Capsular Shrinkage for MDI

Abstract & Commentary

Synopsis: Early 2-year results of 32 multidirectional instability patients treated with arthroscopic thermal capsular shrinkage show encouraging results, but caution is advised.

Source: Frostick SP, et al. Arthroscopic capsular shrinkage of the shoulder for the treatment of patients with multidirectional instability: Minimum 2-year follow-up. Arthroscopy. 2003;19(3):227-233.

Multidirectional instability is a condition that continues to challenge orthopaedic surgeons diagnostically and therapeutically. Originally described by Neer and Foster,1 it includes patients who manifest symptoms of instability in directions additional to the common anterior instability. Supervised physical therapy should always be attempted first before surgical intervention is considered. Open capsular shift was first described with variable success rates. Arthroscopic reconstructions have been advocated recently, but clinical studies are just coming to fruition.

This study by Frostick and colleagues is one of the first to prospectively evaluate patients at 2-year follow-up. Thirty-two patients were operated on at 2 separate institutions. All had instability symptoms and a painful, positive sulcus sign. All diagnoses were confirmed by the 2 experienced senior authors. All patients were followed for 2 years, and Constant scores were obtained at 6-month intervals. Two separate groups eventually developed and were evaluated separately. The largest group was of patients who demonstrated multidirectional instability without a labral lesion, and a smaller group of 8 had an anterior inferior labral lesion as part of their pathology.

In the first group, Constant scores increased from 58 preoperatively to 76 at 6 months and 81 at 2 years. Three patients experienced instability for a 12% failure rate, and 1 patient developed adhesive capsulitis. Fifty-eight percent were completely satisfied, and 25% were improved but not completely satisfied. In the second group (patients undergoing labral repair in addition to thermal capsulorrhaphy), Constant scores increased from 73 preoperatively to 72 at 6 months and 91 at 2 years. No patient experienced instability, and all patients were satisfied. One patient developed adhesive capsulitis but regained full motion after an arthroscopic lysis of adhesions.

Comment by COL Patrick St. Pierre, MD

This paper is one of the first to evaluate the treatment of multidirectional instability by thermal capsular shrinkage alone. The strength of their study is the fact that they have 100% follow-up at 2 years. It is a prospectively collected study but only offers historical controls for comparison. Obviously, this screams for a prospectively randomized study comparing open-shift vs capsular shrinkage vs capsular plication in the future. The inclusion of the labral repair patients is not helpful. There were only 8 patients in this group, making statistical analysis impossible. Their preoperative Constant scores were significantly better (73 vs 58) and improved more slowly but to a higher degree than the labrum-intact patients. This only leads one to question whether these patients are of a different pathological group, and this study does not answer the question.

Therefore, I think we can only assess the results of the first, nonlabral injury group. Frostick et al state that their results of 12% failure compared favorably with the open 4% failure results of Pollock and associates.2 I would suggest that there is still a considerable difference between them. Frostick et al add that 33% of the Pollock group had pain, but this still doesn’t compare with the 42% of the patients not completely satisfied in the current study.

Fitzgerald and colleages3 also reported 2-year results on patients with multidirectional thermal capsulorrhaphy. Their population also had patients with labral pathology and previous surgeries, and they reported a 24% failure rate.

Only 1 study has looked at multidirectional instability treated with arthroscopic capsular plication. McIntyre, and associates4 reported that they had only 1 patient out of 19 with a recurrent instability event 2 years after surgery.

Although the 2-year results presented are promising, they do not convince us that arthroscopic capsular shrinkage alone is as good as or better than an open anterior-inferior capsular shift or arthroscopic capsular plication. A prospectively randomized study is needed to compare these 3 techniques.

COL Dr. St. Pierre is Assistant Professor, Uniformed Services University, Orthopaedic Co-Director, Primary Care Sports Medicine Fellowship, DeWitt Army Community Hospital, Ft. Belvoir, VA.

References

1. Neer CS 2nd, Foster CR. Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: A preliminary report. J Bone Joint Surg Am. 1980;62-A:897-908.

2. Pollock RG, et al. Operative results of the inferior capsular shift procedure for multidirectional instability of the shoulder. J Bone Joint Surg Am. 2000;82-A: 919-928.

3. Fitzgerald BT, et al. The use of thermal capsulorrhaphy in the treatment of multidirectional instability. J Shoulder Elbow Surg. 2002;11:108-113.

4. McIntyre LF, et al. The arthroscopic treatment of multidirectional shoulder instability: Two-year results of a multiple suture technique. Arthroscopy. 1997;13: 418-425.