ABFAS Rearfoot and Forefoot Exam Practice 2026 – Comprehensive Study Guide

The main idea is how a lateral column lengthening procedure affects the plantar ligaments that stabilize the midfoot. In the Evans procedure, the lateral column is lengthened by a calcaneal osteotomy and graft insertion, which changes the relationship between the calcaneus, cuboid, and the bases of the metatarsals. The long plantar ligament runs from the plantar aspect of the calcaneus to the bases of the 2nd through 5th metatarsals and is a key stabilizer of the longitudinal arch, especially on the lateral side. When the calcaneus is lengthened, this ligament is placed under new tension and can become attenuated or rupture, leading to instability of the lateral column and related midfoot complications. This makes disruption of the long plantar ligament the most common complication linked to the Evans procedure.

The other ligaments mentioned are less directly affected by this specific lateral lengthening. The spring ligament supports the talonavicular area and the medial arch; deltoid supports the medial ankle complex; the bifurcating ligament stabilizes the midfoot but is not typically the structure most strained by the Evans osteotomy.