Disclosures: Lane M. Lagattuta, DO: No financial relationships or conflicts of interest

Case Diagnosis: Split Tear of Peroneus Longus

Case Description: The patient is a 21 year old female swimmer who presented with a 2 year history of right ankle pain and instability which began after stepping off a platform. Despite PT and treatment with a boot, the patient continued to have instability and further ankle sprains. MRI was notable for split tearing of peroneus longus and chronically torn ATFL and CFL. She was treated with ultrasound (US) guided Prolotherapy tenotomy and injection with 70% improvement after 4 weeks.

Setting: Academic Quaternary Care University HospitalAssessment/

Results: Traditional treatment for chronic ankle instability, as seen in this patient, includes NSAIDS, rest, early return to motion, ankle support during exercise, and balance, coordination, and exercise training. Despite these treatments and physical therapy, the patient continued to endorse ankle instability. It was recommended she undergo Prolotherapy tenotomy and injection of the ATFL and CFL ligaments and peroneus longus, to which she responded with 70% improvement in symptoms. This included decreased pain, instability and swelling.

Discussion: Peroneal tendon tears occur in 25-77% of patients with chronic lateral ankle instability. Symptoms include lateral or posterolateral ankle pain, swelling posterior to the lateral malleolus and tenderness over the tendons. The tears are more likely to be longitudinal and occur more frequently in the peroneal brevis. One study finding peroneus brevis tears occurred in 88% vs 13% in the peroneus longus.

Conclusion: In patients with chronic ankle instability, peroneus tendon pathology should be in the differential diagnosis as it is often overlooked. Additionally, if conservative treatments fail, Prolotherapy should be considered.

Level of Evidence: Level V

« Back to AAPM&R Annual Assembly 2021

PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/chronic-ankle-instability-due-to-split-tear-of-peroneus-longus/