Failed hindfoot fusion with intra-medullary nails - outcomes following limb salvage with circular frames for infected nonunions

N. Bali, P. Fenton, D. Bose

Introduction: Ankle and hindfoot salvage following infected nonunions is challenging. Revision with a two-stage procedure using internal stabilisation risks retention of bacteria on any implanted metalwork. A circular frame minimises this risk, and we present our experience at a tertiary referral limb reconstruction unit.

Methods: A prospective database was interrogated from 2009 to 2016 to identify patients who presented with infected hindfoot nonunions following hindfoot nails. One patient elected for a primary amputation, and the remainder were treated with open debridement, sampling, dead space management, soft tissue cover, and application of a circular frame using the Ilizarov technique. Outcome scores were collected using the Olerud and Molander score and EQ5D-5L.

Results: 9 patients were treated over a 7-year period. Demographics were 7 male: 2 female, average age 58 years (range 46-73 years). Follow up to latest outcome scorings was 47 months (Range 18-76 months), with one patient deceased. One patient required a local flap, and the rest were primarily closed. All patients achieved fusion across the prepared joints. Olerud and Molander score averaged 52.9 (Range 5-80), EQ5D-5L VAS 59.3 (5-95). Complications included 1 valgus malunion, 1 chronic pain syndrome, and 1 patient who eventually required an amputation secondary to vascular compromise.

Discussion: Revision fixation with a circular frame produced fusion in all cases and is useful for infective cases when internal fixation methods are limited. However clinical outcomes were varied, with chronic pain and vascular compromise leading to a poor result for now, with one considering amputation and the other needing stump revision. With acceptable results in the medium term, salvage with a circular frame should be considered for complex infected hindfoot revision fusion.