Outcome of conjoined tendon and coracoacromial ligament transfer for the treatment of chronic type V acromioclavicular joint separation.

BACKGROUND: Numerous surgical methods are used to treat acromioclavicular (AC) joint dislocations, and an anatomical reconstruction using a free tendon graft has attracted considerable attention, particularly for chronic cases. The purpose of this study was to introduce the results of lateral half conjoined tendon (LHCT) and coracoacromial ligament (CAL) transfer for chronic type V injuries.

MATERIALS AND METHODS: A retrospective evaluation was performed on the clinical and radiographic outcomes of the 12 patients who underwent LHCT and CAL transfer for chronic type V AC injuries and had been followed for 2 years postoperatively. All 12 patients were males with a mean age of 37.3 ± 7.7 years (range: 26-49 years) at surgery. The causes of the injury were traffic accidents (five), falls (three) and sports injuries (four). The mean time elapsed between trauma and surgery was 12.5 ± 5.4 weeks (range: 7-22 weeks).

RESULTS: No reduction loss was observed at the final follow-up. The postoperative coracoclavicular (CC) distance was 8.9 ± 1.6mm, which represented a significant improvement versus the preoperative status (20.3 ± 3.0mm; p < 0.001), and no significant difference was observed between the injured and uninjured contralateral sides (8.7 ± 0.8mm), postoperatively (p = 0.619). The temporary use of a Steinman pin for AC fixation did not cause any complications. On the other hand, there were eight cases of mild radiographic arthrosis at the AC joint and two cases of heterotopic ossification of the CC space, although neither affected the functional outcomes. The mean modified UCLA score was 18.5 ± 2.1 (range: 12-20), which represented an excellent result in 11 of the 12 cases. The single case with a poorer postoperative score had a pre-existing brachial plexus injury.

CONCLUSIONS: Despite the small study cohort, the results of LHCT and CAL transfer in chronic type V AC separation are promising. CAL transfer alone has been shown to be biomechanically insufficient for an AC reconstruction, particularly in chronic situations. The advantage of LHCT transfer is that it does not require a distant donor site or incur the costs of an allograft or implant.