Estimating aspect ratio of the distal femur and proximal tibia in the Emirati population from MRI scans of the knee: a preliminary experience.

Size and shape of knee implants play an important role in the success of total knee arthroplasty. Several studies have identified anthropometric differences of the distal femur and proximal tibia between the genders and ethnicities. Ill-fitting prosthesis can cause overhang or under-fit resulting in persistence of pain, periprosthetic fracture and decreased range of motion. The purpose of this study was to estimate the aspect ratio of distal femur and proximal tibia in the Emirati population and determine whether gender differences exist within this group. Magnetic resonance imaging datasets of unilateral knees scans performed on adult Emirati patients at a tertiary care hospital were retrospectively examined. Knee parameters were obtained from 65 males and 46 females (n = 111). Females showed significantly smaller AP and ML dimensions of distal femur and lower aspect ratios compared to males (p < 0.001). Proximal tibial dimensions (AP and ML) of Emirati women are also significantly smaller compared to men. However, aspect ratio of proximal tibia did not show gender variation (p = 0.956) within the Emirati population. Emirati knees showed significant gender differences in bony dimensions and aspect ratio of the knee, and also have smaller aspect ratios when compared with most other population groups.