Peroneal Tendon Sheath Ultrasound Guided Corticosteroid Injection: Clinical Outcomes and Complications

CATEGORY: Ankle INTRODUCTION/PURPOSE: Painful peroneal tendon pathologies fall into three primary categories: tendinopathy, tendon subluxation/dislocation, and tendon tears/ruptures. For symptomatic peroneal tendinopathy and tears, treatment traditionally begins with NSAIDs, rest/activity modification, physical therapy, and immobilization and with surgery typically reserved for cases of failed non-operative treatment. Ultrasound-guided peroneal tendon sheath (US PTS) corticosteroid injection is an additional nonoperative modality used by many orthopedists, however limited data has been published on its safety and efficacy. The purpose of this study was to assess clinical outcomes following US PTS corticosteroid injection for chronic tendinopathy or tears. We hypothesized that following injection, patients would have improved pain without increased incidence of spontaneous tendon rupture. METHODS: We identified a retrospective cohort of patients who had undergone US PTS corticosteroid injection for pain due to peroneal tendinopathy, tears, or subluxation. Underlying diagnosis was based on clinical exam, MRI results, and/or intraoperative findings, when available. Medical record data was supplemented by email or telephone follow-up. Collected information included patient age, sex, BMI, smoking status, worker’s compensation status, prior surgeries about the foot and ankle, duration of symptoms prior to injection, perceived improvement in pain following injection and its duration, number of injections, progression to surgery, and any perceived adverse outcomes of injection. RESULTS: We identified 96 patients (109 injections). Thirty-seven (38.5%) had previous foot and ankle surgery, with 17 (17.7%) having surgery specifically on the peroneal tendons. 24/96 (25%) progressed to have surgery on their peroneal tendons following injection. Following injection, 38/87 (43.7%) of patients experienced 0 -1 weeks of pain relief, 11/87 (12.6%) 2-6 weeks, 6/87 (6.9%) 7-12 weeks, and 32/87 (36.8%) >12 weeks of pain relief. Pre-injection duration of symptoms correlated positively with post- injection duration of pain relief (p=0.036). There was no significant difference between progression to surgery or duration of pain relief based on peroneal pathology, prior surgery, smoking status, worker’s compensation status, sex, or BMI. There were 2 reported complications (1.8%): one case of self-limited sural nerve irritation and one of peroneus longus tear progression. CONCLUSION: In this series of 109 US PTS corticosteroid injections, the complication rate was 1.8%. Pre-injection symptom duration correlated positively with post-injection pain relief duration. Our study demonstrates US PTS corticosteroid injection is safe in patients with pain originating from peroneal tendon tears or tendinopathy, including those who have undergone prior surgery, and should be considered in a comprehensive protocol of nonoperative management. Further research is needed to elucidate the effect of multiple injections and of injection timing, as well as whether these injections can decrease the rate of patients progressing to surgery.