Background: A midsubstance complete capsular tear is one of the
well-known causes of anterior glenohumeral instability. However, its
prevalence and clinical picture have not been well elucidated. The purpose of
this study was to examine the prevalence of isolated complete capsular tears
and to assess the clinical features as well as the results of surgical
treatment of recurrent anterior glenohumeral instability caused by such
tears.
Methods: Three hundred and three shoulders underwent surgery to
treat recurrent anterior glenohumeral instability at our institution during a
five-year period. Twelve (4.0%) of these shoulders had an isolated complete
capsular tear as the main pathological condition. Those twelve patients (nine
male and three female) were the subjects of the present study. The average age
at the time of the operation was twenty-five years. Patient age; the cause of
the initial dislocation; the position of the arm at the initial dislocation;
and the findings of the preoperative physical examination, of computed
tomographic arthrography, and at surgery were assessed. Eleven patients
underwent arthroscopic capsular repair, and one was treated with an open
capsular repair.
Results: The twelve patients either did not have a Hill-Sachs lesion
or had a chondral indentation-type of Hill-Sachs lesion. When assessed with
arthrography, the Hill-Sachs lesions were small compared with those in
shoulders with an isolated Bankart lesion and, interestingly, they were quite
similar in size to those seen with humeral avulsion of the inferior
glenohumeral ligament. The average Rowe score for the twelve patients improved
from 30.4 points preoperatively to 90.4 points at an average of thirty-one
months postoperatively.
Conclusions: The prevalence of isolated complete capsular tears
causing recurrent glenohumeral instability was 4.0% (twelve of 303). These
tears were associated with either a small or no Hill-Sachs lesion. We believe
that a complete capsular tear should be recognized as one of the essential
lesions causing recurrent anterior shoulder dislocation. Arthroscopic
examination and repair can provide effective treatment.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.