Bilateral Ankle Pain - Recreational Runner

HISTORY: A 32 year-old female recreational runner presented with left ankle pain and swelling. Patient reported insidious onset of lateral ankle pain over 1-2 week period. Denied specific injury or trauma. Patient reported approximately twenty miles per week of recreational running. She endorsed gradual onset of pain around five miles into her daily workout and has been unable to tolerate any physical activity recently due to this. Denied distal numbness or tingling. Patient had history of right sided distal fibular stress fracture several months prior treated conservatively and stated symptoms felt very similar. Patient reported relative amenorrhea for years with contraceptive implant and has had multiple ovarian cysts. FAMILY HISTORY: Reported negative for osteoporosis/osteopenia. PHYSICAL EXAMINATION: Musculoskeletal Examination of the Left Ankle: Inspection/Palpation - Skin intact without any erythema or ecchymosis. Mild localized lateral soft tissue swelling noted. Reproducible tenderness to palpation about 3.5 cm proximal to the distal tip of the lateral malleolus. No significant tenderness over base of the fifth metatarsal or peroneal tendons. ROM/Strength - No pain with active or passive range of motion and strength preserved to dorsiflexion, plantarflexion, inversion and eversion. Special testing - No tenderness to palpation over the syndesmosis and negative squeeze test. No laxity with talar tilt test. DIFFERENTIAL DIAGNOSIS: 1. Fibular stress fracture 2. Lateral ankle sprain 3. Peroneal tendonitis. TEST AND RESULTS: Left ankle radiographs - AP/Lat/Oblique views were obtained and revealed intact ankle mortise with linear area of increased sclerosis through the distal fibula approximately 3.5 cm proximal from the tip of the lateral malleolus. No bony callus formation seen. Localized soft tissue swelling about the lateral aspect of the ankle. No joint effusion. FINAL/WORKING DIAGNOSIS: Bilateral distal fibular stress fracture. TREATMENT AND OUTCOMES: 1. Immobilization with tall walking boot for six weeks and restriction on physical activity. 2. Re-evaluation every three weeks with repeat radiographs showing interval healing. 3. Referral to orthopedic bone health clinic for further work-up of multiple stress fractures. 4. Return to running protocol with physical therapy.