Femoral shaft fractures in children

INTRODUCTION — Femoral shaft fractures in pediatric patients are discussed here. Proximal and distal femur fractures in children are reviewed separately. (See "Hip fractures in children" and "Distal femoral fractures in children".)

EPIDEMIOLOGY — Femoral shaft fractures occur in children with an estimated annual incidence ranging from 10 to 20 fractures per 100,000 children depending upon region [1-5]. The diaphysis is the most common site for pediatric femur fractures, accounting for almost 75 percent of all femur fractures [3,5].

Several observational studies have identified a bimodal age distribution for femoral shaft fractures with peaks in the toddler age group, where falls are the predominant cause of injury, and in the adolescent age group, where motor vehicle collisions cause most of the fractures [2-6]. Across all age groups, boys have higher rates of femoral shaft fractures than girls [2-9].

Mortality from a femur fracture has been estimated at 1 per 600 patients [6], but is most often due to associated injuries sustained as a result of high energy trauma [3].

PERTINENT ANATOMY — The femur is the largest bone in the body. It joins with the acetabulum of the pelvis proximally to form the hip joint and with the patella, tibia and fibula distally to form the knee joint. The pediatric femur can be divided anatomically into the proximal femur (made up of the femoral head, femoral neck, greater and lesser trochanter), the femoral shaft, and the distal femur (made up of the medial and lateral epicondyles, the medial and lateral condyles, and the trochlea) (figure 1). The femoral shaft can be further subdivided into the proximal third (subtrochanteric), middle third (midshaft), or distal third (supracondylar, intercondylar, condylar).

Several muscles of the hip and knee joint insert, originate on, or cross the femoral shaft. With a femoral shaft fracture, these muscles contract causing shortening of the fractured femur. Some traction, either skeletal or skin, is often required initially to prevent further shortening before definitive treatment.

The piriformis fossa is a particularly important femoral landmark (figure 1). The piriformis fossa lies at the base of the femoral neck and joins with the femoral shaft. It is the site of ascending vessels to the femoral neck, which can be compromised during the surgical management of femoral shaft fractures. (See 'Initial treatment' below.)

Unlike the proximal femur, the femoral shaft has a strong vascular supply that supports rapid healing following injury. The vascular supply to the shaft is from both the endosteal and periosteal blood vessels. The medullary artery supplies the inner two-thirds of the femoral shaft, while the periosteal vessels supply the outer third [10]. This strong vascular supply also accounts for the significant blood loss that can accompany a femoral shaft fracture in an adult. Unlike adult femoral shaft fractures, observational studies in children have not found significant hemodynamic compromise associated with isolated pediatric femur fractures [11-13].

MECHANISM OF INJURY — The femoral shaft is quite strong, and it is generally believed that high energy forces are required to fracture this bone. While this perception is generally true for transverse fractures, spiral femoral shaft fractures may result from fairly innocuous falls in ambulatory children, especially when they occur with a rotary force [9,14,15]. The specific mechanism of injury is most often related to the age of the patient:

Infants and toddlers — For infants and toddlers, falls and child abuse are among the leading causes of femoral shaft fracture [2-4,10]. Femur fractures have traditionally been identified as red flags for child abuse among young children (age <4 years). Evidence suggests that certain subgroups, most notably nonambulatory infants and toddlers younger than 24 months are at the highest risk [16]. However, intentional trauma remains an important cause of femoral shaft fractures for all young children and warrants a high index of suspicion in those without a plausible explanation for their injury. (See "Orthopedic aspects of child abuse", section on 'Femur fractures'.)

Children and adolescents — For toddlers to school-age children, falls remain the leading cause of femoral shaft fractures [2-4,8,9,17]. In this age group, even relatively low-energy injuries, such as a fall from a low height or fall while running, may result in a femoral shaft fracture [9,17].

As children reach their teenage years, motor vehicle/pedestrian collisions, motor vehicle collisions, and sports-related injuries account for the majority of femoral shaft fractures [2-4]. These results have been reproduced across several studies and in different countries [7,8].

Patients with predisposing conditions, such as osteogenesis imperfecta, or other reasons for generalized osteopenia, such as cerebral palsy, spina bifida, or other neuromuscular conditions, are at higher risk for femoral shaft fractures [4,10]. These patients require appropriate studies to rule out femoral shaft fractures even when they present with an apparently minor injury.

CLINICAL FINDINGS AND DIAGNOSIS — Most pediatric femoral shaft fractures can be diagnosed upon clinical presentation. The pediatric patient will have localized tenderness and swelling over the affected femoral shaft. Obvious deformity, shortening, and/or crepitus on palpation are usually present. The clinician should look for associated signs of a proximal femur fracture, such as pain in the hip joint and/or a characteristic externally rotated leg position, because femoral shaft fractures may have associated proximal femur fractures [10,18]. The skin needs to be carefully inspected for signs of an open fracture.

As with all fractures, a careful neurovascular exam distal to the site of the fracture before and after splinting is necessary to ensure that the displaced fracture has not damaged nerves or arteries.

Thigh compartment syndrome as a result of a femoral shaft fracture is rare, but carries significant morbidity [19]. Findings include tense thigh swelling and increasing pain, especially with passive movement of distal joints. Other classic symptoms of vascular occlusion (eg, pulselessness, pallor, paresthesias, and paralysis) may be seen with thigh compartment syndrome, as well, but are less common.

Clinical evaluation of a child with a femoral shaft fracture must also identify other concomitant and life-threatening injuries when associated with high energy trauma (eg, high speed motor vehicle collision). In this circumstance, the incidence of associated injuries has been estimated to be 28 to 38 percent and accounts for the majority of morbidity, mortality, and cost associated with the care of children who suffer femoral shaft fractures [2,3,6,11].

The term "Waddell's triad" was coined by Dr. Mercer Rang to describe a common pediatric injury pattern seen in young children who are hit by a motor vehicle when they run into the street. This pattern includes femur fracture, severe head injury, and thoracoabdominal injury [10]. These and other major life-threatening injuries have all been associated with femoral shaft fractures. Thus, a femur fracture is frequently associated with major multiple trauma and warrants a comprehensive assessment for multiple injuries in patients who have sustained high energy trauma. (See "Trauma management: Approach to the unstable child".)

RADIOGRAPHIC ASSESSMENT — Standard anterior posterior (AP) and lateral plain radiographs of the entire affected femur, from hip joint to knee joint, are necessary to identify the fracture and provide pertinent information required for proper treatment (image 1 and image 2).

Based upon the radiographic findings, the femoral shaft fracture can be evaluated for diaphyseal location (proximal, middle or distal third), configuration (transverse, oblique, spiral), angulation, amount of displacement, presence of comminution, and extent of shortening.

Transverse femoral shaft fractures should alert the practitioner to carefully examine the radiographs of the femoral neck because shaft fracture is associated with femoral neck fracture, particularly in instances of high energy trauma. Thus, a clear radiograph of the femoral neck is mandatory.

Given the low frequency of associated ipsilateral femoral neck fractures (<1 percent) in children with femoral shaft fractures, routine computed tomography of the femoral neck in children with femoral shaft fractures caused by low-energy mechanisms is not warranted [20].

Children under two years of age in whom child abuse is suspected should undergo a skeletal survey to be evaluated for other bony injuries. (See "Orthopedic aspects of child abuse", section on 'Skeletal survey'.)

INITIAL TREATMENT — Fractures of the femur represent significant injury, and almost always warrant early, urgent intervention [10].

Stabilization — Patients with high energy trauma (eg, high speed motor vehicle collision) associated with femoral shaft fractures should be rigorously evaluated by standard trauma guidelines, including establishment of an airway with immobilization of the cervical spine, evaluation for pulmonary and circulatory compromise and placement of appropriate vascular access. (See "Trauma management: Approach to the unstable child", section on 'Initial approach' and "Trauma management: Approach to the unstable child", section on 'Primary survey'.)

For children with an isolated femoral shaft fracture and no other serious injury, initial therapy consists of pain management and immobilization.

Analgesia — Parenteral or intranasal opioid analgesia (eg, intravenous morphine or intranasal fentanyl) is most appropriate for initial pain control in children with femur fractures and should be given as soon as possible in the hemodynamically stable child.

Immobilization — Once distal neurovascular function has been tested and evaluation for open wounds of the skin is complete, all femur fractures should be immobilized for comfort. Plaster, fiberglass, and various prefabricated splints are commonly used to provisionally stabilize the fracture.

Splints work best when immobilizing both the hip and the knee. Consequently, splints placed laterally from the iliac crest to the ankle are quite effective. Splints can be further bolstered, or even substituted, by pillows, blankets or other types of bulky padding.

Paramedical staff will frequently use traction splints to stabilize suspected femoral fractures in the field. These traction splints should be removed as soon as possible after arrival in the emergency department to prevent pressure ulcers from developing where the splints compress the skin. The traction splint should be replaced by a padded provisional splint as described above.

Skeletal traction (traction applied to temporary pins drilled through bone), although commonly used in adults, is less frequently used in pediatric patients. Such traction is typically avoided initially because improper pin placement and excessive traction risk injury to growth plates. If a traction pin is deemed necessary, it should be placed by an experienced pediatric orthopedist in an operating room using sterile technique and radiograph guidance.

Child protection — Diagnosis of a femoral shaft fracture in a child, especially a nonambulatory infant, with a questionable mechanism of injury should prompt further evaluation for child abuse (table 1) and involvement of an experienced child protection team (eg, social worker, nurse, child abuse specialist), if available. In many parts of the world (including the United States, United Kingdom, and Australia), a mandatory report to appropriate governmental authorities is also required for cases of suspected abuse. (See "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Social and medicolegal issues", section on 'Reporting suspected abuse'.)

In addition, the medical care team should ensure that children under two years of age with suspected intentional trauma undergo additional evaluation to determine the presence of other injuries once stabilized. The safety of other children in the home must be ensured by local Child Protective Services. (See "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Evaluation and diagnosis of abusive head trauma in infants and children", section on 'Evaluation'.)

INDICATIONS FOR ORTHOPEDIC CONSULTATION — All femoral shaft fractures must be evaluated by an orthopedic surgeon with appropriate pediatric expertise.

DEFINITIVE CARE — Definitive care for fractures of the femoral shaft can vary significantly, from short splint immobilization to open, operative treatment [10,21,22]. In general, treatment largely depends upon the age of the patient, the patient's premorbid function, and the child's ability to tolerate an operation [23]. Children less than five years of age, especially nonambulatory infants, are more commonly treated with nonoperative measures [22]. Multiple trauma or the presence of an open fracture may also significantly alter the treatment plan. In addition, severely injured trauma patients may undergo nonoperative treatment until their hemodynamic status stabilizes so that they can tolerate the significant blood loss often associated with operative repair of femoral shaft fractures.

Treatment options include: bracing, splinting, casting, traction, closed or open reduction with external frame fixation, and internal fixation with a plate or intramedullary rod (table 2).

Nonoperative care — Children five years old and younger rarely require operative intervention [24-26]. Infants <12 months of age are easily treated with a well-padded splint. In neonates, soft cotton roll and a tongue depressor makes a nice splint of appropriate size and padding. The use of a Pavlik harness has also been described in the treatment of femoral shaft fractures in children <4 months of age, and in selectively smaller infants up to six months of age (image 3) [27,28]. Femur fractures in this age group usually heal within a month without long-term complications. (See 'Complications' below.)

In larger infants up to a year of age, a traditional splint, as described previously, or, preferably, a hip spica cast is adequate. For fractures with >2 cm of shortening, a course of skin or skeletal traction should be entertained.

Older infants, toddlers and young children are most commonly treated in a hip spica cast (picture 1) [28-30]. Closed reduction under sedation is required for fractures with more than 10 degrees of angulation. Again, fractures that are significantly shortened (>2 cm) may require a few weeks of traction to reduce residual leg length discrepancy [29]. Traction via application of a short leg cast prior to completion of the hip spica is discouraged due to reports of associated compartment syndrome [31].

Operative intervention — As children approach six years of age, intramedullary flexible rods may be considered in stable fracture patterns. Successful use of plates and external fixators has been described in this age group [10,32]. Extenuating circumstances, such as the multiply traumatized child, the presence of vascular injury, or other soft tissue constraints, are situations in which one of these modalities is more appropriate to implement. The expertise of an orthopedic surgeon well versed in the care of a child is paramount in these situations.

By about age six, much stronger consideration is given to intramedullary fixation (image 4). The larger the child, the more appropriate it is to avoid a hip spica cast. Hip spica casts are much more difficult to manage in larger children, and older children are more capable of ambulating with crutches or a walker [30].

Options for fixation vary by age:

●In children 6 to 10 years of age, closed reduction and flexible intramedullary rod fixation are the treatments of choice [26,33-36]. The use of submuscular bridge plating, a construct that prevents shortening, is more appropriate in highly comminuted, and therefore unstable, fracture patterns in children who weigh more than 50 kg [37-41].

●After age 11, the diameter of the femur will allow intramedullary fixation with a rigid locked rod, which is then the preferred treatment [6,42]. In younger children the traditional piriformis fossa starting point is associated with a small, but significant rate of osteonecrosis of the femoral head (average age 11.7 years). Consequently, a trochanteric starting point is used until skeletal maturity has been attained. Once skeletally mature, a piriformis fossa starting point is preferred for the adolescent population [42]. Traction followed by casting, external fixation and submuscular plating are all appropriate and effective alternatives in this age group as well, but are, again, generally reserved for unusual circumstances as outlined previously.

DISPOSITION — Spica cast care can be daunting for families, particularly in the face of the psychological stress imposed by the injury itself [25]. Patients placed in a spica cast are best served by initial hospital admission for spica cast care and parental education as well as obtaining an appropriate car seat. This not only ensures proper cast care, but allows the patient's family to ease into the burden of caring for a child in a spica cast.

Children who undergo operative repair or are treated in traction require admission to the hospital for ongoing monitoring to prevent neurovascular compromise or malunion [10,35,43,44]. In most instances, children can be transitioned to a spica cast after three weeks of traction.

FOLLOW-UP CARE — Significant healing of femoral shaft fractures usually occurs by six weeks after treatment. As such, treatment by casting, splinting or traction rarely exceeds this time frame. Uncomplicated courses generally do not require more than a year of follow-up. Those with complications may require prolonged monitoring until skeletal maturity is reached.

Treatment with an external fixator allows early mobilization, however, refracture or secondary fracture through the pin holes are well known complications after frame removal [45-48]. As such, external fixators are left in place until solid fracture union is demonstrated radiographically to reduce the risk of refracture [10]. This can be as long as four months after placement of the frame (10 to 16 weeks). Children with internal fixation, be it plating or intramedullary stabilization, are also easily mobilized. Removal of these implants is often performed six months or more after definitive treatment, if at all.

Most children rehabilitate without much formal intervention. For children treated with internal or external fixation, early mobilization is facilitated by a physical therapist prior to discharge from the hospital, but typically, physical therapy is not required thereafter. Knee stiffness is uncommon, but can occur with flexible nails placed distally or with an external fixator [32,33]. In these cases, physical therapy can be beneficial in regaining lost motion.

COMPLICATIONS — As a rule, complications in the treatment of pediatric femur fractures are uncommon [21,30,33,45]. Many undesired outcomes can be overcome through the resiliency of childhood and growth. Complications from femur fractures can be broken down into two general categories: perioperative and remote. Perioperative complications are those encountered early on and are associated with the significant energy required to result in a femur fracture. Remote complications are typically the result of surgical oversight or altered biology. The rate of complications may be higher following the use of flexible intramedullary nails in children with length unstable fractures, children weighing in excess of 49 kg, and children older than 11 years of age [37,39].

Perioperative — Perioperative complications include neurovascular injury, compartment syndrome, and infection. They are often associated with higher energy trauma such as motor vehicle accidents and falls from extreme heights:

●Nerve injuries are often transient, but can result in permanent nerve palsy.

●Vascular injuries warrant further evaluation with angiography or Doppler studies, and require urgent surgical treatment [49].

●Infection typically presents approximately a week postoperatively, but can be delayed by several weeks (low grade infections may manifest as nonunion months after initial treatment) [50].

●Implant prominence or extrusion with use of flexible intramedullary nails may warrant reoperation, generally with in the first few months after initial treatment [37].

Complications related to the altered pathophysiology and anatomy related to the fracture itself and the ensuing prolonged immobilization include fat embolus, venous thrombosis, and obstructive compression of the duodenum by the superior mesenteric artery (cast syndrome). (See "Fat embolism syndrome" and "Venous thrombosis and thromboembolism (VTE) in children: Risk factors, clinical manifestations, and diagnosis" and "Superior mesenteric artery syndrome".)

Remote — Remote complications such as shortening, overgrowth, leg length discrepancy, malunion (angular and rotational), and nonunion are relatively uncommon, and require intervention even less commonly.

●Minor discrepancies in length, rotation, and angular deformity are generally well tolerated [44,51]. In younger children, these abnormalities often resolve spontaneously with growth [52]. In the rare case of symptomatic angular or rotational deformity, corrective osteotomy, ideally over an intramedullary device, is an effective treatment [10].

●Leg length discrepancies are generally small. When the predicted leg length difference at maturity is <2 cm, shoe inserts are the recommended treatment of choice. For predicted differences of 2 to 5 cm, contralateral epiphysiodesis (growth plate obliteration) can be performed prior to reaching skeletal maturity, resulting in the equalization of leg lengths. If the child has already reached skeletal maturity, then femoral shortening with intramedullary fixation is the recommended treatment of choice. Patients with a predicted leg length difference >5 cm are typically treated with femoral lengthening via distraction osteogenesis.

●Nonunion in children is very uncommon [10]. It is typically associated with infections or cases in which significant soft tissue injury has occurred. Workup for infection should always occur in the face of fracture nonunion, including inflammatory markers such as white blood cell count, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Treatment after placement of a solid intramedullary nail may include dynamization of the nail by removing the distal locking screws, thereby allowing compression of the fracture and increasing healing potential. In most other instances, open treatment with curettage of fibrous nonunion and bone grafting with either autograft (gold standard) or demineralized bone matrix are warranted. Rigid fixation with a plate or rigid nail is often required, but not mandatory, as in the adult population.

●Osteonecrosis of the femoral head has been reported in skeletally immature patients who have had a rigid femoral nail placed through the piriformis fossa [53]. The primary blood supply to the femoral head, via the lateral epiphyseal vessels, is interrupted by reaming through the piriformis fossa [54]. Consequently, use of the greater trochanter with appropriately engineered rigid nails is recommended in the skeletally immature child.

●Treatment with an external fixator may result in complications solely associated with this treatment option, and bears special mention [47]. Pin tract infections are very common with the use of external fixators [47]. These can be prevented with good pin care and the pre-drilling of pin holes, thus preventing thermal injury to the bone. Short courses of oral antibiotics can be helpful at keeping pin site infections at bay. Refracture through the original injury or fractures through pin holes after frame removal have also been reported to occur up to 20 percent of the time. Refracture has been attributed to premature frame removal. Because of these complications, the use of external fixation has been relegated to cases where soft tissue injury demands access to the wound and placement of internal fixation may raise concerns about deep infection [10,32].

RETURN TO ACTIVITIES — All patients with femur fractures have early limitations to their mobility. Physical therapy is required in patients who are old enough to navigate with crutches or a walker. A wheelchair is provided for all patients to facilitate longer distances. Once ambulatory, physical therapy is rarely necessary. Occasionally, knee stiffness can develop due to placement of flexible nails about the knee [55].

Full weight bearing, with rare exception, is expected by six weeks after initiation of treatment. By three months, the majority of patients will be able to gradually return to normal activity, with full function typically restored by six months.

Patients treated in an external fixator should be restricted from sports and high impact activities for an additional six to eight weeks after removal of the frame.

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" and "Society guideline links: Child abuse and neglect".)

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 topic (see "Patient education: How to care for your child's cast (The Basics)")

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

SUMMARY AND RECOMMENDATIONS

●Epidemiology – The femur is the largest bone in the body, the diaphysis is the most common site of femur fracture in children (figure 1). (See 'Epidemiology' above and 'Pertinent anatomy' above.)

●Mechanism of injury – For infants and toddlers <24 months old, intentional trauma (ie, child abuse) is an important cause of femoral shaft fracture, especially in nonambulatory infants. (See 'Infants and toddlers' above.)

Falls while playing or motor vehicle collisions are common mechanisms of injury in older children and adolescents. A femur fracture is frequently associated with major multiple trauma and warrants a comprehensive assessment for multiple traumatic injuries when a high energy force has occurred including a complete primary and secondary survey. (See 'Children and adolescents' above and "Trauma management: Approach to the unstable child".)

●Clinical findings and diagnosis – The pediatric patient with a fractured femur will often have localized tenderness and swelling over the affected femoral shaft, with limited mobility of that leg. Obvious deformity, shortening, and/or crepitus on palpation are usually present. (See 'Clinical findings and diagnosis' above.)

Standard anterior posterior (AP) and lateral plain radiographs of the entire affected femur, from hip joint to knee joint, are necessary to identify the fracture and provide pertinent information required for proper treatment (image 1 and image 2). In the patient with femoral shaft fracture resulting from high energy trauma, a clear radiograph of the femoral neck is mandatory. (See 'Radiographic assessment' above.)

Children under two years of age in whom child abuse is suspected should undergo a skeletal survey to evaluate for other bony injuries. (See "Orthopedic aspects of child abuse", section on 'Skeletal survey'.)

●Initial treatment – For children with an isolated femoral shaft fracture and no other serious injury, initial therapy consists of pain management and immobilization. (See 'Initial treatment' above.)

●Definitive care – All femoral shaft fractures must be promptly evaluated by an orthopedic surgeon with appropriate pediatric expertise. Definitive care for fractures of the femoral shaft can vary significantly, from short splint immobilization to open, operative treatment primarily depending on the age of the patient (table 2). The presence of multiple serious injuries and/or an open femur fracture are additional important modifying factors. (See 'Indications for orthopedic consultation' above and 'Definitive care' above.)

Significant healing of pediatric femoral shaft fractures usually occurs by six weeks after treatment. Full weight bearing, with rare exception, is expected at this time. By three months, the majority of patients will be able to gradually return to normal activity, with full function typically restored by six months. (See 'Follow-up care' above and 'Return to activities' above.)

●Child protection – Diagnosis of a femoral shaft fracture in a child, especially a nonambulatory infant, with a questionable mechanism of injury should prompt further evaluation for child abuse (table 1) and involvement of an experienced child protection team (eg, social worker, nurse, child abuse specialist), if available. In many parts of the world (including the United States, United Kingdom, and Australia), a mandatory report to appropriate governmental authorities is also required for cases of suspected abuse. (See "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Social and medicolegal issues", section on 'Reporting suspected abuse'.)