We aimed to retrospectively investigate the morphology of the resected surfaces of
femurs in Chinese patients who underwent total knee arthroplasty (TKA) and to assess
the suitability of contemporary femoral components. Measurements on three-dimensional
reconstruction after virtual bone cutting were performed on 142 knees from Chinese
TKA candidates. The anteroposterior (AP) and mediolateral (ML) dimensions, aspect
ratio (ML/AP), and posterior condylar angle (PCA) were measured in the axial plane;
the height and length of medial and lateral anterior condyles and the maximal width
of the anterior condyles were measured in the frontal plane. Femurs were matched to
the prosthesis with the closest AP size. The ML dimensions of femurs were compared
with the ML dimensions of the prosthesis. The AP and ML dimensions were significantly
larger in male knees (p < 0.01), whereas the difference of aspect ratios was not found to be significantly
different between genders (p = 0.26). Both medial and lateral heights of the anterior condyles were significantly
higher in men after normalization by AP (p < 0.01 and p < 0.05, respectively). The mean PCA averaged 3.8 degrees for Chinese subjects. The
overall prevalence of clinically significant overhang was 6.4% in males and 4.8% in
females. The design of femoral prosthesis with alternative ML dimensions of the femoral
component is a solution to sufficiently avoid overhang while retaining ideal coverage
when dealing with a high variation. Chinese men had higher anterior condyles than
women after normalization by AP dimension. The mean PCA was 3.8 degrees for all patients
with high variability.
Keywords
total knee arthroplasty - anthropometry - prosthetic design - posterior condylar angle
- overhang - anterior condyle
