Rockwood Adults CH34

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SECTION TWO • Upper Extremity

help improve outcomes when managing shoulder instability. In areas of arthroscopic surgery, advances in surgical techniques have allowed bony augmentation procedures, such as Latarjet and bone block augmentation, to be performed more reliably and safely via arthroscopic techniques. 74,145,277,278 Similar to Bankart repairs, arthroscopic surgery in bony augmentation pro- cedures may offer decreased perioperative morbidity, particularly as instrumentation allows the surgery to be performed efficiently. While glenoid bone loss has received the vast majority of attention over the last 5 years, studies that are focused on the consequences of humeral head bone loss and the concept of glenoid tracking of Hill–Sachs lesions popularized by Yama- moto et al. 271 are emerging. Certain locations of the Hill–Sachs lesion coupled with glenoid attritional loss that may be subcrit- ical (less than 20%) may predispose Bankart repairs (especially those done arthroscopically) to failure. As a result, arthroscopic techniques, including infraspinatus capsulotenodesis or rem- plissage, have emerged to deal with Hill–Sachs lesions. Hartzler et al. 85 evaluated the glenoid tracking concept following Bankart repair with and without remplissage of the Hill–Sachs lesions in a bipolar cadaveric model where a less-than-critical 15% gle- noid defect was created along with Hill–Sachs lesions that either engaged (off-track) or did not engage (on-track) with the 90 degrees of external rotation. The authors found that the addi- tion of remplissage was necessary in addition to a standard Ban- kart repair to prevent engagement in all shoulders with off-track Hill–Sachs lesions. 85 Arthroscopic adjuvants such as remplissage may decrease the risk of recurrent instability after arthroscopic Bankart repair. Early clinical studies on remplissage have been favorable in terms reduction of recurrence of anterior instability relative to standard Bankart repairs. 42,43,125,152 Other arthroscopic approaches to addressing the Hill–Sachs lesion and augmenting a standard Bankart repair have been described. 188,261 It remains to be seen if these arthroscopic adjuvant procedures will decrease the recurrence risk in the long term. The definition of “subcritical” or “critical” bone loss has changed in the literature in recent years. This concept is essen- tial for the decision between arthroscopic repair or an open bone block procedure. Shaha et al. 209 found that over 13.5% bone loss was defined as the “subcritical” bone loss that resulted in higher failure rates as defined by poor WOSI scores after arthroscopic repair even in the setting of no recurrence of

instability. Subsequent studies have found that over 17.3% bone loss was the “critical” value in which arthroscopic repair resulted in 47% failure rate as defined by recurrence of instability. 211 Future prospective studies should focus on the true critical bone loss value that will help predict outcome and guide the decision between arthroscopic or bone block procedures in patients with anterior glenohumeral instability and glenoid bone loss. POSTERIOR GLENOHUMERAL INSTABILITY Recognition of symptomatic posterior shoulder instability is increasing with the advent of improved imaging protocols and clarification of imaging and physical examination charac- teristics. Arthroscopic techniques continue to evolve with the advent of percutaneous and knotless anchors. Future investi- gation focused on the optimal treatment for patients with failed posterior instability surgery and those with primary symptom- atic posterior shoulder instability in the setting of glenoid dys- plasia is needed. Controversy regarding surgical treatment for glenoid dysplasia includes use of glenoid osteotomy versus pri- mary arthroscopic repair versus bone blocks versus congruent bone augmentation techniques. Additional controversy regard- ing choice of graft including allograft distal tibia and autograft iliac crest is also unresolved. Additionally, current recommen- dations for management of posterior glenoid bone loss treat- ment are based on anterior shoulder instability protocols, but with deficient clinical evidence. MULTIDIRECTIONAL INSTABILITY MDI is a very complex problem that, despite many advances over the last few decades, is still not well understood. While the main- stay of initial treatment is a nonoperative strengthening program, much controversy exists over when to offer surgical treatment and what type of surgical treatment to perform. Multiple surgical techniques exist, both open and arthroscopic; however, none are deemed to be superior to the others and each has a specific com- plication profile that must be acknowledged. Although all sur- geons agree that the rotator interval is a key anatomic structure involved in the pathology of MDI, there remains controversy on when to address the interval with surgical closure. 171 When sur- gical treatment is performed, most surgeons agree that patients require 6 to 8 weeks of postoperative immobilization.

Annotated References Reference

Annotation

Aboalata M, Plath JE, Seppel G, et al. Results of arthroscopic Bankart repair for anterior-inferior shoulder instability at 13-year follow-up. Am J Sports Med. 2017;45(4):782–787.

This was a long-term follow-up of a total of 143 shoulders with anterior- inferior shoulder instability that underwent an arthroscopic Bankart repair with a minimum of 10-year follow-up. The overall redislocation rate was 18%. Concomitant SLAP repair had no effect on clinical outcome. Redislocation rate was significantly affected by the patient’s age and duration of postoperative rehabilitation. The redislocation rate tended to be higher if the patient had more than 1 dislocation preoperatively. Significant dislocation arthropathy was observed in 12% of patients in this series, and degenerative changes were correlated with the number of preoperative dislocations, patient age, and number of anchors used for the repair. The overall patient satisfaction rate was 92%, and return to the preinjury sport level was 50%.