summary Ankle Sprains are very common twisting injuries to the ankle that are the most common reason for missed athletic participation. Diagnosis can be made clinically with swelling and ecchymosis of the ankle and pain with range of motion. Radiographs are only indicated when clinical examination meets criteria (Ottawa ankle rules). Treatment usually includes a brief period of immobilization followed by early functional physical therapy. Rarely, operative management is indicated in the setting of syndesmosis injury with tibiofibular diastasis or chronic ankle instability with recurrent sprains. Epidemiology Incidence ankle sprains are the most common reason for missed athletic participation Demographics most common injury in dancers Risk factors patient-related limited dorsiflexion, decreased proprioception, balance deficiency environmental-related indoor-court sports have the highest risk (basketball, volleyball) Etiology Pathophysiology Mechanism of injury Inversion type ankle injury on a plantarflexed foot Recurrent ankle sprains can lead to functional instability Ankle sprains consist of high ankle sprain syndesmosis injury 1-10% of all ankle sprains low ankle sprain(this topic) ATFL and CFL injury >90% of all ankle sprains Associated injuries/conditions include osteochondral defects peroneal tendon injuries subtle cavovarus foot intraarticular pathology anterior/anterolateral synovitis (most common) osteochondral defects of the talus anterior ankle impingement deltoid ligament injury (isolated deltoid ligament injuries are very rare) superficial deltoid: limits talar abduction deep deltoid: limits external rotation initally treated conservatively, but may require reconstruction if patient continues to have instability complex regional pain syndrome fractures 5th metatarsal base anterior process of calcaneus lateral or posterior process of the talus Anatomy Ligamentous anatomy of the ankle ATFL most commonly involved ligament in low ankle sprains mechanism is plantar flexion and inversion physical exam shows drawer laxity in plantar flexion CFL 2nd most common ligament injury in lateral ankle sprains mechanism is dorsiflexion and inversion physical exam shows drawer laxity in dorsiflexion subtalar instability can be difficult to differentiate from posterior ankle instability because the CFL contributes to both PTFL less commonly involved Classification Classification of Low Ankle Sprains Ligament disruption Ecchymosis and swelling Pain with weight bearing Grade I None Minimal Normal Grade II Stretch without tear Moderate Mild Grade III Complete tear Severe Severe Presentation Symptoms pain with weight bearing (may or may not be able to bear weight) swelling and ecchymosis recurrent instability catching or popping sensation may occur following recurrent sprains Physical exam focal tenderness and swelling over-involved ligament(s) anterior drawer test looks for excessive anterior displacement of talus relative to tibia limited usefulness in acute setting ATFL best tested in plantarflexion, CFL in dorsiflexion Talar tilt test excessive ankle inversion (> 15 degrees) compared to contralateral side indicated injury to ATFL and CFL Imaging Radiographs indications for radiographs with an ankle injury include (Ottawa ankle rules) inability to bear weight medial or lateral malleolus point tenderness 5MT base tenderness navicular tenderness 96-99% sensitive in ruling out ankle fracture radiographic views to obtain standard ankle series (weight bearing) AP lateral ATFL injury suggested with anterior talar translation mortise ER rotation stress view useful to diagnosis syndesmosis injury in high ankle sprain look for asymmetric mortise widening medial clear space widening > 4mm tibiofibular clear space widening of 6 mm varus stress (talar tilt) view used to diagnose injury to CFL measures ankle instability by looking at talar tilt MRI indications consider MRI if pain persists for 6-8 weeks following sprain useful to evaluate peroneal tendon pathology osteochondral injury syndesmotic injury Treatment Nonoperative RICE, elastic wrap to minimize swelling, followed by therapy indications Grade I, II, and III injuries technique initial immobilization may require short period (approx. 1 week) of weight-bearing immobilization in a walking boot, aircast or walking cast, but early mobilization facilitates a better recovery grade III sprains may benefit from 10 days of casting and nonweightbearing therapy early phase early functional rehabilitation begins with motion exercises and progresses to strengthening, proprioception, and activity-specific exercises strengthening phase once swelling and pain have subsided and patient has full range of motion begin neuromuscular training with a focus on peroneal muscles strength and proprioception training a functional brace that controls inversion and eversion is typically used during the strengthening period and used as prophylactic treatment during high-risk activities thereafter outcomes early functional rehabilitation allows for the quickest return to physical activity supervised physical therapy has shown a benefit in early follow-up but no difference in the long term Operative anatomic reconstruction vs. tendon transfer with tenodesis indications Grade I-III that continue to have pain and instability despite extensive nonoperative management Grade I-III with a bony avulsion technique (see below) arthroscopy indications recurrent ankle sprains and chronic pain caused by impingement lesions anteriorinferior tibiofibular ligament impingement posteromedial impingement lesion of ankle often used prior to reconstruction to evaluate for intra-articular pathology procedure debride impinging tissue Techniques Gould modification of Brostrom anatomic reconstruction procedure an anatomic shortening and reinsertion of the ATFL and CFL reinforced with inferior extensor retinaculum and distal fibular periosteum (Gould modification) results good to excellent results in 90% consider arthroscopic evaluation prior to reconstruction for intra-articular evaluation Tendon transfer and tenodesis (Watson-Jones, Chrisman-Snook, Colville, Evans) procedure a nonanatomic reconstruction using a tendon transfer technique any malalignment must be corrected to achieve success during a lateral ligament reconstruction Coleman block testing used to distinguish between fixed and flexible hindfoot varus results subtalar stiffness is a common complication Rehabilitation Return to play depends on, grade of sprain, syndesmosis injury, associated injuries, and compliance with rehab Return to play Grade I 1-2 weeks Grade II 1-2 weeks Grade III 3-4 weeks High ankle (immobilization) 5-6 weeks High ankle (screw fixation) Season Prevention prevention techniques in athletes with prior sprains includes semirigid orthosis patients who demonstrate cavovarus alignment benefit from a brace with lateral hindfoot/forefoot wedging and first metatarsal recess evertor muscle (peroneals) strengthening proprioception exercises season long prevention program Complications Pain and instability Incidence up to 30% continue to experience symptoms following and acute ankle sprain Risk factors most common cause of chronic pain is a missed injury, including missed fractures (anterior process of calcaneus, lateral or posterior process of the talus, 5th metatarsal) osteochondral lesion injuries to the peroneal tendons injury to the syndesmosis tarsal coalition impingement syndromes Stretch neurapraxia Neuropathic pain in the distribution of the affected nerve Prognosis Natural history pain decreases rapidly during the first 2 weeks after injury 5-33% reports some pain at 1 year increased risk of a sprain to ipsilateral and contralateral ankle