Lateral femoral sliding osteotomy in total knee arthroplasty with valgus deformity greater than twenty degrees

Purpose Lateral femoral sliding osteotomy has been reported as an effective technique for total knee arthroplasty (TKA) with significant valgus deformity. This study aims to investigate its utility in TKA with valgus deformity greater than 20 degrees, for which few studies have examined. Methods Consecutive TKA patients with valgus deformity treated with the sliding osteotomy at our institution were retrospectively studied. Constraint implants were not used. Radiological and clinical parameters at follow-ups were compared with those pre-operatively. Radiological parameters included the hip-knee-ankle angle (HKA), the anatomical lateral distal femoral angle (aLDFA), the anatomical lateral plateau ankle angle (aLPTA), and the angle between the femoral mechanical axis and transepicondylar line (femoral transepicondylar angle, FTEA) which was used to reflect concurrent extra-articular valgus and corresponding local alignment. Clinical outcome measures included the Knee Society Score and Functional Score. Results Twenty-five patients operated on between July 2011 and February 2017 were enrolled. The average follow-up time was 3.3 (1.5 similar to 7.9) years. The pre-operative HKA of 202.7 +/- 2.3 degrees (equivalent to valgus of 22.7 +/- 2.3 degrees) was reduced to 180.4 +/- 2.3 degrees at final follow-ups (P < 0.001). The aLFDA, aLPTA, and FTEA were all significantly improved, with the last one increased from 84.2 +/- 1.8 degrees to 89.6 +/- 1.6 degrees (t = - 11.35, P < 0.001). All clinical scores were significantly improved without major complications. Conclusions Lateral femoral sliding osteotomy can be effective and safe for TKA with severe valgus deformity greater than 20 degrees.