Anthropometry of the medial femoral condyle in the Chinese population: the morphometric analysis to design unicomparmental knee component

BACKGROUND: This study aimed to assess the radii of the distal and posterior articular surfaces of the medial femoral condyle in a Chinese population and provide detailed parameters of the knee joint for the future design of UKA components. METHODS: This study included 500 consecutive Chinese patients who underwent knee MRI from Jan 2019 to Jan 2020. The two most appropriate circles were used to reveal the distal and posterior joint surfaces in the sagittal plane of the MRI images. The radius of the circle representing the distal articular surface in the sagittal plane was measured as R1, and the radius of the posterior articular surface was measured as R2. The distance between the centers of the two rotation circles was recorded as d. An independent t test was used to compare the differences between men and women. The Pearson correlation coefficient was calculated to analyze the correlation between R1 and R2. SPSS v19.0 software was used for statistical analysis. RESULTS: The average values of R1, R2, R1/R2 and d were calculated. Scatter plots were constructed to show the trend of changes in the radius of the distal and posterior articular surfaces of the femoral condyle. R1, R2 and d differed significantly between men and women (p < 0.05). Correlation analysis showed that R1 was positively correlated with R2 (r = 0.61, p < 0.05). CONCLUSIONS: The data of the radii of the distal and posterior articular surfaces of the medial femoral condyle were provided. In the UKA design, the relationships between the radii of the distal and posterior articular surfaces should be taken into account.