**9.1 Glenohumeral bone defects**

42 Modern Arthroscopy

Following surgery, the arm is placed in a sling in slight abduction and reduced internal rotation. Passive external rotation is restricted to 0 degrees. Active flexion and extension of the elbow is encouraged. After 3 weeks, the sling is discontinued, forward flexion is increased and external rotation is allowed to 30 degrees. Isotonic rotator cuff and scapular muscles strengthening is initiated after the 6th week. The return to unrestricted activity and full contact sports is determined on an individual basis and usually is not anticipated until 4

The most common complication is the recurrence of instability, which may be attributed to diagnostic and technical errors, or to additional trauma. Misdiagnosis may occur when a significant glenohumeral bone loss is not properly evaluated or a multidirectional component escapes diagnosis. Inadequate capsular tensioning and restoration of the glenoid concavity are the commonest technical errors met. It is therefore crucial to reassess range of motion and humeral head alignment after the repair. In athletes, the risk of recurrence increases with return to sports, since the demands placed on the shoulder are analogous to

Hardware failure commonly involves misplacement of the suture anchors. Absorbable implants have reduced the occurrence of late anchor displacement and complications during revision surgery. However proper anchor placement is mandatory and a careful evaluation should be performed whenever symptoms appear. Osteopenia along the glenoid rim has been correlated with absorbable anchors along with disuse during the

Nerve injury is not common. Structures at risk, however, include the axillary nerve that lies 1-1.5 cm below the inferior glenohumeral capsule and the musculocutaneous nerve situated 5-8 cm below the coracoid. Manipulation at the extremes of the range of motion should be

A recent concern after arthroscopic instability repair has been chondrolysis (Levine et al, 2005). Although rare, it is devastating because it often requires additional surgery and

**8.7 Postoperative management and rehabilitation** 

Fig. 11. Final view of the re-approximated capsulolabral complex.

to 6 months.

**8.8 Complications** 

postoperative period.

avoided.

those that caused the initial injury.

Studies have shown that compression fractures of the posterior superior humeral head (Hill-Sachs lesion) can occur in 32% to 51% of initial anterior dislocations, while anteroinferior glenoid deficiency in 22% of primary dislocations (Rowe et al, 1978; Rowe et al, 1984). The incidence of both glenoid and humeral head bone defects approaches 100% in cases of chronic anterior shoulder instability (Burkhart and De Beer 2000).

A critical decision on shoulder stabilization today focuses on the degree of bone loss and whether soft tissue reconstruction can be successful. Diagnostic pearls for clinical and imaging evaluation of glenohumeral bone defects have been discussed above. Bone defects between 20% and 30% of the inferior glenoid have shown a high recurrence rate after arthroscopic Bankart repair. However, the size and orientation of glenoid and humeral head defects can be extremely variable, making preoperative assessment and decision making difficult. It is currently suggested that patient with glenoid bone deficiency exceeding 20 to 25% of the articular surface should better be treated with a bone-substituting procedure (Provencher et al, 2010).

Bone grafting procedures, such as iliac bone-block or distal tibia transfer, glenoid allograft augmentation and the Bristow procedure have been advocated to restore osseous glenoid defects and shoulder stability. The Latarjet procedure was introduced in 1954. It delineates an osteotomy of the coracoid just proximal to its angle, which comprises the horizontal part of the coracoid and provides a 2 to 3cm bone segment. This is then transferred along with the attached conjoined tendon and the released coracoacromial ligament through a horizontal division of the subscapularis tendon and fixed at the antero-inferior glenoid, preferably with two screws (Fig 12).

The Latarjet procedure has shown excellent and reliable results both in biomechanical testing and the clinical setting. Quantitative Computed Tomography (qCT) has shown this technique to adequately restore a mean defect of up to 28% the intact inferior glenoid (Hantes et al, 2010). Compared with a structural bone graft, it resulted in significantly less anterior and anteroinferior translation at 60° of abduction. Satisfactory clinical results have also been reported with shoulder function ranging from good to excellent with recurrence rates between 0% and 7%. Complications include bony nonunion, graft displacement, progressive impingement and hardware loosening or migration. Improper graft placement, due to lack of experience or surgical exposure, may predispose to recurrent dislocation (when placed too medially or high) or osteoarthritis (too laterally).

Arthroscopic Treatment of Recurrent Anterior Glenohumeral Instability 45

Significant humeral Hill-Sachs lesions also raise concerns on the success of soft-tissue instability repairs. There is a debate on what size humeral head defects require treatment with bony reconstruction. Some authors suggest that defects involving over 12.5% of the humeral head diameter should raise concerns as potentially significant lesions (Kropf et al, 2007). Open allograft humeral head or autograft transfer reconstructions are indicated for the treatment of engaging Hill-Sachs lesions through deltopectoral or mini-open approaches. The Latarjet procedure has also been used successfully in such cases. Recently, an arthroscopic "remplissage" technique was introduced consisting of an arthroscopic capsulotenodesis of the posterior capsule and infraspinatus tendon to fill the Hill-Sachs lesion (Purchase et al, 2008). In light of such progress, glenohumeral bone loss should no

longer be considered an absolute contraindication for arthroscopic instability repair.

Arthroscopic treatment of shoulder instability has evolved considerably over the past decades. A detailed patient history and thorough physical examination are still considered the milestones for successful treatment planning. Advanced MRI imaging has offered a more accurate diagnosis and improved understanding of the pathology to be addressed. Presently, suture anchor stabilization is the operation that best duplicates the time-tested open procedure. Patient selection criteria, improved surgical techniques and implants available have contributed to the enhancement of clinical and functional outcomes to the point that arthroscopic treatment is considered nowadays the standard of care. However, arthroscopic techniques are demanding and there is a steep learning curve. Bone loss issues, including Hill-Sachs and glenoid rim lesions, remain a concern and a challenge for

Abrams, J. S. (2007). Role of arthroscopy in treating anterior instability of the athlete's

Bigliani, L. U., R. Kelkar, et al. (1996). Glenohumeral stability. Biomechanical properties of

Boileau, P., M. Villalba, et al. (2006). Risk factors for recurrence of shoulder instability after

Bokor, D. J., V. B. Conboy, et al. (1999). Anterior instability of the glenohumeral joint with

Bottoni, C. R., E. L. Smith, et al. (2006). Arthroscopic versus open shoulder stabilization for

Bottoni, C. R., J. H. Wilckens, et al. (2002). A prospective, randomized evaluation of

traumatic, first-time shoulder dislocations. *Am J Sports Med* 30(4): 576-580. Burkhart, S. S. and J. F. De Beer (2000). Traumatic glenohumeral bone defects and their

humeral avulsion of the glenohumeral ligament. A review of 41 cases. *J Bone Joint* 

recurrent anterior instability: a prospective randomized clinical trial. *Am J Sports* 

arthroscopic stabilization versus nonoperative treatment in patients with acute,

relationship to failure of arthroscopic Bankart repairs: significance of the inverted-

passive and active stabilizers. *Clin Orthop Relat Res*(330): 13-30.

arthroscopic Bankart repair. *J Bone Joint Surg Am* 88(8): 1755-1763.

shoulder. *Sports Med Arthrosc* 15(4): 230-238.

**10. Conclusions** 

arthroscopists to manage.

*Surg Br* 81(1): 93-96.

*Med* 34(11): 1730-1737.

**11. References** 

Routinely, the Latarjet procedure is performed through a standard deltopectoral approach. However, an all-arthroscopic alternative has been advocated recently as a consequence of the success of the open procedure and the advancements in arthroscopic instrumentation and techniques. This procedure offers the potential advantages of more accurate graft placement, management of associated joint pathology, such as bidirectional shoulder instability, ease of technique conversion, and faster rehabilitation with decreased joint stiffness and better cosmetic result (Lafosse et al, 2010). Although there is inevitably a steep learning curve, excellent results with good graft positioning and minimal complications have also been reported with arthroscopic Latarjet repair.

Fig. 12. The Latarjet procedure. Notice how the coracoid process graft supplements the articular surface of the original "inverted pear" glenoid to increase its anteroposterior diameter.

Significant humeral Hill-Sachs lesions also raise concerns on the success of soft-tissue instability repairs. There is a debate on what size humeral head defects require treatment with bony reconstruction. Some authors suggest that defects involving over 12.5% of the humeral head diameter should raise concerns as potentially significant lesions (Kropf et al, 2007). Open allograft humeral head or autograft transfer reconstructions are indicated for the treatment of engaging Hill-Sachs lesions through deltopectoral or mini-open approaches. The Latarjet procedure has also been used successfully in such cases. Recently, an arthroscopic "remplissage" technique was introduced consisting of an arthroscopic capsulotenodesis of the posterior capsule and infraspinatus tendon to fill the Hill-Sachs lesion (Purchase et al, 2008). In light of such progress, glenohumeral bone loss should no longer be considered an absolute contraindication for arthroscopic instability repair.
