Objective: The aims of this study were to measure the distal femoral cartilage thicknesses of patients with pes planus by using ultrasound imaging and to explore whether ultrasound measurements are associated with degree of pes planus.
Design: One hundred seven patients (61 men, 46 women; aged 18-45 yrs) with pes planus and 107 age- and sex-matched as well as body mass index-matched healthy controls were enrolled in this study. After clinical assessment of the patients, measurements for pes planus were done on the radiographs, and ultrasound imaging of the distal femoral cartilage was performed from the right medial condyle, the right lateral condyle, the right intercondylar area, the left medial condyle, the left lateral condyle, and the left intercondylar area.
Results: Femoral cartilage values were thicker than those of the control group at all measurement sites (except for the right lateral condyle) (P's < 0.05). In a subgroup analysis regarding the sex difference, right medial condyle and left medial condyle values in the male subjects as well as right lateral condyle, right intercondylar area, left lateral condyle, and left intercondylar area values in the female subjects were found to be thicker (all P < 0.05).
Conclusions: The distal femoral cartilages of the pes planus patients seem to be thicker, and this finding could possibly stem from excessive mechanical stress on the knee joint caused by impaired lower extremity biomechanics.