Method for selection of femoral component in total knee arthroplasty (tka)

Abstract

A method is proposed enabling a surgeon to preoperatively determine the preeminent type and size of prosthesis, from those available, to be used in a particular patient undergoing knee replacement surgery. Parameters of healthy knee geometry were estimated by employing an unsupervised neural network. These estimated parameters were then applied in a χ(2) goodness of fit (GoF) test to determine which femoral prosthesis type and size delivers the most appropriate fit. This approach was used to determine the most suitable match of three implants for 34 different cases. Implant C performed the best and was the optimal fit in 59% of the cases, Implant A was the best fit in 38% of the cases and Implant B the best fit in 3% of the cases. This method shows promise in aiding a surgeon to select the optimal prosthesis type and size from an array of different conventional total knee replacements.

Toward the interpretation of the combined effect of size and body weight on the tribological performance of total knee prostheses

“…An intra-operative variable that is recognised to impact on the load pattern as well as the tribological performance of the prosthesis is the sizing [24]. Due to the complex morphometric relationship of the knee, loss of conformity and abnormal loading can originate from a size mismatch [11,12].…”

“…A proper choice of the prosthesis design and size is of paramount importance for TKR success [11]. Nowadays several TKP designs, shapes and sizes have been conceived, in order to fit most patient anatomies and with the final aim to lessen implant wear [6,12]. A surgeon can choose between two types of tibial inserts, which differentiate fixed and mobile TKP.…”

Does knee implant size affect wear variability?

“…have been investigated [8,9], implant design remains a critical factor influencing wear behaviour. Total knee prostheses (TKP) are commercially available in a wide range of different designs, shapes, and sizes in order to fit patient knee anatomy as well as possible and to minimise wear [8,10]. Surgery success depends on the accurate selection of the prosthesis design as well as on correct sizing of the implant [11].…”

“…The final choice of the component size is generally made during surgery and is of paramount importance; a mismatch in this phase can cause a loss of conformity and an abnormal loading [10,11]. Some studies have hypothesised that the best choice is to maximise the tibial size with respect to the femoral one [13][14][15][16].…”

Mathematical Reconstruction of Human Femoral Condyles

“…The ideal design will aim to restore the patient's original articulating surfaces [37]. To accomplish this it is necessary to be able to predict the original articulating surfaces for a specific individual.…”