Session IX - Upper Extremity

Initial Outcome of Distal Radius Fractures Treated with the TriMed Wrist Fixation System

Paul D. Protomastro, MD; J. Scott Price, MD; Evan Schumer, MD; Bruce Leslie, MD; Mark Koris, MD, The Brigham and Women's Hospital, Boston, MA

Purpose: We assessed the outcome of distal radius fractures treated with the TriMed wrist fixation system.

Methods: From 1997 to 2000, 117 distal radius fractures were reconstructed with use of the TriMed wrist fixation system at two institutions. The patients were 30 men and 58 women, with an average age of 50 years. The clinical, radiographic, and functional outcomes, with a minimum follow-up of 6 months, were analyzed for 88 fractures. Six fractures were type A3, 8 were type B (4, B1, 3, B2, 1, B3), and 64 were type C (9, C1, 24, C2, 31, C3), according to the ASIF classification system, and 6 fractures were open. Thirty fractures received bone graft or a bone substitute in addition to metallic implants.

Results: The average time from injury to operation was 9 days. Active wrist motion was initiated an average of 13 days after the operation. Strengthening was initiated at an average of 5.7 weeks. Average wrist motion at an average of 10.4 months (range, 6 to 29 months) after the operation was 54° of flexion, 55° of extension, 14° of radial deviation, 23° of ulnar deviation, and 76° of both pronation and supination. Grip strength was 86% of that of the uninjured hand. At union, volar tilt averaged 2.3° and radial inclination 22°. Fifty-four wrists had neutral ulnar variance (+/- 2 mm), 7 were ulnar negative, and 27 remained ulnar positive. Articular reduction at union was anatomic in 38 patients. The articular surface was gapped or stepped 1 to 2 mm in 23, and 2 to 3 mm in 9 wrists. Arthrosis was mild in 20 patients, moderate in 4, and severe in 1. Implant migration or irritation necessitated removal in 21 (25%) cases. Transient neuropraxia occurred in 12 patients, and rupture of the extensor pollicis longus tendon occurred in one patient and one had carpal tunnel syndrome. There were two ulnar styloid nonunions, and the distal or radial ulnar joint became painful or unstable in eight patients. Mild finger stiffness persisted in five patients. Loss of fracture reduction in one patient necessitated wrist arthrodesis. There were no infections, nonunions, regional pain syndromes, or implant failures. The outcome was excellent or good in 71, fair in 15, and poor in 2, according to the Gartland and Werley demerit system. Eighty-two percent of patients rated their result as excellent or good. The results of the DASH instrument demonstrated high patient satisfaction and return of the patients to premorbid function; pain and impairment scores were low.

Discussion: Anatomic joint-surface restoration, periarticular deformity correction, and early mobilization have been shown to optimize outcomes in distal radius fractures. The TriMed wrist fixation system achieves these goals along with the added benefits of limited surgical dissection, rigid fixation, and fragment-specific versatility. Our preliminary results indicated that this system is a safe and effective means of reconstructing complex, unstable distal radius fractures. The relatively good function, high patient satisfaction and low complications that we report justify its continued use. Further investigation is necessary to identify patients and fracture patterns that are more likely to benefit from this system over other commonly applied treatment modalities.

Conclusion: The TriMed Wrist Fixation System is a safe and effective means of obtaining deformity correction, rigid fixation and early mobilization in displaced, unstable distal radius fractures.