Loss of Midline Function in Brachial Plexus Birth Palsy Patients.

BACKGROUND: Loss of midline function impairs the child's ability to perform certain activities of daily living such as dressing, buttoning, and perineal care. The purpose of this study was to assess brachial plexus birth palsy (BPBP) patients with loss of midline function with respect to etiology and treatment.

METHODS: A retrospective review of all BPBP patients with loss of midline function was performed. The modified Mallet scale was used with internal rotation assessed via hand on spine and hand to belly. Demographics, extent of BPBP, prior surgical intervention, procedure(s) performed to correct the loss of midline function, complications, and outcomes were assessed.

RESULTS: In total, 20 patients were identified with loss of midline function as defined by the inability to reach midline and touch their umbilicus. Nineteen patients had previously undergone tendon transfers about the shoulder with or without arthroscopic capsular release to improve external rotation. After the initial surgery, modified Mallet scores improved 1 grade for abduction, hand to mouth, hand to neck, and external rotation without altering the hand to spine category. However, the internal rotation category (hand to umbilicus) decreased from an average 2.71 preoperatively to an average 2.15 postoperatively. Nine patients underwent a derotational humeral osteotomy to improve midline function. The average correction of internal rotation was 47.8 degrees (range, 20 to 85 degrees). After this surgery, modified Mallet scores remained unchanged for hand to spine; however, the scores improved back to 2.7 for the internal rotation category. Two complications were noted including 1 plate fracture and 1 fracture through a screw hole.

CONCLUSIONS: BPBP patients who undergo surgical procedures to improve shoulder external rotation and/or obtain joint reduction may inadvertently lose midline function. Derotational humeral osteotomy can effectively restore midline function, which is needed to perform activities of daily living. Surgical procedures to improve external rotation should be performed in a manner that minimizes limitation of midline functions.

LEVEL OF EVIDENCE: Level III-therapeutic.