Arthroscopic capsulolabroplasty for posteroinferior multidirectional instability of the shoulder

Background: Arthroscopic treatment of posteroinferior multidirectional instability of the shoulder is not well documented. Purpose: To evaluate pathologic lesions of posteroinferior multidirectional instability and the results of arthroscopic capsulolabroplasty. Study Design: Prospective nonrandomized clinical trial. Methods: Thirty-one patients with posteroinferior multidirectional instability were prospectively evaluated after arthroscopic capsulolabroplasty (mean follow-up, 51 months). Labral lesion and height were measured in the MRI arthrogram and arthroscopic examination. Results: All patients had a labral lesion and variable capsular stretching in the posteroinferior aspect. There were 11 type I labral lesions (incomplete detachment), 12 type II (the Kim's lesion: incomplete and concealed avulsion), 6 type III (chondrolabral erosion), and 2 type IV (flap tear). All patients with type II and III lesions had chondrolabral retroversion, with lost labral height in the MRI arthrogram and arthroscopic examination. Twenty-one patients had an excellent Rowe score, nine had good scores, and one had a fair score. Thirty patients had stable shoulders, and one had recurrent instability. All patients had improved shoulder scores and function and pain scores. Conclusions: Symptomatic patients with posteroinferior multidirectional instability had posteroinferior labral lesions, including retroversion of the posteroinferior labrum, which were previously unrecognized. Restoration of the labral buttress and capsular tension by arthroscopic capsulolabroplasty successfully stabilized shoulders with posteroinferior multidirectional instability.