Title

A biomechanical model of the effect of subtalar arthroereisis on the adult flexible flat foot.

Publication/Presentation Date

10-1-2004

Abstract

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.

Volume

19

Issue

8

First Page

847

Last Page

852

ISSN

0268-0033

Disciplines

Medicine and Health Sciences | Other Medical Specialties | Surgery

PubMedID

15342157

Department(s)

Department of Surgery

Document Type

Article