The purpose of our study was to evaluate the clinical and radiological outcome after a single AC TightRope® fixation in patients with an acute Rockwood type III-VI AC joint dislocation. We performed a retrospective cohort study of patients who underwent AC TightRope® fixation for an acute Rockwood type III-VI AC joint dislocation. During follow-up functional outcome was assessed using the Constant Murley Score (CS) and the UCLA Shoulder Rating Scale. A standard anteroposterior x-ray of both the operated and the contralateral shoulder was performed. The coracoclavicular (CC) distance was measured and compared with the day 1 postoperative x-ray. Twenty-nine patients participated the study. Mean follow-up time after surgery was 43,4 months. Clinically the results were excellent : The mean CS was 91, the mean UCLA score was 33. Radiologically a mean loss of reduction of 3.2mm was seen. Following radiological findings were seen : Clavicular tunnel widening, coracoclavicular calcifications, and osteolysis at the clavicular button site. Patients treated with a mini-open single AC TightRope® fixation had excellent midterm functional outcomes.