Achilles Tendon, Patellar Tendon, and Femoral Cartilage Thickness in Control vs Asymptomatic Flatfoot Young Adults

Background: Changes in lower extremity alignment in individuals with flatfoot may be associated with differences in morphology of the tendons or cartilage in lower extremities. The purpose of the present study was to investigate the potential association of flatfoot with the morphology of the Achilles tendon, patellar tendon, and femoral cartilage. Methods: This study was conducted with 40 participants with flatfoot (28 females, 12 males) and 40 participants with a normal foot posture (28 females, 12 males). The thickness of the Achilles tendon (at points 2 and 3 cm proximal to the superior aspect of the calcaneus), patellar tendon (at the inferior pole of the patella and 1 cm proximal of the inferior pole of the patella), and femoral cartilage (at the intercondylar area, medial condyle, and lateral condyle) was measured by an ultrasonography device. Results: The Achilles tendon thickness at 2 cm (P = .009) and 3 cm (P = .010) proximal of the superior aspect of the calcaneus was on average 4% to 6% lower in individuals with flatfoot compared with controls. The cartilage thickness at the intercondylar area (P = .005) and medial condyle (P = .018) was on average 8% to 12% greater in individuals with flatfoot; however, the cartilage thickness at the lateral condyle and patellar tendon thickness was similar in both groups. Conclusion: The results obtained suggest that foot posture is associated with the morphology of the Achilles tendon and femoral cartilage.