Stability of volar locking plate systems for AO type C3 fractures of the distal radius: biomechanical study in a cadaveric model.

BACKGROUND: The purpose of the present study was to compare the relative stability of five volar locking plates (all of which are available for the treatment of intraarticular fractures of the distal radius) under loading conditions simulating the physiological forces that occur during early active mobilization. METHODS: Five plating techniques were applied to surgically simulated AO type C3.2 distal radius fractures in formalin-fixed cadavers. The specimens were tested with a servohydraulic materials testing machine with 250 N of axial compression load for 3000 cycles. After cyclic loading, the specimens were loaded until they demonstrated failure in axial compression. The five fixation systems studied included a DRV locking plate (group 1), a Stellar plate (group 2), an Acu-Loc plate (group 3), AO Locking Distal Radius System 2.4 (group 4); and a Matrix SmartLock plate (group 5). RESULTS: None of the plate fixations tested failed during the cyclic loading. Group 2 had a higher elastic limit than groups 4 and 5. There were no significant differences among the five groups for the failure load. Failure occurred at the distal portion of the fixation system, at the ulnar side locking pin, or the locking screw was bent (groups 1, 2, 3); the ulnar side locking screw was broken (groups 3, 4); the locking screw became loose (group 4); and the ulnar side locking screw was uncoupled from the screw hole (group 5). CONCLUSIONS: All of the five volar plate fixation systems provided sufficient stability to permit 3000 repeated motions of the digits after surgery for AO type C3 distal radius fractures.

Prospective study of distal radius fractures treated with a volar locking plate system.

PURPOSE: To prospectively determine the results of treatment of distal radius fractures with a volar locking plate system with no bone graft and early mobilization. METHODS: Internal fixation and early mobilization of dorsally displaced, unstable fractures of the distal radius using a volar locking plate system without bone grafting was investigated in a prospective series of 49 fractures in 49 consecutive patients. All patients were allowed to move the wrist joint immediately after surgery. Physical examination at 5 weeks, 3 months, 6 months, and 1 year after the operation were performed. Radiographic parameters on preoperative, postoperative, and 1-year postoperative radiographs were compared. At 1-year review, the final clinical functions were evaluated with the Gartland and Werley functional scoring system, a modified Green and O'Brien system, and the Disabilities of the Arm, Shoulder, and Hand questionnaire. RESULTS: The average radiographic results at 1 year were 9 degrees of volar tilt; 22 degrees of radial inclination; 1 mm of ulnar variance, and 0 mm of articular incongruity. At 1-year review, an excellent or good result was found according to the system of Gartland and Werley and a modified Green and O'Brien system with scores of 100% and 98%, respectively. The Disabilities of the Arm, Shoulder, and Hand score averaged 6, indicating a high degree of patient satisfaction. There were no cases of infection, complex regional pain syndrome, tendon rupture, tendon irritation, nerve injury, or implant failure. CONCLUSIONS: The volar locking plate fixation without bone grafting and early mobilization is a safe and effective treatment for dorsally displaced, unstable fractures of the distal radius.

Malunited fractures of the distal radius treated with corrective osteotomy using volar locking plate and a corticocancellous bone graft following immediate mobilisation.

We describe our experience of using a volar locking plate for corrective osteotomy and bone grafting combined with early mobilisation in the treatment of distal radius malunions. Corrective osteotomy of the distal radius was performed through a volar approach, and fixated by a volar locking plate associated with corticocancellous iliac bone grafting in three patients aged 16, 71 and 75 years. Two patients had had volarly displaced malunion and one dorsally displaced malunion. Wrist motion was started immediately after surgery. The average follow-up was 15 months (range, 12-20 months). All osteotomies healed at an average 5.7 weeks post-operatively, resulting in a total arc of wrist motion of 133 degrees, forearm rotation of 167 degrees, and grip strength of 70% of that of the contralateral side. This treatment method proved to be effective and safe.