自家上腕二頭筋を用いた関節鏡視下肩鎖関節安定化術（AutoBAHN法）：水平方向の安定化

The surgical treatment of chronic acromioclavicular joint (ACJ) instability is most commonly performed using tendon grafts combined with synthetic stabilization. However, autografts can be associated with donor site morbidity, while allografts often have inferior tissue quality and a higher risk of graft failure. We present a technique of arthroscopically assisted ACJ stabilization using an autologous, rerouted long head of the biceps (LHB) tendon transfer, augmented with a suture button pulley construct for the treatment of symptomatic bidirectional ACJ instability. The LHB tendon is tenodesed to the humerus near the musculotendinous junction and tenotomized just proximal to the fixation point. The proximal attachment of the LHB tendon is preserved. The distal free end of the LHB tendon is rerouted transarticularly and passed anterior to the glenoid, proximally through the lateral end of the clavicle. Intraosseous fixation is achieved using an interference screw. The distal LHB tendon portion spans the superior aspect of the ACJ, providing horizontal stabilization. The autologous biceps acromioclavicular and horizontal neutralization technique offers a local, robust, and cost-effective graft option that avoids potential donor site morbidity, preserves the anatomic origin of the LHB tendon, and provides sufficient length for both vertical and horizontal ACJ stabilization.