[Value of glenoid osteotomy in treatment of posterior shoulder instability]

Purpose of this retrospective study was to evaluate the midterm results of glenoid osteotomy in the treatment of posterior instability and furthermore to evaluate the relevance of etiopathogenesis on the outcome.

Between Jan. 83 and May 94 32 patients underwent surgery due to posterior instability. Retrospectively these patients were classified based on their etiopathogenesis. 28 patients could be reexamined clinically and radiologically after and average of 4.85 years, of which 21 were treated with a glenoid osteotomy. For evaluation the Constant-Murley and the Rowe-Score were used.

The Constant-Score showed 82,2% and the Rowe-Score 71,5% good or excellent results. Evaluation of glenoid osteotomy demonstrated for the patients with atraumatic genesis an excellent result in 76.9% with a recurrence rate of only 15.4%. On the other hand patients with traumatic instability showed a recurrence rate of 50%. The radiologic assessment demonstrated degenerative changes in nearly 30% of cases treated with glenoid osteotomy.

This study shows that glenoid osteotomy can provide good result in the surgical treatment of posterior atraumatic instability. For treatment of traumatic instability, however, glenoid osteotomy is not the procedure due to high recurrence and arthrosis rates.

Posterior glenoid osteotomy should be reserved for patients with atraumatic posterior instability combined with an increased retroversion angle of the glenoid especially because of the high rate of arthrosis.