Simplifying the Volar Distraction Osteotomy for Distal Radius Malunion Repair.

Extra-articular fractures of the distal radius are often treated with a trial of nonoperative management if radiographic parameters are within an acceptable range, especially in the elderly population. Unfortunately, some malunions become symptomatic or become grossly misaligned during nonoperative management which require corrective surgery to restore the normal osseous anatomy and restore function.  We describe correction of a distal radius malunion utilizing a distraction-type volar osteotomy, a volar plate specific distraction device, and a novel resorbable calcium phosphate bone cement (Trabexus) designed to withstand compressive loads.  Twelve patients with 13 distal radius fractures were included in this study. The average patient age was 60.9 years and average time from injury to corrective osteotomy was 96.3 days. Radiographic measures (radial inclination, volar tilt, and ulnar variance) and clinical assessment (wrist/forearm range of motion and grip strength) were done pre- and postoperatively and compared.  The average time from corrective surgical osteotomy to final clinical follow-up was 375.8 days. After surgical intervention, there was a statistically significant improvement in mean volar tilt (-19.8 vs. +0.5 degrees) and mean ulnar variance (+2.8 vs. -0.4 mm). Improvements were also seen in grip strength (1.7 vs. 43.6 lb), wrist flexion (30.5 vs. 48.3 degrees), wrist extension (33.3 vs. 53.8 degrees), forearm pronation (75.0 vs. 88.8 degrees), and forearm supination (53.8 vs. 81.3 degrees). On average, 56.0% of Trabexus bone substitute remained on final clinical radiographs.  This simplified technique of distraction corrective osteotomy after distal radius malunion results in improved clinical and radiographic outcomes for patients.