Semitendinosus Tendon Reconstruction for Recurrent Acromioclavicular Joint Instability Following Repeated Fixation Failure and Postoperative Trauma: A Case Report

Abstract

Recurrent instability following surgical treatment of Rockwood type III acromioclavicular (AC) joint injuries is uncommon but represents a challenging clinical problem, particularly after repeated fixation failure. A 67-year-old man presented with a Rockwood type III AC joint separation following a same-level fall. Initial suture-button fixation failed 45 days postoperatively. Revision hook plate fixation subsequently failed after a further traumatic event, and a third procedure involving rigid AC stabilization with dual plating also resulted in early mechanical failure. Definitive treatment was achieved using biologic reconstruction with a semitendinosus tendon autograft combined with coracoacromial ligament transfer. At 1-year follow-up, radiographs demonstrated maintained reduction of the AC joint, and the patient regained satisfactory shoulder function with full return to daily activities. This case highlights the potential role of semitendinosus tendon reconstruction as a salvage strategy following repeated fixation failure. In such complex revision settings, durable outcomes may depend not only on restoring mechanical stability but also on preserving the biological environment necessary for successful healing.