Comparison of a novel hybrid hook locking plate fixation method with the conventional AO hook plate fixation method for Neer type V distal clavicle fractures.

BACKGROUND: The conventional AO hook locking compression plate (LCP) (Synthes, Solothurn, Switzerland) has only three holes for lateral fragments; therefore it is not suitable for use during the fixation of small-comminuted fragments in some cases. Recently, a novel hybrid hook LCP (TDM, Seoul, Korea) was developed to overcome this limitation. Here, we evaluated the clinical and radiologic outcomes of a novel hybrid hook LCP for Neer type V distal clavicle fractures compared to the outcomes of a conventional AO hook plate.

METHODS: Seventy-eight consecutive patients who underwent hook LCP fixation for Neer type V distal clavicle fractures were included. The subjects were divided into 2 groups: the conventional AO hook LCP group and the novel hybrid hook LCP group. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score, Korean shoulder score (KSS), and Constant score were recorded. The percentage modified coracoclavicular distance (MCCD %) was used for the evaluation of fracture reduction. Typical reported complications, such as secondary dislocation, implant failure or loosening, peri-implant fracture, acromion osteolysis, postoperative acromioclavicular joint arthrosis, non-union, or delayed union, were also analyzed.

RESULTS: There were no differences in the clinical outcomes (ASES, KSS, and Constant scores) between the two groups. Bone union was achieved in a significantly shorter period in the hybrid hook LCP group (13.6±2.0weeks) than in the AO hook LCP group (17.5±4.8weeks, p<0.001). Consequently, the time to implant removal was also significantly shorter in the hybrid hook LCP group (4.0±0.5months) than in the AO hook LCP group (5.4±1.1months, p<0.001). The MCCD% showed no significant differences between the treatment groups. There was no statistically significant difference in the complication rate between the two groups; however, the hybrid hook LCP fixation resulted in a lower prevalence of hook-related complications.

CONCLUSION: The hybrid hook LCP fixation showed satisfactory clinical and radiologic outcomes in comparison with the AO hook LCP fixation. The hybrid hook LCP is useful for multiple screw fixation of inferior comminuted fragments in Neer type V distal clavicle fractures. The bone union was significantly shorter; thus, the time to implant removal was also significantly shorter.

LEVEL OF EVIDENCE: Level III, Retrospective study.