Pronator quadratus repair after volar plate fixation in distal radial fractures: evaluation of the clinical and functional outcome and of the protective role on the flexor tendons-a randomized controlled study

The objective was to evaluate pronator quadratus (PQ) repair following volar plating of distal radial fractures on clinical and functional outcome, as well as flexor tendon friction, during the first 12 months in ideally positioned plates (Soong 0). Confounding factors like variation in plate positioning, anatomical consolidation of the fracture and associated lesions were excluded. Eighty patients were included with distal radius fractures treated by volar locking plate in Soong grade 0 position, who were randomized to group PQ repair and group no repair. Sixty-five patients completed the 1-year follow-up: group PQ repair (n=35) and group no repair (n=30). Primary outcomes included range of motion, grip strength, pain level and QuickDASH. Secondary outcomes included distance between flexor pollicis longus (FPL) and volar rim and the largest distance between FPL and plate (soft tissue thickness occupied by PQ), assessed by ultrasonography. Mobility, grip strength and QuickDASH revealed no significant differences, except extension was significantly higher only in first 3 months and radial deviation was significantly higher only at 6 weeks after PQ repair. Pain level was significantly lower after PQ repair only in the first 3 months. Distance between FPL and volar rim and the largest distance between FPL and plate were significantly higher after PQ repair. No friction contact between FPL and volar rim was measured in both groups at all measurement moments. Consequently, protective flexor tendon effect of PQ repair could consequently not be concluded. In conclusion, clinical and functional short term benefits, except improved wrist extension and reduced pain in the first 3 months, were not proven in this study. In Soong grade 0, PQ repair is probably not necessary to prevent flexor tendon pathology. In Soong grade 1 or 2, this is still to be investigated.Level of evidence2.