Mathematic Modelling of Stress in Healthy Knee Joint and After Arthroplastywith Different Typesof Endoprostheses

Purpose of study. To study stressed-deformed state of the healthy knee joint and after arthroplasty using endoprostheses with either preservation or substitution of the posterior cruciate ligament by the method of numerical mathematical modelling. Materials and methods. Peculiarities of stress distribution in bones were determined on three mathematical models - healthy knee joint and joint after arthroplasty using endoprostheses with either preservation or substitution of the posterior cruciate ligament at the set load (80 kg) in straightened leg and either 45° or 90° knee flexion. Results. In healthy knee joint with a straightened leg the stress in the tibia is 2.3 times higher than in the femur. With knee flexion the stress in bone tissue increases and this increase is more intensive in the femur. After arthroplasty using endoprosthesis with substitution of the posterior cruciate ligament the stress in the tibia and femur is higher at all flexion angles as compared to arthroplasty using endoprosthesis with posterior cruciate ligament preservation Conclusion. The obtained data may be used for mathematical substantiation of the advantage of endoprosthesis with preservation of the posterior cruciate ligament and in complex with the data of national and international registers will enable to optimize the treatment tactics in patients to whom knee arthroplasty is indicated.

knee arthroplasty, stress modelling, osteoarthrosis