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Emergency and Acute Medicine – Ankle Sprain
Core Description
Ankle sprains involve injury to the ligamentous stabilizers of the ankle joint, a hinge joint formed by the tibia, fibula, and talus. Injury severity ranges from ligament stretching with microscopic damage (grade I), to partial tearing (grade II), to complete ligament rupture (grade III).
Mechanisms And Causes
Ankle sprains most often result from forced inversion or eversion, frequently during sports or collisions. Approximately 85–90% involve the lateral ligament complex, including the anterior talofibular, posterior talofibular, and calcaneofibular ligaments. Inversion injury most commonly affects the anterior talofibular ligament; calcaneofibular ligament injury is more likely when the ankle is in neutral position, while isolated posterior talofibular ligament injury is rare. Deltoid ligament injuries typically result from eversion and are often associated with medial malleolar avulsion or talar insertion injury; isolated deltoid injuries are uncommon and should raise concern for associated lateral malleolus or proximal fibular (Maisonneuve) fracture. Syndesmotic sprains involve the distal tibiofibular ligaments, occur frequently in collision sports, and carry higher morbidity with risk of long-term complications. In children younger than 10 years, traumatic ankle pain with normal radiographs most commonly represents a Salter–Harris type I fracture, as the physis is weaker than surrounding ligaments.
Clinical Presentation
Patients usually present with ankle pain, swelling, and difficulty bearing weight. History should include time and mechanism of injury, presence of a pop or crack, prior ankle trauma, relevant medical conditions, treatments attempted before arrival, and ability to bear weight at the scene and in the emergency department. Physical examination focuses on detecting instability and associated injury, including bony tenderness along the posterior edges of the medial and lateral malleoli and the base of the fifth metatarsal, distal neurovascular status, and comparison of range of motion with the uninjured side. Stress testing is often limited by pain. The squeeze test helps identify syndesmotic injury when compression of the tibia and fibula at the midcalf reproduces ankle pain.
Imaging Decision Strategy
The Ottawa Ankle Rules provide a validated approach for determining the need for radiographs. Imaging is recommended for bony tenderness at the posterior edge or distal 6 cm of either malleolus, tenderness at the base of the fifth metatarsal or navicular, or inability to bear weight for four unassisted steps both immediately after injury and in the emergency department.
Diagnostic Evaluation
Radiographs should be obtained when fracture is suspected. Stress radiographs are rarely useful acutely and should not be routinely ordered unless requested by a consultant.
Differential Considerations
Ankle fracture or dislocation, Achilles tendon rupture, Maisonneuve fracture, os trigonum fracture, fifth metatarsal fracture, talar dome lesion, and peroneal tendon injury should be considered.
Initial Management
Prehospital care includes immobilization as needed to reduce pain and prevent further injury.
Emergency Department Care
Initial therapy focuses on preventing further injury and avoiding painful weight bearing using rest, ice, compression, and elevation. Treatment aims to reduce pain and restore function without chronic instability. Evidence supports early mobilization with functional treatment. Grade I and II sprains are managed with elastic bandaging combined with an air-stirrup or gel splint and weight bearing as tolerated. Grade III sprains or those with severe pain may benefit from brief immobilization followed by early functional rehabilitation and orthopedic referral. Crutches may be used initially for comfort. Once swelling and pain resolve, strengthening and proprioceptive exercises improve recovery and reduce reinjury. Return to sports should occur only when running and directional changes are pain free. Bracing or taping reduces recurrence in high-risk sports.
Pharmacologic Therapy
NSAIDs are effective for acute pain control, including oral ibuprofen or topical diclofenac gel. Opioid analgesics may be required for severe pain.
Disposition And Follow-Up
Isolated ankle sprains do not require admission and may be discharged with appropriate treatment, prescriptions, and aftercare instructions. Copies of radiographs may assist early follow-up. Grade I and II sprains should follow up with primary care within 1–2 weeks, while grade III sprains and syndesmotic injuries require orthopedic or sports medicine evaluation within 7–10 days.
Clinical Pearls And Common Errors
Appropriate application of the Ottawa Ankle Rules reduces unnecessary imaging. Functional treatment with early mobilization shortens recovery time, while prolonged immobilization increases the risk of chronic pain and recurrent instability.
Core Description
Ankle sprains involve injury to the ligamentous stabilizers of the ankle joint, a hinge joint formed by the tibia, fibula, and talus. Injury severity ranges from ligament stretching with microscopic damage (grade I), to partial tearing (grade II), to complete ligament rupture (grade III).
Mechanisms And Causes
Ankle sprains most often result from forced inversion or eversion, frequently during sports or collisions. Approximately 85–90% involve the lateral ligament complex, including the anterior talofibular, posterior talofibular, and calcaneofibular ligaments. Inversion injury most commonly affects the anterior talofibular ligament; calcaneofibular ligament injury is more likely when the ankle is in neutral position, while isolated posterior talofibular ligament injury is rare. Deltoid ligament injuries typically result from eversion and are often associated with medial malleolar avulsion or talar insertion injury; isolated deltoid injuries are uncommon and should raise concern for associated lateral malleolus or proximal fibular (Maisonneuve) fracture. Syndesmotic sprains involve the distal tibiofibular ligaments, occur frequently in collision sports, and carry higher morbidity with risk of long-term complications. In children younger than 10 years, traumatic ankle pain with normal radiographs most commonly represents a Salter–Harris type I fracture, as the physis is weaker than surrounding ligaments.
Clinical Presentation
Patients usually present with ankle pain, swelling, and difficulty bearing weight. History should include time and mechanism of injury, presence of a pop or crack, prior ankle trauma, relevant medical conditions, treatments attempted before arrival, and ability to bear weight at the scene and in the emergency department. Physical examination focuses on detecting instability and associated injury, including bony tenderness along the posterior edges of the medial and lateral malleoli and the base of the fifth metatarsal, distal neurovascular status, and comparison of range of motion with the uninjured side. Stress testing is often limited by pain. The squeeze test helps identify syndesmotic injury when compression of the tibia and fibula at the midcalf reproduces ankle pain.
Imaging Decision Strategy
The Ottawa Ankle Rules provide a validated approach for determining the need for radiographs. Imaging is recommended for bony tenderness at the posterior edge or distal 6 cm of either malleolus, tenderness at the base of the fifth metatarsal or navicular, or inability to bear weight for four unassisted steps both immediately after injury and in the emergency department.
Diagnostic Evaluation
Radiographs should be obtained when fracture is suspected. Stress radiographs are rarely useful acutely and should not be routinely ordered unless requested by a consultant.
Differential Considerations
Ankle fracture or dislocation, Achilles tendon rupture, Maisonneuve fracture, os trigonum fracture, fifth metatarsal fracture, talar dome lesion, and peroneal tendon injury should be considered.
Initial Management
Prehospital care includes immobilization as needed to reduce pain and prevent further injury.
Emergency Department Care
Initial therapy focuses on preventing further injury and avoiding painful weight bearing using rest, ice, compression, and elevation. Treatment aims to reduce pain and restore function without chronic instability. Evidence supports early mobilization with functional treatment. Grade I and II sprains are managed with elastic bandaging combined with an air-stirrup or gel splint and weight bearing as tolerated. Grade III sprains or those with severe pain may benefit from brief immobilization followed by early functional rehabilitation and orthopedic referral. Crutches may be used initially for comfort. Once swelling and pain resolve, strengthening and proprioceptive exercises improve recovery and reduce reinjury. Return to sports should occur only when running and directional changes are pain free. Bracing or taping reduces recurrence in high-risk sports.
Pharmacologic Therapy
NSAIDs are effective for acute pain control, including oral ibuprofen or topical diclofenac gel. Opioid analgesics may be required for severe pain.
Disposition And Follow-Up
Isolated ankle sprains do not require admission and may be discharged with appropriate treatment, prescriptions, and aftercare instructions. Copies of radiographs may assist early follow-up. Grade I and II sprains should follow up with primary care within 1–2 weeks, while grade III sprains and syndesmotic injuries require orthopedic or sports medicine evaluation within 7–10 days.
Clinical Pearls And Common Errors
Appropriate application of the Ottawa Ankle Rules reduces unnecessary imaging. Functional treatment with early mobilization shortens recovery time, while prolonged immobilization increases the risk of chronic pain and recurrent instability.
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