[High tibial closed wedge valgus osteotomy].

OBJECTIVE: Well-balanced charge of femoral and tibial cartilage by lateral transfer of the mechanical leg axis in osteoarthritis of the medial compartment and of genu varum.

INDICATIONS: Symptomatic medial compartment osteoarthritis (MCOA). Posttraumatic varus deformity. Varus malalignment and planned reconstructive procedures of the cartilage in the medial knee compartment.

CONTRAINDICATIONS: Cartilage lesion grade ≥III° (according to Outerbridge, 1961) in the lateral compartment. State after lateral meniscectomy. Patellofemoral osteoarthritis with extension lag > 10°. Femoral varus deformity. Knee instabilities. Advanced osteoporosis. Neurological disorders. General risks of adequate bone healing. Obesity (BMI > 30 kg/m(2)).

SURGICAL TECHNIQUE: Preoperative planning according to true-nominal analysis (according to Strecker, 2002) including a maximum and minimum extent of mechanical axis correction (according to Müller and Strecker, 2008). Arthroscopy of the knee to determine the cartilage status. In high tibial closed wedge valgus osteotomies > 10° an oblique osteotomy of the distal diaphyseal fibula is mandatory. Lateral approach and preparation of the tibial head. Partial osteotomy of the proximal tibial tuberosity. Defined angle of valgisation fixed by two laterally introduced K-wires. Bending of a 5-hole DC-plate (DCP). Transversal osteotomy with oscillating saw, medial cortex of tibial head remaining intact. Fixation of pre-bent DCP in the proximal hole. Gentle closing of osteotomy gap with distal cortical "play screw" in plate hole 5. Compression of the osteotomy gap with two interfragmentary screws in holes 2 and 3. Completion of internal fixation and change of "play screw". In case of fibula osteotomy, further resection and internal fixation.

POSTOPERATIVE MANAGEMENT: First day after surgery: removal of drainage, x-ray control, mobilization. Partial weight bearing of 20 kg during 4 weeks postoperatively followed by 20 kg additional load per week according to clinical and radiological findings. Physical training with active and passive motion exercises. Low-molecular-weight heparin for at least 4 weeks.

RESULTS: Between January 2006 and December 2008, procedure performed in 50 patients (27 men, 23 women, mean age 44 years); arthroscopic treatment in 43 patients, and osteotomy of the fibula in 10 patients. The valgus correction was 8.4° (6-13°). No complication during surgery. One non-union was treated by cancellous bone grafting.