Volar Locking Plate Fixation of Distal Radius Fracture with a Flexor Carpi Radialis Brevis and a Hypoplastic Pronator Quadratus.

Abstract

Introduction:Recently, distal radius fracture (DRF) has been treated with internal fixation using volar locking plates and several reports describing patients with a flexor carpi radialis brevis (FCRB) appeared. However, no studies have so far investigated the location of the FCRB relative to the volar locking plate.Case Report:We herein report three cases of DRF with an FCRB. Two patients had a bilateral FCRB, and an FCRB was detected in 5 of 174 limbs (2.9%). In all cases, the FCRB had a muscle belly and was retracted to the radial side and volar plate fixation was performed without difficulty. The pronator quadratus (PQ) under the FCRB was thin. In one case, the PQ was hypoplastic and restoration was impossible. The distance from the plate to the FCRB and that from the plate to the flexor pollicis longus (FPL) tendon were examined postoperatively using ultrasound. In the case in which the PQ could not be restored, the FPL tendon was located close to the plate and the FCRB was in contact with the plate.Conclusion:As volar locking plate fixation of a DRF with an FCRB and a hypoplastic PQ may cause the restoration of the PQ impossible, the operation should be performed more carefully and follow-up is necessary to avoid post-operative FPL tendon injury and FCRB tendinopathy due to friction with the plate.