Atraumatic shoulder instability. Discussion of classification and results after capsular imbrication

This study consists of 27 shoulders in 24 patients whose atraumatic shoulder instability was treated with the imbrication procedure described by Rockwood. Follow-up after 2 years or more showed the following results: 37% excellent, 30% good, 15% fair and 18% poor (Rowe score). No statistically significant differences in the results were observed between the dominant and non-dominant arm, nor in post-operative return to sports activities. Those with voluntary instability had more laxity at follow-up and tended to have poorer results. Those with unidirectional laxity had only good or excellent results and showed no post-operative laxity. We found no other reliable indication of the results of surgery. The difficulties of classifying shoulder instability by such factors as trauma, laxity and direction of instability are discussed. Overall, we consider capsular imbrication to be a good treatment for involuntary atraumatic shoulder instability.