Modified distal tibial oblique osteotomy for osteoarthritis of the ankle: Operative procedure and preliminary results.

Abstract

Low tibial osteotomy is an effective joint-preserving surgery for ankle arthritis. However, poor postoperative wound healing, infection, and delayed or non-union of bones remain significant concerns. We describe a modified distal tibial oblique osteotomy procedure and report preliminary results for varus ankle arthritis. The osteotomy path consisted of an oblique doglegged line from the lateral end of the distal tibia to a proximal point about one-third from the lateral edge and continuing along an arc defined by virtual coronal-plane rotation of the doglegged line to the medial edge. After osteotomy, the distal tibial fragment was rotated distally in the coronal plane for realignment while maintaining contact with the proximal tibia and the distal tibial fragment. The resulting wedge-shaped gap was filled with artificial bone blocks and tibial bone projecting medially from rotation. A locking plate was then applied for stabilization. We evaluated 7 ankles from 6 osteoarthritis patients both clinically and radiographically following this procedure. Bone union was achieved within 3 months for all patients. The Japanese Society for Surgery of the Foot ankle-hindfoot scale improved from a mean of 38.4 points preoperatively to 85.7 points at the latest follow-up. No wound healing problems, infections, or nerve disturbances were observed. Multiple radiographic parameters were also improved following the operation. This procedure maintains close bone contact for better postoperative union, obviates the need for iliac bone harvesting, and reduces tension on medial soft tissue. We believe these modifications are potential advantages for achieving stable results in patients with ankle osteoarthritis.