Thinner femoral cortical thickness in children with knee hemophilic arthropathy

A cross-sectional study was performed to compare the cortical femoral shaft between the leg with knee hemophilic arthropathy and the contralateral leg. Children with hemophilic arthropathy were included. Joint evaluation was made using the Hemophilia Joint Health Score 2.1 (HJHS 2.1) and the Functional Independence Score in Hemophilia (FISH). The cortical femoral shaft in each leg was assessed in three parts (upper, middle, and lower thirds) using computed tomography to evaluate thickness and density in eight different sectors. Thirty children were evaluated; mean age was 12 ± 2 years old. The HJHS score between knees was 6.5 ± 3.8 vs. 2.3 ± 3.0 ( p = 0.003). When comparing the cortical thickness, statistically significant differences were noted for the upper third sector: lateral, anterolateral, and posterolateral, meanwhile for the lower third: posterior, anteroposterior, posteromedial, and anteromedial sectors, being thinner in the femur with knee hemophilic arthropathy. When comparing the cortical densities, differences were noted for the upper third sector: anterior, medial and posteromedial, as well as in the middle third: lateral, anteromedial, and posterolateral sectors ( p = 0.000). We observed a thinner and less dense cortical femoral shaft in the leg with knee hemophilic arthropathy, predominately in the upper and lower third sections. Changes noticed in the affected femur with knee arthropathy likely reflect a reduced cortical bone expansion related to impaired kinematics and loading forces on the affected knee during normal walking and running.