A 26-year-old man comes to the emergency department for evaluation of right ankle pain. The patient was playing basketball just prior to arrival when he jumped in the air and landed on his friend's foot, rolling his right ankle. He immediately fell to the ground. The patient was unable to walk off the basketball court by himself and is unable to walk to the examination room unaided. Blood pressure is 110/80 mm Hg and pulse is 76/min. BMI is 20 kg/m2. The lateral aspect of the right ankle has significant swelling and tenderness to palpation over the lateral malleolus. There is no bruising and no tenderness to palpation over the anterior aspect of the foot. The patient can plantar flex and dorsiflex the ankle. Sensation is normal. Which of the following is the best next step in management of this patient?
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This patient has a lateral ankle injury caused by forceful inversion of the foot, which commonly occurs with running, walking on uneven surfaces (eg, descending stairs), or falling from a height. Most ankle injuries are caused by sprains, in which the ligaments are injured but the bones remain intact. Uncomplicated sprains are typically managed conservatively; however, orthopedic intervention may be required if a bony fracture is present.
The Ottawa ankle rules were developed to determine which patients require imaging to rule out an ankle fracture. These rules have high sensitivity (up to 99%) for detecting fracture and can help reduce the number of unnecessary radiographs. Plain radiographs of the ankle are indicated in patients with pain in the area of the malleolus in association with either:
Further management depends on presentation and x-ray findings. Immediate orthopedics consultation is indicated for any open fracture or in those with evidence of neurovascular impairment.
(Choice A) Nonsteroidal anti-inflammatory drugs are effective for acute ankle pain, whether due to sprain or fracture. However, this patient has clear indications for ankle x-ray, and simple splinting may not be adequate management.
(Choice B) If x-ray reveals a distal fibular fracture, most cases can be managed with a hard (eg, plaster, fiberglass) or soft (eg, air cushion) splint. Surgical intervention is considered for some proximal fibular fractures as well as for complicated (eg, comminuted, spiral) distal fibular fractures.
(Choice C) Ankle aspiration is usually done to evaluate suspected septic or crystalline arthritis. Typical features include erythema, swelling, warmth, and fever.
(Choice D) MRI can visualize the ligaments of the ankle, but it is expensive and rarely needed for acute evaluation of ankle sprains. MRI may be considered to rule out a concomitant talar fracture in patients who do not improve as expected in 6-8 weeks, but x-ray is the preferred initial imaging study.
Educational objective:
Ankle pain after trauma may be caused by a sprain or fracture. The Ottawa ankle rules are used to help determine which patients require imaging. X-ray of the ankle is indicated for patients with pain in the malleolar region in association with either 1) bony tenderness at the posterior margin or tip of the lateral or medial malleolus or 2) inability to bear weight.