Intermediate-Term Clinical Outcomes of Novel Distal Tibial Rotational Osteotomy for Varus Ankle Osteoarthritis

Category: Ankle Arthritis; Ankle Introduction/Purpose: Distal tibial oblique osteotomy for ankle osteoarthritis is an effective procedure with joint preserving. However, there is the risk of nonunion due to open wedge osteotomy and complication associated with autogenous bone harvesting. We performed distal tibial rotational osteotomy (DTRO) for ankle osteoarthritis, which modified osteotomy design is expected to reduce the risk of nonunion without autologous bone grafting and soft tissue complications. We evaluated the clinical and radiographical outcome of DTRO. Methods: A total of 23 feet (4 males and 19 females) who underwent DTRO for ankle osteoarthritis in our institutions between 2016 and 2022 was included. All patients required a minimum of one year follow-up. As a surgical procedure, tri-plane osteotomy was performed using anteromedial approach. Then, the distal tibial fragment was rotated distally in the 3D plane until ankle stability was achieved, and the prominence of the medial tibia was resection after the correction. A medial tibial locking plate was applied for stabilization after filling opening gap with synthetic bone blocks. We evaluated demographic data, radiographical measurements, classification of arthritis severity, and the rate of nonunion, wound complications and reoperation. In addition, JSSF scale (Japanese Society for Surgery of the Foot ankle) and SAFE- Q (Self-Administered Foot Evaluation Questionnaire) were assessed preoperatively and at the latest follow-up. Results: Subjects had an average age of 64 years, an average follow-up period of 42 months, and were classified as stage 2/3a/3b in 1/19/2 feet preoperatively. The average of tibial anterior surface angle changed from 83.7° to 93.5°, and the tibial lateral surface angle changed from 81.0° to 81.9° in pre- and postoperative radiography. The JSSF scale significantly improved from 49.1 to 88.2 (p< 0.01) and the SAFE-Q showed significant improvement in all subscales at the latest follow-up. Bone union was obtained within 3 months in all cases, and no nonunion was observed. Delayed wound healing was observed in 1 case (4.4%). Ankle arthrodesis was needed in 1 case of deep infection and in 1 case of arthritis progression stage 3b to 4. Conclusion: In general, the distal tibia has poor soft tissue and blood flow that may lead the nonunion and soft tissue complications for distal tibial osteotomy. The advantage of DTRO was to maintain tibial bone contact after the osteotomy which may be favorable for bone stability and union, and to resect the medial bone prominence which reduce the tension of soft tissue. In this study, bone union was obtained in all cases without harvesting autogenous bone, and wound complications were low at 4.4%. Good intermediate-term outcomes were obtained, and DTRO can be a favorable surgical procedure for ankle osteoarthritis.