Experimental substantiation of the optimal technique for choosing the rotation of the femoral component of the knee endoprosthesis

There was experimental justification of the optimal technique for choosing the rotation of the femoral component of the knee joint endoprosthesis carried out in this research. The individual morphometric characteristics of the femoral condyles and the condition of the collateral ligaments were taken into account in the experiment. The research was conducted on polymer-embalmed preparations of the knee joint, which were divided into three groups, according to the forms of the femoral condyles. We used the standard technique of positioning the resection block and the technique of individual selection of the rotation of the resection block (rotation of the femoral component of the endoprosthesis), based on the assessment of individual morphometric characteristics of the femoral condyles and the state of the auxiliary elements of the knee joint. To implement this surgical approach, typical resections of the proximal condyles of the tibia and distal condyles of the femur were performed, which technically did not differ from the sawdust used in the standard procedure. Then the knee joint was flexed to an angle of 90°, Homan retractors were removed and two laminar dilators (Laminar Spreader) were installed in the gap between the proximal tibial sawdust and the posterior parts of the lateral and medial condyles of the femur. This technique provided isometric tension of the fibular and tibial collateral ligaments of the knee joint. Then carried out the positioning of the femoral resection block "four in one". In this case, only the line of the proximal tibial sawdust was used as a reference point, for which the posterior flange of the resection block was positioned parallel to the sawed upper articular surface of the tibia. It is established that the use of the considered technique of positioning the femoral resection block ensures the formation of a uniform flexor gap, regardless of the variant anatomy of the femoral condyles. Thus, there was research a uniform flexion gap in the experiment, which ensured isometric movements in the knee joint and its stability at the control points of the amplitude after implantation of the trial or final components of the endoprosthesis.