Proximal tibial valgus osteotomy with callus distraction

OBJECTIVE: Correction of genu varum and unloading of the medial compartment using a proximal osteotomy, callus distraction. INDICATIONS: Symptomatic genu varum due to post-medial-meniscectomy syndrome, medial compartment osteoarthritis, articular cartilage lesions of medial compartment, avascular necrosis of medial femoral condyle, osteoarthritis dissecans of medial femoral condyle, posterolateral and/or anteromedial rotatory instability. CONTRAINDICATIONS: Advanced articular cartilage lesions of lateral compartment. Advanced osteoarthritis of patellofemoral compartment. Extension lag > 10 degrees. Patients > 60 years with low physical demands. SURGICAL TECHNIQUE: Installation of an external fixator under image intensification as close to the joint as possible. Skin incision medial to the tibial tuberosity. Osteotomy between proximal fixator screw and tibial tuberosity leaving the lateral cortex intact. Control of desired distraction under image intensification. Closure of distraction gap. POSTOPERATIVE MANAGEMENT: Start of distraction (1 mm/day) on day 5. Radiographs on day 5-7, after 6 weeks, and after 8-10 weeks. Removal of only the fixator rods once desired correction has been reached and sufficient callus has formed. If correction is maintained after full weight bearing, removal of screws. RESULTS: Between 1998 and 2000, 34 callus distractions were done in 24 patients (six women, 18 men, age 24-64 years). Follow-up of 21 patients after an average of 23 months (6-36 months). Exclusion of one patient after total knee replacement. Pre- and postoperative femorotibial angle 179 degrees (172-183 degrees) and 185 degrees (179-191 degrees), respectively. Median correction was 6 degrees (3-12 degrees). 20 patients would accept the procedure again. Using the score developed by the authors, improvement from 15 points preoperatively to 10 points postoperatively. Complications in 15 corrections, eight of these needing a surgical revision.