Arthrodesis with Hybrid Nail-Frame Construct Allows for Expedited Frame Removal During Neuropathic Limb Salvage

Abstract

Category: Diabetes; Ankle Introduction/Purpose: Charcot (neuropathic) arthropathy is a challenging problem that frequently presents as a limb-threatening condition due to deformity, ulceration and/or infection. Limb salvage relies on establishing a stable, plantigrade foot to limit further soft tissue injury and allow for ambulation. Internal fixation techniques require a period of non-weightbearing following arthrodesis to allow for fusion. Neuropathic patients lack protective sensation and, as a result, often have significant difficulty limiting their weightbearing postoperatively. Thin wire external fixation is a powerful tool for arthrodesis as it can allow for postoperative weight bearing in limb salvage patients. Hybrid fixation with hindfoot nail augmentation may allow additional compression and stability while protecting the arthrodesis site in the setting of poor compliance with weightbearing restrictions in limb salvage patients. Methods: A retrospective review of patients who had undergone ankle and hindfoot arthrodesis treated at a single institution from 2017-2023 was performed. Patients with peripheral neuropathy and either neuropathic arthropathy or a traumatic injury who were treated with tibiotalar, tibiotalolcalcaneal, tibiocalcaneal or pantalar arthrodesis with multiplanar thin-wire external fixation with or without the addition of a hindfoot nail were included. Exclusion criteria were patients undergoing isolated midfoot and/or hindfoot arthrodesis. The typical immediate post operative protocol allowed for at least partial weight bearing for transfers and balance. External fixation was removed at surgeon discretion. All surgeries were performed by fellowship-trained orthopaedic foot and ankle surgeons. Patient demographics and comorbidities were recorded. The primary outcome was successful stable arthrodesis and duration of frame utilization. Secondary clinical outcomes included events requiring return to OR, deep infection, wound healing complications, amputation, and death (Table 1). Results: Sixty-nine patients were included, 15 (22%) had hybrid nail-frame constructs. Average age (57.8 vs 57.4 years) and diabetes status (12/15 vs 39/54) were similar between groups. 4/15 (26.7%) hybrid and 22/54 (40.7%) frame-only patients (p>.05) sustained traumatic ankle fractures while the remainder presented with neuropathic arthropathy. No statistically significant difference was seen between groups in the arthrodesis rate (66.7% hybrid vs. 68.5% frame-only). Hybrid fixation resulted in a statistically significant shorter duration in the frame (77.7 vs 106.6 days, p=0.006) as well as time to stable radiographic and clinical union in those with successful fusion (79.8 vs. 111.0 days, p=0.01). Hybrid fixation had one amputation compared to six in the frame only group although this was not statistically significant. Infection rates were similar between groups. Conclusion: Limb salvage in neuropathic patients is a resource intensive endeavor, however successful salvage reduces long term expenditures and may allow for improved patient function compared to amputation. Arthrodesis with hindfoot nail-frame constructs results in similar rates of stable fusion while reducing the amount of time required for external fixation by nearly a third. While hybrid fixation is not appropriate for all patients (such as those with concern for infection and/or significant bone loss), this fixation method achieved similar results with earlier frame removal.