Development of the glenohumeral joint after subscapular release and open relocation in children with brachial plexus birth palsy: long-term results in 61 patients.

BACKGROUND: We present the long-term results of remodeling of the glenohumeral joint after open subscapularis elongation and relocation of the humeral head in patients with an internal rotation contracture and joint incongruity due to brachial plexus birth palsy.

METHODS: In this before-and-after study, 61 patients who underwent open subscapularis elongation and reduction of the glenohumeral joint were evaluated with respect to joint remodeling, with a mean follow-up period of 10.2 years (range, 7-16 years). The mean age at operation was 3.2 years (range, 8 months to 15 years). Measurements of the percentage of the humeral head anterior to the midscapular line (PHHA), glenoid version, and diameter of the humeral head were recorded using magnetic resonance imaging, comparing the affected joints preoperatively vs. postoperatively (n = 31) and comparing the operated vs. unaffected sides postoperatively (n = 61).

RESULTS: The mean increase in PHHA was 27.6 percentage points (95% confidence interval, 22.4-32.7 percentage points; P < .01), from 13.2% to 40.8%. The glenoid retroversion changed by 14.8° (95% confidence interval, 11.1°-18.4°; P < .01), from 25.4° to 10.6°, approaching a normal value. All patients, even those older than 5 years, showed a clear benefit from surgery.

CONCLUSIONS: Our study confirms that open subscapularis lengthening with joint repositioning, up to the age of 5 years, gives consistent remodeling of incongruent shoulders with surprisingly small differences between the operated and unaffected shoulders at long-term follow-up. The findings indicate that open reduction is useful also in adolescents and challenges the notion that older children should be treated with derotational humeral osteotomy.