Influence of total knee arthroplasty to patellar tilting
- VernacularTitle:全膝关节置换术对髌骨内外倾运动的影响
- Author:
Yixin ZHOU
;
Yi JIANG
;
Hong ZHANG
- Publication Type:Journal Article
- Keywords:
Knee prosthesis;
Patella;
Prosthesis design
- From:
Chinese Journal of Orthopaedics
2000;0(11):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the medial-lateral tilting of patella in two different coordinate systems before and after total knee arthroplasty (TKA). Methods Six fresh-frozen left low limbs from cadaver were tested using a modified Oxford Rig. Anatomically based multiple loading of the quadriceps mechanism was applied(Vastus medialis 24.5 N, Vastus intermedius/rectus femoris 29.4 N, Vastus lateralis 19.6 N). In a three dimensional coordinate system, patellar tilting was tracked using a custom-made Laser tracking device. The femoral trochlea was used as the other coodinate system in skyline view of patellar-femoral joint. Total knee arthroplasty was performed using PFC? posterior cruciate ligament substituting knee system. The tilting angles of patellar were measured before and after TKA. Results In three dimensional coordinate system, when knee flexed 30?,60?,90?,120?,150?, the patella titled :-3.10??2.25?,2.50??1.07?,5.46??2.60?,6.32??2.16?,-2.10??1.90? respectively before total knee arthroplasty was undertaken. After total knee arthroplasty, the patella tilted 3.24??0.35?,2.30??1.39?,1.65??1.17?,1.29??1.03?,-0.86??1.42? respectively. When femoral trochlea was taken as coordinate, the patella tilted 0??0?,0??0?,0??0?,0.24??0.35?,-3.21??1.80?; 0??0?,0??0?,0??0?,0??0?,-1.12??1.20? respectively both before and after TKA (Lateral patella tilting was defined as positive and medial patella tilting, negative). Conclusion Even the relationship between patella and femoral trochlea remains normal, the mode and magnitude of patellar tilting changes significantly after TKA. In early flexion of knee joint, patella tilts medially before TKA while it tilts laterally after TKA. After TKA, patella tilts less laterally than it does before TKA when a knee flexes from 60 to 120 degrees.
