Finite element analysis of femoral prosthesis implant in total knee arthroplasty：positioning parameters and clinical optimization / 中国组织工程研究

ABSTRACT

BACKGROUND:Three-dimensional finite element simulation has been widely used in biomechanics. However, there is little research in knee joint replacement. The study of femoral prosthesis is less. OBJECTIVE:To analyze the optimal positioning parameters of knee replacement and femoral prosthesis implantation, and to verify the efficacy of Gemini-PS knee prosthesis in total knee arthroplasty. METHODS: (1) Knee finite element model in total knee replacement was constructed. Orthogonal experiment was performed in femoral osteotomy positioning parameters. The shift amount A, external rotation degree B, and valgus degree C of femoral prosthesis were selected as the relevant factors for orthogonal experiment. Three values were taken for each parameter to establish orthogonal tables. Nine experimental combined knee replacement finite element models were created and analyzed with finite element. Analysis of variance and range analysis were used by optimization. (2) Totally 42 patients (47 knees) with knee osteoarthritis received total knee arthroplasty with Gemini-PS knee joint prosthesis. Knee joint function was evaluated after replacement with Hospital for Special Surgery knee score and American Knee Society knee score. Knee pain was assessed with Visual Analogue Scale score. RESULTS AND CONCLUSION:(1) Minimal polyethylene substrate surface compressive stress peak was translation 0 mm, external rotation of 3°, valgus 6°; the peak stress was 15.9 MPa. Among the influential factors, the effects of internal and external translation were larger than that of external rotation angle, and greater than that of valgus angle. The optimal positioning parameter combination was pan 0 mm, external rotation 3°, valgus 6° by range analysis and variance analysis. Orthogonal experiment was valid by simulation. (2) 42 patients were folowed up for 12-36 months. One patient affected subcutaneous fat liquefaction of the lower segment of the incision. Hospital for Special Surgery knee score and American Knee Society knee score were significantly higher after implantation (P < 0.05). Visual Analogue Scale score was significantly lower after replacement (P < 0.05). X-ray films showed that osteolysis, dislocation or loosening was not found. The recovery of knee joint was good after operation. (3) These findings: