Tri-plane Osteotomy Correction of Distal Radius Malunion Addresses Shortening, Angular, and Rotational Deformity

INTRODUCTION: Rotational malalignment following fracture of the distal radius may be under appreciated and contribute to subluxation and dysfunction of the distal radioulnar joint. Rotational malunion is demonstrated by both plain radiographic and CT imaging. METHODS: Eleven patients with shortened, angular and rotational malunion underwent correction by performance of triplane osteotomy. Additional radiographic analysis of both “sawbones” models and cadaver wrists was performed to define the degree of rotational offset required to diagnose this deformity. RESULTS: Healing of the osteotomy of the distal radius was achieved in all 11 patients. Fixation utilized low profile anatomyspecific plates. Preoperative pronation/supination arc was 40° and postoperative arc was 130°. In eight of the 11, pain was rated as 0 on a 10 point scale while the other three ranged between 2 and 5. At two year follow-up grip strength measured 80% of the contralateral side while total range of motion measured 76% of the contralateral side. All 11 patients were functional at daily household activities, five out of seven previously working patients were back to work, and all patients felt that their postoperative status was a significant improvement over their preoperative status. Plain x-ray evaluation of “sawbones” radius models demonstrated observable cortical offset with as little as 15° malrotation. However visualuation of DRUJ subluxation required 30° of malrotation, which was readily demonstrated on CT scan images. DISCUSSION AND CONCLUSION: Triplane osteotomy is effective in restoring pronation and supination, diminishing pain and increasing function. Radiographic evidence of medial and/or lateral cortical “step-off” should raise the suspicion of a rotational component to the fracture deformity. CT imaging is helpful in making a definitive diagnosis. Recognition of this “third” component of distal radius facture displacement is important in correcting initial displacement as well as late deformity.