Author:

Keywords:

cruciate retaining total knee arthroplasty, PCL-retaining total knee arthroplasty, PCL balancing, tibiofemoral contact point, Science & Technology, Life Sciences & Biomedicine, Orthopedics, Sport Sciences, Surgery, Cruciate-retaining total knee arthroplasty, MOLECULAR-WEIGHT POLYETHYLENE, KINEMATIC ANALYSIS, FLEXION, ARTHROPLASTY, LIGAMENT, BEHAVIOR, JOINT, Aged, Aged, 80 and over, Arthroplasty, Replacement, Knee, Biomechanical Phenomena, Female, Femur, Humans, In Vitro Techniques, Knee Joint, Knee Prosthesis, Male, Middle Aged, Posterior Cruciate Ligament, Range of Motion, Articular, Tibia, Weight-Bearing, 1103 Clinical Sciences, 1106 Human Movement and Sports Sciences, 3202 Clinical sciences, 4201 Allied health and rehabilitation science, 4207 Sports science and exercise

Abstract:

Purpose: The goal of this study was to investigate whether a new PCL balancing approach with a spacer technique during total knee arthroplasty (TKA) reproduced the correct tibiofemoral contact point (CP) location. It was hypothesized that it should be possible to adequately balance the PCL with this geometrical technique, obtaining correct position and stability of the medial femoral condyle, independent of insert shape. Methods: Nine fresh-frozen full leg cadaver specimens were used. After native testing, prototype components of a new PCL-retaining implant were implanted using navigation and a bone-referencing technique. After finishing the bone cuts, the spacer technique was used to ascertain balancing of the PCL and the tibial cut was corrected if necessary. Passive and squat motions were performed before and after TKA using a dynamic knee simulator while tibiofemoral kinematics were recorded using 6 infrared cameras. CPs (native and implant) were calculated as the projections of the femoral condylar centers on the horizontal plane of the tibia. Results: The spacer technique resulted in correct PCL balancing in all specimens. The kinematic patterns of native and replaced knees showed no statistically significant differences (n.s.) in passive and squat motions. The medial CP after TKA was at the same position as in the native knee. No paradoxical sliding forward was seen after TKA, supporting our hypothesis. Conclusions: The spacer technique can be applied by surgeons during PCL-retaining TKA and will lead to good PCL balancing, indicated by a correct CP, no lift-off in flexion and no posterior sag.