Does the pronator-sparing approach improve functional outcome, compared to a standard volar approach, in volar plating of distal radius fractures? A prospective, randomized controlled trial

BACKGROUND: This study aimed to compare functional outcomes of a volar plate osteosynthesis for distal radius fractures (DRF) performed with either a standard volar approach (SVA), which required detachment of the pronator quadratus muscle, or a pronator-sparing approach (PqSA). MATERIALS AND METHODS: This prospective randomized controlled study included 106 patients scheduled for volar plate osteosyntheses. Patients were allocated to either the SVA group (n = 53) or the PqSA group (n = 53). Patients were blinded to treatment until completion of the study. The primary outcome measure was the Patient-Rated Wrist Evaluation (PRWE). Secondary outcome parameters were the Disabilities of the Arm, Shoulder, and Hand (DASH) score and the Modified Mayo Wrist Score (MMWS). Follow-up examinations were performed at 8 weeks and 3, 6, and 12 months postoperatively. RESULTS: Overall, 91 patients were included in the final analysis: 48 in the SVA group and 43 in the PqSA group. The two cohorts were not significantly different in demographic characteristics, including age, sex, injuries on the dominant side, type of injury, and fracture classification. We found significant differences between groups at 6 months in the mean PRWE (SVA: 12.3 ± 10.4, PqSA: 18.9 ± 14.11 points) and in the mean DASH score (SVA: 12.3 ± 11.9, PqSA: 19.3 ± 16.7 points), which favoured the SVA. We found no significant differences between groups in the MMWS or in the PRWE and DASH scores at any other time points. CONCLUSIONS: This randomized comparative clinical trial failed to demonstrate that a volar plate osteosynthesis performed with a PqSA could improve the outcome, compared to the SVA, in patients with DRF. LEVEL OF EVIDENCE: II Trial registration Comparison of Two Volar Plating Systems for Distal Radius Fractures, ClinicalTrials.gov (NCT03474445), registered 22 March 2018, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03474445?cond=radius&cntry=AT&draw=2&rank=1