Purpose of the study: Defective reduction and secondary displacement after osteosynthesis of distal radius fractures can compromise wrist function. Volar locking plates enable solid fixation which remains stable over time but section of the pronator quadrates necessary for the anterior approach raises the risks of destabilising the distal radioulnar joint and loss of pronation force. Our study was designed to evaluate recovery of grip, pronation and supination force after volar locking plate fixation.

Material and methods: This was a prospective study of 29 fractures of the distal radius with dorsal displacement fixed with a volar locking plate in 28 patients (17 men, 11 women, mean age 48.75 years) from January 2007 to May 2008. The quality of the pronator quadrates suture was assessed at the end of the operation. The assessment included the classical parameters of wrist movement, the Herzberg and Dumontier score, radial slope and ulnar variance on the ap and lateral views of the wrist, and recovery of grip, pronation and supination force compared with the opposite side using an ambulatory device.

Results: The pronator quadratus suture was considered solid in eight cases, precarious in seven. Complete suture was not possible in 14 cases. At mean follow-up of 10 months, patients had on average recovered 77% of the grip force, 74% of the pronation force, and 76% of supination force, compared with the opposite side. Complications included one defective reduction, one secondary displacement (by defective plate position), two dystrophy syndromes, and four posttrauma carpal tunnel syndromes.

Discussion: The literature shows that volar plate fixation enables recovery of 74% to 84% of grip force. Few studies have examined the recovery of pronosupination and none have described results after osteosynthesis for fracture. Our study did not find that section of the pronator quadrates, a muscle difficult to suture, had a deleterious effect.

Conclusion: Osteosynthesis using a volar locking plate for distal fractures of the radius remains a controversial issue. Study of recovery of the grip, pronation and supination force did not reveal any prejudice attributable to this technique.