"In the context in which life expectancy increases and the population becomes more active, the number of people who are affected by gonarthrosis symptoms increases proportionally. By the year 2030, in the United States of America, one in three adults is expected to suffer from gonarthrosis, this prediction will be the beginning of an epidemic. Total knee arthroplasty has been shown to relieve pain and improve joint function; however, studies have shown that active young patients still have limitations in performing high-level activities such as dancing, golfing, skiing, and gardening. Currently, modern TKA implants are designed to reproduce the normal biomechanics of the knee joint, mimicking the physiological "medial pivot" pattern with greater compliance on the medial compartment between the tibial insert and femoral condyle and less congruence on the lateral side. "
In an attempt to standardize the X-ray analysis and to create relevant correlations between it and the functional results, we present a pilot model of an artificial neural network based on a Bayesian belief network (BNN) designed for the automatic analysis of anteroposterior X-ray of the knee following total knee arthroplasty and more precisely the analysis of the tibial component. A prospective analysis was conducted in which 30 patients were analyzed and two groups resulted: the first was made up of 12 cases considered "normal" by the examiners (optimal positioning and cementation) and the second one, which was considered "pathological" (incorrect positioning or cementation) and included 16 cases. Based on 22 points established on the tibial component several geometric sizes (calculated parameters) were computed. Several parameters were compared and the results were up to 75% accuracy, 81.25% sensitivity, and 66.7% specificity. BBNs can be a solution for X-ray evaluation of total knee arthroplasty and can improve the understanding of its evolution. It needs confirmation in time, its accuracy rising with the number of patients introduced in the analysis algorithm.
Rotational malalignment complication following TKA, is common but can be avoided with proper surgical technique. This paper reviews the literature regarding rotational alignment during TKA, femoral and tibial rotation, and highlights the techniques prior in obtaining proper rotational positioning, nevertheless correct positioning in all three planes is important. Proper femoral component positioning in the axial plane is done using as landmarks the posterior condylar line (PCL), surgical transepicondylar axis (sTEA), anatomical transepicondylar axis and the trochlear anteroposterior (AP) axis. The paper describes the angular relationships between these landmarks and the distal femur. Axial tibial positioning is done when using intraarticular landmarks, the combination of more than one landmark could be a solution for solving this problem. The consensus is that femoral component should be positioned according to TEA but the interobserver variability of this land mark is very high. The rotation of the tibial component remains an open subject, most studies suggesting a point between half of the distance of patellar ligament and 1/3 of the internal tuberosity as optimal landmark.
One of the most controversial topics in total knee arthroplasty is rotation of the femoral component. The current gold-standard in total knee arthroplasty consists in positioning the femoral component in 3 degrees of external rotation to the epicondylar axis, having as reference the tangent to the posterior condyles. Achieving the correct rotation of the femoral components is one of the main goals during total knee arthroplasty. Multiple complications can result from internal femoral rotation, such as lateral patellar tilt, patellar subluxation or dislocation, mobilization with movement on pain, and low survival rates of the femoral components. Postoperative rotational assessment of protective components can only be performed correctly using computed tomography. The known evaluation methods are related to anteversion of the femoral neck, femoral trans-epicondylar line, insertion of the posterior cruciate ligament from the tibia and tibial tuberosity. The purpose of this study was to evaluate the rotation of the prosthetic components in the group of patients with the methods validated by studies and to find alternatives to evaluate the rotation of the femoral component. Thirty-four patients diagnosted with gonarthrosis, proposed for total knee arthroplasty, were included in the study. This is a prospective cohort study in which applied statistics consisted of analyzing data using frequency and percentage for qualitative and mean variables and standard deviation for quantitative variables
