Non-Contact Posterior Ankle Injury- Lacrosse

HISTORY: A 42 year-old Lacrosse athlete sustained a non-contact posterior ankle injury. She was playing lacrosse and felt a “pop” in posterior ankle while running and planting her foot. She had minimal pain and was able to bear weight without increased pain. She had bruising of the posterior heel without deformity. She had a history of recurrent episodes of Achilles tendonitis. She was initially seen by an athletic trainer across the country while on vacation and placed in a CAM boot with heel lifts, intermittently weightbearing. She used night splints in plantarflexion intermittently for 3 weeks. She presented for an in-person visit about 5 weeks after initial injury. PHYSICAL EXAMINATION: Ecchymosis with trace edema at the heel over Achilles. Tenderness to palpation at Achilles with palpable defect. No active plantar flexion, but full passive plantarflexion. Limited range of motion with dorsiflexion, but full inversion and eversion. No strength with plantarflexion. Full strength with dorsiflexion, inversion, and eversion. Thompson test was positive. DIFFERENTIAL DIAGNOSIS: 1. Achilles Rupture 2. Acute Achilles peritendinitis 3. Gastrocsoleus strain or rupture 4. Plantaris Rupture 5. Posterior tibialis tendon injury TESTS AND RESULTS:Xray: No fracture or dislocation, no soft tissue abnormality. MRI Tibia and Fibula without contrast and Ankle without contrast: Complete rupture of Achilles tendon with retraction and associated Achilles tendinopathy. FINAL WORKING DIAGNOSIS: Achilles Rupture TREATMENT AND OUTCOMES: 1. Immobilization with non-weight bearing short leg cast in gravity equinus for 4 weeks. 2. Immobilization with short leg cast in slight equinus with built-up heel, weight-bearing as tolerated, for 4 weeks. 3. Hinged cam boot starting in slight equinus with step-wise increase in dorsiflexion, along with non-weightbearing ankle range of motion exercises. 4. Plan to transition to shoe with heel-lifts once able to achieve full dorsiflexion equivalent to unaffected ankle, along with gradual weight bearing Achilles and ankle strengthening exercises. The height of heel-lift will be gradually decreased as tolerated. 5. Final outcome to be determined; however, she has significant improvement in plantar flexion ROM and strength. Her goal is to continue playing lacrosse after rehabilitation.