Glenosphere dissociation combined with nonunion of a clavicular fracture following reverse shoulder arthroplasty

Reverse shoulder arthroplasty (RSA) effectively improves outcomes for cuff tear arthropathy but carries a risk of complications. Glenosphere dissociation is a rare complication, and its occurrence with a shoulder girdle fracture has not been reported. A 77-year-old female who had undergone RSA presented with chronic shoulder pain and a palpable mass. Imaging revealed glenosphere dissociation and clavicular nonunion with scapular malalignment. Surgical intervention included replacing the glenosphere and polyethylene liner, stabilizing the shoulder. Postoperative care involved sling immobilization, leading to pain relief and no recurrent dislocation despite limited functional recovery due to scapular malalignment. We presented a rare case of glenosphere dissociation combined with clavicular nonunion following RSA. While pain relief was achieved by repairing the dislocation, clavicular nonunion contributing to scapular malalignment may hinder functional recovery. Surgical intervention for clavicular stabilization may be necessary in cases prioritizing shoulder function.