Z-Corrective Osteotomy in Malunited Extra-Articular Fractures of Distal Radius

Purpose We sought to assess clinical, radiological, and functional outcomes following treatment of extra-articular malunions of the distal radius using a multiplanar z-corrective osteotomy. Methods Fifteen patients with extra-articular distal radius malunions (13 dorsal and 2 volar) underwent z-corrective osteotomy and volar plate fixation without bone grafting. Correction and maintenance of each deformity was evaluated in terms of various radiographic indices (radial height; volar and radial tilt); osteotomy union; pain (visual analog scale); grip strength; range of motion; Disabilities of the Arm, Shoulder, and Hand scores; and Mayo wrist scores. Results The mean follow-up was 16.4 months. The mean radial height was corrected from -1.3 mm to 4.9 mm. The mean ulnar variance improved from 4.3 mm to -0.4 mm. The sagittal radial tilt and radial inclination were restored from a mean of -17.9 degrees (dorsal) to 3.3 degrees (volar) and from 12.0 degrees to 17.2 degrees, respectively. The Disabilities of the Arm, Shoulder, and Hand and Mayo wrist scores improved from means of 36 and 56 preoperatively to 24.8 and 73.3, respectively, at 6 months and further to 20.6 and 77.6, respectively, at the last follow-up. There were no nonunions or tendon-related problems. The mean pain score decreased from 4.1 preoperatively to 1.0 at 6 months and 0.8 at the last follow-up. The mean grip strength improved from 5.6 kg preoperatively to 15.6 kg at 6 months and 19.7 kg at the last follow-up. There was a statistically significant improvement in range of motion at the wrist. Conclusions The z-osteotomy provides correction of deformity in all 3 planes, along with restoration of radial height. It also maintains a broad area of bone contact between the 2 osteotomized bone fragments, facilitating bony union and eliminating the need for bone grafting. (Copyright (C) 2022 by the American Society for Surgery of the Hand. All rights reserved.)