A biomechanical model of the effect of subtalar arthroereisis on the adult flexible flat foot.
OBJECTIVE: The hypothesis tested was that the increased load on the medial arch in the adult flat foot can be reduced through a 6 mm subtalar arthroereisis.
DESIGN: A three-dimensional multisegment biomechanical model was used in conjunction with experimental data and data from the literature.
BACKGROUND: Biomechanical models have been used to study the plantar fascia, medial arch height, subtalar motion, medial displacement calcaneal osteotomy and distribution of forces in the foot.
METHODS: Responses of a normal foot, a flat foot, and a flat foot with a subtalar arthroereisis to an applied load of 683 N were analyzed and the distribution of support among the metatarsal heads and the moment about various joints were computed.
RESULTS: The flattened foot results in an increase in the load on the head of the first metatarsal from 10% to 24% of the body weight, and an increase in the moment about the talo-navicular joint from 3.4 to 11.9 Nm. Insertion of a 6 mm cylinder into the sinus tarsi, subtalar arthroereisis, results in a shift of the load back toward the lateral column, decreasing the load on the first metatarsal to 6% of the body weight and decreasing the moment about the talo-navicular joint to 6.0 Nm.
CONCLUSIONS: Our analysis indicates that a 6 mm subtalar arthroereisis in an adult flat foot model decreases the load on the medial arch.
Published In/Presented At
Arangio, G. A., Reinert, K. L., & Salathe, E. P. (2004). A biomechanical model of the effect of subtalar arthroereisis on the adult flexible flat foot. Clinical Biomechanics (Bristol, Avon), 19(8), 847-852.
Medicine and Health Sciences | Other Medical Specialties | Surgery
Department of Surgery