Higher Rate of Revision in PFC Sigma Primary Total Knee Arthroplasty With Mismatch of Femoro-Tibial Component Sizes.
Total knee arthroplasty (TKA) systems permit a degree of femoro-tibial component size mismatch. The effect of mismatched components on revision rates has not been evaluated in a large study. We reviewed 21,906 fixed-bearing PFC Sigma primary TKAs using the Australian Orthopaedic Association National Joint Replacement Registry, dividing patients into three groups: no femoro-tibial size mismatch, tibial component size > femoral component size, and femoral component > tibial component. Revision rates were higher when the femoral size was greater than the tibia, compared to both equal size (HR = 1.20 (1.00, 1.45), P = 0.047) and to tibial size greater than femoral (HR = 1.60 (1.08, 2.37), P = 0.019). Potential mechanisms to explain these findings include edge loading of polyethylene and increased tibial component stresses.
['Young|Simon W|SW|', 'Clarke|Henry D|HD|', 'Graves|Stephen E|SE|', 'Liu|Yen-Liang|YL|', 'de Steiger|Richard N|RN|']
D019645:Arthroplasty, Replacement, Knee D001315:Australia D005269:Femur D006801:Humans D015994:Incidence D007719:Knee Joint D007720:Knee Prosthesis D009985:Orthopedics D020959:Polyethylene D016016:Proportional Hazards Models D012042:Registries D012086:Reoperation D015203:Reproducibility of Results D013977:Tibia
total knee arthroplasty component size size mismatch revision rates registry