Tunneling Away Lateral Ankle Pain

Abstract

TITLE: Tunneling Away Lateral Ankle Pain AUTHORS: Geoffrey M. Dreher, DO; David Webner, MD; Kevin DuPrey, DO ACSM Sponsor (if you accept): Thomas Kaminski, PhD, ATC ([email protected]) HISTORY: 60-year-old boilermaker presented with 2-month insidious onset left lateral ankle pain, localized to the lateral malleolus, described as achy and throbbing, 7/10, worse with walking, stairs and climbing ladders. No relief with Acetaminophen or NSAIDs. PHYSICAL EXAMINATION: Left ankle: no edema or ecchymosis, full range of motion with pain in active dorsiflexion and plantarflexion. Strength 5/5, gross sensation intact and 2+ dorsalis pedis and posterior tibial pulses. Tenderness to palpation along the lateral malleolus extending distally approximately 5 cm along lateral ankle. DIFFERENTIAL DIAGNOSIS: 1. Chronic lateral ankle instability 2. Peroneal tendinosis with subluxation 3. Lateral malleolar stress fracture 4. Ankle osteoarthritis 5. Talar osteochondral lesion TEST AND RESULTS: •Left ankle 3 view x-ray: Normal. •Left ankle MRI: Anatomic variant involving conjoined peroneus brevis and longus tendons, located along the anterolateral aspect of distal fibula. Deficient/absent peroneal groove along posterior fibula, which also suggests congenital abnormality. Mild conjoined tendinosis, without surrounding edema. •Left lateral ankle ultrasound: Intact peroneal tendon overlying the lateral maleolus with trace fluid in sheath. The peroneal tendons split just before brevis insertion onto base of 5th metatarsal. FINAL/WORKING DIAGNOSIS: 1. Conjoined left peroneal tendon subluxation with tenosynovitis and absence of fibular groove. TREATMENT AND OUTCOMES: 1. Physical therapy for 6 weeks led to improved balance and walking mechanics, but no change in pain. 2. Immobilization in CAM boot for 6 weeks caused no improvement in pain or swelling out of boot. 3. Corticosteroid injection to peroneal tendons at level of lateral malleolus lead to no improvement. 4. Podiatry referral and surgery including tubularization of peroneal tendons, creation of 6mm fibular groove and repair of peroneal retinaculum. 3 months post-operatively, the patient was full weight bearing pain free with daily activities in lace-up ankle brace.