Ankle fractures in children

INTRODUCTION — This topic will discuss the diagnosis and management of ankle fractures in children. The evaluation and causes of ankle pain in the active child or skeletally immature adolescent and the diagnosis and management of ankle sprains are discussed separately:

●(See "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation" and "Ankle pain in the active child or skeletally immature adolescent: Overview of causes".)

●(See "Ankle sprain in adults: Evaluation and diagnosis".)

BACKGROUND — Ankle fractures are among the most common fractures of the lower extremity in older children. They also account for up to 40 percent of all fractures in the skeletally immature athlete [1]. Ankle fractures occur more often in boys than girls. Many fractures arise from activities such as basketball, soccer, inline skating, and riding motorized scooters [1,2].

Distal fibular physeal fractures are the most common type of pediatric ankle fractures and are associated with a relatively low risk for long-term complications [3]. By contrast, distal tibial physeal fractures are associated with a higher risk for long-term complications [1].

CLINICAL ANATOMY — Anatomically, the ankle joint is best thought of as a hinge, with the talus held in place by the distal tibia (medial malleolus) and distal fibula (lateral malleolus). Immediately above the joint, but below the tibial physis, these bones are held together by strong syndesmotic ligaments. Additional stability is achieved through the medial and lateral ligamentous complexes (figure 1 and figure 2). (See "Ankle fractures in adults".)

●Medially, the superficial and deep fibers of the deltoid ligament extend from the malleolus to the talus, navicular, and calcaneus (figure 1). This thick triangular ligament resists eversion of the ankle joint (figure 3).

●The lateral ligamentous complex consists of three distinct bands that resist excessive inversion of the ankle (figure 3). These include the anterior and posterior talofibular ligaments and the calcaneofibular ligament (figure 2).

The majority of the ankle's stability comes from these ligaments, which are typically stronger than the adjacent physes (figure 4). It should be noted that the medial and lateral ligaments arise directly from the tibial and fibular epiphyses. This anatomy accounts for the high percentage of physeal injuries about the ankle, which are caused by inversion and eversion stress (figure 3) [1,4].

Important developmental anatomy of the ankle includes:

●Distal tibial physis – The distal tibial physis accounts for approximately 3 to 4 mm of limb growth per year and 15 to 20 percent of final leg length [5]. The physis develops between 6 and 24 months of age [1]. A separation of the physis, beginning at approximately two years of age, divides it into medial and lateral portions [5]. The medial malleolus begins to form as an extension of the tibial physis at approximately seven to eight years of age and is fully ossified by the age of 10 years [1,5].

The distal physis begins to close around 12 years in girls and 14 years in boys [1]. Closure begins centrally, extends medially, and is completed laterally over the course of 18 months [1,5]. This pattern of closure has important implications for the types of tibial fractures seen in late adolescence. (See 'Juvenile Tillaux fracture' below and 'Triplane fracture' below.)

●Distal fibular physis – The distal fibular physis appears between 9 and 24 months of age at the level of the ankle joint [1]. Closure generally occurs approximately one to two years after distal tibial physis closure.

MECHANISM OF INJURY — Ankle fractures may occur with the ankle inverted or everted and with the foot neutral, plantarflexed, or dorsiflexed (figure 3).

"Rolling" of the ankle, or an inversion injury, is the most common cause of ankle fracture in children [1]. Frequently, this mechanism occurs when the child trips on stairs, a street curb, uneven ground, or during sports play (eg, basketball, soccer, American football). Inversion injury typically causes a fracture of the fibula. If the force is extreme (eg, foot and ankle entrapment during a motor vehicle collision) or the foot is maximally plantar- or dorsiflexed at the time of impact, then the tibia may also be involved. In these instances, the ankle joint is often unstable.

Eversion injuries are less common but are associated with fractures of the tibia and fibula with accompanying instability of the ankle joint [1].

EVALUATION — The evaluation of ankle fractures is summarized in the algorithm (algorithm 1).

Identify and treat emergency conditions — Patients who have sustained major trauma (table 1) are at risk for multiple traumatic injuries and should undergo a primary survey, stabilization of life-threatening injuries, and a complete physical examination before focused evaluation of any ankle injury. (See "Approach to the initially stable child with blunt or penetrating injury", section on 'Blunt trauma' and "Trauma management: Approach to the unstable child", section on 'Initial approach'.)

Emergency ankle conditions, such as an open fracture, neurovascular compromise, or fracture with dislocation, warrant emergency imaging and consultation with an orthopedist with pediatric expertise. (See 'Initial management' below and 'Indications for orthopedic consultation or referral' below.)

History — Once life- and limb-threatening conditions have been managed or excluded, the clinician should proceed with a focused history. In addition to the mechanism of injury (see 'Mechanism of injury' above), the clinician's history should ascertain the following [1,5]:

●Location(s) of the most significant pain

●Other injured areas (eg, lumbar spine, hip, knee)

●Length of time from injury to presentation

●Neurovascular symptoms (eg, paresthesias, numbness, foot pallor)

●Ability to bear weight after injury

●History of any previous injury or surgery

●Related orthopedic comorbidities (eg, myelomeningocele or cerebral palsy)

An ankle fracture, particularly one sustained in a fall from a height, may mask other injuries, especially spinal column fractures.

Physical examination — A complete evaluation of the entire lower extremity should be conducted before assuming that the injury is confined to the ankle, especially in a child who is younger than five years of age and/or is nonverbal [4].

After an ankle injury, there is often swelling and pain. Analgesia prior to examination (eg, ibuprofen for mild to moderate pain or intranasal fentanyl or intravenous morphine or fentanyl for severe pain) will often facilitate the child's cooperation. We suggest that the clinician avoid the oral route for patients likely to require sedation or general anesthesia for fracture reduction or repair.

Assessment of ankle stability — Once emergency conditions, including ankle injury with neurovascular compromise, have been excluded, the first priority in the examination of ankle injuries is to determine whether the joint is stable and can be managed nonoperatively or the joint is unstable and must be referred.

Typically, an ankle injury is stable if it meets the following criteria:

●Pain is isolated to the lateral or medial malleolus

●There is no deformity, malalignment, or major swelling of the lower leg and foot

An ankle injury is unstable if two or more sites of fracture or ligamentous disruption are suspected, such as a medial malleolar fracture with deltoid ligament disruption or a bimalleolar fracture. (See 'Indications for orthopedic consultation or referral' below.)

Patients with gross deformity (picture 1), severe pain, or concern for an unstable joint should not walk or perform active range of motion of the ankle joint. These patients warrant prompt imaging. (See 'Plain radiography' below.)

If the ankle injury appears stable, the range of motion of the knee, hip, ankle, and subtalar joints (midfoot and toes) should be determined, and the ability to ambulate should be assessed.

Ankle examination — Once emergency conditions and have been excluded, ankle examination may proceed as follows:

●Inspection – Clinicians should inspect the injured ankle for swelling, deformity, or skin abnormalities (eg, lacerations with possible open fracture, tenting, or blistering caused by rapid stretching of the skin).

The amount of swelling is not a reliable guide to the presence of a fracture, especially a nondisplaced Salter-Harris I fracture or an avulsion fracture associated with an ankle sprain [6].

Patients with obvious deformity or malalignment of the foot relative to the lower leg are at greater risk for neurovascular compromise due to the presence of a fracture or fractures that have caused an unstable ankle joint (picture 1). They warrant rapid assessment of neurovascular status, emergency imaging, and consultation with an orthopedist with pediatric expertise. (See 'Identify and treat emergency conditions' above.)

●Palpation – Palpation should include all of the bones of the lower leg, ankle, and foot. Clinicians should palpate the ankle looking for the point of maximal tenderness and other tender areas.

The distal tibial and fibular physes deserve particular attention because the distal fibular physis in particular is the most common area of ankle injury in children. Testing for ligamentous laxity can be deferred until after radiographs are obtained; it is often not tolerated in the setting of an acute fracture. Evaluation of the ligaments of the ankle is discussed separately. (See "Ankle sprain in adults: Evaluation and diagnosis", section on 'Clinical evaluation'.)

Significant tenderness, both medially and laterally, implies that the ankle is potentially unstable due to bimalleolar fracture with injury to the deltoid ligament and lateral complex, even in patients without obvious deformity (figure 1 and figure 2). These patients should not ambulate.

The examination of the distal tibia and fibula should include a careful examination in the area of the anterior joint line in addition to the medial and lateral malleoli, especially in older school-age children and young teenagers. Subtle juvenile Tillaux fractures may present with isolated tenderness in the anterior joint line and swelling extending over the distal fibula, while evaluation of the medial malleolus is normal. (See 'Juvenile Tillaux fracture' below.)

The clinician should also palpate the base of the proximal fifth metatarsal in patients with inversion injuries in order to assess for avulsion fractures and Jones fractures in this area. (See "Metatarsal and toe fractures in children".)

●Neurovascular assessment – Neurovascular examination requires comparison of findings in both feet.

The clinician should palpate the posterior tibial and dorsalis pedis pulse and determine capillary refill. Although pain may interfere with interpretation, the ability to extend and flex the toes tests the deep peroneal (fibular) and tibial nerves, respectively.

Sensory evaluation involves testing of the following nerves in the indicated sites:

•Deep peroneal (fibular) nerve (between the first and second toes on the dorsum)

•Superficial peroneal (fibular) nerve (remainder of the dorsal foot)

•Tibial nerve (sole of foot), which branches beneath the ankle to form the following nerves:

-Medial planter nerve (medial plantar surface from great toe to middle of the fourth toe)

-Lateral plantar nerve (lateral plantar surface from middle fourth toe to fifth toe)

-Sural nerve (lateral foot)

-Saphenous nerve (medial foot)

Imaging

When to obtain

Severe or unstable ankle injury — All pediatric patients with emergency ankle conditions, such as an open fracture, neurovascular compromise, fracture with dislocation, or concern for ankle instability, warrant emergency plain radiographs and acute management by an orthopedist with pediatric expertise. Computed tomography (CT) of the ankle may be indicated subsequently if there is diagnostic uncertainty about the presence of serious injury on plain radiographs or if CT is needed to decide operative versus nonoperative management. (See 'Plain radiography' below and 'Other imaging' below.)

Stable ankle injury — Although stable ankle injuries are common in children, a systematic review of 12 studies found that, at most, 17 percent of all ankle injuries will result in a visible bony fracture on radiograph [7]. Despite the low positive yield of imaging, most children with ankle injuries undergo plain radiography. For example, two reports from Canada indicate that radiographs are ordered on 80 to 95 percent of pediatric patients with acute ankle injuries [7,8], while rates of radiography may approach 100 percent in other settings [9].

In an attempt to minimize the number of potentially unnecessary studies in children with stable ankle injuries, clinical decision rules have been developed to aid in decision-making about imaging [10-12].

Low-Risk Ankle Rule — For children with stable ankle injuries who present to the emergency department, we recommend that the Low-Risk Ankle Rule (LRAR) (figure 5 and algorithm 1) be used to determine the need for plain radiographs. The LRAR has a reported sensitivity for the detection of clinically important ankle fractures in children of 98 to 100 percent and a negative predictive value for high-risk injury of 99.7 percent when the prevalence of clinically important fractures is about 7 percent [8,12].

Children are considered low risk by the LRAR and not in need of radiography at initial presentation if the following conditions are met [8,12]:

●The injury is acute (<3 days old)

●The child is not at risk for pathological fractures (eg, osteogenesis imperfecta or known focal bone lesion such as an osteoid osteoma)

●The child has no congenital anomaly of the feet or ankles

●The child can reliably express pain or tenderness

●Physical examination demonstrates tenderness or swelling confined to the distal fibula and/or adjacent lateral ligaments distal to the anterior tibial joint line (figure 5)

●No gross deformity, neurovascular compromise, or other serious and potentially distracting injury are present

The LRAR regards distal fibular avulsion fractures and nondisplaced Salter-Harris I and II fractures as low-risk injuries because they can be managed with supportive splinting, crutches (as needed), and return to activities as tolerated by the patient. (See 'Distal fibula fractures' below.)

When communicating with caregivers about the decision to treat an ankle injury without imaging based upon the LRAR, the clinician should provide a clear statement about the decision. The following provides a sample script:

"Your child has an ankle injury that typically heals very well with the immobilization that we are providing, limits on weight-bearing on the injured side until your child feels better, and treatment of the symptoms of pain and/or swelling, as needed. At this time, a radiograph would not help us in deciding the best way to treat your child's ankle injury. It is likely that they have a sprain or, in the worst case, a very tiny fracture to the fibula, a bone on the outside of the ankle. Even in the case of a tiny fracture, this heals very well with the treatment we are recommending and without the need for a cast, further radiographs, or follow-up from an orthopedic specialist. However, if you find that your child's injury is not feeling better within a week, please follow up with your doctor."

The ability of the LRAR to significantly reduce the ordering of plain radiographs for ankle injuries in children largely lies with the willingness of the clinician and caregivers to accept the possibility of not identifying nondisplaced fractures, including avulsion fractures or nondisplaced Salter-Harris I or II fractures that might have been visible on plain radiographs. Of note, these fractures occur in the minority of patients not requiring radiography according to the LRAR and, even if present, recover well without radiography when managed empirically with recommended treatment consisting of a removable ankle brace or similar device and return to activities as determined by symptoms. (See 'Diagnosis' below and 'Distal fibula fractures' below.)

The LRAR has been associated with the greatest reduction in radiography during prospective validation studies in children [8]. Specifically, in a multicenter implementation study of the LRAR in six Canadian emergency departments (including community, general, and pediatric facilities) evaluating over 2150 children with ankle injuries, use of the LRAR reduced ankle radiography by 22 percent, with no significant difference in missed high-risk fractures, when compared with routine clinical practice. Reduction in ankle imaging was sustained for up to 72 weeks after implementation, and 94 percent of the participating physicians were willing to apply a symptomatic care strategy to this group of low-risk ankle injuries. These results indicate a high physician acceptance of the rule and the related management strategy. Subsequent cost analysis showed significant overall cost reductions when the LRAR was used [13]. The greatest savings were due to lower radiography costs and fewer orthopedic or emergency department follow-up visits. However, there are few external prospective validation or implementation studies, which may limit generalizability of the LRAR because it has not been evaluated in general ambulatory or urgent care settings.

Other clinical prediction rules — Other than the LRAR, the Ottawa Ankle Rule (OAR) (figure 6) has been most widely studied in children [10]. In contrast to the experience in adults, the use of the OAR in children is less likely to reduce radiographic testing beyond that seen when no clinical rules are used. For example, in prospective validation studies of the OAR in children younger than 16 years of age with acute ankle injuries, the relative reduction in ankle radiography has only been approximately 10 percent [12,14,15]. This reduction is approximately half of the reduction in ankle radiography seen in prospective validation studies of the LRAR [8].

When compared with the LRAR, the OAR has similar to slightly higher sensitivity but lower specificity for high-risk fractures [16-18]. For example, a systematic review of 12 pediatric studies (3130 children over two years of age) reports a pooled sensitivity of 98.5 percent for the OAR and a range of specificity of 8 to 47 percent (pooled estimate was not performed because of significant heterogeneity) [10]. The missed fracture rate given a negative OAR assessment was 1.2 percent (95% CI 0.6-2.3 percent). Another methodologically robust meta-analysis of the diagnostic performance of the OAR included 34 studies, eight of which were pediatric. This reported a pooled OAR sensitivity of 97.9 percent (95% CI 94.9, 99.1) and specificity of 21.0 percent (95% CI 13.1-31.9) [19].

Thus, the strength of the OAR is its consistently high sensitivity across numerous studies in adults and children. However, its limitation is its low specificity, whereby application of the rule results in obtaining radiographs in most children, resulting in limited clinical impact for the goal of reducing unnecessary radiographs. Furthermore, implementation studies of the OAR in children are lacking.

The LRAR also has reportedly high sensitivity for high-risk fractures in prospective multicenter studies, alongside a high specificity, with significant potential to safely reduce unnecessary imaging. There is also a rigorously done implementation study that reinforces the safe use of this rule. (See 'Low-Risk Ankle Rule' above.)

Plain radiography — Plain radiographs are the initial imaging of choice for children with concern for fracture based on physical examination and/or the application of the LRAR.

Standard ankle radiographs consist of the following views:

●Anterior-posterior (AP)

●Lateral

●Mortise

The mortise view is taken from anterior to posterior with the leg internally rotated 20 degrees. This highlights the dome of the talus and the position of the malleoli. This view is critical for detecting ligamentous disruption between the tibia and the fibula (syndesmotic rupture) or other evidence of ankle joint instability, and it allows full visualization of the distal tibial physis.

The clinician should order all three views because, in 15 to 20 percent of children with ankle fractures, the bony abnormality will only be apparent on one view [20].

If the pain is localized to the foot, especially the midfoot zone (navicular) or the base of the fifth metatarsal, then dedicated AP, lateral, and oblique foot films are also indicated. (See "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation", section on 'Imaging' and "Metatarsal and toe fractures in children".)

A careful physical examination of the ankle in conjunction with radiographic review is critical. This approach directs the clinician to the appropriate area of injury and facilitates radiographic interpretation. For example, in patients with nondisplaced Salter-Harris I fractures of the tibia and/or fibula, there is no visible fracture on initial radiographs. Diagnosis of this injury requires correlation of the clinical finding of growth plate tenderness with other radiographic evidence such as adjacent soft tissue swelling or widening of the growth plate [20].

Similarly, subtle juvenile Tillaux fractures may present with tenderness isolated to the anterior joint line and swelling extending over the distal fibula, while palpation of the medial malleolus is free of any tenderness and/or swelling. The physical examination aids the clinician in recognizing this fracture on plain radiograph. (See 'Juvenile Tillaux fracture' below.)

Other imaging — Plain radiographs suffice for the diagnosis and management of most pediatric ankle fractures. Consultation with a pediatric radiologist or orthopedic surgeon is strongly encouraged before obtaining advanced imaging of the ankle. Advanced imaging may be warranted in children with complex fractures on plain radiographs that will require surgical repair or in children with normal plain radiographs but prolonged recovery:

●Computed tomography – Indications for CT of the ankle include [21]:

•Triplane fracture (image 1) (see 'Triplane fracture' below)

•Displaced Salter-Harris III fracture (see 'Juvenile Tillaux fracture' below)

•Salter-Harris IV fractures

•Serious injury with diagnostic uncertainty

•The need for surgical repair versus nonoperative management is unclear from plain radiographs alone

When imaging triplane, displaced Salter-Harris III, or Salter-Harris IV fractures, CT is not needed for initial management in the emergency department but provides key information for later operative repair.

●Magnetic resonance imaging – Magnetic resonance imaging (MRI) of ankle injuries is rarely performed as part of the acute evaluation. Although MRI can better discern between a sprain and a growth plate or ossified bone injury when compared with a plain radiograph [22,23], the information typically does not change initial management. MRI may be useful in children whose radiographic imaging remains normal but whose recovery from injury is prolonged. (See 'Distal fibula fractures' below.)

Fracture classification

Salter-Harris classification — The Salter-Harris classification system provides the easiest and most commonly used method of describing ankle fractures in skeletally immature children and adolescents (figure 7) [5]. This system grades physeal fractures as types I through V. Complications of physeal injury include growth arrest, permanent decreased range of motion, and angular deformity. Salter-Harris I and II ankle fractures are at lower risk for these complications than those that are Salter-Harris III or higher. Higher grades of Salter-Harris fracture often require operative repair. (See "General principles of fracture management: Fracture patterns and description in children", section on 'Physeal fracture description' and 'Initial management' below.)

Juvenile Tillaux fracture — This fracture represents a Salter-Harris III physeal injury that involves the anterolateral portion of the tibia. It typically occurs in children between 12 and 14 years of age as they approach skeletal maturity and have a partially fused tibial physis (image 2) [5]. The typical mechanism of injury is inversion of the ankle with the foot pointed away from the midline (supination with external rotation). This mechanism leads to avulsion of the lateral tibial epiphysis that is attached to the anterior inferior tibiofibular ligament (figure 8). The uninvolved medial portion of the epiphysis is closed.

Triplane fracture — Triplane fracture describes a Salter-Harris IV fracture of the tibia that occurs in the sagittal, coronal, and transverse planes and creates between two and four fracture fragments (image 1) [1,5]. Children with these fractures have an average age of 13 years. The mechanism of injury is debated, but many orthopedists feel it involves inversion of the ankle with extreme turning out of the foot (supination with external rotation) [1].

DIAGNOSIS — Children with ankle fractures typically present with ankle pain, swelling, bony tenderness, and inability to ambulate. Plain radiographs confirm the diagnosis for many of these children. (See 'Plain radiography' above.)

The most common pediatric ankle injury presents after ankle inversion with tenderness over the distal fibula and plain radiographs that do not show a bony abnormality [8,12,16]. In the past, these ankle injuries, when occurring in skeletally immature children, were presumed to be a Salter-Harris I fracture through the distal fibular physis (growth plate) rather than an ankle sprain [1,4,24]. However, prospective, observational studies with magnetic resonance imaging (MRI) as the gold standard have demonstrated that the vast majority of these children actually have sprain injuries rather than physeal fractures [22,23,25,26]. As an example, in a multicenter, prospective, observational study of 135 children (5 to 12 years of age) with a clinical diagnosis of a distal fibular Salter-Harris I fracture and normal plain radiographs, MRI demonstrated a nondisplaced Salter-Harris I distal fibular fracture in four cases (3 percent), with two of these patients having only partial injuries to the growth plate and all four also having associated ligamentous injuries. Among the 131 children without physeal injuries, 104 (79 percent) had ligamentous injuries, 38 of which were associated with radiographically occult distal fibular avulsion fractures, indicating a high-grade sprain. The remaining 27 (21 percent) had isolated bone contusions, a very mild injury [25].

Thus, evidence suggests that the majority of children with inversion ankle injuries and no bony abnormality on plain radiographs have sprains and that nondisplaced Salter-Harris I fractures of the distal fibula are uncommon. These findings have important implications for management of pediatric patients with inversion injuries. (See 'Distal fibula fractures' below.)

The diagnosis and management of ankle sprains are discussed separately. (See "Ankle sprain in adults: Evaluation and diagnosis".)

INITIAL MANAGEMENT — The goals for initial care of ankle fractures in children are to reverse neurovascular compromise, provide analgesia, and promptly identify injuries that warrant urgent referral to an orthopedist (algorithm 1).

Absent pulse — The clinician should promptly identify children with vascular insufficiency and urgently involve an orthopedic surgeon with appropriate pediatric expertise. Rarely, these children may require partial closed reduction in the emergency department by the emergency clinician or orthopedist in an attempt to restore distal circulation. Patients who display a cold, white, or cyanotic foot despite reduction attempts require urgent operative treatment.

Analgesia and initial care — For children with no signs of neurovascular compromise, initial therapy consists of measures to reduce swelling, pain management, and restriction of ambulation.

●Based on limited data in humans and animals [27], we suggest trying to reduce swelling with an insulated ice pack, bandage, and elevation.

●Oral analgesia (eg, ibuprofen) may suffice for patients with mild to moderate pain who have suffered a nondisplaced ankle fracture, especially a Salter-Harris I fracture or an avulsion fracture of the distal fibula. Opioid analgesia (eg, intranasal fentanyl or intravenous fentanyl or morphine) is most appropriate for initial pain control in patients with severe pain and should be given prior to radiographic evaluation. We suggest that the clinician avoid the oral route for patients likely to require sedation or general anesthesia for fracture reduction or repair.

●Unless a patient meets criteria for no radiography by the Low-Risk Ankle Rule (LRAR) (figure 5), we recommend obtaining a radiograph for pediatric ankle injuries. (See 'Low-Risk Ankle Rule' above.)

●Weightbearing should be discouraged in any patient with pain that results in limited ability to walk, deformity, distal tibial fractures, proximal fibula fractures, and/or an unstable ankle injury (see 'Evaluation' above). In particular, patients with significant deformity or concern for an unstable ankle joint should not be allowed to bear weight on the affected leg.

INDICATIONS FOR ORTHOPEDIC CONSULTATION OR REFERRAL — The clinician should obtain prompt orthopedic consultation for children with any of the following ankle fractures [1]:

●Fractures with neurovascular compromise

●Open fractures

●Unstable fractures (eg, bimalleolar fractures)

●Salter-Harris III (including juvenile Tillaux fractures), IV (including Triplane fractures), or V physeal fractures

In addition, patients with displaced Salter-Harris I or II physeal fractures typically undergo orthopedic reduction at the initial emergency department visit, although these injuries will heal well as long as reduction occurs within one week.

DEFINITIVE CARE

Distal fibula fractures

●Nondisplaced Salter-Harris I or II and avulsion fractures – These fractures typically result from inversion ankle stress in the skeletally immature child. These injuries are stable and are at very low risk for any long-term complications such as refracture, growth arrest, malunion, and/or osteoarthritis [3]. With Salter-Harris I fractures, there is a fracture through the distal fibular physis (figure 4 and figure 7). Salter-Harris II fractures are similar to Salter-Harris I fractures except that there is a fracture extending into the metaphyseal cortex that produces a triangular fragment known as the Thurston-Holland or corner sign (image 3). Avulsion fractures occur when a small piece of bone is pulled off of the distal fibula by the lateral ligamentous complex.

We recommend that children with nondisplaced Salter-Harris I or II or avulsion fractures of the distal fibula receive immobilization with a removable ankle brace (eg, Air Stirrup or AirCast ankle brace) (picture 2) or similar device, a posterior below-knee plaster or fiberglass splint (figure 9 and figure 10), a controlled ankle motion (CAM) walker boot, or tubular bandage rather than casting [3,28,29]. Of these options, we prefer a removable ankle brace because it may encourage more rapid return to activity while providing sufficient protection for these low-risk injuries. Children with appropriate capability may be given crutches and be made non-weightbearing if they cannot ambulate without a limp until pain subsides. Children who are considered low risk by the Low-Risk Ankle Rule (LRAR) (figure 5) and do not receive radiographs should also receive this treatment if pain is sufficient to significantly interfere with ambulation. (See 'Low-Risk Ankle Rule' above.)

Anticipated recovery time constitutes key anticipatory guidance for caregivers. These injuries are still fractures, and pain is expected to persist for two to four weeks, limiting activities to some degree. However, pain does gradually abate in this timeframe in the vast majority of children. Return to full activities, including competitive sports, typically occurs by 6 to 12 weeks.

Despite the benign nature of this group of fractures, these fractures have traditionally been managed using a below-knee cast for three to four weeks because, theoretically, it was believed that a cast offered greater protection [1]. However, disadvantages to this approach include delay in returning to normal activities, patient discomfort, development of a tight cast, skin ulceration, and, rarely, compartment syndrome [3,28,30].  

However, the fibula is not prone to refracture and, based upon several small trials, return to activity is achieved sooner when immobilization other than casting is used [3,25,28,31]. For example, in a randomized trial of 104 children with nondisplaced distal fibular Salter-Harris I, II, or avulsion fractures, a greater proportion of the 54 children who received a removable ankle brace had returned to normal baseline activity at four weeks when compared with the 50 children who received a fiberglass below-knee walking cast (81 versus 60 percent) [3]. In addition, the removable brace was superior with respect to patient preferences and was also cost-effective. In another small trial of 45 children with suspected distal fibular Salter-Harris I physeal fractures, functional recovery (ie, return to normal activities) did not differ between immobilization with a fiberglass posterior splint or an Air-Stirrup ankle brace [31]. Finally, in a trial of 135 children with inversion ankle injuries and no fracture seen on plain radiograph who received a removable ankle brace and self-regulated return to activities, the 42 children with fractures detectable only by magnetic resonance imaging (MRI; primarily distal fibular avulsion fractures) had a comparable recovery with those with isolated ligamentous injuries [25].

●Displaced Salter-Harris I or II fractures – Displaced Salter-Harris I or II fractures require prompt orthopedic consultation for reduction and casting.

●Salter-Harris III through V fractures – These fractures of the fibula are very rare and have not been reported to occur as isolated injuries [20]. When present, they require prompt orthopedic evaluation along with the concomitant tibial injury. Treatment is focused on management of the tibia fracture. Fibular injuries are usually stable once the tibial fracture is reduced (figure 7) [5].

Distal tibia fractures

●Nondisplaced Salter-Harris I or II fractures – Salter-Harris I injuries of the tibia are rare and present with tenderness and swelling over the distal tibial physis (figure 4 and figure 7).

Salter-Harris II tibial fractures are much more common and may occur with inversion, eversion, or plantarflexion mechanisms (figure 3). Salter-Harris II fractures are similar to Salter-Harris I fractures except that there is a fracture extending into the metaphyseal cortex that produces a triangular fragment known as the Thurston-Holland or corner sign (image 3).

Initial management of these fractures consists of immobilization in a below-knee posterior splint (figure 10) or below-knee cast and no weightbearing pending evaluation and continued care by an orthopedist with pediatric expertise [4]. If applied at initial presentation, below-knee casts may also be bivalved to prevent excessive compression of the cast with swelling over the first 48 hours after injury. Children with appropriate capability should be given crutches. (See "Basic techniques for splinting of musculoskeletal injuries", section on 'Posterior leg splint'.)

Orthopedic treatment for these children usually requires a short leg cast for two to three weeks followed by a short leg walking cast for an additional two to three weeks. Return to full activities typically occurs by 10 to 12 weeks.

●Displaced Salter-Harris I or II – Displaced Salter-Harris I or II fractures of the tibia require prompt orthopedic consultation for reduction and cast immobilization with ongoing care directed by an orthopedist with pediatric expertise [1]. While often reducible in the emergency department, those that are not anatomically reduced may have periosteum or torn deltoid ligament interposed in the fracture site and require open operative treatment.

●Salter-Harris III – The juvenile Tillaux fracture represents the most common Salter-Harris III fracture in skeletally immature children and typically occurs in young teenagers [1]. The mechanism of injury commonly involves inversion of the ankle with the foot pointed away from the midline (supination with external rotation) (figure 3 and image 2). This mechanism leads to avulsion of the lateral tibial epiphysis that is attached to the anterior inferior tibiofibular ligament (figure 8). The uninvolved medial portion of the epiphysis is closed. Rarely, a Salter-Harris III fracture occurs in the medial malleolus before physeal closure; this most often follows an injury with eversion stress and is typically accompanied by a fracture of the distal fibula.

In addition to plain radiographs, computed tomography (CT) of these fractures is often indicated to evaluate the extent of displacement. Juvenile Tillaux fractures with >2 mm of displacement warrant urgent orthopedic consultation for closed or open reduction. Some of these fractures may require percutaneous pinning to maintain reduction [1]. After discussion with an orthopedist, children with nondisplaced Salter-Harris III fractures, as determined by CT, may be given crutches and placed in a posterior below-knee splint or cast pending evaluation and continued care by an orthopedist with pediatric expertise within one week.

Patients with nondisplaced Salter-Harris III fractures typically undergo long leg casting for four to six weeks with conversion to a short leg cast or boot for an additional two to four weeks [1]. Weightbearing is initiated based on radiographic healing and clinical examination. Patients should anticipate eight weeks of non-weightbearing. Return to full activities frequently occurs by 10 to 12 weeks.

Patients with displaced fractures requiring reduction and/or instrumentation warrant close, ongoing orthopedic care to ensure adequate reduction and to determine the optimal timing for hardware removal and return to normal activities [1].

●Salter-Harris IV – Type IV fractures involve the ankle joint, and urgent orthopedic consultation is indicated. If located medially, these fractures are caused by inversion stress and are shearing-type injuries that need fixation.

Triplane fracture describes a Salter-Harris IV fracture of the tibia that occurs in the sagittal, coronal, and transverse planes and creates between two and four fracture fragments (image 1) [1,5]. The mechanism of injury is debated, but many orthopedists feel it involves inversion of the ankle with extreme turning out of the foot (supination with external rotation).

CT is required to discern the degree of displacement in patients with Salter-Harris IV fractures. Open reduction with internal fixation of these injuries is usually necessary to obtain adequate reduction. Failure to reestablish articular continuity may result in premature arthritis [4]. In addition, risk of growth arrest is significant. (See 'Complications' below.)

These injuries warrant close, ongoing orthopedic care to ensure adequate reduction and to determine the optimal timing for hardware removal and, ultimately, return to normal activities.

●Salter-Harris V – These rare fractures result from axial loading of the extremity (eg, a fall on the heel from a height, leading to physeal compression) (figure 7). Patients with multisystem trauma may be at particular risk for unrecognized Salter-Harris V injuries.

Initial plain films may show narrowing of the physis but are frequently unremarkable. Any suspected Salter-Harris V fracture warrants urgent orthopedic assessment. These patients need ongoing orthopedic care for several years because of the high risk of growth arrest and need for corrective surgery. Unfortunately, many of these injuries are difficult to detect and may not come to attention until growth arrest has already occurred [1,5].

DISCHARGE AND FOLLOW-UP — Children who have received operative care warrant inpatient admission for 24- to 48-hour observation of neurovascular status and soft tissue compartments. Once discharged, these patients are followed closely and may require weekly orthopedic evaluation with radiographs to determine the optimal timing for subsequent hardware removal.

Children with displaced ankle fractures that undergo reduction in the emergency department should follow up with an orthopedic surgeon within a few days.

Nondisplaced distal fibular fractures (nondisplaced Salter-Harris I, II, and avulsion) may be followed by a primary care physician who is comfortable managing these injuries or an orthopedic surgeon in approximately 7 to 10 days [32]. For any ankle injury, whether or not clinical decision rules are applied and/or plain radiographs are obtained, the following anticipatory guidance is essential [7]:

●A small number of nonsignificant fractures may not be identified either by the application of a clinical decision rule or radiography at the time of injury.

●The clinical course is also of significant importance in determining whether a fracture is present, and diagnosis may ultimately require repeat evaluation and a radiograph at 7 to 10 days after injury when bone healing is apparent.

Children with the appropriate capability should also receive crutches.

Detailed cast care instructions should be given to casted children and their caregivers. (See "Patient education: Cast and splint care (Beyond the Basics)".)

Home pain management — Most children with uncomplicated ankle fractures have adequate pain control with ibuprofen (10 mg/kg; maximum single dose: 800 mg) [33].

Patients with Salter-Harris III or higher fractures, especially those who require operative fixation, typically require oral opioid pain medication for the first few days after discharge (eg, oxycodone or oral prompt-release morphine) in addition to ibuprofen. However, pain that does not improve or worsens warrants prompt reevaluation by the orthopedist.

COMPLICATIONS — Potential complications of ankle fractures include the following:

●Growth arrest – Ankle fractures in children usually involve the physis (growth plate) (figure 4). Growth arrest is most commonly seen in children with Salter-Harris III or IV fractures of the tibia, especially when initial reduction is incomplete. Thus, all tibial growth plate fractures should be monitored closely by an orthopedist for up to two years to observe for proper healing [4].

●Osteochondral defect – Defects in the talar dome may occur after ankle fractures in children and should be suspected in patients with persistent pain [34]. Plain radiographs can identify osseous injury, while magnetic resonance imaging (MRI) is necessary to visualize cartilaginous injury. Operative treatment is typically necessary for resolution.

●Osteoarthritis – Arthritis has been reported in up to 29 percent of patients with a Salter-Harris III or IV ankle fracture and seems to be most associated with the degree of fracture displacement and the presence of residual displacement after reduction [35].

●Ankle stiffness – Posttraumatic ankle stiffness has been observed in up to 6 percent of patients after ankle fracture and is associated with osteoarthritis [35].

●Complex regional pain syndrome – Complex regional pain syndrome (previously reflex sympathetic dystrophy) may follow an ankle fracture and is identified by marked pain with light touch to the skin (allodynia), swelling, and vasomotor changes. Splinting results in worsening symptoms. Multidisciplinary pain evaluation and treatment, including physical therapy, is sometimes helpful. (See "Complex regional pain syndrome in children".)

●Compartment syndrome – Patients with physeal fractures of the tibia (eg, Salter-Harris II or triplane fractures) can develop external retinacular syndrome [34]. This type of compartment syndrome is characterized by severe ankle pain and swelling, weakness on toe extension, increased pain with passive toe flexion, and decreased sensation in the first web space (between the great and second toe). Fracture reduction and fixation and external retinacular release typically resolve the pain and weakness [34]. However, the sensation deficit may persist.

The diagnosis and management of acute compartment syndrome is discussed separately. (See "Acute compartment syndrome of the extremities".)

OUTCOMES — Most children with ankle fractures will enjoy a return to baseline activities without any long-term complications [1]. Once a patient's immobilization device has been removed, return to activities may be facilitated with ankle range of motion exercises. Patients with significant ankle stiffness remaining at four weeks after brace or cast removal may benefit from formal physical therapy sessions.

ADDITIONAL INFORMATION — Several UpToDate topics provide additional information about fractures, including the physiology of fracture healing, how to describe radiographs of fractures to consultants, acute and definitive fracture care (including how to make a cast), and the complications associated with fractures. These topics can be accessed using the links below:

●(See "General principles of fracture management: Bone healing and fracture description".)

●(See "General principles of fracture management: Fracture patterns and description in children".)

●(See "General principles of acute fracture management".)

●(See "General principles of definitive fracture management".)

●(See "General principles of fracture management: Early and late complications".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: General management of pediatric fractures" and "Society guideline links: Lower extremity fractures in children" and "Society guideline links: Acute pain management".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Ankle fracture (The Basics)" and "Patient education: How to care for your child's cast (The Basics)" and "Patient education: How to use crutches (The Basics)")

●Beyond the Basics topic (see "Patient education: Cast and splint care (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Evaluation and initial management – The child with an ankle fracture typically has a history of inversion or eversion of the ankle (figure 3) with swelling and pain near the ankle joint. Most patients are unable to walk or have significant limitation of ambulation. (See 'Evaluation' above.)

Emergency conditions to identify early include:

•Absent pulse – The clinician should promptly identify children with vascular insufficiency and obtain emergency imaging and consultation with an orthopedic surgeon with appropriate pediatric expertise. Rarely, these children will require partial closed reduction under sedation in the emergency department by the emergency clinician or orthopedist in an attempt to restore distal circulation. Patients who display a cold, cyanotic foot despite reduction attempts require emergency operative exploration and vascular repair. (See 'Absent pulse' above.)

•Obvious deformity – In patients with an obvious deformity (picture 1), marked swelling with moderate to severe pain, signs of an unstable joint, or high suspicion for a displaced fracture, analgesia (eg, intranasal fentanyl or intravenous fentanyl or morphine) is advisable prior to physical examination and radiography. These patients should undergo prompt imaging with plain radiographs and should not perform active range of motion or attempt to walk prior to imaging. (See 'Analgesia and initial care' above and 'Severe or unstable ankle injury' above.)

●Diagnosis – For otherwise healthy children 3 to 16 years of age with acute (≤72 hours) ankle injuries without neurovascular compromise, significant deformity, or concern for an unstable joint, we recommend that clinicians use the Low-Risk Ankle Rule (LRAR) (figure 5 and algorithm 1) (see 'Low-Risk Ankle Rule' above) rather than other clinical decision rules (eg, Ottawa Ankle Rule [OAR]).

•If a clinician suspects a clinically important ankle fracture (eg, unstable joint or fracture requiring reduction) based upon physical examination and/or the application of the LRAR, the child should undergo plain radiographs. (See 'When to obtain' above.)

•Plain radiographs confirm the diagnosis of ankle fractures for many of these children. For the most common pediatric ankle injury, ankle inversion with tenderness over the distal fibula, plain radiographs frequently do not show a bony abnormality, and the majority of these patients do not have fractures. (See 'Diagnosis' above.)

●Fracture classification – Pediatric ankle fractures are most commonly described using the Salter-Harris classification system (figure 7). The juvenile Tillaux fracture represents a unique type of Salter-Harris III fracture (image 2). Triplane ankle fractures in children are Salter-Harris IV fractures (image 1). (See 'Fracture classification' above.)

●Specialty consultation – In addition to emergency consultation for patients with an absent pulse, the clinician should obtain prompt orthopedic consultation for children with any of the following ankle fractures (see 'Identify and treat emergency conditions' above and 'Indications for orthopedic consultation or referral' above):

•Open fractures

•Unstable fractures (eg, bimalleolar fractures)

•Salter-Harris III (including juvenile Tillaux fractures), IV (including Triplane fractures), or V physeal fractures

Furthermore, patients with displaced Salter-Harris I or II physeal fractures typically undergo orthopedic reduction at the initial emergency department visit.

●Initial management – For children with an ankle fracture and no signs of neurovascular compromise, initial therapy consists of measures to reduce swelling, pain management, and restriction of ambulation. (See 'Analgesia and initial care' above.)

●Distal fibula fractures – We recommend that children with nondisplaced Salter-Harris I or II or avulsion fractures of the distal fibula receive immobilization with a removable ankle stirrup brace (picture 2), a posterior, below-knee plaster or fiberglass splint (figure 9), or controlled ankle movement (CAM) boot rather than a cast (Grade 1B). Of these options, we routinely use a removable ankle brace. A significant portion of children who are considered low risk by the LRAR (figure 5) and do not receive radiographs also can have these fractures and should receive this treatment. Children with appropriate capability (typically older than eight years of age) should be given crutches and be made non-weightbearing until pain subsides. (See 'Distal fibula fractures' above.)

●Distal tibia fractures – Patients with a nondisplaced Salter-Harris I or II fracture of the tibia should undergo immobilization in a below-knee posterior splint (figure 10) or below-knee cast and no weightbearing pending evaluation and continued care by an orthopedic surgeon. (See 'Distal tibia fractures' above.)