Clinical Outcomes and Complications During and After Medial Open-Wedge High Tibial Osteotomy Using a Locking Plate: A 3- to 7-Year Follow-up Study.

BACKGROUND

Outcomes and complications at mid- or long-term follow-up after medial open-wedge high tibial osteotomy (MOWHTO) with the TomoFix locking plate have not been fully evaluated.

PURPOSE

To evaluate the complications and midterm clinical outcomes after MOWHTO using a TomoFix.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Enrolled in this study were 80 patients (85 knees) who underwent MOWHTO with the TomoFix locking plate between 2009 and 2013. There were 66 women and 14 men, with a mean age of 61.5 years at the time of surgery. The diagnosis was medial osteoarthritis in 76 knees and spontaneous osteonecrosis of the knee in 9 knees. Metal removal and second-look arthroscopy were performed in all cases. Clinical and radiological examinations were performed at final follow-up after surgery (mean, 4.5 years).

RESULTS

The mean Japanese Orthopaedic Association score and Knee injury and Osteoarthritis Outcome Score improved significantly from pre- to postoperatively ( < .0001). The weightbearing line percentage shifted to pass through a point 67.7% lateral from the medial edge of the tibial plateau. The Caton-Deschamps index changed significantly from 0.88 to 0.66 at final follow-up ( < .0001). The mean posterior tibial slope changed significantly from 8.9° to 11.9° at final follow-up ( < .0001). Limb length was significantly increased after MOWHTO (10.3 mm; < .0001). During plate removal, 14 locking screws were found to be broken in 9 knees (10.6%). The articular cartilage grade of the patellofemoral joint was significantly higher in the second arthroscopy than in the first arthroscopy ( < .0001). The cumulative rate of all complications was 41.2%, with major complications (ie, those requiring additional or extended treatment) in 24.7%.

CONCLUSION

Postoperative outcome scores indicated significant improvement after MOWHTO, although the cumulative rate of all complications was 41.2% and the rate of major complications was 24.7%. These results indicate that MOWHTO with the TomoFix is a technically demanding procedure. Careful preoperative planning and meticulous surgical technique are needed to decrease the incidence of complications associated with MOWHTO.