A novel treatment of grade III acromioclavicular joint dislocations with a C-hook implant

This study evaluates the results of the new surgical treatment of complete acromioclavicular (ac) dislocations using coracoclavicular (cc) fixation with a shape memory metal C-hook implant.

Fifteen patients were prospectively analyzed. They all had a Tossy III ac dislocation due to trauma. The ac ligament was reinserted using a surgical bone anchor, and the position of the joint was restored by fixing it with a C-hook. After 3 months the C-hook was removed. Functional status, symptom severity, X-rays and patient satisfaction were analyzed during clinical control visits. The follow-up time was 1 year.

At 12 weeks, full shoulder function had been achieved by 93% of the patients. The final control visit showed full recovery of active ROM in all patients. Two patients had mild pain during certain movements. X-rays showed the precise anatomical position of ac joint with no statistically significant differences compared to the healthy side. Patient contentment was excellent in 14 cases and satisfactory in one case. The average sick-leave was 58 days, including the removal operation. Minor osteolysis of the clavicle was noticed in two patients.

The new C-hook implant provides accurate anatomical reduction, conserves the articular surfaces and enables fast functional recovery with excellent patient contentment. Technically, the implant is easy to use. Based on this study, the C-hook presents a reliable novel treatment option in surgical ac repair.