Effect of changes in the centre of rotation after hip arthroplasty on knee joint function

Abstract

Introduction: A common complication after hip arthroplasty is pain and inflammation in other large joints, especially the knee joint. Displacement of the centre of rotation of the femoral head after endoprosthetics can change the redistribution of force vectors acting on the femur, change its tilt and pressure on the surface of the knee joint. Objective: The investigation of the effect of displacement of the centre of rotation of the hip joint after arthroplasty on the knee joint.Methods: Using SolidWorks software and the SimulationXpress tool, a 3D model of the lower limb was created that reproduced the interaction between the components of the musculoskeletal system.Results: As a result, it was found that the displacement of the centre of rotation of the hip joint medially and laterally from the anatomical position leads to a significant increase in pressure on the corresponding tibial condyles. The increase in load is linear and increases from a minimum value of 1.77 N⋅m in anatomical position to 123.79 N⋅m with a medial displacement of up to 8 mm.Conclusions: This study indicates the need for proper restoration of the centre of rotation of the hip joint after implantation and the possible consequences of changes in knee joint loads. The data may be useful for specialists working in the field of implantology and the development of hip prosthesis systems