[Modified pendulum osteotomy to correct severe tibial varus deformity].

Objective: Correction of a severe tibial varus deformity near the knee joint with only a slight influence on leg length and patella height.

Indications: Medial osteoarthritis and/or cartilage damage with a severe varus deformity > 10° with a medial proximal tibial angle (MPTA) < 80°.

Contraindications: Femoral varus deformity with lateral distal femoral angle > 91°, severe lateral cartilage damage, lateral osteoarthritis, lateral meniscus loss.

Surgical technique: Skin incision of approx. 8-10 cm between the tibial tuberosity and the head of the fibula. Exploration of the peroneal nerve. Detachment of the extensors. Insertion of an obliquely ascending guidewire ending approximately 10 mm below the medial articular surface. Insertion of a second guidewire. This aims at the middle of the first wire (hemi wedge). Check the wire position under fluoroscopy. Osteotomy with an oscillating saw under cooling. Removal of the wedge and closure of the osteotomy. Percutaneous needling of the medial collateral ligament with a cannula to carefully lengthen the ligament. Check the correction result with a metal rod. Osteosynthesis with lateral angle-stable plate.

Postoperative management: Partial weight-bearing with 10 kg for 6 weeks postoperatively, free range of motion.

Results: Reports from the literature show that good clinical results can be achieved with this procedure for severe tibial varus deformities. Postoperative leg length discrepancies are less common with this procedure than with laterally closing osteotomy.