Leg Injury—ATV Accident

Abstract

HISTORY: A 16-year-old female presented with a 2 week history of right knee and lower leg pain following an ATV accident. Outside radiographs of the right tibia-fibula, femur, and right foot were reported as normal. She had noted worsening knee pain as well as tingling in her 2nd-5th toes. She was using crutches and non-weight bearing (WB) at presentation. PHYSICAL EXAMINATION: Exam revealed 3/5 muscle strength with great toe flexion/extension, 3/5 strength with ankle dorsiflexion, and 4/5 strength with plantar flexion, inversion, and eversion. Decreased sensation noted in the right 1st web space as well as the lateral, medial, and posterior lower leg. Tinel’s sign postive at fibular head. Lateral proximal tibia and lateral knee joint line tender to palpation. 4/5 strength with painful flexion/extension of knee, but range of motion (ROM) intact. She had 2+ posterior tibialis and dorsalis pedis pulses. DIFFERENTIAL DIAGNOSIS: 1) Proximal Lateral Tibia bony stress injury 2) Peroneal Neuropathy 3) Intra-articular knee derangement TEST AND RESULTS: Due to examination, a knee MRI was obtained as was an EMG/Nerve Conduction Study (NCS) to assess the peroneal nerve. MR Knee revealed a non-depressed subchondral fractures of anterior lateral tibial plateau and femoral condyle. Semimembranosus tendon partial tear near tibial insertion. Grade 1 MCL injury. The EMG/NCS reveaed a mild, acute-subacute, peroneal neuropathy. FINAL WORKING DIAGNOSIS: Non-displaced fractures of lateral tibial plateau and lateral femoral condyle with peroneal neuropraxia. TREATMENT AND OUTCOMES: 1) Initial visit- Ankle Foot Orthosis (AFO) and hinge knee brace provided while MRI and EMG/NCS pending. Remained non-WB with crutches. 2) After MRI and EMG/NCS 1 week later- began home passive and active assisted ROM exercises at home. Continued AFO and crutches when not at home. 3) 4 weeks after first evaluation- began toe-touch WB with progression to partial WB as tolerated and also began PT with right knee/ankle stretching and strengthening. Continued to wear AFO to allow for peroneal nerve healing as she progressed to WB as tolerated. 4) 3 months post injury- AFO removed for activities of daily living but advised against exertional impact activity while completing PT.