CME OnDemand: 2022 AOFAS Annual Meeting-Use of Pro in Evaluating TAA and its Indications

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The study investigated the joint contact mechanics in patients with flexible flatfoot deformity. This deformity often leads to osteoarthritis in the peritalar joints, which can cause further complications in treatment. The researchers aimed to compare the joint contact mechanics in neutrally aligned feet and collapsed feet.<br /><br />To conduct the study, a finite element model of the foot was used, which included all 28 bones, 72 ligaments, cartilage, and soft tissue. The model was loaded with body weight to simulate quiet stance. The collapsed foot model was created by simulating transection of several ligaments and unloading of the posterior tibial tendon.<br /><br />The results showed that peak contact pressures were increased in the tibiotalar and subtalar joints but decreased in the talonavicular joint in the collapsed foot compared to the neutrally aligned foot. The center of pressure in all three joints was significantly different between the two conditions. In the talonavicular joint, peak pressure shifted towards the central region of the navicular bone in the collapsed foot, while it was evenly distributed in the neutrally aligned foot. Similarly, peak pressure in the subtalar and tibiotalar joints shifted towards the lateral region in the collapsed foot.<br /><br />The study concluded that ligament tearing in flexible flatfoot deformity leads to increased and lateralized contact pressure in the tibiotalar and subtalar joints, while the pressure in the talonavicular joint decreases paradoxically. This may be due to the malaligned medial column's inability to transmit force from the hindfoot to the forefoot. The findings suggest that future treatments for flexible flatfoot deformity should aim to normalize contact pressure in the peritalar joints to prevent disease progression and the development of arthritis.

Asset Subtitle

Yash Suri, MS

Keywords

joint contact mechanics

flexible flatfoot deformity

osteoarthritis

peritalar joints

ligaments

peak contact pressures

tibiotalar joint

subtalar joint

talonavicular joint

disease progression