Treatment of complex foot deformities with hexapod external fixator in growing children and young adult patients

Abstract

Background: Treatment of complex foot deformities in growing children and young adult patients is challenging. The traditional approach consists of extensive soft tissues releases, osteotomies and/or arthrodesis. More recently, distraction osteogenesis has been proposed as an alternative strategy. The aim of this study was to describe our treatment strategy and report clinical outcomes of the patients affected from complex foot deformities treated by distraction osteogenesis and hexapod external fixator.

Materials and methods: We retrospectively reviewed 10 consecutive patients with complex foot and ankle deformities treated from 2014 to 2016 at our unit. A TrueLok external fixator system was used in all patients. Final outcome was classified as good, fair and poor according to the criteria indicated by Paley and Ferreira. The results were also evaluated by the pre-operative and post operative American Orthopedic Foot and Ankle Score (AOFAS) and The Manchester-Oxford Foot Questionnaire (MOXFQ).

Results: A plantigrade foot was obtained in eight patients at the end of treatment, while in two patients a recurrence of the deformity was noted. Result was classified as good in 6 patients, fair in 2 patients, and poor in 2 patients. The AOFAS score improved from 33.9±21.2 pre-operatively to 67.25±15.1 post-operatively (p=0.005). A statistically significant improvement was observed for the MOXFQ score as well (from 60.6±23.3 to 33.0±25.2, p=0.020).

Conclusions: Our study shows that the TrueLok hexapod external fixator is a safe and effective tool in treatment of complex rigid foot deformities. Nevertheless, deformity recurrence can be observed in some cases and treatment remains challenging. Distraction osteogenesis should be reserved as a salvage solution for particularly complex cases and should be performed at dedicated specialized centers.

Keywords: Clubfoot; Complex foot deformities; Distraction osteogenesis; Hexapod external fixator.