Free functional gracilis transfer for reconstruction of isolated anterior deltoid atrophy following surgical proximal humerus fixation.

Background: Palsy of the clavicular head of the deltoid is a complication after surgical fixation of proximal humerus fractures. Flexion of the shoulder joint may be impaired as a result. Additionally, patients may complain of joint instability, visible atrophy, and pain. Where nerve reconstruction is not possible, muscle transfers remain as secondary reconstructive procedures.

Methods: Three patients with anterior deltoid palsy after proximal humerus fixation received a free functional gracilis transfer to the shoulder. Postoperatively, patients underwent biofeedback-based rehabilitation. Before and after the intervention, subjective complaints, pain level, and active range of motion (ROM) were recorded. At the final follow-up, patients completed a Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire.

Results: The surgery was successful in all patients, with first muscle signals registered through surface electromyography approximately four months postoperatively. At the last follow-up (>3 years), the patients showed improved shoulder stability and pain scores. In two patients with preoperative restrictions, active ROM improved. The DASH score showed minimal to no disability in two patients and moderate disability in the third. Two patients voiced satisfaction with the restoration of the ventral bulk of the shoulder.

Conclusions: Free functional gracilis muscle transfer is a novel approach for secondary reconstruction in patients with anterior deltoid atrophy who do not qualify for nerve intervention. It addresses shoulder instability and pain and may improve active ROM. The addition of fresh muscle tissue to the ventral shoulder can improve its natural contour and prevent protrusion of the humeral head.