Minimally Invasive (MIS) TTC Fusions: A 52 Patient Case Series with High Rate of Limb Salvage

Category: Ankle Arthritis; Hindfoot Introduction/Purpose: TTC fusion is a common procedures to address complex hindfoot and ankle pathologies. It is a versatile procedure and can be used in many situations as either a primary procedure or limb salvage. Additionally, TTC is often used in the setting of neuropathy, Charcot deformities and failed ankle fracture ORIF. Given the medical and surgical complexity of the patient population, minimally invasive surgery (MIS) procedures may offer a option to more safely address these complicated problems, but only if the procedure can address all aspects of the deformity correction as well as successful fusion. We present the results of the largest case series of all MIS TTC fusions. We hypothesize that the surgical outcomes will be on par if not superior to traditional technique. Methods: This retrospective case series presents all patients MIS TTC fusion between January 1, 2019, and June 1, 2023 as part of a multi-center retrospective review of cases. Patients were identified through the operating room (OR) schedule, and their data was collected from medical charts stored in the institution's EHR. We report on demographics, complications, and fusion outcomes of TTC fusions for this population. Of the 52 cases, 27 cases (52%) also required osteotomies of the malleoli or midfoot for deformity correction which was also performed with an MIS technique when needed. Results: There were 52 patients included in the study. The primary diagnosis was Charcot ankle deformity in 11/52 (21%), Neuropathic ankle fracture in 15/52 (29%), Acute trauma in medical frail patient was 9/52 (17%), arthritis in 13/52 (25%) and other in 4/52 (8%). 26/52 (50%) had severe peripheral neuropathy. 40/52 (76%) patients had some combination of ESRD, poorly controlled diabetes, severe peripheral vascular disease, extremely poor soft tissue coverage. 45/52 (86%) patients achieved successful radiographic fusion. 2/52 (4%) achieved a stiff, asymptomatic pseudo arthrodesis. There were 9/52 (17%) complications: 2 patient deaths, 1 infection, 2 periprosthetic fractures, 1 nail subsidence, 2 delayed healing, 1 wound complications requiring flap closure. limb salvage was achieved in 47 of the 50 (94%) patients who survived to a surgical endpoint. Conclusion: MIS TTC fusion minimizes wound healing complications and infection. Deformity correction was performed with osteotomies when needed. The prevelence of medical comorbidities in this population is underscored by the 2 of patients who died within the early postoperative period (< 1 month). However, the high rate of limb salvage (94% of living patients, 90% of all patients) demonstrates the value of this technique to achieve deformity correction and bony union even in such a compromised patient population. The authors believe that MIS TTC fusion is a critical skill that will assist in treating many of our sickest and most complex patients.