Summary Ankle Fractures are very common fractures in the pediatric population that are usually caused by direct trauma or a twisting injury. Diagnosis is made with plain radiographs of the ankle. A CT scan may be required to further characterize the fracture pattern and for surgical planning. Treatment may be nonoperative or operative depending on patient age, fracture displacement, and fracture morphology. Epidemiology Incidence accounts for 25-40% of all physeal injuries (second most common) accounts for 5% of all pediatric fractures Demographics more common in males 2:1 typically occur between 8-15 years-old Risk factors participation in sports increased BMI Anatomic location pediatric ankle fractures are a common injury that includes SH type I SH type II SH type III Tillaux fractures medial malleolus fractures SH type IV triplane fractures medial malleolus fractures Pathophysiology Mechanism of injury direct trauma twisting injury, i.e. rotation about a planted foot and ankle Anatomy Physeal considerations distal tibial physis accounts for 35-40% of overall tibial growth and 15-20% of overall lower extremity growth rate of growth is 3-4 mm/year growth continues until 14 years in girls and 16 years in boys closure occurs during an 18 month transitional period pattern of closure occurs in a predictable pattern: central > anteromedial > posteromedial > lateral distal fibular physis closure occurs 12-24 months after closure of distal tibial physis Ligaments (origins are distal to the physes) medial ligaments deltoid ligament superficial anterior talotibial ligament posterior talotibial ligament tibionavicular ligament calcaneotibial ligament deep primary restraint to lateral displacement of talus lateral ligaments anterior talofibular ligament (ATFL) calcaneofibular ligament (CFL) posterior talofibular ligament (PTFL) syndesmosis ligaments anterior inferior tibiofibular ligament (AITFL) extends from anterior aspect of lateral distal tibial epiphysis (Chaput tubercle) to the anterior aspect of distal fibula (Wagstaffe tubercle) plays an important role in transitional fractures (Tillaux, Triplane) posterior inferior tibiofibular ligament (PITFL) extends from posterior aspect of lateral distal tibial epiphysis (Volkmanns tubercle) to posterior aspect of distal fibula inferior transverse ligament (ITL) extends from posterior distal fibula across posterior aspect of distal tibial articular surface functions as posterior labrum of the ankle interosseous ligament (IOL) continuous with interosseous membrane located between AITFL and PITFL Classification Anatomic Salter-Harris Classification Type I 15% Fracture extends through the physis Type II 45% Fracture extends through the physis and exits through the metaphysis, forming a Thurston-Holland fragment Type III 25% Fracture extends through the physis and exits through the epiphysis Seen with medial malleolus fractures and Tillaux fractures Increased risk of physeal arrest Type IV 25% Fracture involves the physis, metaphysis and epiphysis Can occur with lateral malleolus fractures, usually SH I or II Seen with medial malleolus shearing injuries and triplane fractures Increased risk of physeal arrest Type V 1% Crush injury to the physis Can be difficult to identify on initial presentation (diagnosis is usually made when growth arrest is seen on follow-up radiographs) Increased risk of physeal arrest Type VI rare Perichondral ring injury Results from open injury (i.e. lawnmower) or iatrogenic during surgical dissection Mechanism of injury Dias & Tachdjian Classification (patterned off adult Lauge-Hansen classification) Supination-inversion Grade 1 Adduction or inversion force avulses the distal fibular epiphysis (SH I or II) Occasionally can be transepiphyseal Rarely occurs with failure of lateral ligaments Grade 2 Further inversion leads to distal tibial fracture (usually SH III or IV, but can be SH I or II) Occasionally can cause fracture through medial malleolus below the physis Supination-plantarflexion Plantarflexion force displaces the tibial epiphysis posteriorly (SH I or II) Thurston-Holland fragment is composed of the posterior tibial metaphysis and displaces posteriorly Occurs without fibular fracture Can be difficult to see on AP radiograph Supination-external rotation Grade 1 External rotation force leads to distal tibial fracture (SH II) Distal fragment displaces posteriorly Thurston-Holland fragment displaces posteromedially Easily visible on AP radiograph (fracture line extends proximally and medially) Grade 2 Further external rotation leads to low spiral fracture of fibula (anteroinferior to posterosuperior) Pronation/eversion-external rotation External rotation force leads to distal tibial fracture (SH I or II) and transverse fibula fracture Occasionally can be transepiphyseal medial malleolus fracture (SH II) Distal tibial fragment displaces laterally Thurston-Holland fragment is lateral or posterolateral distal tibal metaphysis Can be associated with diastasis of ankle joint Axial compression Leads to SH V injury of distal tibial physis Can be difficult to identify on initial presentation (diagnosis typically made when growth arrest is seen on follow-up radiographs) Presentation Symptoms common symptoms pain inability to bear weight Physical exam inspection ecchymosis & swelling deformity (if displaced) focal tenderness distal fibula physeal tenderness may represent non-displaced SHI Imaging Radiographs recommended views AP mortise lateral optional views full-length tibia (or proximal tibia) to rule out Maisonneuve-type fracture CT scan indications assess fracture displacement (best obtained post-reduction) assess articular step-off preop planning Treatment Nonoperative removable walking boot vs. NWB short-leg cast for 4 weeks indications distal fibula non-displaced (< 2mm) isolated distal fibular fracture closed reduction and NWB cast for 6 weeks indications distal fibula displaced (> 2mm) SH I or II fracture with acceptable closed reduction distal tibia displaced SH I or II fracture with acceptable closed reduction (no varus, < 10° valgus, < 10° recurvatum/procurvatum, < 3mm physeal widening) Operative CRPP indications distal fibula displaced (> 2mm) SH I or II fracture with unacceptable closed reduction and > 2 years of growth remaining distal tibia displaced SH I or II fracture with unacceptable closed reduction (varus, > 10° valgus, > 10° recurvatum/procurvatum, > 3mm physeal widening) and > 2 years of growth remaining displaced SH III or IV fracture with < 2mm displacement following closed reduction ORIF indications distal fibula displaced (> 2mm) isolated distal fibula fracture (usually SH I or II) with unacceptable closed reduction and < 2 years of growth remaining distal tibia displaced SH I or II fracture with unacceptable closed reduction (varus, > 10° valgus, > 10° recurvatum/procurvatum, > 3mm physeal widening) and < 2 years of growth remaining displaced SH III or IV fracture with > 2mm displacement following closed reduction Techniques Closed reduction sedation requires adequate sedation and muscle relaxation technique only attempt reduction two times to prevent further physeal injury confirm reduction with mortise view acceptable reduction for tibia is <2mm post-op immobilize for 6 weeks NWB short-leg cast if isolated distal fibula fracture NWB long-leg cast if distal tibia fracture complications failed reduction may have interposed periosteum, tendons, or neurovascular structures CRPP vs. ORIF reduction percutaneous manipulation with K wires may aid reduction open reduction may be required if interposed tissue present instrumentation transepiphyseal fixation best if at all possible cannulated screws parallel to physis Tillaux and triplane fractures 2 parallel epiphyseal screws medial malleolus shear fractures transphyseal fixation smooth K wires Complications Ankle pain and degeneration high rate associated with articular step-off > 2mm Growth arrest medial malleolus SH IV fractures have the highest rate of growth disturbance risk factors degree of initial displacement 15% increased risk of physeal injury for every 1mm of displacement residual physeal displacement > 3mm can represent periosteum entrapped in the fracture site high-energy injury mechanism SH III and IV fractures types partial arrests can lead to angular deformity distal fibular arrest results in ankle valgus defomity medial distal tibia arrest results in varus deformity complete arrests can result in leg-length discrepancy treatment angular deformity physeal bar resection if < 20 degrees of angulation with < 50% physeal involvement and > 2 years of growth remaining osteotomy ipsilateral fibular epiphysiodesis bar of >50% physeal involvement in a patient with at least 2 years of growth fibular epiphysiodesis helps prevent varus deformity leg-length discrepancy physeal bar resection if < 50% physeal involvement and > 2 years of growth remaining contralateral epiphysiodesis if near skeletal maturity with significant expected leg-length discrepancy Extensor retinacular syndrome typically seen in posteriorly displaced fractures Malunion rotational deformity can occur after triplane fractures, SH I or II fractures usually leads to an increased external foot rotation angle treatment is derotational osteotomy anterior angulation or plantarflexion deformity occurs after supination-plantarflexion SH II fractures valgus deformity occurs after external rotation SH II fractures Reflex sympathetic dystrophy more common in girls treatment options include physical therapy, psychological counseling, drug therapy, sympathetic blockade