Summary Ankle fractures are very common injuries to the ankle which generally occur due to a twisting mechanism. Diagnosis is made with plain radiographs of the ankle. Treatment can be nonoperative or operative depending on fracture displacement, ankle stability, presence of syndesmotic injury, and patient activity demands. EPIDEMIOLOGY Incidence 187 per 100,000 adults annually Demographics bimodal distribution young, active login to view 1 more bullet elderly login to view 1 more bullet Location breakdown by fracture type isolated malleolus fracture 70% bimalleolar 20% trimalleolar 7% Risk Factors male younger age obesity smoking alcohol consumption Etiology Pathophysiology mechanism of injury twisting injury Associated conditions orthopedic open fractures (2%) syndesmotic injury (10%) chondral injury peroneal tendon tears (4%) Anatomy Osteology modified hinge joint consisting of tibia, fibula, and talus tibial plafond and talus are broader anteriorly and wider laterally Ligaments 3 ligamenotus complex stabilize ankle deltoid login to view 7 more bullets lateral ligament complex login to view 9 more bullets syndesmosis login to view 12 more bullets Tendons peroneal tendons peroneus longus and brevis pass along posterior groove of lateral malleolus at risk with posterolateral fibular plating posterior tibial tendon located posterior and inferior at the level of the medial malleolus at risk with posterior placement of medial malleolus screws Neurovascular structures anterior tibial artery and deep peroneal nerve course over anterior ankle between EDL and EHL at risk with anterior approach posterior tibial artery and tibial nerve course posterior to medial malleolus between FDL and FHL at risk with posteromedial approach superficial peroneal nerve crosses anteriorly over fibula about distal 1/3 at risk with posterolateral and direct lateral approach to fibula proximally and with anterior/anterolateral approaches sural nerve at risk with posterolateral and direct lateral approach to fibula Biomechanics deltoid ligament (deep portion) primary restraint to anterolateral talar displacement fibula acts as buttress to prevent lateral displacement of talus trapezoidal shape of talus dorsiflexion results in fibula ER and lateral translation, accommodating anteriorly wider talus plantarflexion results in narrower, posterior aspect of the talus leading to IR of talus Classification Lauge-Hansen based on combination of foot position and direction of force applied at the time of injury has been shown to predict the observed (via MRI) ligamentous injury in less than 50% of operatively treated fractures Lauge-Hansen Classification Supination - Adduction (SAD) 1. Talofibular sprain or distal fibular avulsion2. Vertical medial malleolus and impaction of anteromedial distal tibia Supination - External Rotation (SER) 1. Anterior tibiofibular ligament sprain2. Lateral short oblique fibula fracture (anteroinferior to posterosuperior)3. Posterior tibiofibular ligament rupture or avulsion of posterior malleolus4. Medial malleolus transverse fracture or disruption of deltoid ligament Pronation - Abduction (PAB) 1. Medial malleolus transverse fracture or disruption of deltoid ligament2. Anterior tibiofibular ligament sprain3. Transverse comminuted fracture of the fibula above the level of the syndesmosis Pronation - External Rotation (PER) 1. Medial malleolus transverse fracture or disruption of deltoid ligament2. Anterior tibiofibular ligament disruption3. Lateral short oblique or spiral fracture of fibula (anterosuperior to posteroinferior) above the level of the joint4. Posterior tibiofibular ligament rupture or avulsion of posterior malleolus Danis-Weber (location of fibular fracture) A - infrasyndesmotic (generally not associated with ankle instability) B - transsyndesmotic C - suprasyndesmotic AO / OTA 44A - infrasyndesmotic 44B - transsyndesmotic 44C - suprasyndesmotic Anatomic / Descriptive isolated medial malleolar isolated lateral malleolar isolated posterior malleolar bimalleolar-equivalent bimalleolar trimalleolar Variants Bosworth fracture-dislocation hyperplantarflexion injury (6%) curbstone fracture avulsion fracture of posterior tibia resulting from tripping LeFort–Wagstaffe fracture AITFL avulsion off anterior fibular tubercle usually seen with SER-type fracture patterns Tillaux–Chaput fracture AITFL avulsion of anterior tibial margin (tibial counterpart of LeFort–Wagstaffe fracture) PRESENTATION Symptoms severe ankle pain difficulty or inability to ambulate Physical exam inspection and palpation ecchymosis and swelling around the ankle login to view 1 more bullet deformity with displaced fractures palpate proximal fibula for Maisonneuve fracture soft tissue assessment login to view 4 more bullets motion ankle motion generally limited neurovascular peripheral vascular disease diabetic neuropathy Imaging Radiographs recommended views ankle series login to view 3 more bullets dynamic stress views login to view 6 more bullets full-length tibia radiographs login to view 1 more bullet optional comparison view of contralateral ankle weight bearing views login to view 1 more bullet findings syndesmotic injury login to view 11 more bullets lateral malleolus fractures login to view 5 more bullets posterior malleolus fractures login to view 3 more bullets CT scan indications trimalleolar ankle fracture login to view 3 more bullets supination-adduction injury login to view 1 more bullet views axial and sagittal views most useful to assess posterior malleolus findings size and shape of posterior malleolus fragment entrapped loose fragments impaction comminution MRI Indications evaluate for soft tissue or cartilaginous injuries findings deltoid injury syndesmotic injury lateral ankle ligament complex peroneal tendon injury chondral lesions of talus DIFFERENTIAL Ankle sprain may be able to bear weight positive anterior drawer or talar tilt test radiographs without fracture Syndesmotic injury positive Hopkin's squeeze test increased medial clear space or tibiofibular diastasis on stress view lambda sign on MRI Achilles tendon rupture palpable gap over achilles inability or weakness with plantar flexion increased resting dorsiflexion when prone with knees bent positive Thompson's test Pilon fracture high energy, axial load significant articular involvement CT showing 4 common components of pilon Chaput fragment, Volkmann fragment, medial malleolus, central impaction Subtalar dislocation high energy with extensive soft tissue injury, 25% open x-ray shows dislocation of talus from calcaneous or navicular bone Treatment Nonoperative indications stable ankle fracture login to view 4 more bullets unfit for surgery modalities short-leg AO splint short-leg cast CAM boot Operative open reduction internal fixation indications login to view 7 more bullets technique login to view 20 more bullets outcomes login to view 12 more bullets postoperative rehabilitation login to view 2 more bullets external fixation indications login to view 4 more bullets modalities login to view 3 more bullets outcomes login to view 1 more bullet Isolated Medial Malleolus Fracture Nonoperative indications isolated medial malleolus fracture without talar shift avulsion tip fracture login to view 1 more bullet technique NWB for 4-6 weeks outcomes good outcomes with >95% union rate for isolated injury Operative ORIF indications login to view 1 more bullet technique login to view 8 more bullets outcomes login to view 1 more bullet Isolated Lateral Malleolus Fracture Nonoperative indications stable mortise with no talar shift login to view 2 more bullets distal fibular stress fractures technique immediate WBAT in CAM boot brief period of immobilization in splint Operative open reduction and internal fixation (ORIF) indications login to view 2 more bullets technique login to view 12 more bullets outcomes login to view 1 more bullet Bimalleolar-Equivalent Fracture (deltoid ligament tear with fibular fracture) Nonoperative indications low demand and unable to tolerate surgery Operative ORIF of lateral malleolus +/- syndesmotic fixation indications login to view 1 more bullet technique login to view 3 more bullets outcomes login to view 1 more bullet Bimalleolar (MEDIAL AND LATERAL) Fracture Nonoperative indications low demand and unable to undergo surgical intervention Operative ORIF indications login to view 1 more bullet fibula technique login to view 3 more bullets medial malleolus technique login to view 6 more bullets Posterior Malleolar Fracture Nonoperative indications < 25% of articular surface involved login to view 1 more bullet < 2 mm articular stepoff stable syndesmosis Operative ORIF indications login to view 4 more bullets technique login to view 17 more bullets Bosworth Fracture-Dislocation Overview rare fracture-dislocation of ankle where fibula is entrapped behind tibia and is irreducible posterolateral ridge of the distal tibia hinders reduction of the fibula open reduction of fibula and internal fixation is required Hyperplantarflexion Variant Overview fracture-dislocation of the ankle due to hyperplantarflexion main feature is a vertical shear fracture of the posteromedial tibial rim "spur sign" is pathognomonic double cortical density at the inferomedial tibial metaphysis 79% sensitive, 100% specific ORIF of posterior malleolus with antiglide plating Open Ankle Fracture Operative emergent operative debridement and ORIF indicated if soft tissue amendable primary closure at index procedure can be performed in appropriately-selected grade I, II, and IIIA open fractures in otherwise healthy patients without gross contamination external fixation indications login to view 2 more bullets Associated Syndesmotic Injury Overview 10% of all ankle fractures higher incidence with higher fibula fractures login to view 3 more bullets fixation usually not required when fibula fracture within 4.5 cm of plafond Evaluation static views tibiofibular clear space login to view 1 more bullet tibiofibular overlap medial clear space dynamic views manual external-rotation stress login to view 3 more bullets gravity-stress login to view 2 more bullets Cotton/hook test login to view 2 more bullets Treatment syndesmotic screw or suture fixation indications login to view 3 more bullets technique login to view 22 more bullets postoperative login to view 3 more bullets Diabetic Ankle Fractures (with or without Neuropathy) Pathophysiology poor circulation impairs wound and fracture healing loss of protective sensation poor bone quality Nonoperative treatment stable unimalleolar ankle fractures poor outcomes and increased risk for: loss of reduction (greatest risk) Charcot arthropathy malunion nonunion Operative treatment risks prolonged healing high risk of hardware failure high risk of infection lower functional outcomes need for future amputation enhanced fixation multiple quadricortical syndesmotic screws (even in the absence of syndesmotic injury) tibiotalar Steinmann pins or hindfoot nailing ankle spanning external fixation augment with intramedullary fibula K-wires stiffer, more rigid fibular plates (instead of 1/3 tubular plates) login to view 2 more bullets recent evidence supports acute or subacute tibiotalocalcaneal fusion in these patients delay weightbearing maintain non-weightbearing postop for 8-12 weeks (instead of 4-8 weeks in normal patients) Complications Nonoperative ulceration from cast delayed union or nonunion malunion post-traumatic arthritis DVT (5%) ankle stiffness Operative wound problems (~5%) deep infections (1-2%) up to 20% in diabetic patients login to view 1 more bullet malunion articular impaction of tibial plafond in SAD injuries should be addressed at time of surgery corrective osteotomy requires obtaining anatomic fibular length and mortise correction for optimal outcomes post-operative stiffness Loss of dorsiflexion with posterior fixation post-traumatic arthritis rare with anatomic reduction and fixation very common in "log-splitter" type injuries (trans-syndesmotic fracture-dislocations in which the talus is driven into the distal tibiofibular articulation) neurologic injury superficial peroneal nerve injury (10-15%) login to view 2 more bullets hardware irritation hardware removal ~20% risk factors login to view 3 more bullets peroneal tendonitis (5-40%) login to view 4 more bullets posterior tibial tendonitis login to view 1 more bullet complex regional pain syndrome PROGNOSIS Excellent for stable ankle fractures treated nonoperatively Outcomes following operative treatment generally very favorable 90% mild/no ankle pain with minimal limitations and near full functional recovery at 1 yr Positive predictors for good outcomes login to view 4 more bullets Risk factors for adverse outcomes older age osteoporosis diabetes peripheral vascular disease female higher ASA smoking alcohol use lower level of education