Morphometry of the proximal tibia to design the tibial component of total knee arthroplasty for the Korean population.

We carried out an anthropometric analysis using three dimensional computer tomographic measurements of the cut surface of the proximal tibia in 200 knees that were obtained from 50 male and 50 female Korean cadavers. We measured the mediolateral (ML), middle anteroposterior (AP), medial and lateral anteroposterior dimensions and the aspect ratio (ML/AP) of the resected proximal tibial surface; we then compared this data with the five conventionally used symmetric total knee components. We found that the ML (73.5+/-5.6 mm) and AP (47.3+/-3.8 mm) average dimensions of our study population were smaller than the dimensions of the symmetric commercially available TKA implants. We found a progressive decrease in the aspect ratio with the increasing anteroposterior dimension of the proximal tibia, as compared to the constant aspect ratio shown by the conventional tibial prostheses. The smaller sized prostheses were found to show mediolateral undersizing and the larger sized prostheses were found to show mediolateral overhang. This study may provide guidelines for designing a suitable tibial component of total knee prostheses for the Korean population, the aspect ratio of which decreases with increasing anteroposterior dimension.