Mid-Term Outcome after Selective Neurotization of the Infraspinatus Muscle in Patients with Brachial Plexus Birth Injury.

Active shoulder external rotation in adduction can be restored by selective neurotization of the infraspinatus muscle with the spinal accessory nerve in select patients with brachial plexus birth injury. Does the improved shoulder external rotation stand the test of time? METHODS: Fourteen consecutive brachial plexus birth injury patients with active shoulder external rotation in adduction of ≤ 0 degrees and active shoulder elevation ≥ 90 degrees underwent selective neurotization of the infraspinatus muscle at mean 2 years of age between 2012 and 2016. All 14 patients had congruent shoulders joints with passive external rotation in adduction of 30 degrees. Pre-and postoperative electromyography was done to seven patients. Shoulder function and the subjective outcome was assessed after a mean follow-up of 3.8 years. RESULTS: Shoulder external rotation in adduction improved by a mean 57 degrees in the 12 children who did not develop shoulder internal rotation contracture. Shoulder external rotation in abduction and shoulder abduction increased in all 14 patients. Reinnervation of the supraspinatus muscle was evident in all seven children who underwent postoperative EMG. Thirteen patients' parents were satisfied with the outcome. CONCLUSIONS: Functionally significant shoulder external rotation can be restored and maintained by reinnervation of the infraspinatus muscle in brachial plexus birth injury patients with congruent shoulder joints, if internal rotation contracture does not develop.

Muscle changes in brachial plexus birth injury with elbow flexion contracture: an MRI study.

BACKGROUND: Muscle pathology of the arm and forearm in brachial plexus birth injury (BPBI) with elbow flexion contracture has not been evaluated with MRI. OBJECTIVE: To determine whether limited range of motion of the elbow in BPBI is correlated with specific patterns of muscular pathology. MATERIALS AND METHODS: For 15 BPBI patients, total active motion (TAM) of the elbow (extension-flexion) and the forearm (pronation-supination) were measured. MRI of the elbow joints and musculature allowed assessment of elbow congruency. Fatty infiltration and size reduction of the muscles were graded semiquantitatively. RESULTS: Mean TAM of the elbow was 113 degrees (50 degrees-140 degrees) and that of the forearm 91 degrees (10 degrees-165 degrees). The greater the size reduction of the brachioradialis muscle, the more diminished was elbow TAM. The more extensive the BPBI and muscle pathology of the pronator teres muscle, the more limited was the TAM of the forearm. Pathology of the supinator and brachialis muscles was evident in every patient. CONCLUSION: Extensive BPBI may result in marked limitation of TAM. Elbow flexion contracture seems to be caused mainly by brachialis muscle pathology. Prosupination of the forearm is better preserved when the pronator teres is not severely affected. MRI can reliably show the extent of muscle pathology in BPBI.