Original ResearchComparative study of type B distal radius fractures with and without lunate facet involvement treated by volar locking plate, an observational study

- Standard plain radiographs seem incapable of detecting those occult distal radius fractures, leading to certain high incidence of misdiagnose or missed diagnosis (9.5%).
- Patients with lunate facet involvement would obtain more slowly recovery, and were at increased risk of reduction loss and articular step-off, compared to those not involving lunate facet.
- Type B distal radius fractures involving lunate facet was likely to result in reduction loss during the bony union period.

PurposeThis study aimed to evaluate the results of volar locking plate for treatment of type B distal radius fractures involving the lunate facet and compare them with those without involvement in lunate facet.Methods: This was a retrospective study. A total of 93 patients with type B distal radius were treated by single volar locking plate between January 2014 and December 2015. Preoperative digital radiographs were used to initially diagnose and further classify this injury according to AO/OTA classification system. CT scanning or reconstruction was used to diagnose the complex or suspicious cases. Patients with lunate facet involvement were defined as group 1 (n = 21) and the remaining without luante facet involvement as group 2 (n = 72). Postoperative immediate radiographs and radiographs at last visit were analyzed. We evaluated clinical outcomes at minimum of 12 months and performed statistical analysis using the SPSS 19.0 software package.ResultsBony union was reached in all participants, at the median time of 8 weeks. At the final follow-up, there were no significant difference observed in term of volar tilt and radial inclination between both groups (P, 0.172; 0.514). Articular step-off in group 1 was significantly greater than those of group 2 (P, 0.016). Significant articular step-off (>2 mm) occurred in 4 patients (19.0%) in group 1 and 3 (4.2%) in group 2 (P = 0.044). At 3-months postoperatively, group 1 showed worse results than group 2 for most variables (P < 0.05). At 6-months postoperatively, the differences for wrist flexion, supination, ulnar deviation and VAS in motion remained significant between both groups (P < 0.05). At the last follow-up, no significant differences were observed for any variable (P > 0.05). Five minor complications occurred in group 1 and 11 in group 2, and the difference was not significant (P = 0.346).ConclusionsPatients with distal radius fractures involving lunate facet would obtain more slow recovery, especially for wrist flexion, supination, ulnar deviation and VAS in motion. In addition, patients with lunate facet fractures would be at higher risk of loss of reduction and final articular step-off.