**4. Anterosuperior approach**

The anterosuperior approach to the shoulder was first described by Mackenzie in 1993 [40]. It does not utilize an internervous plane as it requires detachment of the anterior deltoid off the acromion as well as release of the coracoacromial ligament to reach the glenohumeral joint. Though it was initially designed to provide increased exposure of the glenoid for shoulder arthroplasty, it is also frequently used in the open repair of difficult-to-manage rotator-cuff tears [41], proximal humerus fractures, and even long head of the biceps repair. The previously described protocol for anesthesia induction, positioning, and prepping should be utilized for the anterosuperior approach just as it was for the deltopectoral approach.

#### **4.1. Superficial dissection**

After the operative arm has been draped, the surgery should begin with the surgeon palpating the bony landmarks of the shoulder including the anterior and posterior aspects of the acromion, as well as the anterior border of the clavicle and the acromioclavicular joint. An approximately 5–7-cm incision should be drawn on the shoulder in line with the longitudinal axis of the clavicle (**Figure 7**). The incision should start just posterior to the anterolateral corner of the acromion and should be carried down through the skin and the subcutaneous tissue until the fascia overlying the deltoid muscle is reached. Careful hemostasis should be achieved with electrocautery. The surgeon should then identify the raphe between the anterior and middle portions of the deltoid (**Figure 8**). Once identified, the raphe should be split in line with the deltoid fibers for approximately 5 cm from the lateral border of the acromion. Care should be taken not to extend the incision beyond 5 cm from the lateral margin of the acromion in order to minimize the risk of damage to the axillary nerve [42]. A stay suture may be placed in the distal aspect of the deltoid to mark the level of the axillary nerve and to help prevent inadvertent damage during dissection. At several instances throughout the course of the surgery, the stay suture should be checked to ensure the integrity of the suture. If it is ever found to be compromised, it should be removed and replaced.

**4.2. Deltoid and coracoacromial ligament handling**

suture repair of the deltoid back to the acromion [44].

be described in this section.

*4.2.2. Acromial osteotomy*

*4.2.1. Deltoid peel*

At this point, the deltoid separates the surgeon from accessing the glenohumeral joint. The anterosuperior approach to the shoulder mandates the removal of a portion of the deltoid off of the acromion. There are two methods for releasing the anterior deltoid that have been described in the literature. These two methods, acromial osteotomy versus deltoid peel, will

Surgical Approaches in Shoulder Arthroplasty http://dx.doi.org/10.5772/intechopen.70363 75

**Figure 8.** Fat stripe identifying the raphe between the anterior and middle portions of the deltoid.

The original article by Mackenzie advocated for the removal of approximately 1–2 cm of the deltoid from its origin on the anterior acromion [40]. The deltoid should be reflected in a subperiosteal fashion and care should be taken not to remove more than 2 cm of the deltoid off of the acromion as repairing the deltoid back to the acromion can be difficult. After the deltoid has been retracted out of the way, an acromioplasty of the anterior acromion may be performed to facilitate exposure to the proximal humerus [43]. The coracoacromial ligament may be removed from the undersurface of the acromion using sharp dissection or electrocautery. The acromial branch of the thoracoacromial artery may be encountered deep to the deltoid and should be ligated to prevent retraction and excess bleeding. The subdeltoid bursa can be divided at this time and the long head of the biceps may be identified and then tenotomized at its origin. Peeling the tendon from the acromion requires soft tissue-to-bone healing; however, one recent study showed no changes in axillary nerve or deltoid function 3 months after

Rather than peeling the deltoid off the acromion and relying on muscle-to-bone healing, Mole describes an acromial osteotomy to facilitate healing with more robust bone-to-bone healing [7].

**Figure 7.** Surface landmarks with incision marked out for the anterosuperior approach. Care should be taken to ensure that the incision is not carried out more than 5 cm below the edge of the acromion to avoid iatrogenic axillary nerve injury. This is a Right shoulder cadeveric specimen.

**Figure 8.** Fat stripe identifying the raphe between the anterior and middle portions of the deltoid.

#### **4.2. Deltoid and coracoacromial ligament handling**

At this point, the deltoid separates the surgeon from accessing the glenohumeral joint. The anterosuperior approach to the shoulder mandates the removal of a portion of the deltoid off of the acromion. There are two methods for releasing the anterior deltoid that have been described in the literature. These two methods, acromial osteotomy versus deltoid peel, will be described in this section.

#### *4.2.1. Deltoid peel*

arthroplasty, it is also frequently used in the open repair of difficult-to-manage rotator-cuff tears [41], proximal humerus fractures, and even long head of the biceps repair. The previously described protocol for anesthesia induction, positioning, and prepping should be

After the operative arm has been draped, the surgery should begin with the surgeon palpating the bony landmarks of the shoulder including the anterior and posterior aspects of the acromion, as well as the anterior border of the clavicle and the acromioclavicular joint. An approximately 5–7-cm incision should be drawn on the shoulder in line with the longitudinal axis of the clavicle (**Figure 7**). The incision should start just posterior to the anterolateral corner of the acromion and should be carried down through the skin and the subcutaneous tissue until the fascia overlying the deltoid muscle is reached. Careful hemostasis should be achieved with electrocautery. The surgeon should then identify the raphe between the anterior and middle portions of the deltoid (**Figure 8**). Once identified, the raphe should be split in line with the deltoid fibers for approximately 5 cm from the lateral border of the acromion. Care should be taken not to extend the incision beyond 5 cm from the lateral margin of the acromion in order to minimize the risk of damage to the axillary nerve [42]. A stay suture may be placed in the distal aspect of the deltoid to mark the level of the axillary nerve and to help prevent inadvertent damage during dissection. At several instances throughout the course of the surgery, the stay suture should be checked to ensure the integrity of the suture. If it is ever

**Figure 7.** Surface landmarks with incision marked out for the anterosuperior approach. Care should be taken to ensure that the incision is not carried out more than 5 cm below the edge of the acromion to avoid iatrogenic axillary nerve

utilized for the anterosuperior approach just as it was for the deltopectoral approach.

found to be compromised, it should be removed and replaced.

injury. This is a Right shoulder cadeveric specimen.

**4.1. Superficial dissection**

74 Advances in Shoulder Surgery

The original article by Mackenzie advocated for the removal of approximately 1–2 cm of the deltoid from its origin on the anterior acromion [40]. The deltoid should be reflected in a subperiosteal fashion and care should be taken not to remove more than 2 cm of the deltoid off of the acromion as repairing the deltoid back to the acromion can be difficult. After the deltoid has been retracted out of the way, an acromioplasty of the anterior acromion may be performed to facilitate exposure to the proximal humerus [43]. The coracoacromial ligament may be removed from the undersurface of the acromion using sharp dissection or electrocautery. The acromial branch of the thoracoacromial artery may be encountered deep to the deltoid and should be ligated to prevent retraction and excess bleeding. The subdeltoid bursa can be divided at this time and the long head of the biceps may be identified and then tenotomized at its origin. Peeling the tendon from the acromion requires soft tissue-to-bone healing; however, one recent study showed no changes in axillary nerve or deltoid function 3 months after suture repair of the deltoid back to the acromion [44].

#### *4.2.2. Acromial osteotomy*

Rather than peeling the deltoid off the acromion and relying on muscle-to-bone healing, Mole describes an acromial osteotomy to facilitate healing with more robust bone-to-bone healing [7]. Once the dissection has been carried down to the lateral border of the acromion and the deltoid, an osteotome is used to remove a fleck of acromial bone along with the attached deltoid and coracoacromial ligament. This should be retracted, facilitating access now to the glenohumeral joint. Again, if the acromial branch of the thoracoacromial artery is encountered, it should be ligated. If needed, an acromioplasty should be performed in order to better visualize the humerus in preparation for the humeral osteotomy. The subdeltoid bursa should be incised and long head of the biceps tendon should be identified and released at its origin.

#### **4.3. Humeral exposure**

After releasing the deltoid and coracoacromial ligament, the humerus is ready to be osteotomized and prepared for implantation. If any question regarding the competency of the subscapularis, supraspinatus, or infraspinatus exists, they may be assessed at this point. In order to visualize the posterior rotator cuff, the arm should be extended and internally rotated to bring the greater tuberosity into the operative field (**Figure 9**). Originally, Mackenzie described a subscapularis tenotomy to allow for anterior dislocation and osteotomy; however, traditionally, the subscapularis has been preserved in this approach. The humeral head should be delivered by subluxating the head anterosuperiorly and the capsular attachments should be removed along the humeral neck. Care should be taken when removing the capsular attachments to cut toward the bone to minimize the risk of damage to surrounding structures. Once the neck is able to be visualized, the humeral head may be cut along the anatomic neck of the humerus with the assistance of implant-specific cutting guides as needed. Again, the excised head should not be removed from the operative field as it may be useful when determining implant size. Once the neck cut has been made, any osteophytes that are observed may be removed using a rongeur or an osteotome. Posterior and inferior osteophytes may be difficult to reach utilizing this approach.

**4.4. Glenoid exposure**

**4.6. Closure**

**4.5. Preparation for implantation**

deltoid was detached from the acromion.

After the humeral neck has been cut, a curved retractor may be placed on the inferior aspect of the glenoid in order to retract the remainder of the humerus posteroinferiorly out of the operative field (**Figure 10**). Another retractor should be placed between the anteroinferior glenoid and the subscapularis tendon in order to protect the axillary nerve as it courses near the undersurface of the glenoid neck. The capsulo-labral attachments should be circumferentially removed from the glenoid periphery using either sharp dissection with a 15 blade or electrocautery.

Surgical Approaches in Shoulder Arthroplasty http://dx.doi.org/10.5772/intechopen.70363 77

**Figure 10.** After retraction of the humerus, the anterosuperior approach allows for exceptional glenoid exposure.

Once the humerus and glenoid have been sufficiently exposed, they are ready for preparation. Traditionally, a guide pin is placed in the center aspect of the glenoid in order to establish the axis for the central peg of the glenoid component. Great care should be taken with this particular approach to ensure that adequate inferior tilt of the glenoid component is achieved as the presence of the humerus can significantly interfere with the coronal position of the implant. After the appropriate plane has been achieved, the glenoid is reamed and prepared according to the implant-specific methods. The glenoid component should then be placed, and once it has been, the intramedullary canal of the humerus is identified and subsequently reamed and/or broached according to the protocols for the implant. Trial components are placed and

stability and motion should be verified prior to placement of the final components.

Once the components have been placed, the shoulder should be reduced and taken through a full range of motion to ensure adequate stability and range of motion. The wound should be irrigated copiously with normal saline and any topical antibiotics should be placed in the wound. If a drain is desired, it should be placed prior to wound closure. The most important aspect of wound closure is the repair of the deltoid muscle back to the acromion. The method for repair of the deltoid back to the acromion will vary slightly based on the method that the

**Figure 9.** After the deltoid has been peeled off the acromion, the humeral head and rotator-cuff insertion are now visible.

**Figure 10.** After retraction of the humerus, the anterosuperior approach allows for exceptional glenoid exposure.

## **4.4. Glenoid exposure**

Once the dissection has been carried down to the lateral border of the acromion and the deltoid, an osteotome is used to remove a fleck of acromial bone along with the attached deltoid and coracoacromial ligament. This should be retracted, facilitating access now to the glenohumeral joint. Again, if the acromial branch of the thoracoacromial artery is encountered, it should be ligated. If needed, an acromioplasty should be performed in order to better visualize the humerus in preparation for the humeral osteotomy. The subdeltoid bursa should be incised and long head

After releasing the deltoid and coracoacromial ligament, the humerus is ready to be osteotomized and prepared for implantation. If any question regarding the competency of the subscapularis, supraspinatus, or infraspinatus exists, they may be assessed at this point. In order to visualize the posterior rotator cuff, the arm should be extended and internally rotated to bring the greater tuberosity into the operative field (**Figure 9**). Originally, Mackenzie described a subscapularis tenotomy to allow for anterior dislocation and osteotomy; however, traditionally, the subscapularis has been preserved in this approach. The humeral head should be delivered by subluxating the head anterosuperiorly and the capsular attachments should be removed along the humeral neck. Care should be taken when removing the capsular attachments to cut toward the bone to minimize the risk of damage to surrounding structures. Once the neck is able to be visualized, the humeral head may be cut along the anatomic neck of the humerus with the assistance of implant-specific cutting guides as needed. Again, the excised head should not be removed from the operative field as it may be useful when determining implant size. Once the neck cut has been made, any osteophytes that are observed may be removed using a rongeur or an osteotome. Posterior and inferior osteophytes may be difficult to reach utilizing this approach.

**Figure 9.** After the deltoid has been peeled off the acromion, the humeral head and rotator-cuff insertion are now visible.

of the biceps tendon should be identified and released at its origin.

**4.3. Humeral exposure**

76 Advances in Shoulder Surgery

After the humeral neck has been cut, a curved retractor may be placed on the inferior aspect of the glenoid in order to retract the remainder of the humerus posteroinferiorly out of the operative field (**Figure 10**). Another retractor should be placed between the anteroinferior glenoid and the subscapularis tendon in order to protect the axillary nerve as it courses near the undersurface of the glenoid neck. The capsulo-labral attachments should be circumferentially removed from the glenoid periphery using either sharp dissection with a 15 blade or electrocautery.

#### **4.5. Preparation for implantation**

Once the humerus and glenoid have been sufficiently exposed, they are ready for preparation. Traditionally, a guide pin is placed in the center aspect of the glenoid in order to establish the axis for the central peg of the glenoid component. Great care should be taken with this particular approach to ensure that adequate inferior tilt of the glenoid component is achieved as the presence of the humerus can significantly interfere with the coronal position of the implant. After the appropriate plane has been achieved, the glenoid is reamed and prepared according to the implant-specific methods. The glenoid component should then be placed, and once it has been, the intramedullary canal of the humerus is identified and subsequently reamed and/or broached according to the protocols for the implant. Trial components are placed and stability and motion should be verified prior to placement of the final components.

#### **4.6. Closure**

Once the components have been placed, the shoulder should be reduced and taken through a full range of motion to ensure adequate stability and range of motion. The wound should be irrigated copiously with normal saline and any topical antibiotics should be placed in the wound. If a drain is desired, it should be placed prior to wound closure. The most important aspect of wound closure is the repair of the deltoid muscle back to the acromion. The method for repair of the deltoid back to the acromion will vary slightly based on the method that the deltoid was detached from the acromion.

If the deltoid was peeled subperiosteally off the acromion, it must be repaired using a large-diameter, non-absorbable suture in a transosseous fashion. Many large-diameter suture needles are strong enough to pass through the acromion without using a power drill; however, if the bone is hard, a drill may be used [44]. The suture should be passed through the deltoid with sufficient purchase to ensure that the suture does not pull through the muscle. If the acromial osteotomy was utilized, suture should be passed around the fleck of the acromion with sufficient purchase in the deltoid to again prevent pulling through the suture within the substance of the deltoid.

of weakening of the deltoid through this exposure. There is no literature regarding the status of the deltoid repair or deltoid function after using this approach. However, because the repair of the deltoid to the acromion relies on muscle-to-bone healing, the deltoid may have difficulty healing and subsequent dysfunction. This could be particularly problematic when placing a reverse shoulder prosthesis that relies on intact deltoid function to be successful. If a fleck of acromion is taken, there is a theoretical risk of iatrogenic fracture to the acromion when harvesting the fleck. However, one study, comparing the two approaches, found a significantly higher rate of acromion fracture with the deltopectoral approach compared to the anterosuperior approach [7]. A final disadvantage of the anterosuperior approach is the inability to extend the incision distal if a periprosthetic humeral fracture is encountered. Because it does not utilize an intermuscular plane, it is not able to be extended to the midshaft of the humerus. Furthermore, at the distal aspect of the incision lies the axillary nerve. Webb, in his surgical technique for proximal humerus fractures, states that should distal exposure be needed, the axillary nerve can be identified, protected, and a plate may be placed underneath the axillary nerve [44].

Surgical Approaches in Shoulder Arthroplasty http://dx.doi.org/10.5772/intechopen.70363 79

The deltopectoral and anterosuperior approaches are by and large the most commonly used approaches for shoulder arthroplasty; however, there are other approaches to the glenohumeral joint which have been described in the literature. Lafosse et al. described an approach for anatomic total shoulder arthroplasty that spares all of the rotator-cuff tendons and is performed through the rotator interval [50]. The approach mimics that of the anterosuperior approach in that the deltoid is split in line with its fibers in the raphe between the anterior and middle portions of the deltoids. Again, similar to the anterosuperior approach, the authors had difficulty removing the inferior osteophytes as well as performing an anatomic humeral neck cut and sizing of the humeral head. Two-year follow-up data from this approach do show promising results, though no comparison was made to the deltopectoral approach.

Bellamy et al. performed a cadaveric study analyzing more minimally invasive approaches to the subscapularis including a partial tenotomy and a subscapularis split [51]. In this study, they measured the average area of the glenoid and the humerus that they could visualize through each of these approaches. They found that all of these approaches had adequate exposure of the glenoid; however, the split provided poor exposure of the humerus for

Gagey et al. presented the results of 53 patients who underwent anatomic total shoulder arthroplasty over a 6-year span via a posterolateral approach [52]. This approach begins with the patient in the lateral decubitus position and a posterior incision is made and carried down between the raphe of the posterior and middle portions of the deltoid. The bursa is then released to identify the tendons of the external rotators. The tendons are then removed via an osteotomy of the greater tuberosity. This allows for exposure to the glenohumeral joint. The osteotomy is then repaired in a manner similar to the lesser tuberosity osteotomy described in the deltopectoral section. Adequate exposure was achieved for placement of shoulder arthroplasty components; however, the authors did note two cases of posterior deltoid atrophy that was

humeral-based procedures, while the partial tenotomy provided sufficient exposure.

**5. Alternate approaches**

Once the deltoid has been adequately repaired to the acromion, the deltoid raphe should be sutured with a 0 vicryl or polydioxanone (PDS) suture in a running whipstitch or figure-of-eight interupted fashion. Care should again be taken to avoid suturing below the previously placed stay suture to avoid damaging the axillary nerve. With the raphe closed, the subcutaneous layer may be closed with an absorbable 2-0 suture and the skin with a nylon, running monocryl or other method of skin closure. A dry dressing or an incisional vacuum should be placed over the wound and the arm placed into a sling with abduction pillow prior to awakening the patient.

#### **4.7. Advantages**

The anterosuperior approach provides several advantages to the deltopectoral approach. Perhaps, the greatest of these is the subscapularis sparing nature of the approach. Though originally Mackenzie described the approach with a subscapularis tenotomy, modern-day surgeons have typically modified this approach to spare the subscapularis. Utilizing a subscapularis tenotomy with adequate repair, Miller et al. showed, both clinically and functionally, that the subscapularis was deficient following shoulder arthroplasty in a majority of cases [45]. Jackson et al. showed high re-rupture rates following repair of a tenotomy using ultrasound and then showed that it was associated with decreased function [46]. Furthermore, early literature has shown that subscapularis-deficient shoulders have higher rates of instability [36], though other studies have shown no significant difference [47].

The anterosuperior lateral approach is also superior in terms of exposure to the posterior structures of the shoulder, including the posterior glenoid and the rotator cuff. This exposure may be particularly useful for three- or four-part proximal humerus fractures where the greater tuberosity fragment attached to the rotator cuff is pulled posterior and superior [44]. The exposure of the glenoid via the anterosuperior approach is, historically, felt to be superior to that of the deltopectoral approach. It allows for visualization of the entire glenoid and for better sagittal positioning of the glenoid component. Furthermore, it allows for easier preparation of the glenoid, particularly in obese patients and in cases where the glenoid may be retroverted.

#### **4.8. Disadvantages**

Despite having superior exposure of the glenoid as a whole, exposure of the inferior aspect of the glenoid is more difficult via the anterosuperior approach. As such, it is more difficult to provide sufficient inferior tilt of the glenoid component which may lead to scapular notching and subsequent failure of the glenoid component [35, 48, 49]. Furthermore, the presence of inferior osteophytes is a relative contraindication to this approach due to the extreme difficulty in accessing and removing these osteophytes. In addition, there is a theoretical disadvantage of weakening of the deltoid through this exposure. There is no literature regarding the status of the deltoid repair or deltoid function after using this approach. However, because the repair of the deltoid to the acromion relies on muscle-to-bone healing, the deltoid may have difficulty healing and subsequent dysfunction. This could be particularly problematic when placing a reverse shoulder prosthesis that relies on intact deltoid function to be successful. If a fleck of acromion is taken, there is a theoretical risk of iatrogenic fracture to the acromion when harvesting the fleck. However, one study, comparing the two approaches, found a significantly higher rate of acromion fracture with the deltopectoral approach compared to the anterosuperior approach [7]. A final disadvantage of the anterosuperior approach is the inability to extend the incision distal if a periprosthetic humeral fracture is encountered. Because it does not utilize an intermuscular plane, it is not able to be extended to the midshaft of the humerus. Furthermore, at the distal aspect of the incision lies the axillary nerve. Webb, in his surgical technique for proximal humerus fractures, states that should distal exposure be needed, the axillary nerve can be identified, protected, and a plate may be placed underneath the axillary nerve [44].
