Pelvic, hip, and femoral fractures in pediatric patients, though uncommon, can have potentially devastating complications. These fractures can occur from either low-energy or high-energy mechanisms. Fracture location, stability, and patient age help guide treatment of these injuries. Common complications of pediatric pelvic, hip, and femoral fractures include osteonecrosis and physeal arrest. The most recent research related to pelvic, hip, and femoral fractures in pediatric patients is explored.

Pelvic fractures in pediatric patients are uncommon and comprise fewer than 0.2% of all fractures in children, most of which are apophyseal avulsions.¹ The incidence of pediatric pelvic fractures is estimated at 1 in 100,000 children, with 40% to 80% as a result of motor vehicle collisions.¹ In more of a general trauma setting, pelvic ring fractures can occur. Many adult pelvic ring fractures cause pelvic instability; however, pediatric pelvic ring fractures can remain stable with a complete fracture on one side of the ring and an incomplete fracture on the other side. The classification generally used in pediatric pelvic fractures is the Torode and Zieg classification, which was derived from a retrospective series of 141 patients.² The classification describes four patterns (later expanded to five) of injury (Figure 1). The first was an apophyseal avulsion injury, typically of the hamstrings (ischial tuberosity), sartorius (anterior superior iliac spine), or rectus femoris (anterior inferior iliac spine). The second was an isolated fracture of the iliac wing, the third was a stable pelvic ring fracture, and the fourth an unstable pelvic ring fracture.

Apophyseal avulsion injuries are considered to be uncommon injuries but can occur in up to 16% of athletic injuries in the at-risk adolescent age group.³ The injury occurs as a result of a rapid change in direction with an unbalanced contraction of the involved muscle, typically during soccer, gymnastics, or football. The traction of the muscle through the apophyseal secondary ossification center results in an avulsion injury of the apophysis. The mean age of injury is 14.5 years, and the most common avulsion is the anterior inferior iliac spine (46%) followed by the anterior superior iliac spine (32%), the ischial tuberosity (12%), and the iliac crest (11%).⁴

In general, most apophyseal fractures should be managed nonsurgically. Guidelines recommend a short period of limited weight bearing of 3 to 4 weeks with ice and NSAIDs for the first week, followed by increasing
resistance training at 4 weeks and stretching at 6 to 8 weeks.⁵ Surgical treatment is controversial and level of evidence guiding decision making is poor. Clear indications for surgery are lacking, of which symptomatic nonunion is likely the least controversial indication. A surgical indication of displacement more than 15 mm in ischial tuberosity fractures and anterior superior iliac spine fractures is supported by low-level studies or expert opinion, as is 2 cm for fractures of the anterior inferior iliac spine.⁵,⁶,⁷ These indications are patient
dependent, however, and a larger case series showed approximately 86% of patients were asymptomatic at 3 months independent of bony union.⁸

Torode and Zieg type II or isolated iliac wing fractures are almost five times more common in skeletally immature patients than in older patients (29% of all pelvic fractures versus 6%).⁹ This relationship is reversed in more unstable patterns such as acetabular fractures (more than seven times more common in mature children), sacroiliac, or pubic symphysis diastasis (almost four times as common in skeletally mature patients).⁹

Although iliac wing fractures account for approximately 25% of nonavulsion pelvic fractures in children, there is a paucity of primary research describing outcomes.¹⁰ The fractures are almost exclusively managed nonsurgically, with no clearly identifiable surgical indications apart from expanding hematoma, symptomatic nonunion, or an open injury that requires débridement. Generally, a period of 4 to 6 weeks of limited weight bearing is likely to result in bony union. Given the generally benign nature of this entity, the goal of treatment is to limit symptoms while the patient recovers. Because the abdominal wall musculature attaches to the iliac wing, it stands to reason that protected weight bearing with crutches or walker until union is likely to produce fewer symptoms than non-weight bearing where the entire involved hemipelvis would be held against gravity by muscles attached to the cranial aspect of the iliac wing.

Torode and Zieg type III injuries describe a stable pelvic ring injury, and Torode and Zieg type IV fractures are unstable pelvic ring injuries, with stability referring to the bony stability of the pelvic ring. Difficulty exists in determining stability for two key reasons. First, because of the nature of children’s bone, fractures may exist that are torus or incomplete fractures, which are inherently stable. Second, the abundant and thick periosteum in younger children can render unstable adult patterns stable in a child. One study described a group of patients characterized as having type IIIB fractures in which fractures of the anterior and posterior ring existed but the fracture itself was still stable. Although no changes in orthopaedic management were made, these children were more likely to receive blood transfusions and have a longer length of stay in the hospital.¹¹ The Tile classification is a clinically helpful way to consider stability in this setting, where Tile A fractures are vertically stable and rotationally stable, Tile B fractures are partially stable, generally rotationally unstable but vertically stable (in the case of lateral compression/anterior-posterior compression). Finally, Tile C fractures are vertically and rotationally unstable.¹² The challenge comes because unless the child is at or close to skeletal maturity, static radiographic indications either on plain radiograph, CT, or MRI are less reliable than in adult patients because of the common presence of incomplete fractures and a thick periosteum.

A series of maneuvers has been suggested that could be performed under anesthesia to check stability under the three fracture patterns generally seen: lateral compression, anterior-posterior compression, and vertical shear.¹³ These maneuvers can detect occult pelvic instability and help determine if surgical intervention is warranted in borderline fractures, particularly when a Tile type B fracture occurs in a skeletally immature child. Tile type A pelvic ring fractures can almost universally be managed nonsurgically and include minimally displaced symphyseal disruptions, oblique rami fractures, and incomplete fractures of the sacrum. These generally do not require examination under anesthesia and can be managed with a period of protected weight bearing. After the patient gets out of bed and mobilizes, AP, inlet, and outlet radiographic views or a flamingo view can be obtained (weight bearing on involved side) to rule out latent instability. Tile type B fractures are more likely to be unstable in skeletally mature or close to mature adolescents. These may present with the classic crescent fracture with fractures of the pubic rami in the case of lateral compression fractures or symphyseal diastasis with concomitant disruption of the posterior sacroiliac ligaments or bone in the case of an anterior-posterior compression injury. In younger children the instability may not be so obvious, and a stress examination under anesthesia can differentiate a stable versus unstable pelvis. An examination under anesthesia should be considered, particularly in cases where the child needs an anesthetic for an unrelated reason if the diagnosis is in question.¹³ Tile C injuries are typically more severe and often are unstable on presentation. These types of ring injuries are also more common in more skeletally mature patients.⁹ Pediatric pelvic fractures found to be unstable should be considered for surgical fixation. Remodeling of the pelvic ring is lackluster, even in younger children, and the degree of functional disability has been related to the amount of pelvic asymmetry.¹⁴,¹⁵

Unstable pelvic injuries may present with a cadre of other serious issues ranging from closed head injury to hemodynamic instability to urogenital injury. Lateral
compression injuries are often bumper injuries in a child, and when struck by a moving vehicle, the child’s body hits the ground first, followed by a head strike. Dissimilar from adults, mortality is more often caused by head injury than by exsanguination, and this is theorized to be a result of the increased capacity for vasoconstriction that occurs in the venous plexus surrounding the anterior pelvic ring.¹⁶ These vessels are commonly disrupted by anterior-posterior compression-type injuries, and as such, patients with this pattern are most likely to present with hemodynamic instability, and they are also most likely to benefit from the volume reduction afforded by a pelvic binder. Although urethral and bladder neck injury can occur with any pubic symphysis disruption, they are most likely to occur with vertical shear injuries because the bladder is tethered to the anterior pelvis by suspensory ligaments. Urologic consultation and cystography should be considered in these injury patterns.

Acute management of pediatric pelvic fractures should be based on hemodynamic and fracture stability. Torode and Zieg type I to III injuries (Tile A) can be managed with limitations in weight bearing alone. Torode and Zieg type IV or Shore modification IIIB (Tile B) fractures should be assessed for hemodynamic stability and then an assessment made of fracture stability either with a static study such as a CT scan, or in a more skeletally immature patient, with an examination under anesthesia. Torode and Zieg type IV fractures should be assessed for hemodynamic instability, acute issues addressed, and compressive binders placed in the case of anterior-posterior injuries with ongoing blood loss. A femoral traction pin should be placed on the high side of the hemipelvis in the case of vertical shear fractures. Advanced Trauma Life Support protocols should be carried out with primary and secondary surveys, followed by a trauma assessment for ongoing sources of blood loss. Careful neurologic workup and imaging are critical along with assessment of the integrity of the urogenital system.¹⁶ Although outcomes of nonsurgical treatment are generally good, when instability exists, percutaneous or open fixation as indicated also results in good outcomes with a favorable complication profile.¹⁷,¹⁸

Traumatic hip dislocation is an uncommon occurrence in childhood (Figure 2). The mechanism of injury is generally lower energy in younger children (age 10 years and younger) or higher energy in older children and adolescents.¹⁹ Younger children generally have more ligamentous laxity than older children, so the incidence of bony injury is lower in younger children. Femoral head fractures, epiphyseal separations, and posterior wall fractures can be seen in older children and adolescents, and careful evaluation for these injuries postreduction should be undertaken.²⁰

After the dislocation has been identified, an urgent sedated reduction should be undertaken, because osteonecrosis is more common when reduction is delayed more than 6 hours.²¹ Most dislocations in children can be
managed with sedation and closed reduction using gentle traction. Postreduction imaging should be performed either with CT or MRI. Although both are acceptable, MRI may be superior to CT in that there is no radiation associated with MRI, and MRI is superior for examining interposition of soft tissue or assessing chondral injury postreduction.¹⁹ If closed reduction is unsuccessful or if reduction is nonconcentric because of interposed soft tissue or fracture, open reduction should be performed. In terms of surgical approach, when a posterior dislocation is present, a posterior approach is recommended, and when an anterior dislocation is present, an anterior approach is recommended. This is thought to minimize surgical trauma to the opposite side of the joint and allow for repair of the damaged capsule and tissues.²²

Complications include noncongruent joint reduction, femoral head epiphysiolysis, missed fractures (including femoral head and posterior wall fractures), osteonecrosis, hip instability, osteoarthritis, and neurologic injury (specifically sciatic nerve injury). The outcome of pediatric hip dislocation varies based on the energy of injury, the promptness of identification and reduction, the identification of other injuries, and reduction congruency. Asymptomatic coxa magna is common.¹⁹ The patient should be observed for at least 6 months and preferably 1 year for changes in the femoral head including osteonecrosis.

Pediatric femoral neck fractures are rare injuries, accounting for fewer than 1% of fractures in children. Although rare, these fractures account for a disproportionate amount of disability, pain, and loss of function because of potential complications that can occur. The blood supply of the proximal femur is limited to branches of the medial femoral circumflex because the proximal physis blocks contributions of the lateral femoral circumflex. This renders the blood supply to the capital epiphysis very tenuous and at risk for osteonecrosis of the femoral head with displaced proximal femoral fractures²³ (Figure 3).