Stabilization of acute, complete acromioclavicular joint dislocations with a new C hook implant

Although coracoclavicular fixation is currently popular for type III acromioclavicular (AC) dislocations, a surgical gold standard is lacking. The purpose of this study was to evaluate the preliminary outcome of surgical treatment of complete AC dislocations with a new nitinol C hook implant. When the implant is cooled (<5 degrees C), it softens enough to be easily inserted under the coracoid process with a hole drilled in the clavicle. Cooling is induced with ice water. When the implant reaches body temperature, it hardens and anatomic reduction is achieved. Patients with acute type III AC dislocations were prospectively evaluated. The AC ligament was reinserted with the use of a bone anchor, and the position of the joint was restored by fixing it with a new C hook. Clinical and radiographic control checkups were carried out at 3, 8, and 12 weeks and 2 years postoperatively. Certain patient-related variables, functional status, symptom severity, and patient satisfaction were assessed. By 12 weeks, all patients had achieved full functional status. Radiographs showed accurate anatomic reduction. Overall subjective satisfaction was very good in all cases. No complications or implant failures occurred. On the basis of this pilot study, the new C hook implant provides secure anatomic reduction with very good functional recovery and patient satisfaction. The main benefit of the implant is the ease of insertion. It preserves the articular surfaces and allows slight movement of the AC joint during abduction of the arm. The C hook implant is a new surgical concept with potentially better patient recovery.