Does a Fibula-Sparing Approach Improve Outcomes in Tibiotalocalcaneal Arthrodesis?

Abstract

Category: Ankle; Ankle Arthritis; Trauma Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is generally considered a salvage operation for either complex deformity or arthritis about the hindfoot. Several methods can be used to achieve a TTC arthrodesis, including: intramedullary nail fixation, screws, plates, and a fine wire frame. We hypothesized that fibula sparing TTC arthrodesis would improve the union rate and decrease complications in TTC arthrodeses. To best of our knowledge, this is the largest study of TTCs in current literature and no comparative studies have been performed to investigate whether fibular resection influences union and complication rate. Methods: After obtaining approval from the IRB, a retrospective review of the TTC fusions performed at a single academic institution was performed. Orthopaedic surgeons specializing in foot and ankle surgery performed all operations. Eligible patients included those whom underwent a TTC fusion either with or without fibular resection constructs from 2005 to 2017, were 18 years or older at the time of surgery, and had at least two-year follow-up. Patients were excluded if their clinical or radiographic data were unavailable for review. Preoperative diagnosis and indications, fixation methods, clinical success, and complications were obtained from the patient chart and operative reports. 152 patients (155 ankles) underwent TTC arthrodesis, mean age 57.5 years. 94 ankles comprised the fibula-sparing group and 61 comprised the fibular resection group. Statistical analysis was performed using t-Student and Chi-squared test with a p-value of 0.05 defining significance. Results: Common diagnoses included: arthritis (n=66), prior non-union of the ankle or subtalar joint (42), Charcot neuro- arthropathy (25), failed total ankle arthroplasty (TAA) (21) and avascular necrosis of the talus (36). Pre-operative diagnosis of failed TAA was associated with post-operative nonunion (47.6%, p=0.029). In 108 ankles (70%), hindfoot intramedullary arthrodesis nailing was performed, with supplemental plating or screw augmentation in 39 cases. Plating was used in 46 patients (30%). There was no difference in complications (p=0.62) or nonunion (p=0.11) between plating vs nail arthrodesis. There was no difference in non-union rate (26% fibula-resection vs 29% fibula-sparing, p=0.74) or complication rate (49% in fibula-resection vs 53% fibula-sparing, p=0.63) in the fibula-resection compared to the fibula-sparing groups. Most common complications included: non-unions, hardware irritation/failure (17.4%), infection (16.1%), and tibial stress fractures (8.4%). Conclusion: Tibiotalocalcaneal arthrodesis is used primarily as a salvage operation for severe deformity, arthritis of both the ankle and subtalar joints, and situations in which bone loss necessitates a larger fusion procedure. There appears to be no difference in the union rate or complication rates in fibula-sparing or fibula resection during the approach for these fusion operations.