Clinical Outcomes of Posterior Tibial Tendon Sheath Ultrasound-Guided Corticosteroid Injections

CATEGORY: Ankle; Basic Sciences/Biologics; Sports INTRODUCTION/PURPOSE: The treatment of progressive collapsing foot deformity (PCFD) typically begins with nonoperative management including physical therapy, bracing, nonsteroidal anti-inflammatory medications, and activity modifications. Surgical intervention is not typically performed until nonoperative treatment has failed. Corticosteroid injections into the posterior tibial tendon sheath (PTTS) is a burgeoning nonoperative treatment modality for PCFD. The purpose of our study was to assess the safety of ultrasound-guided corticosteroid injections into the posterior tibial tendon sheath for posterior tibialis tendon tendinopathy. Secondary outcomes include duration of pain relief, amount of pain relief, need for repeat injections and progression to surgery. METHODS: We retrospectively reviewed all patients in our electronic medical record who underwent a PTTS steroid injection between 2015 to 2020 for the diagnosis of posterior tibial tendon dysfunction, and/or posterior tibialis tendon insufficiency, and/or ankle pain. Demographic information was obtained from the patient record in addition to MRI data, clinical response to injection based on follow up visits, number of total injections, and progression to surgery. Thirty-eight posterior tibial tendon sheath ultrasound-guided injections in 33 patients met criteria during the 5 year study period. RESULTS: Thirty-three patients were included in the study with 38 injections. Two patients (6.1%) had 3 posterior tibial tendon injections, one patient (3%) had 2 injections, and the rest had only a single injection yielding a total of 38 injections included in the study. Eighteen of 38 (47%) injections yielded good or better pain relief. Seven of 33 patients (21%) progressed to surgery. There were no reported complications with the 38 performed injections. CONCLUSION: Ultrasound-guided corticosteroid injections into the posterior tibial tendon sheath is a safe nonoperative treatment modality for posterior tibialis tendon tendinopathy. The efficacy of the injection appears highly variable with 47% of injections yielding 'good' or better clinical results. When evaluating BMI, obese patients (BMI >= 30.0) were found to have a more sustained response to injection (P = 0.029) and more pain relief (P = 0.049) compared to non-obese patients.