform both biceps tenodesis and subscapularis repair.

Keywords: subscapularis tendon, rotator cuff tear, Lafosse classification, needle shuttle, biceps tenodesis

### 1. Introduction

The subscapularis (SSC) muscle is one of the four components of the rotator cuff along with the supraspinatus, infraspinatus and teres minor muscles. The first SSC tendon tears have been reported in 1834 by John Gregory Smith. In 1954, Hauser reported two cases of full-thickness tears repaired with an open approach using trans-osseous sutures [1]. In 1960, McLaughlin reported an SSC tear associated with recurrent anterior shoulder instability. More recently, the first major series with 16 patients including isolated SSC tears were described by Gerber in 1991 [2]. Early studies of rotator cuff tendon tears focused on the supraspinatus tendon. However, SCC tendon tears have garnered increasing attention over the last decade: clinical exam and

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

radiographic imaging occurred in a better diagnosis of SSC tears, and recent improvements in arthroscopic instrumentation allow easier repair of the SSC tendon.

3. Pathogenesis

be assessed.

drome [23].

4. SSC tear classification

The SSC tendon tears can have either a traumatic and/or a degenerative aetiology. In most cases, the two aetiologies are intricate: an acute traumatic event is reported, on a previous degenerate and fragile tendon. In young patients however, traumatic SSC tears are usually secondary to a forced external rotation in high-energy trauma, with or without combined posterosuperior cuff lesion. In more elderly patients, a SSC traumatic tear can be a consequence of a shoulder dislocation, and associated rotator cuff tears or neurologic injury must

Subscapularis Tendon Tears: Classification, Diagnosis and Repair

http://dx.doi.org/10.5772/intechopen.77349

81

In cases with degenerative aetiology, two theories are classically described. The extrinsic aetiology is related to the subacromial impingement syndrome that is the most common disease of the shoulder joint after the sixth decade of life, particularly in overhead workers [19]. Even if its prevalence is high, the aetiology of this syndrome and the histologic and ultrastructural changes in the rotator cuff are not well known. The friction and pressure in the narrow subacromial space probably result in tendon micro-traumatism. In degenerative SSC tears, a subcoracoid impingement may injure the anterosuperior portion of the rotator cuff involving the SSC tendon, the LHBT or all the other rotator cuff tendons. Some anatomic studies reported the close relation of the medial glenohumeral ligament (MGHL) to the upper SSC near its humeral footprint [20]. Based on arthroscopic findings, the MGHL may abrade

The intrinsic theory is that the subacromial pain is multifactorial and could be attribute to the chronic inflammation and degeneration of the rotator cuff and the subacromial bursa [22]. Farfaras found that degenerative histological changes in the form of fibrils with smaller diameters were present in the SSC tendon in patients with subacromial impingement syn-

There is no consensus or clear classification regarding SSC tears. We used the classification of

Type 1 is an isolated and partial separation of the SSC tendon fibres from the lesser tuberosity

Type 2 is a separation of the SSC tendon fibres from the lesser tuberosity and partial tear in the bicipital sling without involvement of the anterior LHBT pulley or tendinous slip. The probe introduced through the partial sling tear (consisting very often in a cleft in the anterior wall)

Type 3 is a complete separation of the SSC tendon fibres from the lesser tuberosity and complete tear in the anterior wall of the bicipital sling. The anterior LHBT pulley is normal, distended or, rarely, completely torn. The tendon retraction is minor because the superficial

against the upper edge of the SSC medial to its insertion [21].

Lafosse to classify the SSC lesions into five types [24].

with a normal bicipital sling, regardless of the appearance of the LHBT.

can lift the superficial SSC layer separated from the lesser tuberosity.

Misdiagnosed SSC tendon tears may result in rotator unbalanced force couple, leading to persistent shoulder pain and weakness after cuff repair. SSC tendon tears can be difficult to diagnose on clinical examination, and lesions may be hidden on arthroscopy, essentially in the presence of an intact biceps pulley or rotator interval [3]. The aim of this chapter is to update the classification of SSC tendon tears, better identify SSC tears on specific clinical exam and radiographic imaging, and their arthroscopic management. Even if lesions are well recognized, arthroscopic SSC repair is a technically demanding procedure with a long learning curve [4]. This could be linked to the narrow subcoracoid space making the repair difficult and to the close presence of neural structures at the anterior border of the muscle belly that should be preserved.

### 2. Anatomy

The SSC tendon is the only anterior tendon of the rotator cuff, and the SSC is the largest of the rotator cuff muscles. The SSC muscle is the major internal rotator of the shoulder and contributes more to shoulder elevation strength than the supraspinatus or infraspinatus tendons [5, 6]. It is important in passive and active stabilization of the glenohumeral joint [7]. The SSC is inserted between the scapula and the humerus.

The scapula attachment is a wide surface area of the subscapularis fossa. The directions of the muscle fibres are anteriorly and laterally towards the humeral lesser tuberosity medially to the bicipital groove. There are three distinct layers in the muscle belly that are well seen with ultrasound or magnetic resonance imaging (MRI) sagittal views. The SSC humeral insertion is tendinous in the two superior thirds and muscular in the lower third. The two superior thirds and the inferior third of the SSC muscle are innervated, respectively, by the upper and lower subscapularis nerves, which are both branches of the posterior chord of the brachial plexus. Electromyographic studies have shown differences in neural activity between the upper and lower portion of the SSC muscle, suggesting that they could work as two different muscular units during shoulder movements [8].

The SSC tendon contributes to the formation of an anatomical space called the rotator interval, which is a tendinous gap in the rotator cuff, exclusively covered by fibrous capsule made of blended fibres coming from the SSC and supraspinatus tendons. It is a triangular-shaped space bordered inferiorly by the superior edge of the SSC tendon and superiorly by the anterior edge of the supraspinatus tendon. The medial base is delimitated by the coracoid process, and the lateral apex is the intertubercular sulcus [9]. The coracohumeral ligament, the superior glenohumeral ligament and the superior fibres of the SSC tendon reinforce the lateral rotator interval and act as a pulley system for the long head of the biceps tendon (LHBT) to prevent its dislocation [10–12]. That may explain why pathologies of the SSC tendon and LHBT are intimately connected [13–18], and why SSC should always be assessed and repaired in patients with rotator cuff tears including the SSC tendon.

### 3. Pathogenesis

radiographic imaging occurred in a better diagnosis of SSC tears, and recent improvements in

Misdiagnosed SSC tendon tears may result in rotator unbalanced force couple, leading to persistent shoulder pain and weakness after cuff repair. SSC tendon tears can be difficult to diagnose on clinical examination, and lesions may be hidden on arthroscopy, essentially in the presence of an intact biceps pulley or rotator interval [3]. The aim of this chapter is to update the classification of SSC tendon tears, better identify SSC tears on specific clinical exam and radiographic imaging, and their arthroscopic management. Even if lesions are well recognized, arthroscopic SSC repair is a technically demanding procedure with a long learning curve [4]. This could be linked to the narrow subcoracoid space making the repair difficult and to the close presence of neural structures at the anterior border of the muscle belly that should be preserved.

The SSC tendon is the only anterior tendon of the rotator cuff, and the SSC is the largest of the rotator cuff muscles. The SSC muscle is the major internal rotator of the shoulder and contributes more to shoulder elevation strength than the supraspinatus or infraspinatus tendons [5, 6]. It is important in passive and active stabilization of the glenohumeral joint [7]. The SSC is inserted

The scapula attachment is a wide surface area of the subscapularis fossa. The directions of the muscle fibres are anteriorly and laterally towards the humeral lesser tuberosity medially to the bicipital groove. There are three distinct layers in the muscle belly that are well seen with ultrasound or magnetic resonance imaging (MRI) sagittal views. The SSC humeral insertion is tendinous in the two superior thirds and muscular in the lower third. The two superior thirds and the inferior third of the SSC muscle are innervated, respectively, by the upper and lower subscapularis nerves, which are both branches of the posterior chord of the brachial plexus. Electromyographic studies have shown differences in neural activity between the upper and lower portion of the SSC muscle, suggesting that they could work as two different muscular

The SSC tendon contributes to the formation of an anatomical space called the rotator interval, which is a tendinous gap in the rotator cuff, exclusively covered by fibrous capsule made of blended fibres coming from the SSC and supraspinatus tendons. It is a triangular-shaped space bordered inferiorly by the superior edge of the SSC tendon and superiorly by the anterior edge of the supraspinatus tendon. The medial base is delimitated by the coracoid process, and the lateral apex is the intertubercular sulcus [9]. The coracohumeral ligament, the superior glenohumeral ligament and the superior fibres of the SSC tendon reinforce the lateral rotator interval and act as a pulley system for the long head of the biceps tendon (LHBT) to prevent its dislocation [10–12]. That may explain why pathologies of the SSC tendon and LHBT are intimately connected [13–18], and why SSC should always be assessed and repaired in patients

arthroscopic instrumentation allow easier repair of the SSC tendon.

2. Anatomy

80 Recent Advances in Arthroscopic Surgery

between the scapula and the humerus.

units during shoulder movements [8].

with rotator cuff tears including the SSC tendon.

The SSC tendon tears can have either a traumatic and/or a degenerative aetiology. In most cases, the two aetiologies are intricate: an acute traumatic event is reported, on a previous degenerate and fragile tendon. In young patients however, traumatic SSC tears are usually secondary to a forced external rotation in high-energy trauma, with or without combined posterosuperior cuff lesion. In more elderly patients, a SSC traumatic tear can be a consequence of a shoulder dislocation, and associated rotator cuff tears or neurologic injury must be assessed.

In cases with degenerative aetiology, two theories are classically described. The extrinsic aetiology is related to the subacromial impingement syndrome that is the most common disease of the shoulder joint after the sixth decade of life, particularly in overhead workers [19]. Even if its prevalence is high, the aetiology of this syndrome and the histologic and ultrastructural changes in the rotator cuff are not well known. The friction and pressure in the narrow subacromial space probably result in tendon micro-traumatism. In degenerative SSC tears, a subcoracoid impingement may injure the anterosuperior portion of the rotator cuff involving the SSC tendon, the LHBT or all the other rotator cuff tendons. Some anatomic studies reported the close relation of the medial glenohumeral ligament (MGHL) to the upper SSC near its humeral footprint [20]. Based on arthroscopic findings, the MGHL may abrade against the upper edge of the SSC medial to its insertion [21].

The intrinsic theory is that the subacromial pain is multifactorial and could be attribute to the chronic inflammation and degeneration of the rotator cuff and the subacromial bursa [22]. Farfaras found that degenerative histological changes in the form of fibrils with smaller diameters were present in the SSC tendon in patients with subacromial impingement syndrome [23].

### 4. SSC tear classification

There is no consensus or clear classification regarding SSC tears. We used the classification of Lafosse to classify the SSC lesions into five types [24].

Type 1 is an isolated and partial separation of the SSC tendon fibres from the lesser tuberosity with a normal bicipital sling, regardless of the appearance of the LHBT.

Type 2 is a separation of the SSC tendon fibres from the lesser tuberosity and partial tear in the bicipital sling without involvement of the anterior LHBT pulley or tendinous slip. The probe introduced through the partial sling tear (consisting very often in a cleft in the anterior wall) can lift the superficial SSC layer separated from the lesser tuberosity.

Type 3 is a complete separation of the SSC tendon fibres from the lesser tuberosity and complete tear in the anterior wall of the bicipital sling. The anterior LHBT pulley is normal, distended or, rarely, completely torn. The tendon retraction is minor because the superficial tendon layer is normally attached to the bicipital sling and connected to the superficial fibres of the supraspinatus (superficial layer of the rotator interval, which produces the comma sign after separation from the bony structures).

6. Radiographic imaging

A full shoulder series of plain radiographs is useful to assess evidence of trauma (bony avulsion), acromioclavicular or glenohumeral arthritis, lateral acromial morphology (critical shoulder angle), humeral head subluxation and any changes at the SSC humeral footprint [25, 26].

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Ultrasonography is a noninvasive diagnosis method allowing a dynamic exam. It is accurate and sensitive for detecting of rotator cuff tears but could be more limited for evaluation of the size of tears, in particular, for the detection of small tears [27]. Ultrasound is useful to assess muscle fatty infiltration, LHBT dislocation or degenerative biceps tendon and subcoracoid impingement.

MRI or computed tomography arthrogram is more reliable compared to ultrasonography for cuff assessment, LHBT (Figures 1–3) and fatty muscle belly infiltration (Figure 4). In some cases however, it could fail to diagnose the presence of SSC tears [28], indirect signs, as LHBT subluxation must be analysed (Figure 5). Diagnostic accuracy could be improved with MR

Figure 1. Axial view of computed tomography arthrogram showing the LHBT in the groove.

Figure 2. Axial view of computed tomography arthrogram showing a medial subluxation of the LHBT, related to a SSC tear.

Type 4 is a complete separation of the SSC tendon fibres from the lesser tuberosity leaving a free edge that can remain continuous with the fibrous scar tissue attached either to the humerus or to the subacromial bursa. The degree of retraction varies, but the stump may reach the level of the glenoid labrum. At this stage, the comma sign is readily identified and connects the subscapularis to the supraspinatus if this last is torn.

Type 5 can be considered as a complete SSC tear combined with an anterior and superior humeral head translation, combined with coracoid impingement and SSC muscle fatty infiltration. This classification is useful to assess the reparability and the risk of retear.

### 5. Clinical assessment

The shoulder pain related to a SSC tendon tear may be more anterior compared to the typical pain observed in patients with superior rotator cuff tear, essentially when SSC tears are associated with biceps dislocation. Weakness in internal rotation and difficulty to touch the lumbar spine with the hand may also be reported by the patients but are nonspecific of a SSC tear. The three more sensitive and specific clinical tests to assess SSC tendon are the lift-off test, the belly-press test and the bear-hug test.

The lift-off test described by Gerber is performed by placing the hand behind the back at the level of the lumbar spine and asking the patient to lift the hand posteriorly from the back. It is positive when the patient is not able to raise the hand. The examiner can also place the patient's hand raised and ask the patient to maintain the position. The test is positive if the patient is not able to maintain the hand raised and beat up his back.

The belly-press test starts with the elbow slightly anterior to the body and flexed to 90. The patient is asked to press the hand against his belly without elbow movement. The test is considered positive if the pressing force is weaker than contralaterally.

The bear-hug test is performed with the palm of the hand of the affected side on the opposite shoulder, the fingers extended and the elbow ahead of the body with the shoulder flexed to 90. The patient is asked to keep the position while the examiner attempts to pull the hand of the patient away from the opposite shoulder by applying a force in external rotation perpendicular to the forearm. The test is positive when the patient cannot keep the hand on the opposite shoulder or the strength in internal rotation is impaired compared to the opposite side.

These tests are however subjective. The SSC strength can be assessed using a dynamometer, providing objective values and allowing force comparison with the contralateral shoulder.

### 6. Radiographic imaging

tendon layer is normally attached to the bicipital sling and connected to the superficial fibres of the supraspinatus (superficial layer of the rotator interval, which produces the comma sign

Type 4 is a complete separation of the SSC tendon fibres from the lesser tuberosity leaving a free edge that can remain continuous with the fibrous scar tissue attached either to the humerus or to the subacromial bursa. The degree of retraction varies, but the stump may reach the level of the glenoid labrum. At this stage, the comma sign is readily identified and connects

Type 5 can be considered as a complete SSC tear combined with an anterior and superior humeral head translation, combined with coracoid impingement and SSC muscle fatty infil-

The shoulder pain related to a SSC tendon tear may be more anterior compared to the typical pain observed in patients with superior rotator cuff tear, essentially when SSC tears are associated with biceps dislocation. Weakness in internal rotation and difficulty to touch the lumbar spine with the hand may also be reported by the patients but are nonspecific of a SSC tear. The three more sensitive and specific clinical tests to assess SSC tendon are the lift-off test,

The lift-off test described by Gerber is performed by placing the hand behind the back at the level of the lumbar spine and asking the patient to lift the hand posteriorly from the back. It is positive when the patient is not able to raise the hand. The examiner can also place the patient's hand raised and ask the patient to maintain the position. The test is positive if the

The belly-press test starts with the elbow slightly anterior to the body and flexed to 90. The patient is asked to press the hand against his belly without elbow movement. The test is

The bear-hug test is performed with the palm of the hand of the affected side on the opposite shoulder, the fingers extended and the elbow ahead of the body with the shoulder flexed to 90. The patient is asked to keep the position while the examiner attempts to pull the hand of the patient away from the opposite shoulder by applying a force in external rotation perpendicular to the forearm. The test is positive when the patient cannot keep the hand on the opposite shoulder or the strength in internal rotation is impaired compared to

These tests are however subjective. The SSC strength can be assessed using a dynamometer, providing objective values and allowing force comparison with the contralateral

patient is not able to maintain the hand raised and beat up his back.

considered positive if the pressing force is weaker than contralaterally.

tration. This classification is useful to assess the reparability and the risk of retear.

after separation from the bony structures).

82 Recent Advances in Arthroscopic Surgery

5. Clinical assessment

the opposite side.

shoulder.

the belly-press test and the bear-hug test.

the subscapularis to the supraspinatus if this last is torn.

A full shoulder series of plain radiographs is useful to assess evidence of trauma (bony avulsion), acromioclavicular or glenohumeral arthritis, lateral acromial morphology (critical shoulder angle), humeral head subluxation and any changes at the SSC humeral footprint [25, 26].

Ultrasonography is a noninvasive diagnosis method allowing a dynamic exam. It is accurate and sensitive for detecting of rotator cuff tears but could be more limited for evaluation of the size of tears, in particular, for the detection of small tears [27]. Ultrasound is useful to assess muscle fatty infiltration, LHBT dislocation or degenerative biceps tendon and subcoracoid impingement.

MRI or computed tomography arthrogram is more reliable compared to ultrasonography for cuff assessment, LHBT (Figures 1–3) and fatty muscle belly infiltration (Figure 4). In some cases however, it could fail to diagnose the presence of SSC tears [28], indirect signs, as LHBT subluxation must be analysed (Figure 5). Diagnostic accuracy could be improved with MR

Figure 1. Axial view of computed tomography arthrogram showing the LHBT in the groove.

Figure 2. Axial view of computed tomography arthrogram showing a medial subluxation of the LHBT, related to a SSC tear.

arthrography in assessing rotator cuff tendon tears [29], essentially in the evaluation of SSC tears [30]. Lee recently reported that T1 SPIR is a more sensitive and accurate imaging

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Repair of a torn SSC tendon restores the internal rotation strength of the shoulder and could stabilize the joint providing a fine balance between internal and external rotator muscles. Indications for arthroscopic SSC repair include patients with a painful shoulder combined with evidence of SSC tear, without fatty muscle degeneration on imaging. In young patients with traumatic tear, there is no place for medical treatment: surgical repair (open or arthroscopic approach) should be quickly performed to avoid both tendon retraction and fatty infiltration that lead to lower clinical outcomes. In older patients with degenerative tear, the medical treatment must be first attempted with corticosteroid injections that are well known to be effective on pain [32]. Contraindications to repair are major glenohumeral arthropathy, fatty SSC muscle infiltration stage >2, active infection and significant medical comorbidities. Regarding patients with rotator cuff combined with frozen shoulder, the author recommends to not repair as long as the shoulder is stiff. The medical treatment should be first initiated with injections and rehabilitation until the complete range of motion is recovered. Once the shoulder has passive full motion, then

The surgery may be performed in the beach chair or lateral position, under general anaesthesia in combination with interscalene regional nerve block, to decrease postoperative pain. The beach chair position allows mobilization of the arm during the procedure, as shoulder internal rotation or the Burkhart posterior lever push is applied (the assistant applies a lever from anterior to posterior). However, arm mobilization is not systematically required, and SSC repair may also be

Standard arthroscopic instruments are required to perform a successful repair of the SSC tendon: angled arthroscopic elevators, electrocautery, ablation wands, suture retrievers, knot pushers and shuttling instruments for passing of the suture through the tendon, like a spinal needle. The author prefers to use a 30 arthroscope; however, the use of a 70 arthroscope may improve the joint view in difficult cases. Instead of 70 arthroscope, switching sticks could be used during SSC repair procedures to change the viewing portal. This makes the visualization of the SSC tendon in subcoracoid space and its release easier, through an anterior-lateral viewing portal easier. Although the authors use no cannula during SSC repair, it can be helpful

According to Burkhart, the author recommends to perform arthroscopic SSC repairs following

performed using a light superior limb traction, exactly as superior rotator cuff repairs.

sequence compared to T2 TSE in detecting SSC tendon tear on 3 T MRA [31].

SSC repair can be performed depending on the patient's complaints.

7. Indications of arthroscopic repair

8. Arthroscopic repair procedure

for young surgeons to manage all the sutures.

a meticulous order of steps, whatever SSC tear patterns [33]:

Figure 3. Sagittal view of computed tomography arthrogram showing medial subluxation of the LHBT, related to a SSC tear. The LHBT is in front of the lesser tuberosity.

Figure 4. Axial view of computed tomography arthrogram with muscle analysis. No fat infiltration of the SSC belly muscle.

Figure 5. Sagittal view of computed tomography arthrogram showing medial subluxation of the LHBT (two upper arrows), related to a SSC superior third tear. The inferior part of the SSC tendon is well inserted (inferior arrow).

arthrography in assessing rotator cuff tendon tears [29], essentially in the evaluation of SSC tears [30]. Lee recently reported that T1 SPIR is a more sensitive and accurate imaging sequence compared to T2 TSE in detecting SSC tendon tear on 3 T MRA [31].

### 7. Indications of arthroscopic repair

Figure 3. Sagittal view of computed tomography arthrogram showing medial subluxation of the LHBT, related to a SSC

Figure 4. Axial view of computed tomography arthrogram with muscle analysis. No fat infiltration of the SSC belly muscle.

Figure 5. Sagittal view of computed tomography arthrogram showing medial subluxation of the LHBT (two upper arrows),

related to a SSC superior third tear. The inferior part of the SSC tendon is well inserted (inferior arrow).

tear. The LHBT is in front of the lesser tuberosity.

84 Recent Advances in Arthroscopic Surgery

Repair of a torn SSC tendon restores the internal rotation strength of the shoulder and could stabilize the joint providing a fine balance between internal and external rotator muscles. Indications for arthroscopic SSC repair include patients with a painful shoulder combined with evidence of SSC tear, without fatty muscle degeneration on imaging. In young patients with traumatic tear, there is no place for medical treatment: surgical repair (open or arthroscopic approach) should be quickly performed to avoid both tendon retraction and fatty infiltration that lead to lower clinical outcomes. In older patients with degenerative tear, the medical treatment must be first attempted with corticosteroid injections that are well known to be effective on pain [32]. Contraindications to repair are major glenohumeral arthropathy, fatty SSC muscle infiltration stage >2, active infection and significant medical comorbidities. Regarding patients with rotator cuff combined with frozen shoulder, the author recommends to not repair as long as the shoulder is stiff. The medical treatment should be first initiated with injections and rehabilitation until the complete range of motion is recovered. Once the shoulder has passive full motion, then SSC repair can be performed depending on the patient's complaints.

### 8. Arthroscopic repair procedure

The surgery may be performed in the beach chair or lateral position, under general anaesthesia in combination with interscalene regional nerve block, to decrease postoperative pain. The beach chair position allows mobilization of the arm during the procedure, as shoulder internal rotation or the Burkhart posterior lever push is applied (the assistant applies a lever from anterior to posterior). However, arm mobilization is not systematically required, and SSC repair may also be performed using a light superior limb traction, exactly as superior rotator cuff repairs.

Standard arthroscopic instruments are required to perform a successful repair of the SSC tendon: angled arthroscopic elevators, electrocautery, ablation wands, suture retrievers, knot pushers and shuttling instruments for passing of the suture through the tendon, like a spinal needle. The author prefers to use a 30 arthroscope; however, the use of a 70 arthroscope may improve the joint view in difficult cases. Instead of 70 arthroscope, switching sticks could be used during SSC repair procedures to change the viewing portal. This makes the visualization of the SSC tendon in subcoracoid space and its release easier, through an anterior-lateral viewing portal easier. Although the authors use no cannula during SSC repair, it can be helpful for young surgeons to manage all the sutures.

According to Burkhart, the author recommends to perform arthroscopic SSC repairs following a meticulous order of steps, whatever SSC tear patterns [33]:


#### 8.1. Glenohumeral diagnostic arthroscopy.

To perform the glenohumeral diagnostic arthroscopy, a standard posterior viewing portal is first established. Then, two instrumental portals are planned with a spinal needle. An anteriorsuperior portal is performed by evaluating the optimal direction of the future suture anchor that will be positioned in the bicipital groove, using the needle. This portal is easily performed in patients with a full-thickness anterior supraspinatus tendon tear combined to the SSC tear. In cases with intact supraspinatus tendon, the needle may be inserted immediately anterior at the anterior border of the supraspinatus tendon through the rotator interval. This portal allows lateral-row suture of the SSC tendon and can be used as a viewing portal. Then, the anterior portal is performed along the lateral edge of the coracoacromial ligament using also the needlepointing (Figure 6). This instrumental portal allows access to the medial part of the SSC footprint and the SSC medial-row suture. Thus, three portals are enough to perform an arthroscopic SSC repair. The author recommends performing the two instrumental portals before the joint exploration that requires sometimes a shaver to wash or cauterization of a

bleeding vessel. The diagnostic arthroscopy allows analysing the glenoid and humeral articular surfaces, the shoulder ligaments, the labrum and the LHBT, the posterior and superior

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In patients with rotator cuff tears and particularly in cases with SSC tears, the LHBT requires a specific assessment. The viewing aspect of the LHB is analysed (normal, partial or complete

Figure 8. Preoperative view showing an SSC superior third tear combined with a medial subluxation of the LHBT that is

rotator cuff and the SSC tendon (Figures 7 and 8).

Figure 7. Preoperative view showing an SSC superior third tear.

8.2. Long head of the biceps management

delaminated.

Figure 6. Preoperative view showing the anterior portal.

Figure 7. Preoperative view showing an SSC superior third tear.

1. Perform a glenohumeral diagnostic arthroscopy.

3. Clear the rotator interval.

86 Recent Advances in Arthroscopic Surgery

6. Prepare the humeral SSC footprint.

8.1. Glenohumeral diagnostic arthroscopy.

Figure 6. Preoperative view showing the anterior portal.

7. Repair the subscapularis tendon.

2. Perform biceps tenotomy or tenodesis, depending on surgeon's habit.

4. If the subscapularis tendon has adhesions, perform a skeletonization of the coracoid

To perform the glenohumeral diagnostic arthroscopy, a standard posterior viewing portal is first established. Then, two instrumental portals are planned with a spinal needle. An anteriorsuperior portal is performed by evaluating the optimal direction of the future suture anchor that will be positioned in the bicipital groove, using the needle. This portal is easily performed in patients with a full-thickness anterior supraspinatus tendon tear combined to the SSC tear. In cases with intact supraspinatus tendon, the needle may be inserted immediately anterior at the anterior border of the supraspinatus tendon through the rotator interval. This portal allows lateral-row suture of the SSC tendon and can be used as a viewing portal. Then, the anterior portal is performed along the lateral edge of the coracoacromial ligament using also the needlepointing (Figure 6). This instrumental portal allows access to the medial part of the SSC footprint and the SSC medial-row suture. Thus, three portals are enough to perform an arthroscopic SSC repair. The author recommends performing the two instrumental portals before the joint exploration that requires sometimes a shaver to wash or cauterization of a

process and perform a three-sided (anterior, posterior and superior) release.

5. Perform a coracoplasty if the subcoracoid coracohumeral distance is <7 mm.

bleeding vessel. The diagnostic arthroscopy allows analysing the glenoid and humeral articular surfaces, the shoulder ligaments, the labrum and the LHBT, the posterior and superior rotator cuff and the SSC tendon (Figures 7 and 8).

### 8.2. Long head of the biceps management

In patients with rotator cuff tears and particularly in cases with SSC tears, the LHBT requires a specific assessment. The viewing aspect of the LHB is analysed (normal, partial or complete

Figure 8. Preoperative view showing an SSC superior third tear combined with a medial subluxation of the LHBT that is delaminated.

Figure 9. Preoperative view showing an SSC superior third tear combined with a medial subluxation of the LHBT that is degenerative.

degeneration), and then using a stick, the stability at the pulley is assessed by pushing a medial force to dislocate the tendon from the groove above the SSC tendon (Figure 9). Sometimes the tendon is already torn. LHBT tenotomy or tenodesis at the groove is indicated in most patients before the SSC tendon repairs to increase the SSC view and make repair easier. The author performs the biceps tenodesis using a triple-loaded anchor that is impacted at the top of the bicipital groove in order to reattach the LHBT in its anatomical position. Thus, one of these sutures is used for the biceps tenodesis with a loop suture technique (the two other sutures will be used later for the lateral row of the SSC repair) (Figure 10). In younger patients, the biceps tenodesis should be performed with an interference screw [34]. Some authors described other techniques of biceps tenodesis according to the bone fixation: the tendon can be tenodesed beneath the pectoralis tendon and removed entirely from the bicipital groove [35]. Controversies still exist regarding the best localization for the biceps tenodesis [36–42].

#### 8.3. Rotator interval debridement and SSC release.

Using an ablation wand through the instrumental anterior and anterior-lateral portals, the rotator interval is cleared: first the anterior capsule is resected, then the MGHL, and more medially until the coracoid process. It is easy by following the superior border of the SSC tendon to find the lateral and inferior borders of the coracoid process. There is no danger of nervous injury when the dissection is performed laterally to the pectoral minor tendon. If the SSC tendon is retracted, it can be loaded with a traction wire that may temporarily favour the reduction and assess the tendon reducibility. The three-sided release corresponds to an anterior, posterior and superior release. The superior release is performed during the coracoid process exposition (Figure 11). The anterior release is performed using an ablation wand between the SSC tendon and the conjoint tendon (Figure 12). It exposes to neurologic injury (axillary and musculocutaneous nerves) if performed too medially. The posterior release is safe and performed by introducing a 15 elevator between the posterior SSC tendon and the anterior glenoid neck. If there are combined SSC and supraspinatus tears, it is important to preserve the comma sign [43]. It corresponds to tissue composed of the humeral attachments of the superior glenohumeral and coracohumeral ligaments that concomitantly tear and remain attached to the superolateral corner of the subscapularis. The comma sign is pathognomonic of a combined SSC and supraspinatus tear [44]. Once the SSC is repaired, this tissue helps to

Figure 10. (a) Biceps tenodesis using lasso loop technique; (b) biceps tenodesis using lasso loop technique; (c) biceps tenodesis using lasso loop technique; (d) biceps tenodesis using lasso loop technique. The section before the fixation

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A single-row technique or a double-row technique can be used. The author recommends that type 4 lesions require a double-row technique that could be biomechanically advantageous

reduce and suture the posterosuperior rotator cuff.

allows undertension of the biceps; and (e) final aspect after biceps tenodesis.

8.4. SSC suture

Figure 10. (a) Biceps tenodesis using lasso loop technique; (b) biceps tenodesis using lasso loop technique; (c) biceps tenodesis using lasso loop technique; (d) biceps tenodesis using lasso loop technique. The section before the fixation allows undertension of the biceps; and (e) final aspect after biceps tenodesis.

and performed by introducing a 15 elevator between the posterior SSC tendon and the anterior glenoid neck. If there are combined SSC and supraspinatus tears, it is important to preserve the comma sign [43]. It corresponds to tissue composed of the humeral attachments of the superior glenohumeral and coracohumeral ligaments that concomitantly tear and remain attached to the superolateral corner of the subscapularis. The comma sign is pathognomonic of a combined SSC and supraspinatus tear [44]. Once the SSC is repaired, this tissue helps to reduce and suture the posterosuperior rotator cuff.

#### 8.4. SSC suture

degeneration), and then using a stick, the stability at the pulley is assessed by pushing a medial force to dislocate the tendon from the groove above the SSC tendon (Figure 9). Sometimes the tendon is already torn. LHBT tenotomy or tenodesis at the groove is indicated in most patients before the SSC tendon repairs to increase the SSC view and make repair easier. The author performs the biceps tenodesis using a triple-loaded anchor that is impacted at the top of the bicipital groove in order to reattach the LHBT in its anatomical position. Thus, one of these sutures is used for the biceps tenodesis with a loop suture technique (the two other sutures will be used later for the lateral row of the SSC repair) (Figure 10). In younger patients, the biceps tenodesis should be performed with an interference screw [34]. Some authors described other techniques of biceps tenodesis according to the bone fixation: the tendon can be tenodesed beneath the pectoralis tendon and removed entirely from the bicipital groove [35]. Controver-

Figure 9. Preoperative view showing an SSC superior third tear combined with a medial subluxation of the LHBT that is

Using an ablation wand through the instrumental anterior and anterior-lateral portals, the rotator interval is cleared: first the anterior capsule is resected, then the MGHL, and more medially until the coracoid process. It is easy by following the superior border of the SSC tendon to find the lateral and inferior borders of the coracoid process. There is no danger of nervous injury when the dissection is performed laterally to the pectoral minor tendon. If the SSC tendon is retracted, it can be loaded with a traction wire that may temporarily favour the reduction and assess the tendon reducibility. The three-sided release corresponds to an anterior, posterior and superior release. The superior release is performed during the coracoid process exposition (Figure 11). The anterior release is performed using an ablation wand between the SSC tendon and the conjoint tendon (Figure 12). It exposes to neurologic injury (axillary and musculocutaneous nerves) if performed too medially. The posterior release is safe

sies still exist regarding the best localization for the biceps tenodesis [36–42].

8.3. Rotator interval debridement and SSC release.

degenerative.

88 Recent Advances in Arthroscopic Surgery

A single-row technique or a double-row technique can be used. The author recommends that type 4 lesions require a double-row technique that could be biomechanically advantageous

Figure 11. SSC superior release, with exposition of the coracoid process.

from 1 to 4 depending on the extent of the lesion and the type of repair procedure. In patients requiring a double-row suture, the author inserts the medial anchor through the anterior portal in the medial part of the SSC footprint and the lateral anchor through the anterosuperior portal in the bicipital groove. Thus, the same anchor can be used for both the biceps tenodesis and the lateral row of the SSC repair. The same tools used to repair the rotator cuff may be used to pass the sutures, using small instruments, which pass within the tendon itself. Considering the narrow subcoracoid space, it is not easy to pass the sutures through the SSC tendon. The author performs the double-row sutures with 5.5 mm BioComposite Corkscrew FT, Arthrex. The medial suture is passed through the SSC tendon with a shuttle needle with a loop inside, which seems to be a noninvasive technique compared to BirdBeak (Figure 15). The lateral suture can be

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Chernchujit recently described arthroscopic SSC repair by a double-row knotless technique performed with an extra-articular SSC view [47]. The patient is placed in the beach chair position with an assistant to hold the arm. He uses a standard arthroscopic posterior portal with a 30 scope for glenohumeral diagnostic, and the arthroscope is shifted to the subacromial space. Through an anterior-superior portal, subacromial decompression, acromioplasty and

performed with a classic suture pass (FastPass Scorpion, Arthrex).

Figure 14. Decortication and exposition of the SSC footprint using a burr.

Figure 13. Decortication and exposition of the SSC footprint.

Figure 12. SSC anterior release, with exposition of the conjoint tendon.

regarding postoperative strength and iterative tears [45]. In most cases with SSC tear stages 1–3, a single-row repair may be enough. The principles are similar as for all cuff repairs: decortication of the footprint using a burr through anterior and/or anterior-superior instrumental portals to create a bleeding base (Figures 13 and 14). The lateral border of the lesser tuberosity corresponds to the bicipital groove within the biceps tendon previously tenotomised or tenodesed. If the SSC tendon release does not create enough lateral excursion for an anatomic repair, a 5–7 mm medialization of the footprint may be performed without decrease in functional outcomes [46]. Knotless anchors or bridging sutures can be alternatively used; the number of anchors may vary

Figure 13. Decortication and exposition of the SSC footprint.

Figure 14. Decortication and exposition of the SSC footprint using a burr.

regarding postoperative strength and iterative tears [45]. In most cases with SSC tear stages 1–3, a single-row repair may be enough. The principles are similar as for all cuff repairs: decortication of the footprint using a burr through anterior and/or anterior-superior instrumental portals to create a bleeding base (Figures 13 and 14). The lateral border of the lesser tuberosity corresponds to the bicipital groove within the biceps tendon previously tenotomised or tenodesed. If the SSC tendon release does not create enough lateral excursion for an anatomic repair, a 5–7 mm medialization of the footprint may be performed without decrease in functional outcomes [46]. Knotless anchors or bridging sutures can be alternatively used; the number of anchors may vary

Figure 11. SSC superior release, with exposition of the coracoid process.

90 Recent Advances in Arthroscopic Surgery

Figure 12. SSC anterior release, with exposition of the conjoint tendon.

from 1 to 4 depending on the extent of the lesion and the type of repair procedure. In patients requiring a double-row suture, the author inserts the medial anchor through the anterior portal in the medial part of the SSC footprint and the lateral anchor through the anterosuperior portal in the bicipital groove. Thus, the same anchor can be used for both the biceps tenodesis and the lateral row of the SSC repair. The same tools used to repair the rotator cuff may be used to pass the sutures, using small instruments, which pass within the tendon itself. Considering the narrow subcoracoid space, it is not easy to pass the sutures through the SSC tendon. The author performs the double-row sutures with 5.5 mm BioComposite Corkscrew FT, Arthrex. The medial suture is passed through the SSC tendon with a shuttle needle with a loop inside, which seems to be a noninvasive technique compared to BirdBeak (Figure 15). The lateral suture can be performed with a classic suture pass (FastPass Scorpion, Arthrex).

Chernchujit recently described arthroscopic SSC repair by a double-row knotless technique performed with an extra-articular SSC view [47]. The patient is placed in the beach chair position with an assistant to hold the arm. He uses a standard arthroscopic posterior portal with a 30 scope for glenohumeral diagnostic, and the arthroscope is shifted to the subacromial space. Through an anterior-superior portal, subacromial decompression, acromioplasty and

bursectomy are performed to improve visualization and make the SSC suture easier. The anterior portal is established in the rotator interval region. A cannula is inserted through the anterior portal, and a 70 arthroscope is used for the SSC repair. The rotator interval is cleared, the biceps tenotomy is performed, and SSC tendon is released to obtain a good reduction. The SSC footprint is prepared by microfracture, and two anchors are inserted to form the medial row. Suture loops are passed through the SSC tendon using a specific device. The suture bridge technique is then performed, with arm rotated externally. Knotless anchors are inserted on the lesser tuberosity to form the lateral row of the SSC repair. Special attention will be devoted to

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When performed at early stages, arthroscopic repair is highly successful [48], whereas in patients with irreparable tears (tendon retraction to the level of the glenoid with grade III or IV fatty muscle infiltration) tendon repair is not indicated. To restore shoulder mechanics, some nonanatomic techniques have been reported in the literature such as pectoralis major or latissimus dorsi tendon transfers [49, 50]. These procedures have, however, a high rate of iterative ruptures and complications [51]. Allograft used to repair SSC irreparable tear has also shown fair clinical outcomes and tendon healing on postoperative imaging [52]. More recently and on the model of irreparable supraspinatus tear, superior capsule reconstruction was used in patients with irreparable SSC tears. Anterior capsule reconstruction technique using a human acellular dermal patch requires an open approach, eventually after an arthroscopic diagnosis confirmation of SSC irreparable tear [53, 54]. A standard delto-pectoral incision is made starting to the coracoid process tip. The cephalic vein is exposed and retracted laterally or may be ligated if necessary. The conjoint tendon is identified, and its lateral border is dissected. The subscapularis muscle and anterior capsular deficiency are exposed. After vertical arthrotomy, a Fukuda retractor may be placed into the joint to retract laterally the humeral head exposing the glenoid and the anterior glenoid rims. After anterior labral debridement, three 3.0 mm knotted anchors are inserted into the anterior glenoid rim at the 5-, 3- and 1-o'clock positions. On the humeral footprint, a double-row bridging repair may be performed using four anchors. A 3.5 mm thick human acellular dermal patch is then prepared at the matching size of the SSC tear and then sutures to the glenoid and humeral anchors. Marking several parallel lines perpendicular to the length of the graft for reference could be useful to ensure that

Cartaya and Valenti described an alternative technique for irreparable tears of the upper two-thirds of the SSC tendon, an arthroscopic-assisted pectoralis minor transfer with a bone chip from the coracoid process [55]. The patient is positioned in the beach chair position, without upper limb traction, to easily mobilize the arm during the procedure. A shoulder diagnostic examination through the standard posterior viewing portal confirms the presence of an irreparable SSC tendon tear. The SSC is released by clearing the rotator interval and excising the coracohumeral ligament; the MGHL and the LHBT are tenotomised. Compared to arthroscopic Latarjet, the coracoid process with conjoint tendon, coracoacromial ligament and pectoral minor are dissected. This stage requires switching the arthroscope from posterior to anterior-superior portal to increase pectoral minor visualization and to create a superior coracoid expanded portal. This instrumental portal allows performing the osteotomy

adequate tensioning.

the final graft shape is still rectangular.

Figure 15. (a) (b) A shuttle needle with a loop inside is introduced from anterior to posterior through the SSC tendon; (c) one suture of the anchor is retrieved with the loop through the anterolateral portal; (d) outside, the surgeon passes the suture inside the loop, and the loop is pulled from posterior to anterior. The suture goes through the SSC tendon; (e) this technique is repeated as many times as required; (f) (g) two sutures of the anchor can be retrieved at the same time; (h) SSC suture; (i) (j) final aspect.

bursectomy are performed to improve visualization and make the SSC suture easier. The anterior portal is established in the rotator interval region. A cannula is inserted through the anterior portal, and a 70 arthroscope is used for the SSC repair. The rotator interval is cleared, the biceps tenotomy is performed, and SSC tendon is released to obtain a good reduction. The SSC footprint is prepared by microfracture, and two anchors are inserted to form the medial row. Suture loops are passed through the SSC tendon using a specific device. The suture bridge technique is then performed, with arm rotated externally. Knotless anchors are inserted on the lesser tuberosity to form the lateral row of the SSC repair. Special attention will be devoted to adequate tensioning.

When performed at early stages, arthroscopic repair is highly successful [48], whereas in patients with irreparable tears (tendon retraction to the level of the glenoid with grade III or IV fatty muscle infiltration) tendon repair is not indicated. To restore shoulder mechanics, some nonanatomic techniques have been reported in the literature such as pectoralis major or latissimus dorsi tendon transfers [49, 50]. These procedures have, however, a high rate of iterative ruptures and complications [51]. Allograft used to repair SSC irreparable tear has also shown fair clinical outcomes and tendon healing on postoperative imaging [52]. More recently and on the model of irreparable supraspinatus tear, superior capsule reconstruction was used in patients with irreparable SSC tears. Anterior capsule reconstruction technique using a human acellular dermal patch requires an open approach, eventually after an arthroscopic diagnosis confirmation of SSC irreparable tear [53, 54]. A standard delto-pectoral incision is made starting to the coracoid process tip. The cephalic vein is exposed and retracted laterally or may be ligated if necessary. The conjoint tendon is identified, and its lateral border is dissected. The subscapularis muscle and anterior capsular deficiency are exposed. After vertical arthrotomy, a Fukuda retractor may be placed into the joint to retract laterally the humeral head exposing the glenoid and the anterior glenoid rims. After anterior labral debridement, three 3.0 mm knotted anchors are inserted into the anterior glenoid rim at the 5-, 3- and 1-o'clock positions. On the humeral footprint, a double-row bridging repair may be performed using four anchors. A 3.5 mm thick human acellular dermal patch is then prepared at the matching size of the SSC tear and then sutures to the glenoid and humeral anchors. Marking several parallel lines perpendicular to the length of the graft for reference could be useful to ensure that the final graft shape is still rectangular.

Cartaya and Valenti described an alternative technique for irreparable tears of the upper two-thirds of the SSC tendon, an arthroscopic-assisted pectoralis minor transfer with a bone chip from the coracoid process [55]. The patient is positioned in the beach chair position, without upper limb traction, to easily mobilize the arm during the procedure. A shoulder diagnostic examination through the standard posterior viewing portal confirms the presence of an irreparable SSC tendon tear. The SSC is released by clearing the rotator interval and excising the coracohumeral ligament; the MGHL and the LHBT are tenotomised. Compared to arthroscopic Latarjet, the coracoid process with conjoint tendon, coracoacromial ligament and pectoral minor are dissected. This stage requires switching the arthroscope from posterior to anterior-superior portal to increase pectoral minor visualization and to create a superior coracoid expanded portal. This instrumental portal allows performing the osteotomy

Figure 15. (a) (b) A shuttle needle with a loop inside is introduced from anterior to posterior through the SSC tendon; (c) one suture of the anchor is retrieved with the loop through the anterolateral portal; (d) outside, the surgeon passes the suture inside the loop, and the loop is pulled from posterior to anterior. The suture goes through the SSC tendon; (e) this technique is repeated as many times as required; (f) (g) two sutures of the anchor can be retrieved at the same time; (h)

SSC suture; (i) (j) final aspect.

92 Recent Advances in Arthroscopic Surgery

of the medial wall of the coracoid process with the PM tendon using a 10 mm chisel. The bone chip is exteriorized through the same portal and sutured to a double-button device. The footprint is prepared with a burr to create a concave zone matching the shape of the bone chip. An eyelet drill pin is positioned at the centre of the SSC footprint from anterior to posterior until the posterior subcutaneous tissue. The pin is then drilled across all the humeral head, through the posterior humeral cortex to create a complete bone tunnel. After the sutures are loaded in the eyelet of the drill pin, the pin is then retrieved posteriorly through a small skin incision. The sutures are carefully pulled to apply the button over the humeral posterior cortex and to obtain a good compression of the bone chip on the lesser tuberosity, under arthroscopic control. Clinical outcomes after this procedure could be better compared to other techniques according to the use of bone-to-bone fixation. Nevertheless, the author advises to have extensive knowledge of the anatomy to avoid nervous injury (musculocutaneous or axillary nerves).

repair, the concept of "à la carte" surgery is applicable, meaning that surgeon may repair all tendon torn in the same procedure to restore anatomy. The clinical outcomes of recent studies confirm that successful arthroscopic repair of the tendon can lead to an improvement in shoulder function and strength, as well as a reduction in pain. We recommend arthroscopic single or double-row repair using spinal needle as shuttle, after biceps tenotomy or tenodesis.

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[1] Hauser ED. Avulsion of the tendon of the subscapularis muscle. The Journal of Bone and

[2] Gerber C, Krushell RJ. Isolated rupture of the tendon of the subscapularis muscle. Clinical features in 16 cases. Journal of Bone and Joint Surgery. British Volume (London). 1991;

[3] Neyton L et al. The hidden lesion of the subscapularis: Arthroscopically revisited. Arthros-

[4] Visona E et al. Orthopedic resident's learning curve for arthroscopic subscapularis tendon repair: Short-term clinical and radiographic outcomes. Musculoskeletal Surgery. 2017;101

[5] Keating JF et al. The relative strengths of the rotator cuff muscles. A cadaver study. Journal

[6] Kuechle DK et al. Shoulder muscle moment arms during horizontal flexion and elevation.

[7] Abboud JA, Soslowsky LJ. Interplay of the static and dynamic restraints in glenohumeral

[8] O'Connell NE, Cowan J, Christopher T. An investigation into EMG activity in the upper and lower portions of the subscapularis muscle during normal shoulder motion. Physio-

[9] Le Corroller T et al. The rotator interval: Hidden lesions? Journal de Radiologie. 2007;88

of Bone and Joint Surgery. British Volume (London). 1993;75(1):137-140

instability. Clinical Orthopaedics and Related Research. 2002;400:48-57

Journal of Shoulder and Elbow Surgery. 1997;6(5):429-439

therapy Research International. 2006;11(3):148-151

Author details

Laurent Baverel

References

73(3):389-394

(Suppl 2):145-151

(11 Pt 1):1669-1677

Address all correspondence to: l.baverel@gmail.com Institut Locomoteur de l'Ouest, Saint Grégoire, France

copy Techniques. 2016;5(4):e877-e881

Joint Surgery. American Volume. 1954;36-A(1):139-141

#### 8.5. Open approach SSC repair

In some patients, particularly in young 12–14 year-old patients, during traumatic event with forced external rotation, a bony avulsion of the lesser tuberosity occurs without tendon tear. Clinical exam finds positive SSC test, and radiographic imaging confirms this isolated SSC lesion. In that case, the author recommends an open delto-pectoral approach. The avulsed fragment is found below the coracoid process, released and removed from the soft tissue and synthetized on humerus after bone decortication. Needle anchors or screw may be used, depending on the bone fragment size. Arthroscopic management is quite possible in these cases, but the author does not recommend this approach, because it is technically demanding, with difficult exposure and repair.

### 9. Postoperative care and rehabilitation

The patient is usually discharged on the same day after recovering from anaesthesia. Cryotherapy is initiated in the immediate postoperative period. Rehabilitation of subscapularis tears follows the same principles of rotator cuff rehabilitation, using brace for 6 weeks. However, pendulum exercises are immediately initiated, as well as early passive- and activeassisted motion, first performed in supine position and progression to the sitting and standing position. Strengthening activities are authorized after 3 months, and return to manual work or to sports intensively are not allowed before 6 months, to avoid iterative SSC rupture. In general, the rehabilitation program should carefully consider the extent of the tissue retraction and the tendon condition in terms of resistance and elasticity.

### 10. Conclusion

When a SSC tendon tear is clinically suspected with specific tests, surgeons should confirm and assess its reparability on preoperative MR imaging or arthro-CT. During arthroscopic cuff repair, the concept of "à la carte" surgery is applicable, meaning that surgeon may repair all tendon torn in the same procedure to restore anatomy. The clinical outcomes of recent studies confirm that successful arthroscopic repair of the tendon can lead to an improvement in shoulder function and strength, as well as a reduction in pain. We recommend arthroscopic single or double-row repair using spinal needle as shuttle, after biceps tenotomy or tenodesis.

### Author details

of the medial wall of the coracoid process with the PM tendon using a 10 mm chisel. The bone chip is exteriorized through the same portal and sutured to a double-button device. The footprint is prepared with a burr to create a concave zone matching the shape of the bone chip. An eyelet drill pin is positioned at the centre of the SSC footprint from anterior to posterior until the posterior subcutaneous tissue. The pin is then drilled across all the humeral head, through the posterior humeral cortex to create a complete bone tunnel. After the sutures are loaded in the eyelet of the drill pin, the pin is then retrieved posteriorly through a small skin incision. The sutures are carefully pulled to apply the button over the humeral posterior cortex and to obtain a good compression of the bone chip on the lesser tuberosity, under arthroscopic control. Clinical outcomes after this procedure could be better compared to other techniques according to the use of bone-to-bone fixation. Nevertheless, the author advises to have extensive knowledge of the anatomy to avoid nervous injury

In some patients, particularly in young 12–14 year-old patients, during traumatic event with forced external rotation, a bony avulsion of the lesser tuberosity occurs without tendon tear. Clinical exam finds positive SSC test, and radiographic imaging confirms this isolated SSC lesion. In that case, the author recommends an open delto-pectoral approach. The avulsed fragment is found below the coracoid process, released and removed from the soft tissue and synthetized on humerus after bone decortication. Needle anchors or screw may be used, depending on the bone fragment size. Arthroscopic management is quite possible in these cases, but the author does not recommend this approach, because it is technically demanding,

The patient is usually discharged on the same day after recovering from anaesthesia. Cryotherapy is initiated in the immediate postoperative period. Rehabilitation of subscapularis tears follows the same principles of rotator cuff rehabilitation, using brace for 6 weeks. However, pendulum exercises are immediately initiated, as well as early passive- and activeassisted motion, first performed in supine position and progression to the sitting and standing position. Strengthening activities are authorized after 3 months, and return to manual work or to sports intensively are not allowed before 6 months, to avoid iterative SSC rupture. In general, the rehabilitation program should carefully consider the extent of the tissue retraction

When a SSC tendon tear is clinically suspected with specific tests, surgeons should confirm and assess its reparability on preoperative MR imaging or arthro-CT. During arthroscopic cuff

(musculocutaneous or axillary nerves).

8.5. Open approach SSC repair

94 Recent Advances in Arthroscopic Surgery

with difficult exposure and repair.

10. Conclusion

9. Postoperative care and rehabilitation

and the tendon condition in terms of resistance and elasticity.

Laurent Baverel

Address all correspondence to: l.baverel@gmail.com

Institut Locomoteur de l'Ouest, Saint Grégoire, France

### References


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**Chapter 7**

Provisional chapter

**Diagnosis and Treatment of the Meso-Acromion of the**

DOI: 10.5772/intechopen.76267

The failed fusion between two acromial apophyses, called an os acromiale, is often asymptomatic and found incidentally during evaluation for unrelated shoulder pathology. Though this is frequently not the primary pain source, a mobile os acromiale fragment can cause inflammation at the pseudarthrosis site, rotator cuff impingement, or AC joint arthritis. Varying operative techniques exist with good to satisfactory results for symptomatic patients. Several operative techniques have been described including open excision, open reduction-internal fixation (ORIF), arthroscopic acromioplasty or subacromial decompression, and arthroscopic excision. Open excision of a meso-acromion can lead to persistent pain and deltoid weakness and atrophy. The management of a meso-acromial fragment with ORIF can also result in persistent pain and deltoid weakness and atrophy with nonunion of the fragments. Arthroscopic excision of the meso-acromion is described as a viable

Keywords: shoulder arthroscopy, os acromiale, meso-acromion, surgical technique,

An os acromiale is usually found incidentally during the evaluation for unrelated shoulder pathology as most patients are often asymptomatic for this condition [1]. The acromial apophysis develops from four main classification centers: (1) the pre-acromion, (2) the mesoacromion, (3) the meta-acromion and (4) the basi-acromion [2]. The os acromiale represents a failure of fusion between two of these apophyses [2]. The types of os acromiale are defined by

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Diagnosis and Treatment of the Meso-Acromion of the

William B. Stetson, Stephanie Morgan, Brian Chung, Nicole Hung, Genevieve Mazza and Alex McIntyre

William B. Stetson, Stephanie Morgan, Brian Chung, Nicole Hung, Genevieve Mazza and Alex McIntyre

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.76267

alternative for surgical candidates.

Abstract

acromion

1. Introduction

**Shoulder**

Shoulder

#### **Diagnosis and Treatment of the Meso-Acromion of the Shoulder** Diagnosis and Treatment of the Meso-Acromion of the Shoulder

DOI: 10.5772/intechopen.76267

William B. Stetson, Stephanie Morgan, Brian Chung, Nicole Hung, Genevieve Mazza and Alex McIntyre William B. Stetson, Stephanie Morgan, Brian Chung, Nicole Hung, Genevieve Mazza and Alex McIntyre

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.76267

#### Abstract

The failed fusion between two acromial apophyses, called an os acromiale, is often asymptomatic and found incidentally during evaluation for unrelated shoulder pathology. Though this is frequently not the primary pain source, a mobile os acromiale fragment can cause inflammation at the pseudarthrosis site, rotator cuff impingement, or AC joint arthritis. Varying operative techniques exist with good to satisfactory results for symptomatic patients. Several operative techniques have been described including open excision, open reduction-internal fixation (ORIF), arthroscopic acromioplasty or subacromial decompression, and arthroscopic excision. Open excision of a meso-acromion can lead to persistent pain and deltoid weakness and atrophy. The management of a meso-acromial fragment with ORIF can also result in persistent pain and deltoid weakness and atrophy with nonunion of the fragments. Arthroscopic excision of the meso-acromion is described as a viable alternative for surgical candidates.

Keywords: shoulder arthroscopy, os acromiale, meso-acromion, surgical technique, acromion

### 1. Introduction

An os acromiale is usually found incidentally during the evaluation for unrelated shoulder pathology as most patients are often asymptomatic for this condition [1]. The acromial apophysis develops from four main classification centers: (1) the pre-acromion, (2) the mesoacromion, (3) the meta-acromion and (4) the basi-acromion [2]. The os acromiale represents a failure of fusion between two of these apophyses [2]. The types of os acromiale are defined by

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

the unfused segment immediately anterior to the site of nonunion [3]. For example, failed fusion between the meta-acromial and meso-acromion ossification centers is called a mesoacromiale [3]. Although the reported prevalence of os acromiale in skeletally mature shoulders has ranged from 1.3 to 30% [2–4], it is not frequently diagnosed as a cause of pain [2, 4, 5]. The great majority of os acromiale are meso-acromions (Figure 1). Pre-acromial fragments occur much less frequently and a meta-acromiale is rare [3].

usually satisfactory [14, 15]. However, open excision of a symptomatic meso-acromion has led to poor results with residual pain, weakness, and deltoid dysfunction [5, 8, 16]. Arthroscopic subacromial decompression has led to good results in many studies, but the satisfaction rate has ranged from 0 to 85% [1, 7, 9. 10]. However, in those studies many of the patients had subacromial impingement and the os acromiale was asymptomatic. ORIF has also led some mixed results with many different surgical techniques described [2, 3, 5, 6, 11–13, 17]. Hardware complications, nonunion, and the need for hardware removal are common after ORIF

Diagnosis and Treatment of the Meso-Acromion of the Shoulder

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103

There are some patients who are not candidates for open reduction and internal fixation or for arthroscopic subacromial decompression because of many reasons including concomitant AC joint osteoarthritis, history of previous arthroscopic subacromial decompression with recurrence of pain, or advanced age and the risk of nonunion or the unwillingness to undergo a second surgery for hardware removal, which is very common after ORIF. Arthroscopic exci-

Plain radiographs are the mainstay of diagnostic imaging. An axillary view should be made routinely to diagnose and confirm the presence of an os acromiale. More frequently, the diagnosis is made incidentally. Lee and colleagues [18] described the double-density sign on a standard anteroposterior radiograph of the shoulder and a cortical irregularity on the supraspinatus outlet view which was highly suggestive of an os acromiale (Figure 1). MRI or

Figure 2. MRI left shoulder that shows an intact rotator cuff, healing of the previous SLAP repair, moderate AC joint

osteoarthritis, and a meso-acromion with sclerotic changes and soft tissue swelling at the meso-acromion site.

sion of the meso-acromion is described as a viable alternative for surgical candidates.

even when radiographic union has occurred [1–3, 5, 11, 13].

2. Diagnostic imaging

A mesotype of os acromion is uncommon shoulder pathology but when symptomatic, presents the surgeon with a diagnostic dilemma with inconsistent outcome treatment options with various surgical techniques. It is not frequently diagnosed as a cause of pain [2, 4, 5] but when other factors have been ruled out, such as impingement or other shoulder pathology, what is the best treatment option is dependent on the age of the patient and their activity level.

The condition can be symptomatic secondary to pain or inflammation at the pseudarthrosis site from the mobile fragment impinging on the rotator cuff [5, 6] or arthritic changes of the acromioclavicular joint due to hypermobility of the os [2]. The diagnosis of a symptomatic os acromiale can be difficult but can be made by the presence of pain and local tenderness over the anterior acromion and the nonunion site [3, 5] a hyper-mobile fragment at the anterior acromion [3], positive impingement signs [5, 7], and positive local injection tests [3].

The area of fibrous union or non-union of the os acromiale fragment may become painful after the patient has minor trauma [1] or from repetitive overhead activities of the shoulder. The persistent pain may be due to acromioclavicular (AC) joint arthropathy as a result of motion of the os acromiale site or from local inflammation at the non-union site [5]. Because there are multiple potential causes of shoulder pain, it is important to rule out other sources of shoulder pain. A thorough clinical examination is needed to define the source of the pain.

When non-surgical treatment fails, surgical management is warranted. A number of surgical techniques have been widely described such as open fragment excision [8], arthroscopic acromioplasty [1, 7, 9, 10], open reduction and internal fixation (ORIF) [2, 3, 5, 6, 11–13], or arthroscopic excision [14, 15]. The excision of a pre-acromion arthroscopically or open is

Figure 1. Radiograph views showing a meso-acromion: axillary lateral (A), supraspinatus outlet (B), and anteriorposterior view of the glenohumeral joint.

usually satisfactory [14, 15]. However, open excision of a symptomatic meso-acromion has led to poor results with residual pain, weakness, and deltoid dysfunction [5, 8, 16]. Arthroscopic subacromial decompression has led to good results in many studies, but the satisfaction rate has ranged from 0 to 85% [1, 7, 9. 10]. However, in those studies many of the patients had subacromial impingement and the os acromiale was asymptomatic. ORIF has also led some mixed results with many different surgical techniques described [2, 3, 5, 6, 11–13, 17]. Hardware complications, nonunion, and the need for hardware removal are common after ORIF even when radiographic union has occurred [1–3, 5, 11, 13].

There are some patients who are not candidates for open reduction and internal fixation or for arthroscopic subacromial decompression because of many reasons including concomitant AC joint osteoarthritis, history of previous arthroscopic subacromial decompression with recurrence of pain, or advanced age and the risk of nonunion or the unwillingness to undergo a second surgery for hardware removal, which is very common after ORIF. Arthroscopic excision of the meso-acromion is described as a viable alternative for surgical candidates.

### 2. Diagnostic imaging

the unfused segment immediately anterior to the site of nonunion [3]. For example, failed fusion between the meta-acromial and meso-acromion ossification centers is called a mesoacromiale [3]. Although the reported prevalence of os acromiale in skeletally mature shoulders has ranged from 1.3 to 30% [2–4], it is not frequently diagnosed as a cause of pain [2, 4, 5]. The great majority of os acromiale are meso-acromions (Figure 1). Pre-acromial fragments occur

A mesotype of os acromion is uncommon shoulder pathology but when symptomatic, presents the surgeon with a diagnostic dilemma with inconsistent outcome treatment options with various surgical techniques. It is not frequently diagnosed as a cause of pain [2, 4, 5] but when other factors have been ruled out, such as impingement or other shoulder pathology, what is the best treatment option is dependent on the age of the patient and their activity level. The condition can be symptomatic secondary to pain or inflammation at the pseudarthrosis site from the mobile fragment impinging on the rotator cuff [5, 6] or arthritic changes of the acromioclavicular joint due to hypermobility of the os [2]. The diagnosis of a symptomatic os acromiale can be difficult but can be made by the presence of pain and local tenderness over the anterior acromion and the nonunion site [3, 5] a hyper-mobile fragment at the anterior

acromion [3], positive impingement signs [5, 7], and positive local injection tests [3].

pain. A thorough clinical examination is needed to define the source of the pain.

The area of fibrous union or non-union of the os acromiale fragment may become painful after the patient has minor trauma [1] or from repetitive overhead activities of the shoulder. The persistent pain may be due to acromioclavicular (AC) joint arthropathy as a result of motion of the os acromiale site or from local inflammation at the non-union site [5]. Because there are multiple potential causes of shoulder pain, it is important to rule out other sources of shoulder

When non-surgical treatment fails, surgical management is warranted. A number of surgical techniques have been widely described such as open fragment excision [8], arthroscopic acromioplasty [1, 7, 9, 10], open reduction and internal fixation (ORIF) [2, 3, 5, 6, 11–13], or arthroscopic excision [14, 15]. The excision of a pre-acromion arthroscopically or open is

Figure 1. Radiograph views showing a meso-acromion: axillary lateral (A), supraspinatus outlet (B), and anterior-

posterior view of the glenohumeral joint.

much less frequently and a meta-acromiale is rare [3].

102 Recent Advances in Arthroscopic Surgery

Plain radiographs are the mainstay of diagnostic imaging. An axillary view should be made routinely to diagnose and confirm the presence of an os acromiale. More frequently, the diagnosis is made incidentally. Lee and colleagues [18] described the double-density sign on a standard anteroposterior radiograph of the shoulder and a cortical irregularity on the supraspinatus outlet view which was highly suggestive of an os acromiale (Figure 1). MRI or

Figure 2. MRI left shoulder that shows an intact rotator cuff, healing of the previous SLAP repair, moderate AC joint osteoarthritis, and a meso-acromion with sclerotic changes and soft tissue swelling at the meso-acromion site.

CT scan can also be used to confirm an os acromiale and to determine if there are any sclerotic or inflammatory changes at the site which may be indicative of degeneration or symptomatic findings. Bone scans may help illustrate the inflammatory response at the non-union site [5]. MRI and MR arthrogram are also helpful to determine if there is any other intra-articular (SLAP lesion) or other pathology (partial or full thickness rotator cuff tear) which may be a source of pain (Figure 2).

represents only a small portion of the os acromiales whereas the meso-acromion represents a

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The results of an open excision for a meso-acromion from other authors are poor. Armengol and colleagues [20] reported on a case series of 41 patients with an os acromiale in conjunction with rotator cuff tears. Five patients had open fragment excision and all five had poor results. Warner and colleagues [5] reported on 3 patients who underwent fragment excision, one with a pre-acromion who had an excellent result, but the other two had meso-acromions, which were openly excised. These two patients had poor results with persistent weakness and pain. It is likely that the pain and weakness they had after surgery was due to the loss of the normal acromial fulcrum for function of the deltoid. Open fragment excision has limited indications and is recommended for a symptomatic pre-acromion with a relatively small fragment or as a

There are many studies that deal with open reduction and internal fixation of symptomatic meso-acromions using different techniques including the use of tension-band wires, sutures, or cannulated screws with or without bone graft. Internal fixation is technically difficult and has led to frequent nonunion rates and often requires hardware removal as a result of postoperative irritation [12]. Aboud and colleagues [1] reported on 19 patients with a meso-acromion, 8 (42%) which were treated with open reduction and internal fixation. Even though all 8 patients achieved union of the fragment, only 3 of these 8 (38%) patients achieved a satisfactory result. Peckett and colleagues [13] reviewed 26 patients with symptomatic meso os acromiale that were treated with either K-wires or screws and a tension band. If bone stock was adequate, local bone graft was placed in the pseudarthrosis site but there was no mention in how many cases this was performed. The rate of union was 96% (25 of 26) and 24 of 26 were satisfied with their results. However, no objective or subjective shoulder scores were reported. There were two postoperative fractures and eight patients had postoperative pain that was subsequently

Ryu and colleagues [17] reported on 4 patients with symptomatic meso-acromions treated with diagnostic arthroscopy followed by open reduction and internal fixation using partially threaded, 3.5 mm cannulated screws, such that compression could be achieved across the fibrous union site. All of the patients reported complete satisfaction with the procedures with an average postoperative UCLA rating score of 35, a maximum score of 35 indicates that patients were pain-free and had returned to their previous activities without restriction. All regained full range of motion and full strength without any complications or reoperations for

Warner and colleagues [5] reported on 11 patients (12 shoulders) who underwent ORIF with iliac crest bone grafting comparing two fixation techniques. Each technique incorporated debridement of the nonunion site with incorporation of iliac crest autograft spanning the debrided nonunion site. Five shoulders in 4 patients underwent ORIF with a tension-band procedure including the use of pins and wires. Four of these 5 shoulders (80%) resulted in

much larger portion.

salvage procedure after a failed ORIF [19].

4.2. Open reduction and internal fixation

relieved by wire or screw removal.

symptomatic hardware.

### 3. Nonsurgical management

Nonsurgical treatment for an isolated symptomatic os acromiale is generally recommended as the initial approach [19]. Rest and restriction of activities accompanied by a structured physical therapy program along with a course of nonsteroidal anti-inflammatory medications similar to a typical impingement protocol is a reasonable approach [19]. A subacromial corticosteroid injection can also be used and may help or eliminate the pain due to impingement or subacromial bursitis.

A selective injection into the os acromiale site with lidocaine (lidocaine injection test of 5 cc's of 1% lidocaine with reexamination 10 min later) as a diagnostic tool or with a corticosteroid can also help to determine whether or not the os acromiale is the source of the pathology and may also help relieve the symptoms and surgery may not be necessary.

### 4. Surgical options

Once the os acromiale or, in particular, the meso-acromion, has been determined to be the source of pain and non-operative treatment options have failed, there are a number of different surgical options ranging from acromioplasty to open resection, open reduction and internal fixation, and arthroscopic resection. The results in the literature vary considerably and are controversial. Depending on the type of os acromiale, the age of the patient, and their activity level, the best surgical options vary for each individual patient. For the sake of this discussion and review for surgical options, we will only address the most common type of os acromiale: the meso-acromion.

### 4.1. Open excision

Open fragment excision of the symptomatic meso-acromion has had mixed results in the literature due to residual deltoid weakness and dysfunction post-operatively [19]. Mudge and colleagues [8] reported on 6 patients with an os acromiale who underwent open fragment excision but all of them also had associated rotator cuff tears which were repaired with an open technique. Four had excellent results, but two had poor results which may have been due to the severity of the rotator cuff tear or possibly due to the excision of the os acromiale. It is also unclear from their research what type of os acromiale was present as the pre-acromion represents only a small portion of the os acromiales whereas the meso-acromion represents a much larger portion.

The results of an open excision for a meso-acromion from other authors are poor. Armengol and colleagues [20] reported on a case series of 41 patients with an os acromiale in conjunction with rotator cuff tears. Five patients had open fragment excision and all five had poor results. Warner and colleagues [5] reported on 3 patients who underwent fragment excision, one with a pre-acromion who had an excellent result, but the other two had meso-acromions, which were openly excised. These two patients had poor results with persistent weakness and pain. It is likely that the pain and weakness they had after surgery was due to the loss of the normal acromial fulcrum for function of the deltoid. Open fragment excision has limited indications and is recommended for a symptomatic pre-acromion with a relatively small fragment or as a salvage procedure after a failed ORIF [19].

### 4.2. Open reduction and internal fixation

CT scan can also be used to confirm an os acromiale and to determine if there are any sclerotic or inflammatory changes at the site which may be indicative of degeneration or symptomatic findings. Bone scans may help illustrate the inflammatory response at the non-union site [5]. MRI and MR arthrogram are also helpful to determine if there is any other intra-articular (SLAP lesion) or other pathology (partial or full thickness rotator cuff tear) which may be a

Nonsurgical treatment for an isolated symptomatic os acromiale is generally recommended as the initial approach [19]. Rest and restriction of activities accompanied by a structured physical therapy program along with a course of nonsteroidal anti-inflammatory medications similar to a typical impingement protocol is a reasonable approach [19]. A subacromial corticosteroid injection can also be used and may help or eliminate the pain due to impingement or

A selective injection into the os acromiale site with lidocaine (lidocaine injection test of 5 cc's of 1% lidocaine with reexamination 10 min later) as a diagnostic tool or with a corticosteroid can also help to determine whether or not the os acromiale is the source of the pathology and may

Once the os acromiale or, in particular, the meso-acromion, has been determined to be the source of pain and non-operative treatment options have failed, there are a number of different surgical options ranging from acromioplasty to open resection, open reduction and internal fixation, and arthroscopic resection. The results in the literature vary considerably and are controversial. Depending on the type of os acromiale, the age of the patient, and their activity level, the best surgical options vary for each individual patient. For the sake of this discussion and review for surgical options, we will only address the most common type of os acromiale:

Open fragment excision of the symptomatic meso-acromion has had mixed results in the literature due to residual deltoid weakness and dysfunction post-operatively [19]. Mudge and colleagues [8] reported on 6 patients with an os acromiale who underwent open fragment excision but all of them also had associated rotator cuff tears which were repaired with an open technique. Four had excellent results, but two had poor results which may have been due to the severity of the rotator cuff tear or possibly due to the excision of the os acromiale. It is also unclear from their research what type of os acromiale was present as the pre-acromion

also help relieve the symptoms and surgery may not be necessary.

source of pain (Figure 2).

104 Recent Advances in Arthroscopic Surgery

subacromial bursitis.

4. Surgical options

the meso-acromion.

4.1. Open excision

3. Nonsurgical management

There are many studies that deal with open reduction and internal fixation of symptomatic meso-acromions using different techniques including the use of tension-band wires, sutures, or cannulated screws with or without bone graft. Internal fixation is technically difficult and has led to frequent nonunion rates and often requires hardware removal as a result of postoperative irritation [12]. Aboud and colleagues [1] reported on 19 patients with a meso-acromion, 8 (42%) which were treated with open reduction and internal fixation. Even though all 8 patients achieved union of the fragment, only 3 of these 8 (38%) patients achieved a satisfactory result.

Peckett and colleagues [13] reviewed 26 patients with symptomatic meso os acromiale that were treated with either K-wires or screws and a tension band. If bone stock was adequate, local bone graft was placed in the pseudarthrosis site but there was no mention in how many cases this was performed. The rate of union was 96% (25 of 26) and 24 of 26 were satisfied with their results. However, no objective or subjective shoulder scores were reported. There were two postoperative fractures and eight patients had postoperative pain that was subsequently relieved by wire or screw removal.

Ryu and colleagues [17] reported on 4 patients with symptomatic meso-acromions treated with diagnostic arthroscopy followed by open reduction and internal fixation using partially threaded, 3.5 mm cannulated screws, such that compression could be achieved across the fibrous union site. All of the patients reported complete satisfaction with the procedures with an average postoperative UCLA rating score of 35, a maximum score of 35 indicates that patients were pain-free and had returned to their previous activities without restriction. All regained full range of motion and full strength without any complications or reoperations for symptomatic hardware.

Warner and colleagues [5] reported on 11 patients (12 shoulders) who underwent ORIF with iliac crest bone grafting comparing two fixation techniques. Each technique incorporated debridement of the nonunion site with incorporation of iliac crest autograft spanning the debrided nonunion site. Five shoulders in 4 patients underwent ORIF with a tension-band procedure including the use of pins and wires. Four of these 5 shoulders (80%) resulted in persistent nonunion. The other 7 patients had an ORIF using cannulated screws and an 18 gauge wire passed through the screws in a figure of 8 fashion. Six of 7 were successful unions. Nine of the 12 shoulders treated with ORIF required hardware removal. Two patients who failed ORIF had open excision of a grossly unstable meso-acromion with persistent pain and weakness following the procedure.

acromionizer burr, leaving the periosteal sleeve and deltoid attachment. A rotator cuff tear was identified in 16 (52%) of the 31 shoulders. Arthroscopic repair was performed in 9 shoulders and a mini open repair (lateral deltoid splitting) in 7 shoulders. Eighty-nine percent had good or excellent results with little difference in deltoid strength and in subjective or objective change in the appearance or contour of the anterior deltoid in those patients in which the

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Pagnani and colleagues [15] reported on 12 patients (14 shoulders) with persistent shoulder pain that interfered with athletic participation. Symptoms included impingement-like pain with overhead activity and weight lifting, night pain, and an inability to sleep on the affected side. All had tenderness at or near the meso-acromion. All were males between the age of 18 to 25 years and all were engaged in competitive athletics. Eleven of the twelve patients were elite collegiate or professional athletes. Nine patients (11 shoulders) were treated with arthroscopic excision of the anterior acromial fragment. Using an arthroscopic technique, the acromial fragment was carefully shelled out and the deltoid fascia insertion onto the remaining acromion was preserved to prevent deltoid disruption. With a minimum of two-year followup with a range of 2–6.5 years and an average follow-up of 3.72 years, all patients were able to return to full athletic participation by 14 weeks after surgery. No deltoid function was compromised by the procedure and there was no evidence of deltoid weakness or cosmetic

Reviewing the literature, the studies of Pagnani [15] and Campbell [14] are the only ones dealing with the arthroscopic excision of symptomatic meso-acromions. The surgical technique requires no special instrumentation and may be reproducibly performed by those familiar with arthroscopic techniques of the shoulder. The advantages include more rapid rehabilitation, better range of motion and shorter surgical times [12]. There is also no need for a second surgery for symptomatic metal removal. Even though both studies reported excellent results, most orthopedic surgeons are reluctant to recommend or perform an arthroscopic excision for fear of resultant muscle weakness, cosmetic deformity and/or perhaps the techni-

A shoulder diagnostic arthroscopy should be performed in the lateral decubitus position while the patient is under general anesthesia. A 15-point diagnostic arthroscopy of the glenohumeral joint is performed, addressing any intra-articular pathology including loose body removal, labral debridement or repair, capsular release, and evaluation and debridement of the articular side of the rotator cuff. The subacromial space is entered into and the arthroscopic shaver is introduced through a separate lateral incision. Then, the subacromial space is examined, addressing bursitis, impingement, and bursal sided rotator cuff tears. The soft tissues are then taken off of the undersurface of the acromion and the coracoacromion (CA) ligament is released but not cut. A radiofrequency device is preferred versus a shaver as it causes less bleeding and allows for better visualization (Figure 3). The anterior and lateral edges of the acromion are then identified along with the pseudoarthrosis or synchondrosis site of the meso-

meso-acromion was removed.

deformity post-operatively.

acromion (Figure 4).

cal difficulty of performing such a procedure.

4.4.1. Surgical technique for arthroscopic excision

Hertel and colleagues [21] reported on 15 shoulders in 12 patients who underwent ORIF for unstable os acromiale fragments using tension band wiring with the use of bone grafting. Two surgical approaches were used. An anterior deltoid-off approach was used on 7, whereas the other 8 shoulders were approached trans-acromially to preserve the deltoid origin. Union occurred in 3 of 7 cases approached anteriorly and in 7 of 8 shoulders repaired without detachment of the deltoid. The investigators concluded that fusion was more successful when the vascularity of the acromial epiphysis was maintained, likely through the acromiale branch of the thoracoacromial artery.

The techniques and approaches associated with the most successful types of ORIF include those with rigid internal fixation and preservation of the blood supply of the os acromiale fragment [21]. However, even in cases of successful union, patients may still have hardware discomfort requiring hardware removal [19].

### 4.3. Arthroscopic subacromial decompression and acromioplasty

Arthroscopic subacromial decompression and acromioplasty is used primarily when impingement with or without a rotator cuff tear is present and the nonunion site of the os acromiale is nontender and considered to be incidental [19]. As with other treatment options, the results are variable. Wright and colleagues [7] reported on 13 patients following an arthroscopic acromioplasty of a meso-acromion and found no decrease in anterior deltoid strength and no occurrence of deltoid detachment. None of these patients had pre-operative symptoms or signs localized to the os acromiale pseudo-arthrosis site. Good or excellent results were found in 11 of the 13 cases with an average UCLA shoulder rating scale of 31.

Hutchinson and colleagues [9] reported on 3 cases of impingement syndrome with an associated os acromiale treated with arthroscopic subacromial decompression. Each had good or excellent results in the early post-operative period but the pain returned each case requiring additional surgical intervention. Repeat arthroscopic debridement and excision of the fragment resulted in a good result in one patient while the other two patients the os acromiale was not removed. Both patients had residual pain with impingement like symptoms and pain with overhead activities following the second procedure.

### 4.4. Arthroscopic excision

Arthroscopic excision can be a better option with a larger os acromiale such as a mesoacromion. Campbell and colleagues [14] reported on 28 patients with 31 os acromiale. Three patients had a pre-acromion and 28 patients had a meso-acromion. After failing conservative management, the patients were taken to surgery and arthroscopic excision of the preacromions and meso-acromions was performed in 14 shoulders (45%) using a 4.5 mm flat acromionizer burr, leaving the periosteal sleeve and deltoid attachment. A rotator cuff tear was identified in 16 (52%) of the 31 shoulders. Arthroscopic repair was performed in 9 shoulders and a mini open repair (lateral deltoid splitting) in 7 shoulders. Eighty-nine percent had good or excellent results with little difference in deltoid strength and in subjective or objective change in the appearance or contour of the anterior deltoid in those patients in which the meso-acromion was removed.

Pagnani and colleagues [15] reported on 12 patients (14 shoulders) with persistent shoulder pain that interfered with athletic participation. Symptoms included impingement-like pain with overhead activity and weight lifting, night pain, and an inability to sleep on the affected side. All had tenderness at or near the meso-acromion. All were males between the age of 18 to 25 years and all were engaged in competitive athletics. Eleven of the twelve patients were elite collegiate or professional athletes. Nine patients (11 shoulders) were treated with arthroscopic excision of the anterior acromial fragment. Using an arthroscopic technique, the acromial fragment was carefully shelled out and the deltoid fascia insertion onto the remaining acromion was preserved to prevent deltoid disruption. With a minimum of two-year followup with a range of 2–6.5 years and an average follow-up of 3.72 years, all patients were able to return to full athletic participation by 14 weeks after surgery. No deltoid function was compromised by the procedure and there was no evidence of deltoid weakness or cosmetic deformity post-operatively.

Reviewing the literature, the studies of Pagnani [15] and Campbell [14] are the only ones dealing with the arthroscopic excision of symptomatic meso-acromions. The surgical technique requires no special instrumentation and may be reproducibly performed by those familiar with arthroscopic techniques of the shoulder. The advantages include more rapid rehabilitation, better range of motion and shorter surgical times [12]. There is also no need for a second surgery for symptomatic metal removal. Even though both studies reported excellent results, most orthopedic surgeons are reluctant to recommend or perform an arthroscopic excision for fear of resultant muscle weakness, cosmetic deformity and/or perhaps the technical difficulty of performing such a procedure.

### 4.4.1. Surgical technique for arthroscopic excision

persistent nonunion. The other 7 patients had an ORIF using cannulated screws and an 18 gauge wire passed through the screws in a figure of 8 fashion. Six of 7 were successful unions. Nine of the 12 shoulders treated with ORIF required hardware removal. Two patients who failed ORIF had open excision of a grossly unstable meso-acromion with persistent pain and

Hertel and colleagues [21] reported on 15 shoulders in 12 patients who underwent ORIF for unstable os acromiale fragments using tension band wiring with the use of bone grafting. Two surgical approaches were used. An anterior deltoid-off approach was used on 7, whereas the other 8 shoulders were approached trans-acromially to preserve the deltoid origin. Union occurred in 3 of 7 cases approached anteriorly and in 7 of 8 shoulders repaired without detachment of the deltoid. The investigators concluded that fusion was more successful when the vascularity of the acromial epiphysis was maintained, likely through the acromiale branch

The techniques and approaches associated with the most successful types of ORIF include those with rigid internal fixation and preservation of the blood supply of the os acromiale fragment [21]. However, even in cases of successful union, patients may still have hardware

Arthroscopic subacromial decompression and acromioplasty is used primarily when impingement with or without a rotator cuff tear is present and the nonunion site of the os acromiale is nontender and considered to be incidental [19]. As with other treatment options, the results are variable. Wright and colleagues [7] reported on 13 patients following an arthroscopic acromioplasty of a meso-acromion and found no decrease in anterior deltoid strength and no occurrence of deltoid detachment. None of these patients had pre-operative symptoms or signs localized to the os acromiale pseudo-arthrosis site. Good or excellent results were found in 11

Hutchinson and colleagues [9] reported on 3 cases of impingement syndrome with an associated os acromiale treated with arthroscopic subacromial decompression. Each had good or excellent results in the early post-operative period but the pain returned each case requiring additional surgical intervention. Repeat arthroscopic debridement and excision of the fragment resulted in a good result in one patient while the other two patients the os acromiale was not removed. Both patients had residual pain with impingement like symptoms and pain with

Arthroscopic excision can be a better option with a larger os acromiale such as a mesoacromion. Campbell and colleagues [14] reported on 28 patients with 31 os acromiale. Three patients had a pre-acromion and 28 patients had a meso-acromion. After failing conservative management, the patients were taken to surgery and arthroscopic excision of the preacromions and meso-acromions was performed in 14 shoulders (45%) using a 4.5 mm flat

weakness following the procedure.

106 Recent Advances in Arthroscopic Surgery

of the thoracoacromial artery.

discomfort requiring hardware removal [19].

4.3. Arthroscopic subacromial decompression and acromioplasty

of the 13 cases with an average UCLA shoulder rating scale of 31.

overhead activities following the second procedure.

4.4. Arthroscopic excision

A shoulder diagnostic arthroscopy should be performed in the lateral decubitus position while the patient is under general anesthesia. A 15-point diagnostic arthroscopy of the glenohumeral joint is performed, addressing any intra-articular pathology including loose body removal, labral debridement or repair, capsular release, and evaluation and debridement of the articular side of the rotator cuff. The subacromial space is entered into and the arthroscopic shaver is introduced through a separate lateral incision. Then, the subacromial space is examined, addressing bursitis, impingement, and bursal sided rotator cuff tears. The soft tissues are then taken off of the undersurface of the acromion and the coracoacromion (CA) ligament is released but not cut. A radiofrequency device is preferred versus a shaver as it causes less bleeding and allows for better visualization (Figure 3). The anterior and lateral edges of the acromion are then identified along with the pseudoarthrosis or synchondrosis site of the mesoacromion (Figure 4).

Figure 3. Viewing anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, a radiofrequency device (RF) (Arthrocare 90 degrees wand) is inserted into the sub-acromial space through a lateral portal. This device is used to strip all the soft tissues off the undersurface of the acromion.

Figure 5. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the arthroscopic oval burr (AOB) (4.5 mm Dyonics; Smith & Nephew) is inserted through the lateral portal. The

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Figure 6. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position with the burr in the lateral portal, arthroscopic burring is performed by sweeping the arthroscopic oval burr (AOB) along the undersurface of the meso-acromion (MA) from posterior to anterior with meticulous technique to

Figure 7. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the arthroscopic shaver (AS) is introduced through the lateral portal to remove any residual soft tissues from the remainder of the acromion and to make sure that the entire meso-acromion has been removed. The remaining acromion

meso-acromion (MA) can be visualized superior to the burr.

prevent disruption of the deltoid fibers.

can be visualized superiorly.

Figure 4. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the radiofrequency device has removed all the soft tissues from the undersurface of the acromion. The posterior border of the meso-acromion (PB-MA), the synchondrosis site (SYN), and the acromion are all visualized.

The entire meso-acromion should be identified and stripped of all soft tissues, using an oval burr via the lateral portal while viewing posteriorly (Figure 5). Arthroscopic excision using a burr is performed with careful attention not to damage or disrupt the deltoid fibers, which are attached to the remaining portion of the acromion. Meticulous technique is required to prevent disruption of the deltoid fibers (Figure 6). Once this is completed, co-planning of the distal aspect of the clavicle should be performed if there is any evidence of arthritis. The soft tissue shaver can then be reinserted to debride any residual soft tissue and ensure complete removal of the meso-acromion. (Figure 7).

#### 4.4.2. Post-operative care for arthroscopic excision

X-rays should be taken post-operatively to assure adequate resection of the meso-acromial fragment (Figure 8). Patients should be placed into a sling for 2 weeks to allow the incisions to heal and are instructed on active elbow flexion and extension exercises, active gripping exercises of a small exercise ball with gentle, pendulum exercises. After 2 weeks, the patient's sling should be discontinued and are placed into an aggressive physical therapy program for active assisted range of motion, followed by a strengthening program. Post-operative visits should be

Figure 5. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the arthroscopic oval burr (AOB) (4.5 mm Dyonics; Smith & Nephew) is inserted through the lateral portal. The meso-acromion (MA) can be visualized superior to the burr.

Figure 6. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position with the burr in the lateral portal, arthroscopic burring is performed by sweeping the arthroscopic oval burr (AOB) along the undersurface of the meso-acromion (MA) from posterior to anterior with meticulous technique to prevent disruption of the deltoid fibers.

The entire meso-acromion should be identified and stripped of all soft tissues, using an oval burr via the lateral portal while viewing posteriorly (Figure 5). Arthroscopic excision using a burr is performed with careful attention not to damage or disrupt the deltoid fibers, which are attached to the remaining portion of the acromion. Meticulous technique is required to prevent disruption of the deltoid fibers (Figure 6). Once this is completed, co-planning of the distal aspect of the clavicle should be performed if there is any evidence of arthritis. The soft tissue shaver can then be reinserted to debride any residual soft tissue and ensure complete removal

Figure 4. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the radiofrequency device has removed all the soft tissues from the undersurface of the acromion. The posterior

border of the meso-acromion (PB-MA), the synchondrosis site (SYN), and the acromion are all visualized.

Figure 3. Viewing anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, a radiofrequency device (RF) (Arthrocare 90 degrees wand) is inserted into the sub-acromial space through a lateral portal. This device is

X-rays should be taken post-operatively to assure adequate resection of the meso-acromial fragment (Figure 8). Patients should be placed into a sling for 2 weeks to allow the incisions to heal and are instructed on active elbow flexion and extension exercises, active gripping exercises of a small exercise ball with gentle, pendulum exercises. After 2 weeks, the patient's sling should be discontinued and are placed into an aggressive physical therapy program for active assisted range of motion, followed by a strengthening program. Post-operative visits should be

of the meso-acromion. (Figure 7).

4.4.2. Post-operative care for arthroscopic excision

used to strip all the soft tissues off the undersurface of the acromion.

108 Recent Advances in Arthroscopic Surgery

Figure 7. Viewing the subacromial space anteriorly from the posterior portal in a left shoulder in the lateral decubitus position, the arthroscopic shaver (AS) is introduced through the lateral portal to remove any residual soft tissues from the remainder of the acromion and to make sure that the entire meso-acromion has been removed. The remaining acromion can be visualized superiorly.

Once the meso-acromion has been determined to be the cause of the pain, the senior author recommends arthroscopic excision using the techniques described in this book chapter. At the time of surgery, the meso-acromion is most often loose and the synchondrosis is easily identified arthroscopically and removed. In our experience, we have not seen any evidence of deltoid weakness or atrophy in the patients we have treated with arthroscopic excision and all have been able to resume normal overhead activities with virtually no pain and no subjec-

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Symptomatic os acromiale are uncommon shoulder pathology but have several management options. When conservative management fails, operative management is warranted. Arthroscopic excision is a much better option than open resection or even ORIF. ORIF of mesoacromial fragments has led to mixed results [1, 2, 5, 13] and is not a good option in patients who are older or who have AC joint osteoarthritis. We prefer arthroscopic excision of the os acromiale/meso-acromion fragment and have found it to be a reliable technique that gives good long term patient satisfaction with no loss of strength. Future studies need to be done to address and analyze the surgical option of the arthroscopic excision of symptomatic os acromiale and in particular, meso-acromion, in certain patient populations. This could lead to a better understanding and treatment options of this difficult and challenge clinical shoulder problem.

, Brian Chung1,2, Nicole Hung1

2 Department of Orthopaedic Surgery, Keck School of Medicine at the University of Southern

[1] Abboud JA, Silverberg D, Pepe M, et al. Surgical treatment of os acromiale with and without associated rotator cuff tears. Journal of Shoulder and Elbow Surgery. 2006;15(3):

, Genevieve Mazza<sup>1</sup>

tive or objective evidence of weakness.

5. Summary and conclusions

Conflict of interest

Author details

and Alex McIntyre1,2

California, USA

References

The authors have no conflicts of interest to report.

\*Address all correspondence to: wbstetsonmd@gmail.com 1 Stetson Powell Orthopedics and Sports Medicine, USA

William B. Stetson1,2\*, Stephanie Morgan1

265-270. DOI: 10.1016/j.jse.2005.08.024

Figure 8. Post-operative X-rays showing complete excision of the meso-acromion: supraspinatus outlet (A), axillary lateral (B), and AP of the glenohumeral joint (C).

Figure 9. A (left) and B (right) shows no evidence of any cosmetic deformity from resection of the meso-acromion.

regularly scheduled, assessing improvement in range of motion and strength. Particular attention should be focused on the deltoid, looking for evidence of weakness or atrophy. After the patient is fully recovered, the cosmetic appearance of the shoulder should not be appreciably different (Figure 9).

#### 4.5. Author's indications for surgery and preferred technique

The senior author (WBS) has been treating shoulder patients for over 20 years. As discussed here in this chapter, many meso-acromions are incidental findings on x-ray and are asymptomatic and should be left alone. If there is ever a question of whether the meso-acromion is the source of a patient's shoulder pain, we prefer the technique of a local injection of 5 cc's of 1% lidocaine into the synchondrosis of the meso-acromion and if that gives pain relief, it is usually diagnostic for a symptomatic meso-acromion that needs to be addressed surgically. We will also often follow the local lidocaine injection with a corticosteroid injection into the area as this can give some patients long lasting pain relief.

Once the meso-acromion has been determined to be the cause of the pain, the senior author recommends arthroscopic excision using the techniques described in this book chapter. At the time of surgery, the meso-acromion is most often loose and the synchondrosis is easily identified arthroscopically and removed. In our experience, we have not seen any evidence of deltoid weakness or atrophy in the patients we have treated with arthroscopic excision and all have been able to resume normal overhead activities with virtually no pain and no subjective or objective evidence of weakness.

### 5. Summary and conclusions

Symptomatic os acromiale are uncommon shoulder pathology but have several management options. When conservative management fails, operative management is warranted. Arthroscopic excision is a much better option than open resection or even ORIF. ORIF of mesoacromial fragments has led to mixed results [1, 2, 5, 13] and is not a good option in patients who are older or who have AC joint osteoarthritis. We prefer arthroscopic excision of the os acromiale/meso-acromion fragment and have found it to be a reliable technique that gives good long term patient satisfaction with no loss of strength. Future studies need to be done to address and analyze the surgical option of the arthroscopic excision of symptomatic os acromiale and in particular, meso-acromion, in certain patient populations. This could lead to a better understanding and treatment options of this difficult and challenge clinical shoulder problem.

### Conflict of interest

The authors have no conflicts of interest to report.

### Author details

regularly scheduled, assessing improvement in range of motion and strength. Particular attention should be focused on the deltoid, looking for evidence of weakness or atrophy. After the patient is fully recovered, the cosmetic appearance of the shoulder should not be appreciably

Figure 9. A (left) and B (right) shows no evidence of any cosmetic deformity from resection of the meso-acromion.

Figure 8. Post-operative X-rays showing complete excision of the meso-acromion: supraspinatus outlet (A), axillary

The senior author (WBS) has been treating shoulder patients for over 20 years. As discussed here in this chapter, many meso-acromions are incidental findings on x-ray and are asymptomatic and should be left alone. If there is ever a question of whether the meso-acromion is the source of a patient's shoulder pain, we prefer the technique of a local injection of 5 cc's of 1% lidocaine into the synchondrosis of the meso-acromion and if that gives pain relief, it is usually diagnostic for a symptomatic meso-acromion that needs to be addressed surgically. We will also often follow the local lidocaine injection with a corticosteroid injection into the area as

4.5. Author's indications for surgery and preferred technique

this can give some patients long lasting pain relief.

different (Figure 9).

lateral (B), and AP of the glenohumeral joint (C).

110 Recent Advances in Arthroscopic Surgery

William B. Stetson1,2\*, Stephanie Morgan1 , Brian Chung1,2, Nicole Hung1 , Genevieve Mazza<sup>1</sup> and Alex McIntyre1,2

\*Address all correspondence to: wbstetsonmd@gmail.com

1 Stetson Powell Orthopedics and Sports Medicine, USA

2 Department of Orthopaedic Surgery, Keck School of Medicine at the University of Southern California, USA

### References

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[2] Atoun E, van Tongel A, Narvani A, Rath E, Sforza G, Levy O. Arthroscopically assisted internal fixation of the symptomatic unstable os acromiale with absorbable screws. Journal of Shoulder and Elbow Surgery. 2012;21(12):1740-1745. DOI: 10.1016/j.jse.2011.12.011

[17] Ryu RK, Fan RS, Dunbar WH. The treatment of symptomatic os acromiale. Orthopedics.

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[18] Lee DH, Lee KH, Lopez-Ben R, Bradley EL. The double-density sign: A radiographic finding suggestive of an os acromiale. The Journal of Bone & Joint Surgery. 2004;86-A

[19] Johnston PS, Paxton ES, Gordon V, Kraeutler MJ, Abboud JA, Williams GR. Os acromiale: A review and an introduction of a new surgical technique for management. The Orthope-

[20] Armengol J, Brittis D, Pollock RG, Flatow EL, Self EB. The association of an unfused acromial epiphysis with tears of the rotator cuff: A review of 42 cases. Journal of Shoulder

[21] Hertel R, Windisch W, Schuster A, Ballmer FT. Transacromial approach to obtain fusion of unstable os acromiale. Journal of Shoulder and Elbow Surgery. 1998;7(6):606-609

dic Clinics of North America. 2013;44(4):635-644. DOI: 10.1016/j.ocl.2013.06.015

1999;22(3):325-328

(12):2666-2670

and Elbow Surgery. 1994;17:975-976


[17] Ryu RK, Fan RS, Dunbar WH. The treatment of symptomatic os acromiale. Orthopedics. 1999;22(3):325-328

[2] Atoun E, van Tongel A, Narvani A, Rath E, Sforza G, Levy O. Arthroscopically assisted internal fixation of the symptomatic unstable os acromiale with absorbable screws. Journal of Shoulder and Elbow Surgery. 2012;21(12):1740-1745. DOI: 10.1016/j.jse.2011.12.011

[3] Kurtz CA, Humble BJ, Rodosky MW, Sekiya JK. Symptomatic os acromiale. The Journal of

[4] Sammarco VJ. Os acromiale: Frequency, anatomy, and clinical implications. The Journal of Bone and Joint Surgery. American Volume. 2000;82A(3):394-400. DOI: 10.1097/00003086-

[5] Warner J, Beim GM, Higgins L. The treatment of symptomatic os acromiale. The Journal of

[6] Demetracopoulos CA, Kapadia NS, Herickhoff PK, Cosgarea AJ, McFarland EG. Surgical stabilization of os acromiale in a fast-pitch softball pitcher. The American Journal of Sports

[7] Wright RW, Heller MA, Quick DC, Buss DD. Arthroscopic decompression for impingement syndrome secondary to an unstable os acromiale. Arthroscopy. 2000;16(6):595-599.

[8] Mudge MK, Wood VE, Frykman GK. Rotator cuff tears associated with os acromiale. The

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**Section 3**

**Hip**

### **Section 3**
