Hook plate fixation versus locking plate fixation for distal clavicle fracture: a multicenter propensity score-matched study

Hook plate fixation and locking plate fixation are two standard internal fixation implants for treating distal clavicle fractures. We aimed to clarify the following: 1) Does the locking plate offer better clinical outcomes than the hook plate? 2) Is bone union better with a locking plate than hook plate? and 3) Are complications different between the locking plate and hook plate? We conducted a retrospective multicenter study of 338 patients who underwent surgery from 2014 to 2018 in our 10 hospitals, which comprise the TRON group. Of them, 208 patients treated using any plates were eligible. After 30 patients were excluded for various reasons, 178 patients were included. We classified them into two groups, locking plate group (Group L) and hook plate group (Group H), using propensity score matching. We confirmed bone union with an X-ray, evaluated the UCLA shoulder score, and compared the frequency of complications. After matching, Group L and Group H included 49 patients each. The UCLA score was higher in Group L than in Group H at each follow-up point. We confirmed bone union in all patients in Group L, but it was not confirmed in three patients (6.1%) in Group H. No statistically significant differences were observed except for plate migration, which was observed in nine patients (18.4%) in Group H but in no patients in Group L. The postoperative UCLA score was significantly better in Group L. We recommend the locking plate as a surgical treatment for distal clavicle fractures.