Acromion osteolysis and fracture following hook plate fixation after acute acromioclavicular joint dislocation in an elderly patient: A case report

Abstract

BackgroundAcromioclavicular (AC) joint injury is common after shoulder trauma with Rockwood type III cases and above requiring surgical intervention. Hook plates offer stable fixation of the AC joint while allowing early movement and natural healing of the coracoclavicular ligament. However, hook plate fixation can lead to complications such as subacromial shoulder impingement, rotator cuff lesions and in rare cases acromial osteolysis and fracture. Case reportWe report one case of acromial fracture following hook plate fixation for AC joint dislocation. A 76-year-old lady sustained a hard fall on her left shoulder. Radiographs detected an AC joint dislocation, and fixation was performed using a Synthes® clavicular hook plate. At 3 weeks follow-up, the patient’s radiographs revealed focal osteopenia and osteolysis at the acromion. By 7 weeks, there was acromial fracture with hook plate cut-out. Upon removal of the hook plate, the acromial fracture was secured with Ethibond® sutures. There was non-union at 6 months follow-up and conservative management was chosen. ConclusionHook plate fixation is a rare but significant complication of hook plate fixation in AC joint injuries. This report provides insight into the development of this complication and recommends the consideration of newer, alternative therapies such as TightRope® fixation.