Residual brachial plexus birth palsy frequently leads to muscle imbalance around the shoulder. The most prevalent deformity is an adduction and internal rotation contracture. This position promotes glenoid retroversion and posterior humeral head subluxation. This study assessed twenty-three children who had either subluxation or dislocation that required open reduction and tendon lengthening, with a mean age at surgery of 2 years, 5 months. Although the authors do not indicate the specifics regarding the procedure, the patients were immobilized for 6 weeks using a shoulder spica, and an additional 6 weeks in an orthosis. The orthosis was removed for daily exercise and bathing. CT scans were used to assess the pre-operative and follow-up results. Serial CT scans reveal that glenoid version continued to reduce by approximately 9% per year after open reduction. The duration of follow-up was 3 years and 7 months, although considerable variability existed between 22 months and 5 « years. The difference in the glenoid version between a dislocated shoulder and the normal side, lessened over time. No significant differences between pre-operative and post-operative angles of version were noted in the uninvolved side.
This study provides valuable information regarding glenoid version in brachial plexus birth palsy. It is known that glenoid retroversion is prevalent in this population, especially as the shoulder becomes more contracted. This study lends further support for open reduction to decrease the abnormal version of affected shoulders. Unfortunately, it lacks clinical correlation and does not discuss the position of the humeral head. Furthermore, clinical outcome measures, such as range of motion and ability to perform daily tasks are not included. This information would further strengthen the case for early glenohumeral reduction. Nonetheless, the need for early passive motion after brachial plexus birth palsy and maintenance of a congruent reduction between the glenoid and humeral head are supported.
J Pediatric Orthop