Capsulolabral Augmentation for the the Management of Posteroinferior Instability of the Shoulder

Background: Posteroinferior instability of the shoulder has been associated with capsular laxity. The purposes of the present study were to describe the pathological morphology of the posteroinferior aspect of the glenolabral fossa in patients with primary posteroinferior instability and to prospectively examine the efficacy of managing this instability with use of an arthroscopic posteroinferior capsulolabral augmentation procedure.

Methods: Forty-one patients who had posteroinferior instability of the shoulder were managed with an arthroscopic shift of the posteroinferior aspect of the capsule to the adjacent labrum and were followed for a minimum of twelve months. Thirty-two patients had a primary procedure, and nine had a revision procedure. The mean duration of follow-up was twenty-eight months (range, twelve to sixty-nine months). All of the patients had presented with a symptomatic, positive finding on the jerk test and had participated in a minimum of six months of rehabilitation that had failed to relieve the symptoms. The patients were evaluated prospectively with a motion and stability examination and the Simple Shoulder Test. In addition, they completed the Short Form-36 Health Survey (SF-36) and a questionnaire on the outcome of treatment.

Results: Lesions affecting the posteroinferior aspect of the glenolabral concavity were seen in thirty-four patients (83 percent): five had labral detachment, seven had chondral or labral erosion, nine had capsular and synovial stripping, and thirteen had a labral split or tear. The mean score (and standard deviation) on the Simple Shoulder Test improved from 5.5 +/- 3.4 points to 8.1 +/- 3.3 points (p = 0.0023), and two of the eight SF-36 parameters improved significantly (p < 0.05). Conversely, nineteen patients who were receiving Workers' Compensation did not show any improvement in either of the two parameters. Thirty-five patients had improved stability of the shoulder, and the findings on all physical examinations had improved significantly (p < 0.0001). Twenty-eight patients had a perception of residual stiffness; this finding was in contrast to the mean score on the flexibility examination, which had not changed significantly at the time of the latest follow-up.

Conclusions: Posteroinferior instability of the shoulder is associated not only with capsular laxity but also with well defined lesions of the glenolabral concavity. Arthroscopic capsulolabral augmentation to reduce posterior capsular laxity and to restore the depth of the glenolabral concavity has been shown to be effective treatment of this condition after a mean duration of follow-up of twenty-eight months.