In Vivo Knee Kinematics: How Important Are the Roles of Femoral Geometry and the Cruciate Ligaments?

BackgroundWhile posterior cruciate-retaining (PCR) implants are a more common total knee arthroplasty (TKA) design, newer bicruciate-retaining (BCR) TKAs now being considered as an option for many patients, especially those that younger. While PCR remove the ACL, BCR TKA designs keep both cruciate ligaments intact, it is believed resection of ACL greatly affects overall kinematic patterns designs. The objectives this study to assess in vivo kinematics subjects implanted with either or and compare normal during flexion. These were achieved emphasis on understanding roles ligaments, well role changes femoral geometry nonimplanted anatomical femurs vs having metal component.MethodsTibiofemoral 50 (40 subjects) (10 analyzed using fluoroscopy while performing deep bend activity. compared previously published data subjects). Kinematics determined specific intervals flexion where PCL was most dominant.ResultsIn early flexion, experienced normal-like patterns, possibly attributed ACL. In mid-flexion, groups exhibited variable which could be due transitional ligament function period. deeper functioned similar knee, leading assumption properly balanced functioning groups. Interestingly, late (after 90°), all three appeared statistically similar.ConclusionSubjects greater weight-bearing than group. Subjects pattern lateral condyle rollback axial rotation