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 highest incidence in male is between 15-24 years of age elderly highest incidence in females is 75-84 years of age 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 2 components superficial extends from medial malleolus to broad insertion onto navicular, sutentaculum tali, and talus resists hindfoot eversion deep extends from medial malleolus to talus resists ER of talus lateral ligament complex 3 components anterior talofibular ligament (ATFL) primary restraint to anterior displacement, IR, and inversion of talus most frequently injured lateral ligament calcaneofibular (CFL) deep to peroneal tendons 2nd most commonly injured posterior talofibular ligament (PTFL) strongest ligament of lateral complex and least likely to be disrupted syndesmosis 5 components anterior inferior tibiofibular ligament (AITFL) originates from anterolateral tubercle of distal tibia (Chaput) inserts anteriorly onto lateral malleolus (Wagstaffe) posterior inferior tibiofibular ligament (PITFL) broad origin from posterior tibia (Volkmann's fragment) inserts onto posterior aspect of lateral malleolus strongest component of syndesmosis intraosseous ligament (IOL) distal continuation of intraosseous membrane intraosseous membrane inferior transverse ligament (ITL) 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 medial sided swelling, tenderness, and ecchymosis not sensitive for medial stability deformity with displaced fractures palpate proximal fibula for Maisonneuve fracture soft tissue assessment soft tissue injury fracture blisters skin tenting open wounds motion ankle motion generally limited neurovascular peripheral vascular disease diabetic neuropathy Imaging Radiographs recommended views ankle series AP lateral mortise dynamic stress views manual stress view most appropriate stress radiograph to assess competency of deltoid ligament assess on mortise view foot dorsiflexed and ER with tibia stabilized more sensitive to injury than medial tenderness, ecchymosis, or edema gravity stress radiograph is equivalent to manual stress radiograph full-length tibia radiographs rule out Maisonneuve-type fracture optional comparison view of contralateral ankle weight bearing views difficult for patients to tolerate in acute setting findings syndesmotic injury decreased tibiofibular overlap measure at point of maximum overlap normal >6 mm on AP view normal >1 mm on mortise view it has also been reported that there is no actual correlation between syndesmotic injury and tibiofibular clear space or overlap measurements increased medial clear space normal ≤ 4 mm on mortise or stress view medial clear space of >5mm with external rotation stress applied to a dorsiflexed ankle is predictive of deep deltoid disruption increased tibiofibular clear space measure clear space 1 cm above joint normal <6 mm on both AP and mortise views lateral malleolus fractures talocrural angle bisection of line through tibial anatomical axis and line through tip of both malleoli shortening of lateral malleoli fractures can lead to increased talocrural angle talocrural angle is not 100% reliable for estimating restoration of fibular length can also utilize realignment of the medial fibular prominence with the tibiotalar joint posterior malleolus fractures double contour sign misty mountains sign spur sign CT scan indications trimalleolar ankle fracture operative planning 25% of surgeons would change operative technique after CT assess morphology of posterior malleolus supination-adduction injury assess for anteromedial impaction of tibial plafond and talar articular cartilage injury 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 isolated stable medial malleolus fracture isolated stable lateral malleolus fracture avulsion tip fractures of medial or lateral malleolus posterior malleolar fracture with < 25% joint involvement or < 2mm step-off unfit for surgery modalities short-leg AO splint short-leg cast CAM boot Operative open reduction internal fixation indications any talar displacement bimalleolar or bimalleolar-equivalent fracture posterior malleolar fracture with > 25% or > 2mm step-off Maisonneuve fracture Bosworth fracture-dislocations open fractures symptomatic malleolar nonunions technique goal of treatment is stable anatomic reduction with restoration of mortise see fracture patterns below for specific treatment positioning supine direct reduction of medial and lateral malleolus fractures indirect reduction of posterior malleolus syndesmotic fixation prone or lateral facilitates direct reduction of posterior malleolus approach direct lateral approach to fibula common approach for fibula ORIF syndesmotic fixation syndesmotic fixation posterolateral approach to ankle concomitant access to posterior fibula and posterior malleolus prone or lateral posteromedial approach to ankle access to medial malleolus and posterior malleolus direct medial approach to ankle common approach for medial malleolus ORIF outcomes overall success rate of 90% prolonged recovery expected (2 years to obtain final functional result) anatomic reduction is considered most important factor for satisfactory outcome 1 mm shift of talus leads to 42% decrease in tibiotalar contact area worse outcomes associated with: decreased level of education smoking alcohol use presence of medial malleolar fracture ORIF superior to closed treatment of bimalleolar fractures restoration of marginal impaction of tibial plafond in SA ankle fracture leads to optimal functional outcomes improved incisional perfusion with Allgöwer-Donati sutures postoperative rehabilitation proper braking response time (driving) returns to baseline at 9 weeks after surgery braking travel time is significantly increased until 6 weeks after initiation of weight bearing in both long bone and periarticular fractures of lower extremity external fixation indications staging procedure severe open fractures with gross contamination poor soft tissue requiring close monitoring unstable reduction modalities ankle-spanning external fixator circular frame hybrid outcomes lower risk of redislocation and skin complication in ankle fracture dislocation vs splint Isolated Medial Malleolus Fracture Nonoperative indications isolated medial malleolus fracture without talar shift avulsion tip fracture deep deltoid inserts on posterior colliculus technique NWB for 4-6 weeks outcomes good outcomes with >95% union rate for isolated injury Operative ORIF indications any talar shift (static or stress view) technique lag screw fixation lag screw fixation stronger if placed perpendicular to fracture line antiglide plate with lag screw best for vertical shear fractures biomechanically superior to unicortical/bicortical screw fixation alone tension band fixation fragment too small poor bone quality outcomes bicortical 3.5 mm fully-threaded screw (lag by technique) superior to unicortical 4.0 mm partially-threaded screw (lag by design) Isolated Lateral Malleolus Fracture Nonoperative indications stable mortise with no talar shift > 4-5 mm of medial clear space widening on stress views considered unstable recent studies show deep deltoid intact with 8-10 mm of widening on stress view technique immediate WBAT in CAM boot brief period of immobilization in splint Operative open reduction and internal fixation (ORIF) indications presence of talar shift on static or stress view (bimalleolar equivalent) >3 mm displacement technique plate lateral one-third tubular or anatomic distal fibular plate stiffest fixation construct for the fibula is a locking plate posterolateral one-third tubular plate (antiglide mode) posterior antiglide plating is biomechanically superior to lateral plate disadvantage of peroneal tendon irritation if plate too distal retrograde intramedullary fixation several implant choices newer implants have improved axial and rotational control with distal/proximal fixation useful for poor soft-tissue envelopes or high risk for wound-healing complication outcomes similar outcomes with operative and non-operative treatment if stable mortise 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 lateral malleolus fracture with talar shift (static or stress view) technique assess syndesmotic stability after fixation of lateral malleolus not necessary to repair medial deltoid ligament explore medially if unable to reduce mortise and deltoid ligament potentially interposed outcomes lower rate of nonunion and fracture displacement with operative treatment Bimalleolar (MEDIAL AND LATERAL) Fracture Nonoperative indications low demand and unable to undergo surgical intervention Operative ORIF indications any displacement or talar shift (static or stress view) fibula technique lateral plate posterolateral plate retrograde intramedullary fixation medial malleolus technique antiglide plate tension band wiring lag screws screws perpendicular to fracture plane Posterior Malleolar Fracture Nonoperative indications < 25% of articular surface involved size should be calculated on CT since plain radiographs are unreliable < 2 mm articular stepoff stable syndesmosis Operative ORIF indications > 25% of articular surface > 2 mm articular stepoff syndesmotic instability posterior subluxation of talus technique approach posterolateral approach interval between FHL and peroneal tendons common approach since posterior malleolus fractures are frequently posterolateral posteromedial approach percutaneous decision of approach will depend on location of fracture, degree of displacement, and need for fibular fixation fixation methods antiglide plate percutaneous A to P lag screws fix fibula first must be well reduced syndesmosis injury stiffness of syndesmosis restored to 70% normal with isolated fixation of posterior malleolus vs 40% with isolated syndesmosis fixation PITFL may remain attached to posterior malleolus and syndesmotic stability may be restored with isolated posterior malleolar fixation stress examination of syndesmosis still required after posterior malleolar fixation 40-90% of distal third spiral tibia fractures have an associated posterior malleolus fracture 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 significant soft tissue compromise unstable fracture in splint/cast Associated Syndesmotic Injury Overview 10% of all ankle fractures higher incidence with higher fibula fractures Weber A fracture <10% Weber B fractures ~40-50% Weber C fracture patterns (>80%) fixation usually not required when fibula fracture within 4.5 cm of plafond Evaluation static views tibiofibular clear space measure tibiofibular clear space 1 cm above joint tibiofibular overlap medial clear space dynamic views manual external-rotation stress abduction/external rotation stress of dorsiflexed foot lateral stress radiograph has greater interobserver reliability than an AP/mortise stress film instability of the syndesmosis is greatest in the anterior-posterior direction gravity-stress patient placed in lateral decubitus position similar effectiveness to manual ER stress test Cotton/hook test intraoperative assessment bone hook around fibula used to pull while placing counter traction on tibia Treatment syndesmotic screw or suture fixation indications widening of medial clear space tibiofibular clear space (AP) greater than 5 mm tibiofibular overlap (mortise) narrowed technique length and rotation of fibula must be accurately restored "Dime sign"/Shentons line to determine length of fibula fixing lateral and/or posterior malleolus first my obviate need for syndesmotic fixation outcomes are strongly correlated with anatomic reduction placing reduction clamp on middle medial tibial ridge and the lateral fibular ridge at the level of the syndesmosis (1-2 cm proximal to mortise) will achieve reliable anatomic reduction maximum dorsiflexion not required during screw placement (over-tightening) open reduction required if closed reduction unsuccessful or questionable Improved reduction with direct visualization of the syndesmosis at the level of the joint one or two cortical screw(s) or suture-button devices 2-4 cm above joint angled posterior to anterior 20-30 degrees (fibula posterior to tibia) controversies number of screws 1 or 2 most commonly reported number of cortices 3 or 4 most commonly reported size of screws 3.5 mm or 4.5 mm screws implant suture button has lower rate of malreduction and reoperation rate than screws hardware removal with screws no difference in outcomes seen with hardware maintenance (breakage or loosening) or removal at 1 year outcome may be worse with maintenance of intact screws postoperative screws should be maintained in place for at least 8-12 weeks must remain non-weight bearing, as screws are not biomechanically strong enough to withstand forces of ambulation any postoperative malalignement or widening should be treated with open debridement, reduction, and fixation 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) compression plates small fragment locking plates 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 largest risk factor for diabetic patients is presence of peripheral neuropathy 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%) At risk with lateral approach to distal fibula, posterolateral, and anterior/anterolateral approaches Two terminal nerve branches that innervate dorsum of the foot hardware irritation hardware removal ~20% risk factors younger age women longer operative time peroneal tendonitis (5-40%) posterolateral plating of fibula risk factors distal placement of fibula plate protruding screw head in most distal hole of fibula plate posterior tibial tendonitis at risk with posterior medial malleolus screw placement 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 age <40 male ASA 1 or 2 absence of diabetes Risk factors for adverse outcomes older age osteoporosis diabetes peripheral vascular disease female higher ASA smoking alcohol use lower level of education