Background: Persistent muscle imbalance and soft-tissue contractures can lead to progressive glenohumeral joint dysplasia in patients with brachial plexus birth palsy. The objective of the present investigation was to determine the effects of tendon transfers and open glenohumeral reduction on shoulder function and dysplasia in patients with preexisting joint deformity secondary to brachial plexus birth palsy.
Methods: Twenty-three patients with preexisting glenohumeral deformity underwent latissimus dorsi and teres major tendon transfers to the rotator cuff with concomitant musculotendinous lengthening of the pectoralis major and/or subscapularis and open glenohumeral joint reduction for the treatment of internal rotation contracture and external rotation weakness. Shoulder function was assessed with use of the modified Mallet classification system and the Active Movement Scale. Glenoid version and humeral head subluxation were quantified radiographically, and glenohumeral deformity was appropriately graded. The mean duration of clinical and radiographic follow-up was thirty-one and twenty-five months, respectively.
Results: Clinically, all patients demonstrated improved global shoulder function, with the mean aggregate Mallet score improving from 10 points preoperatively to 18 points postoperatively (p < 0.01). The mean modified Mallet score for external rotation improved from 2 to 4 (p < 0.01). Similarly, the mean Active Movement Scale score for external rotation improved from 3 to 6 (p < 0.01). The mean Mallet hand-to-spine score improved from 1 to 2 (p < 0.01). The mean Active Movement Scale score for internal rotation remained constant at 6. Radiographically, the mean glenoid version improved from -39° preoperatively to -18° postoperatively (p < 0.01). The mean percentage of the humeral head anterior to the middle of the glenoid similarly improved from 13% to 38% (p < 0.01). The mean glenohumeral deformity score improved from 3 to 2 (p < 0.01). Nineteen (83%) of the twenty-three patients demonstrated glenohumeral remodeling; one patient had progressive worsening of glenohumeral deformity.
Conclusions: Tendon transfers to the rotator cuff, combined with musculotendinous lengthenings and open reduction of the glenohumeral joint, improve global shoulder function and lead to glenohumeral joint remodeling in the majority of selected patients with mild-to-moderate preexisting glenohumeral dysplasia secondary to brachial plexus birth palsy. Future study of the long-term outcomes of these procedures will help to clarify the ultimate effect on glenohumeral joint function.
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.