Long-term functional symptoms after total knee arthroplasty

Background: The standard of the surgical treatment for arthrosis of the knee joint (KJ) at the later stages is total arthroplasty, which allows relieving the pain and eliminating the existing deformity. However, there are not enough data on the long-term results after the surgery that is important for understanding the dynamics of the recovery and predicting the result. Aims: Study of clinical, functional, and biomechanical symptoms in patients after total arthroplasty of the knee joint in the long-term period. Methods: 22 patients after knee joint replacement and 20 relatively healthy adults (control group) were examined in long-term periods. The biomechanics of walking was studied at an arbitrary pace. The temporal characteristics of the gait cycle, shock loads and movements in the hip joints (HJ) and KJ were recorded. We recorded the time characteristics of the walking cycle, shock loads and movements in the hip joint (HJ) and KJ. The patients were divided into two subgroups according to the results of the biomechanical study. The patients from subgroup 1 had good functionality with a swing amplitude of the knee joint of 50 degrees or more, the movement algorithm was preserved. The patients from subgroup 2 had a swing amplitude of up to 50 degrees, the movement algorithm was impaired. Results: The temporal characteristics of the waking cycle of knee arthroplasty patients did not differ significantly from the control group in the long term. Abduction-adduction and rotation movements in HJ and KJ show a decrease in the amplitudes, more pronounced in the second subgroup. The main changes in the kinematics of the hip joint are characterized by a decrease in the range of motion and a longer extension time during the support period, which was found for both sides, especially in the second subgroup. The greatest changes were observed in the kinematics of the knee joints movements. They included a decrease in the amplitude of all the movements, not only on the endoprosthesis side, but also on the opposite side. Conclusions: There is no complete restoration of the knee joint function after total arthroplasty in the long term. The function of both lower limbs is symmetrically decreased. The fact of functionally different (less severe and more severe) results may be associated with the initial functional state of the joint before arthroplasty or with the subsequent period of rehabilitation.