Copyright © 2009 by The Journal of Bone and Joint Surgery, Inc.

Commentary & Perspective

Commentary & Perspective on
"Predisposing Factors for Recurrent Shoulder Dislocation After Arthroscopic Treatment"
by Giuseppe Porcellini, MD, et al.

Commentary & Perspective by
Brett D. Owens, MD*†,
Keller Army Hospital, West Point, NY

Posted November 2009

While the technical improvements in arthroscopic Bankart repair have allowed the outcomes to approach those of the classic open repair method1, recurrent instability remains a concern. The ability to identify risk factors for failure with arthroscopic Bankart repair may allow surgeons to augment their arthroscopic capsulolabral repair or opt for open stabilization in high-risk patients. To date, investigators have recognized the following factors as having negative prognostic value in patients undergoing primary arthroscopic Bankart repair: poor soft-tissue quality2, sulcus sign and/or inferior laxity2,3, bilaterality2, participation in collision sports2,4, glenoid bone loss3,5,6, bone loss in the humeral head3,6, and repairs consisting of three or fewer anchors3.

Porcellini et al. report on a large series of arthroscopic Bankart repairs in a selected population and hypothesize that risk factors for recurrence can be determined on the basis of preoperative data. During a three-year period, 647 shoulders underwent surgical stabilization for instability by a single surgeon. Of these, 422 (65%) met the strict inclusion criteria for this study and 385 (91%) were successfully followed for three years. The authors excluded patients with atraumatic mechanisms, voluntary instability, ligamentous laxity, sulcus sign, prior surgery, osseous Bankart lesions, glenoid bone loss, and those not treated surgically within twelve months of dislocation, those with seven or more dislocations, and those whose repair required fewer or more than three suture anchors. The authors do not provide the specific reasons for their exclusion of 203 patients in this study. The authors also make no mention of Hill-Sachs lesions in their inclusion criteria. There was no quantification made of the cohort's activity level, although the authors do state that none of the patients were professional athletes.

After the performance of an arthroscopic Bankart repair with suture anchors, patients were followed for three years and failure was defined as either a recurrent subluxation or dislocation. However, the authors do not clarify this distinction in their results and do not mention subluxation again in the manuscript. In thirty-one (8.1%) of the 385 patients, the procedure was classified as a failure due to recurrence. The authors analyzed these failures and found that the following factors were statistically significant: age of twenty-two years or less, male sex, and a time to surgery of greater than six months.

While these results are not surprising, they do warrant some scrutiny. The first two factors identified (age of twenty-two years or less and male sex) are two known risk factors for initial glenohumeral instability7 as well as recurrence following nonoperative treatment8. These variables may serve as proxy measures for activity, with the possibility that a higher proportion of these patients may return to contact athletics. That a greater than six-month delay in stabilization was associated with a higher failure rate may be explained by the incremental pathologic changes noted with repetitive instability events9. The differentiation between a medialized anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion and a classic Bankart avulsion has been previously investigated. Ozbaydar et al. showed that patients with ALPSA lesions had a history of sustaining more instability events prior to stabilization and had a higher failure rate with stabilization as compared with those with Bankart lesions10. Porcellini et al. failed to show a significant difference in failure rates when comparing the type of lesion and the number of instability events in this study, and the authors suggest that the study may be underpowered to show this effect.

The major methodological concern with this study is the authors' decision to dichotomize their patient variables for analysis. The authors do not provide reasoning for their selection of twenty-two years of age at time of dislocation, six months until stabilization, or three dislocation events as cut-off points in their dichotomization. Nor do the authors provide an explanation for their decision to exclude patients with seven or more dislocation events or who underwent stabilization more than one year after the injury.

Despite these methodological concerns, there are some important take-home points from this study. The authors report an acceptable rate of recurrence (8.1%) in a large (385 shoulders) series of arthroscopic Bankart repairs. Porcellini et al. were able to show a higher rate of failure in patients who were twenty-two years of age or younger and male, which may be explained by greater activity level in that population. This supports the aggressive surgical treatment of these high-risk patients. They also found a higher failure rate in patients who undergo stabilization later than six months after their initial event, lending further credence to the concept of early stabilization in high-risk patients who have sustained a first-time glenohumeral dislocation.

*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.

The views expressed in this paper are those of the author and do not reflect the official policy or position of the Department of the Army, the Department of Defense, or the United States Government.

References

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10. Ozbaydar M, Elhassan B, Diller D, Massimini D, Higgins LD, Warner JJ. Results of arthroscopic capsulolabral repair: Bankart lesion versus anterior labroligamentous periosteal sleeve avulsion lesion. Arthroscopy. 2008;24:1277-83.