[PERSONALIZED DISTAL FEMORAL VALGUS RESECTION ANGLE IN PRIMARY TOTAL KNEE ARTHROPLASTY].
To investigate the feasibility and effectiveness of a personalized distal femoral valgus resection angle for improving postoperative coronal alignment of lower limb in total knee arthroplasty (TKA). A retrospective analysis was made on the clinical data of 50 patients who received primary TKA between January 2013 and February 2013. There were 11 male and 39 female patients with degenerative knee osteoarthritis. The patients were divided into 2 groups. In test group (n=25), the resection angle was adjusted to the femoral mechanical anatomical angle (FMA); in control group (n=25), a fixed distal valgus resection angle of 5° was used. There was no significant difference in gender, age, body mass index, disease duration, sides, grade, preoperative FMA, mechanical femorotibial angle (MFT), and preoperative Knee Society Score (KSS) between 2 groups (P > 0.05). Whole long X-ray film was taken to measure FMA and MFT at 3 days after operation, postoperative KSS was used to evaluate the knee function after 6 and 15 months. MFT was (-0.20 ± 1.87)° in test group and was (1.71 ± 3.67)° in control group, showing significant difference between 2 groups (t = 2.32, P = 0.02). The ideal MFT angle (0 ± 3)° was achieved in 22 patients (88%) of test group and in 16 patients (64%) of control group, showing significant difference between 2 groups (χ2 = 2.32, P = 0.02). Primary healing of incision was obtained in all patients of 2 groups. No deep venous thrombosis occurred. The patients of 2 groups were followed up 15 months after operation. There was significant difference in KSS between test and control groups at 6 months (88.23 ± 2.57 vs. 82.92 ± 2.59) (t = 7.26, P = 0.00) and at 15 months (90.76 ± 2.77 vs. 88.65 ± 1.77) (t = 3.20, P = 0.02). No sign of prosthesis loosening was observed by X-ray examination. Compared with using of a fixed distal femoral resection angle, an individual FMA can significantly improve the postoperative MFT and promote early recovery of the knee function.