ObjectiveTo explore the surgical technique and effectiveness of sliding osteotomy of medial femur condyle in handling soft tissue balance of severe valgus deformity in total knee arthroplasty (TKA). MethodsBetween June 2008 and February 2014, 18 cases (19 knees) of severe valgus knees undergoing sliding osteotomy of medial femur condyle in primary TKA were included. Of the 18 patients, 6 were male and 12 were female with an average age of 52.3 years (range, 29-72 years), including 3 cases (3 knees) of osteoarthritis, 11 cases (12 knees) of rheumatoid arthritis, 3 cases (3 knees) of post-traumatic arthritis, and 1 case (1 knee) of deformities in skeletal dysplasia. Before surgery, the tibial-femur angle (TFA) was (33.0±2.9)°; the Hospital for Special Surgery (HSS) score was 41.6±7.7; the Knee Society Score (KSS) lateral stability score was 6.0±5.4. All cases were rated as type II according to Krackow classification of valgus knee. During primary TKA, sliding osteotomy of medial femur condyle was performed via a medial parapatellar approach. ResultsIncision healed by first intention in all cases. Peroneal nerve palsy occurred in 1 patient, which was cured after 6 months of conservative treatment. Eighteen cases were followed up 19 months to 7 years, with an average of 5.7 years. All patients had no complications of deep vein thrombosis, deep infection, and prosthesis loosening. X-ray films showed that bone healing was achieved in all cases at 6 months. At last follow-up, the TFA was (4.8±1.8)°, showing significant difference when compared with preoperative value (t=62.61, P=0.00). The HSS score was 87.2±10.5 and the KSS lateral stability score was 12.4±3.1, all showing significant differences when compared with preoperative scores (t= —33.35, P=0.00; t= —6.83, P=0.00). ConclusionSliding osteotomy of medial femur condyle is effective for correcting severe valgus knee deformity during TKA. Satisfactory joint function and stability may be achieved.