Minimally Invasive Surgery Using the Circular External Fixator to Correct Neglected Severe Stiff Equinocavus Foot Deformities

Abstract

Background: Stiff equinocavus deformities of the foot are challenging to treat, often requiring extensive soft tissue dissection and bone removal. These procedures frequently yield suboptimal results and not infrequently amputation. Minimally invasive surgery using a circular external fixator potentially avoids the trauma to the soft tissue and may lead to improvement in outcomes and a lower amputation rate. The objective of this study was to evaluate the efficacy of minimally invasive surgery using a circular external fixator and limited soft tissue release to correct stiff equinocavus deformities. Methods: The treatment outcome of 29 patients (31 feet) with stiff equinocavus deformities of the foot and ankle treated with minimally invasive surgery and circular external fixation were reviewed after a mean follow-up period of 63 months. Patients’ demographics and cause of the deformities were recorded. Weight bearing radiographs of the foot were compared pre and postoperatively. Results: Outcome was satisfactory (plantigrade foot with improvement/resolution of pain) in 21 of 31 extremities, fair in 6 of 31 extremities, and poor in 4 of 31 extremities. In the majority of patients, a significant improvement in the equinocavus deformities was achieved with a statistically significant improvement in calcaneus and navicular height. Two patients with Charcot-Marie-Tooth and severely insensate feet had a poor outcome, resulting in transtibial amputation. Conclusion: Minimally invasive surgery with gradual correction of neglected stiff equinocavus deformities using a modular circular external fixator is a reliable initial limb salvage strategy. Minimally invasive surgery and gradual correction of neglected severe stiff equinocavus deformities using the modular circular external fixator to gradually correct neglected severe stiff equinocavus deformities, is a safe initial limb salvage strategy which may simplify secondary procedures such as arthrodesis. Level of evidence: IV.