Patient Reported Outcomes Following Triple Arthrodesis for Adult Acquired Flat Foot Deformity: Minimum Two Year Follow Up

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: The posterior tibial tendon (PTT) acts as the primary dynamic stabilizer of the medial longitudinal arch and insufficiency of the PTT can result in a broad range of symptoms from asymptomatic to debilitating arthritis in association with flat foot deformity. Staging of AAFD is based on the degree of deformity and broken into four groups. Triple arthrodesis (TA), a simultaneous fusion of the talonavicular, subtalar, and calcaneocuboid joint, is used for patients with intractable pain, instability, and stage 3-4 deformity due to hindfoot pathology. The purpose of this study was to identify patient-specific variables that independently influence PROMIS, Foot Function Index (FFI), and VAS scores as well as complication rates. Methods: A retrospective analysis was conducted of patients that underwent Triple Arthrodesis at our facility from 2014-2021. Patients were selected if they underwent an isolated triple arthrodesis. All cases included either a gastrocnemius recession versus a percutaneous tendo-achilles lengthening depending on the patient’s Silverskiold examination. The electronic medical record was utilized to collect basic patient demographics, previous foot and ankle surgeries, hardware failures, additional procedures, and surgical complications. To evaluate outcomes, we compared Patient Reported Outcomes Measurement Information System (PROMIS) survey scores with the general population and pre-operative vs. post-operative Visual Analog Scale (VAS) scores. Foot Function Index (FFI) scores and scores were utilized as a validation tool for our results. One hundred and thirty two patients met the criteria for our study with a total of 50 participants completing the PROMIS and FFI surveys. Results: The average time point at which the outcomes were collected was 5.50 years postoperatively, ranging from 1.65 to 7.57 years. The average PROMIS physical function was 38.35, pain interference was 61.52, and depression was 49.82 for this population. The mean FFI scores were 58.56 for pain, 60.07 for disability, 48.07 for activity limitation. There was a significant decrease in preoperative and postoperative VAS scores from 5.4 to 2.55 (p < 0.001). Three patients experienced wound complication related to decreased sensation. Conclusion: Our results indicated that only PROMIS depression scores were within one standard deviation of the population mean following a triple arthrodesis procedure. PROMIS physical function and pain interference were both outside of one standard deviation for the population.