【Abstract】 Objective To investigate the surgical technique and the cl inical results of total knee arthroplasty (TKA)in treating end-stage gonarthrosis combined with valgus knee deformity. Methods Between November 1998 and October2010, 64 patients (72 knees) with end-stage gonarthrosis combined with valgus knee deformity underwent TKA by a medialparapatellar approach. Of the 64 patients, 18 were male and 46 were female with an average age of 62.5 years (range, 23-82 years),including 44 cases (49 knees) of osteoarthritis, 17 cases (20 knees) of rheumatoid arthritis, 2 cases (2 knees) of haemophilicarthritis, and 1 case (1 knee) of post-traumatic arthritis. Bilateral knees were involved in 8 cases, and single knee in 56 cases. Theflexion and extension range of motion (ROM) of the knee joint was (82.2 ± 28.7)°; the femur-tibia angle (FTA) was (18.0 ± 5.8)°;according to Knee Society Score (KSS) criterion, the preoperative cl inical score was 31.2 ± 10.1 and functional score was37.3 ± 9.0. According to Krackow’s classification, there were 65 knees of type I and 7 knees of type II. By medial parapatellarapproach, conventional osteotomy and Ranawat soft tissue release were performed in all cases. Prosthesis of preserved posteriorcruciate l igament were used in 7 cases (7 knees), posterior stabil ize prosthesis in 54 cases (60 knees), constrained prosthesisin 4 cases (5 knees). Results Incisions healed by first intention in all cases. Peroneal nerve palsy occurred in 1 patient withhaemophilic arthritis, severe valgus deformity (FTA was 41°), and flexion contracture (20°), which was cured after 1 year ofconservative treatment. Revison surgery was performed in 1 case of deep infection at 2 years after surgery. All the patients werefollowed up 4.9 years on average (range, 1-13 years). At last follow-up, the FTA was (7.0 ± 2.5)°, showing significant differencewhen compared with preoperative value (t=15.502, P=0.000). The KSS cl inical score was 83.0 ± 6.6 and functional score was85.1 ± 10.5, the flexion and extension ROM of the knee joint was (106.1 ± 17.0)°, all showing significant differences whencompared with preoperative values (P lt; 0.05). Five patients had 12-15° valgus knee deformity, but the function of the affectknees were good. Conclusion TKA is an effective way for the patients with end-stage gonarthrosis combined with valgusknee deformity by medial parapatellar approach combined with conventional osteotomy and Ranawat soft tissue release. Thecorrection of deformity and improvement of joint function can be achieved significantly. The cl inical result is satisfactory.