Surgical Treatment of Infantile Shoulder Dislocation Following Brachial Plexus Birth Injury.

Background: Glenohumeral dysplasia following brachial plexus birth injury (BPBI) can present as dislocation of the glenohumeral joint in infancy. Multiple nonoperative treatment strategies have been reported for these early dislocations, yet none are universally successful; thus, surgical treatment may be required. However, reports of surgical treatment in infancy are scarce. The present study retrospectively reviews the outcomes of patients with BPBI treated surgically for glenohumeral dislocation under 1 year of age.

Methods: Medical records were retrospectively reviewed for patients treated surgically for glenohumeral dislocation under 1 year of age. Dislocation was defined on magnetic resonance imaging (MRI) as a percentage of the humeral head anterior to the scapular line (PHHA) <10%, or on ultrasound, as the humeral head ossific nucleus entirely posterior to the posterior scapular line. The primary outcome was defined as the need for reoperation. Additional outcomes included Mallet scores for global shoulder function and PHHA and glenoid version measurements on follow-up MRI. Patients with <1 year follow-up were excluded.

Results: Thirty-two patients underwent surgical intervention for shoulder dislocation at ages 5 months to <1 year with average follow-up of 4.6 years. Of these 32 patients, 25 underwent internal rotation contracture release and external rotation tendon transfer (ERTT), with 3 (12.0%) requiring revision surgery; 7 underwent release alone, with 6 (85.7%) requiring revision surgery. Across all groups, patients ultimately had improved passive and active external rotation (20.0 to 80.0 degrees, -90.0 to 30.0 degrees, respectively, P <0.0001) and global Mallet scores (14.5/30 to 19.5/30, P <0.001) without worsened internal rotation function. The indications for requiring further surgical intervention for the 9 patients were recurrent IR contracture, redislocation, persistent ER weakness, and weak abduction.

Conclusions: Surgical treatment of infantile shoulder dislocation following BPBI can improve glenohumeral alignment and global shoulder function. The inclusion of external rotation tendon transfers at the index procedure lowers the risk of reoperation, whereas not sacrificing internal rotation function when combined with partial subscapularis release.

Level of evidence: Level IV.