Introduction: Scope and Purpose
The evolution of the treatment of pediatric femoral fractures has paralleled societal changes and expectations in the delivery of health care. Historically, clinicians were content to provide adequate treatment with acceptable functional outcomes. Today, patients and their caregivers expect optimal outcomes with less disruption in their lives. A trend demonstrating increased operative care for fractures has been noted. Current expectations include a return to preinjury function as soon as possible with the minimum amount of intervention, little need for additional caregiver assistance, and an excellent long-term outcome.
Anatomy and Development
As the longest, most voluminous, and strongest bone of the human body, the femur consists of a tubular shaft, hemispheric head, and bicondylar distal end. The anatomy of the greater trochanter deserves attention because it serves as an important landmark in the treatment of femoral shaft fractures. In the sagittal plane, the tip of the trochanter is located eccentrically at the junction of the first and second thirds of the greater trochanter. This point is posterior to the femoral head as noted on a lateral radiograph. This position varies with relative changes in the version of the head and neck. The femur constitutes 26% of the total adult height. The contribution of femoral growth by the proximal and distal femoral growth plates is 29% and 71%, respectively ( Fig. 14-1 ).
The femur forms from the mesoderm at approximately 4 weeks of embryonic life. Eight weeks after fertilization of the ovum, during the transition from embryonic to fetal life, the primary ossification center of the diaphysis begins transforming from a cartilage anlage into bone. At 16 weeks, the entire femoral shaft is ossified.
The proximal secondary ossification centers are rarely present at birth. Proximally, the cartilaginous mass develops in three distinct stages: (1) femoral head at 6 months of age, (2) greater trochanter at 3 to 4 years of age, and (3) lesser trochanter at 7 to 9 years of age. The role of the greater trochanteric apophysis in proximal femoral development is important in treating femoral shaft fractures. Indirect evidence suggests that the role of this ossification center on the angulation of the femoral neck becomes less significant by 8 years of age.
The distal secondary ossification centers are present at birth. The use of evolving techniques to evaluate distal femoral development has introduced some controversy about the actual dates of appearance of these ossification centers.
The femoral shaft blood supply consists of endosteal and periosteal contributions. An equal proportion of individuals have either one or two nutrient arteries that supply the femoral diaphysis as branches of the deep femoral artery. The vessels enter the shaft posteromedially at the proximal and distal third junctions, respectively. The nutrient arteries give rise to the endosteal or intramedullary blood supply to the inner two thirds of the cortex. Generally, two periosteal vessels supply the outer third of the cortex. One vessel each arises from the femoral and deep femoral arteries. This dual blood supply is important because methods of treatment that involve reaming of the intramedullary canal destroy the endosteal blood supply. Fortunately, the intact periosteum and its blood supply remain, allowing adequate blood flow for fracture healing via periosteal invasive remodeling.
Knowledge of the blood supply to the femoral head is imperative in the treatment of femoral shaft fractures. The blood supply to the femoral head is provided primarily from the ascending branches of the medial femoral circumflex artery, the most notable of which is the lateral ascending cervical artery. This branch crosses through the piriformis fossa on its way to the femoral head ( Fig. 14-2 ).
Femoral osteology is unique. Many of the features are dynamic and evolve from childhood to adulthood. For instance, the orientation of the femoral shaft in relation to the femoral head and neck changes during childhood. The neck–shaft angle and amount of anteversion present in the femoral neck decreases with growth, beginning at 150° and 40°, respectively, and finally resting at 130° and 10°. An anterior bow exists in the upper third of the femoral shaft and is maintained throughout life. This curvature requires consideration when rigid intramedullary nailing is used as a treatment option.
Demographics and Mechanism of Injury
The incidence of femoral fractures is on the rise, similar to the rise in nearly all pediatric injuries. Increased participation in organized sports and extracurricular activities is driving this trend. Femoral fractures represent the most common reason for hospitalization for traumatic pediatric orthopaedic injuries, accounting for 21.7% of admissions in a U.S.-based, nationwide study during 1997. Femoral fractures are costly as well; the length of stay and hospital charges lead that of any other extremity injury as noted in the same study. Although these are most commonly isolated injuries, femoral fractures can be associated with additional injuries.
Femoral shaft fractures occur twice as often in boys than in girls. Predictors of femoral fractures change with age. The risks have been found to be higher among children with lower socioeconomic indicators across all age groups.
The incidence of femoral fractures is bimodal, with the initial peak at 2 to 3 years of age and a second peak at 17 to 18 years.
Children experience isolated femoral fractures more often than adults. Fatalities from femoral fractures are rare in children: usually 1 in 600, or 0.17%. Although the mortality rate exceeds that of any other extremity injury, it is one half the rate of spine and pelvic injuries. Death associated with femoral fractures is generally caused by the presence of multiple associated injuries, particularly in association with significant closed head injuries.
Of note, pediatric femoral fractures can result from nonaccidental trauma, pathologic causes, and stress syndromes. Fractures associated with nonaccidental trauma tend to occur in the distal femur or in combination with the distal femur. Up to 30% of femoral shaft fractures in children younger than 4 years may be the result of child abuse, and the most common cause of femoral fractures in nonambulatory infants is nonaccidental trauma. Factors suggestive of child abuse include bruises, burns, multiple fractures in various stages of healing, and late presentation (see Chapter 18 ).
The femur is a very common location for pathologic fractures in children. These fractures occur through weak bone that lacks normal biomechanical properties as a result of intrinsic processes, such as metabolic bone disease or tumors. Extrinsic processes, such as hardware removal or radiation, can also weaken the bone and result in a fracture. Although one third of pathologic fractures occur in the proximal and distal ends of the femur, the diaphysis remains a relatively common location for fractures resulting from fibrous dysplasia and osteosarcoma.
Stress or fatigue fractures occur when an exceptional repetitive force, such as with athletic training, is exerted on bone that fails to remodel. A precipitating event or increase in activity is rarely identified in the history, although the diagnosis is characterized by pain and a limp. This vague presentation is common to many pediatric conditions and creates a diagnostic challenge.
Evaluation
History and Physical Examination
The history is important because treatment varies depending on the mechanism of injury. In particular, the energy required to cause the injury is important. The treatment of a fracture resulting from a high-energy motor vehicle accident is approached differently than a pathologic or stress fracture. High-energy fractures are more likely to have associated soft tissue injury. The presence of significant soft tissue injury or periosteal stripping should influence the treatment options because these injuries are less amenable to closed treatment.
A suspicious history may lead one to investigate nonaccidental trauma as a cause of the fracture. Differentiating between nonaccidental and accidental trauma is anxiety-provoking for both the physician and the caregiver. The well-being of the child is paramount, yet preserving a working relationship with the caregivers can be done with care and time. Understanding the demographics and different disease processes responsible for nonaccidental trauma can assist in narrowing the differential diagnosis. The injury plausibility method helps tabulate historical data into the likelihood of injury from falling from stairs, a common occurrence yet also a common false reason given to explain child abuse (see Chapter 18 for additional detail).
The history may assist with the identification of accompanying injuries. For instance, the Waddell triad describes the associated head injury, intrathoracic or abdominal injury, and femoral fracture that can occur from a pedestrian versus motor vehicle accident. The Waddell triad is actually less common than previously thought, and the more common ipsilateral upper extremity and pelvic injuries should be closely evaluated.
The physical examination of an injured, conscious child always begins by gaining the patient’s trust and reassuring the family. A reliable examination of the injured extremity can begin only after a nonthreatening relationship is established. Careful inspection for obvious deformities or swelling is performed, and any soft tissue defects are measured and recorded. Careful palpation of the nontraumatized areas is done to identify secondary injuries. A motor and sensory examination is performed, and peripheral pulses are documented. The examination of the injured extremity is compared with the status of the uninvolved extremity. Any difference warrants further evaluation.
In patients with ipsilateral fractures proximal and distal to the knee (floating knee), it is imperative to evaluate the vascular status of the extremity more carefully. Hard signs of vascular injury are obvious and include pulsatile hemorrhaging, an expanding hematoma, a palpable thrill or audible bruit, or a pulseless limb. More subtle physical clues include unequal pulses, decreased two-point discrimination distal to the fracture, or a nonpulsatile hematoma. However, physical examination alone is not reliable enough to preclude further workup in high-risk injuries. An ankle–brachial index (ABI) can be used in the emergency department as a screening test. A value less than 0.9 warrants additional radiographic imaging.
Assessment of the injured portion of the thigh is reserved for last and should be performed gently. Traction, reduction, or wound probing should be minimized in patients likely to undergo surgery. These maneuvers should be conducted in the operating room, when possible. The exception is in patients whose deformity and pain can be relieved by manipulation and splinting. If manipulation is performed, serial neurovascular checks should be conducted.
It is imperative during the initial assessment of femoral fractures to search for accompanying injuries. In patients with isolated femoral shaft fractures, hemodynamic insufficiency is rare, and volume support is not customarily required. If a patient is seen with hypotension, hypovolemia, or anemia, further investigation must be performed to identify another cause for the bleeding other than the femoral fracture. Typically, only patients with additional trauma have significant decreases in both hemoglobin concentrations and hematocrit levels compared with patients with isolated femoral fractures. An obvious decrease in hematocrit or hemoglobin concentration in a child with a femoral fracture nearly always indicates additional injury.
In high-energy trauma, examination is dictated by the Advanced Trauma Life Support (ATLS) protocol. The initial assessment is directed to the airway, breathing, and chest compressions (ABCs), and attention to any limb injury is focused on circulatory (hemorrhage) control from open injuries. All limbs are stripped of clothing during the initial examination. Once the patient is stabilized, a secondary survey can be conducted. The limbs are evaluated for further injury by examination for bruising or deformity and palpation for tenderness, crepitus, diminished pulses, and limited joint range of motion. If the patient is stable, further radiographic imaging can then be performed if additional fractures are a concern.
Ipsilateral intraarticular knee injuries are a very common (up to 70%) associated injury with diaphyseal femoral fractures in the adult population. The pediatric incidence is unknown, but one should have increased suspicion for these injuries in older children and adolescents. Cruciate and collateral ligament tears and meniscal and osteochondral injuries can occur. Examination for intraarticular injuries is difficult in the acute care setting. A complete ligamentous examination is most easily obtained intraoperatively after stabilization of the femoral fracture and postoperatively by serial evaluation.
Imaging
High-quality anteroposterior (AP) and lateral plain films that include both the hip and knee joints are generally the only radiographic studies required to diagnose and treat pediatric femoral shaft fractures. The advent of the picture archiving and communication system (PACS) has greatly facilitated measurement of intramedullary canal size and femoral length.
Many practitioners advocate traction films for evaluating stability and predicting treatment outcomes after femoral fractures. The “telescope test” described by Thompson and colleagues predicts that unacceptable final shortening of 25 mm is 20 times more likely if initial shortening of 30 mm or more was identified during the test. The telescope test is a gentle compressive force applied manually across the fracture site. Radiographs are made on standard cassettes with the x-ray beam perpendicular to the fracture site so that maximum overriding of the fracture fragments can be documented. Interestingly, a resting radiographic overlap was not predictive of the final outcome in this study.
Excessive shortening is presumed to result from associated soft tissue injury. Often, the history and physical examination can help predict the likelihood of excessive shortening. Documentation of excessive shortening can often justify the use of more invasive treatment methods.
Computed tomography (CT) can be helpful in the evaluation of physeal or periarticular fractures but is not required in isolated femoral shaft fractures. A bone scan may be useful for the detection of suspected stress or pathologic fractures but is unlikely to yield helpful information in a traumatic fracture. Bone scans have been described as an adjuvant modality for diagnosis of orthopaedic injuries missed in the initial screening of multiply injured patients with head injuries.
Magnetic resonance imaging (MRI) is valuable for assessment of intraarticular pathology, stress fractures, and pathologic lesions. Ipsilateral epiphyseal, ligamentous, meniscal, and osteochondral pathology are relatively common. In particular, one should be concerned about osteochondral injury or bone bruises in patients with persistent knee pain after a healed diaphyseal femoral fracture. MRI is increasingly becoming the diagnostic modality of choice for stress fractures.
Vascular compromise should be evaluated in an expeditious manner. Arteriograms are the historical gold standard for investigating vascular insufficiency. Assessment with duplex ultrasound, ABI, or both may be useful for determining the need for an arteriogram in equivocal cases. Identification of an arterial injury is more likely to occur when the physician suspects and evaluates for a vascular injury. Physical examination alone has proved inadequate for diagnosing vascular compromise.
Adequate radiographic imaging must be performed to ensure acceptable treatment. However, lifetime risks associated with radiation exposure are inversely proportional to the age of the patient at the time of exposure. All available precautions, including gonadal shielding, must be taken to reduce radiation exposure risk. A pediatric CT protocol should be used for evaluation of pediatric trauma patients so that radiation exposure is limited.
Classification
Classification systems provide descriptive information and serve as a basis for selecting optimal treatment, predicting the outcome, and comparing results of various treatment modalities. Maurice E. Müller believed this general theorem and stated that “a classification is useful only if it considers the severity of the bone lesion, and serves as a basis for treatment and for evaluation of the results.” He subsequently developed the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, which is commonly used in describing adult fractures as combined in the Orthopaedic Trauma Association (OTA)-AO classification system.
Currently, no universally accepted pediatric fracture classification system exists. Neither the AO nor any other classification system is commonly used to describe pediatric femoral shaft fractures. Pediatric femoral shaft fractures are classified according to (1) cause, (2) soft tissue integrity, (3) anatomy, and (4) fracture pattern.
The cause of the femoral fracture determines the nomenclature. Pathologic fractures are the result of tumors, metabolic disorders, or other processes resulting in abnormal bone biomechanics. Stress fractures occur secondary to overuse syndromes. Nonaccidental fractures are caused by intentional harm.
The status of the soft tissue envelope plays an important role in the treatment of femoral fractures. Fractures are considered open if the bone communicates with a wound in the skin and closed if the skin is intact. Ballistic wounds warrant close attention. In particular, “wadding,” which is the barrier between the pellets and gunpowder in shotgun shells, must be accounted for. It is important to note that injuries with intact skin can also have compromised soft tissues. The soft tissue envelope and thick periosteum play a significant role in pediatric fracture stability, and this is inversely proportional to the age of the child. Excessive soft tissue injury and periosteal stripping result in unacceptable instability and preclude certain treatment options. Specific examples include bicycle spoke injuries and mangled extremities.
The anatomic location of the femoral fracture has important implications for treatment. Femoral shaft fractures are considered to be subtrochanteric, diaphyseal, or supracondylar. Subtrochanteric femoral fractures present unique problems in fracture management. Fractures in this region have limited capacity to compensate for malalignment, and the strong deforming muscle forces place the proximal fragment in a flexed, abducted, and externally rotated position. This malalignment makes maintenance of fracture reduction difficult. The definition of a pediatric subtrochanteric femoral fracture is controversial. Pombo and Shilt advocated that a fracture that occurs within 10% of the total length of the femur below the lesser trochanter should be classified as subtrochanteric. Other published definitions include a fracture that occurs in the proximal third of the femur, within 2 to 3 cm below the lesser trochanter, and in the proximal fourth of the femur. The length of the femur increases with age, and children of the same age can have different femoral lengths. Therefore, a definition that takes into account the wide range of femoral lengths in the pediatric population may be the most accurate. Supracondylar femoral fractures historically presented similar problems with definition and management. Butcher and Hoffman defined a supracondylar femoral fracture as one in which the distance from the fracture to the knee joint center was equal to or less than the width of the femoral condyles. Hyperextension of the distal fragment is common secondary to forces from the gastrocnemius muscle. Although less common, a residual flexion deformity at the fracture site can result in interference with patellar tracking. Recognition of these difficult fractures from the more easily treated diaphyseal fractures is critical.
Finally, the fracture pattern provides further understanding of its inherent stability. Commonly described fracture patterns include simple transverse, short oblique, long oblique, long spiral, or comminuted. Simple and short oblique fracture patterns are considered “length-stable.” Long oblique, long spiral, and comminuted fracture patterns are considered “length-unstable.” Specifically, long oblique and comminuted fractures are defined as follows:
Long oblique: The length of the obliquity is twice the diameter of the femur at the level of the fracture.
Comminuted or multifragmentary: More than one continuous fracture is present, of which there are two types:
Butterfly or wedge: The two main fragments maintain some contact.
Complex: No contact is present between the two main fracture fragments.
This differentiation is critical because the method of treatment may need to be modified so that adequate stability is ensured for the specific fracture pattern.
Management
As indicated earlier, patients and their families are increasingly well informed and expect optimal outcomes with the least disruption in their lives. This approach is reasonable but must be tempered by the physician’s knowledge of available options, his or her technical ability, and potential complications. The management trend of pediatric femoral shaft fractures has progressed from pervasively nonoperative to operative at most centers. Evidence-based reviews demonstrate fair to good evidence that operative treatment reduces the rate of malunion and total adverse events. This trend, cited in multiple sources in the literature, has reduced inpatient length of stay by nearly 75% and has decreased the overall cost of treatment by more than 60% in comparison with traction alone and by almost 30% in comparison with traction followed by casting in certain series. An operative approach has historically been more prevalent in patients with multiple injuries. The benefits noted in the operative management of the multiply injured patient are now also evident in patients with isolated injuries. Patients with an isolated injury are now seldom treated more conservatively than those with additional injuries.
Certain accompanying injuries deserve further attention. In particular, the underlying cause must be considered in patients with vascular injuries. Direct arterial repair with or without end-to-end anastomosis, interposition of an autogenous reversed saphenous vein graft, and, in rare cases, ligation are all potential treatment options in patients with direct vessel injury. In blunt trauma, however, endovascular stenting of the involved vessel has been described and may be an acceptable treatment alternative.
Emergent Treatment
The optimal timing of surgical stabilization of femoral shaft fractures in children is controversial. Polytrauma patients who are not medically stable enough to undergo definitive fixation can be treated with temporary external fixation or traction, with conversion to intramedullary nailing within 2 weeks if their medical condition improves. Patients who are medically stable should undergo definitive fixation on their initial presentation. Although the exact timing of operative management of open fractures is controversial, open fractures should be treated with urgent irrigation and débridement and temporary or definitive fracture fixation.
Indications for Definitive Care
The treatment of femoral shaft fractures has traditionally been age based ( Table 14-1 ). Although age may serve as one reasonable guideline, the large variance in patient morphometry and skeletal age precludes this demographic as the sole guide to treatment. Using age alone fails to address problems in children who are extremely large or small and immature for their chronologic age. Hence, many treatment failures occur as a result of mismatching between the biomechanical demands of the fracture and the stability provided by a chosen treatment ( Fig. 14-3 ). For consistency purposes, the authors use an age-based approach, realizing that there is acceptable variability at each end of the age limits proposed to accommodate the aforementioned variance in patient morphometry.
| ≤6 MONTHS | 6 MONTHS TO 5 YEARS | 5 TO 11 YEARS | ≥11 YEARS | |
|---|---|---|---|---|
| Stable | Pavlik | Spica cast | Flexible intramedullary nailing | Rigid trochanteric entry intramedullary nailing |
| Spica cast | ||||
| Unstable | Pavlik | Spica cast | Flexible intramedullary nailing | Rigid trochanteric entry intramedullary nailing |
| Spica cast | Plating | Plating | Plating | |
| External fixation | External fixation |
Fractures in infants 6 months or younger can be treated in a Pavlik harness or spica cast. Neonatal fractures heal quickly in 2 to 3 weeks and remodel significantly. Pavlik harness treatment may be preferable secondary to the many reported disadvantages of spica casting.
Fractures with less than 2 cm of shortening in children 6 months to 5 years of age can be treated with early spica casting or traction with delayed spica casting. However, fractures with greater than 2 cm of shortening are unstable and may require an alternative treatment method, such as plating or external fixation. Fractures are generally considered unstable because of significant shortening or angulation. Either parameter can occur secondary to excessive soft tissue stripping or the nature of the bony injury. Both are indicative of high-energy injury. Typically, overriding of the fracture segments by 2 cm is an indirect measure of disruption of the periosteal sleeve. Long oblique, long spiral, and comminuted fracture patterns are length-unstable. The telescope test (described in the section on Imaging) can be used to determine fracture stability. In unstable fractures, the authors prefer to use a submuscular plating technique because of the well-reported complications of external fixation.
Length-stable fractures of the femur in children 5 to 11 years of age can be treated with flexible intramedullary nailing. ∗
∗
Children with femoral shaft fractures treated with flexible intramedullary nailing have been found to have less residual angular deformity, less leg-length discrepancy, shorter hospitalization, earlier ambulation, earlier return to school, lower overall cost, better scar acceptance, and higher overall parent satisfaction than children treated with traction and spica casting. Earlier advancement to full weight-bearing, shorter time to regain full range of motion, earlier return to school, lower complication rate, and less residual malalignment have also been reported with flexible intramedullary nailing compared with external fixation. This technically simple, economic, safe modality of treatment can be used when the intramedullary canal size allows and should be used until it is no longer biomechanically sound to do so. Children who weigh more than 49 kg who are treated with titanium elastic nails are at increased risk of a poor outcome. Therefore an alternative treatment option, such as plating or rigid trochanteric entry intramedullary nailing, should be used. Unstable fractures in this age group can be treated with stainless steel flexible intramedullary nails, plating, or external fixation.Finally, children age 11 years to skeletal maturity can be treated with rigid trochanteric entry intramedullary nailing if the femoral canal is large enough to accommodate the nail. Rigid nailing has been used safely in the treatment of adult femoral shaft fractures for decades. This universally accepted treatment method has multiple advantages over historical methods and has few disadvantages. For this reason, it has remained the mainstay of treatment since its inception five decades ago. This modality has also been shown to be successful in the pediatric population. One notable difference between rigid nailing in adult and pediatric patients is the risk of avascular necrosis of the femoral head. This complication results from injury to the posteriorly based blood supply to the femoral head in patients with open proximal femoral physes. A 2% risk of avascular necrosis of the femoral head has been associated with a rigid nail inserted at the piriformis fossa. Modern pediatric rigid nails are inserted at the lateral aspect of the greater trochanter. The risk of avascular necrosis can be decreased with the use of a lateral trochanteric entry point. Thorough knowledge of the technique is required before use of this technique is advised.
As true for most guidelines, these are general recommendations. The specific characteristics of the fracture and patient’s status must be considered. Individual circumstances always dictate fracture management.
Nonoperative Treatment
Skin Traction
General indications for the use of this modality are limited and should be avoided in children weighing more than 12 kg. Skin integrity must be intact and not compromised by soft tissue injury. A well-applied Thomas splint can provide adequate treatment and result in outcomes similar to that for early hip spica casting. Alternatively, modified Bryant traction can be used in neonatal fractures that require little weight for reduction and a short period of treatment. However, the Pavlik harness is the preferred method of treatment in this age group.
Technique
The limb should be cleaned with soap and water and dried. The appropriate length of adhesive strapping should be measured and placed on a level surface with the adhesive side up. A square wooden spreader (a section of a wooden crutch will suffice) of about 7.5 cm (with a central hole) should be placed in the middle of the adhesive strapping. The limb should be gently elevated off the bed while longitudinal traction is applied. The strapping should be applied to the medial and lateral sides of the limb and should allow the spreader to project 15 cm below the sole of the foot. The medial and lateral malleoli should be padded with felt or cast padding. An elastic wrap (ACE bandage) or gauze bandage should be wrapped firmly over the strapping. Both limbs should be included so that equal traction is provided. The patient’s knees should remain extended, and the hips should be flexed to 90°. The traction pulley can be attached to intravenous poles in younger children as opposed to a standard traction apparatus because the traction weight required is much less. The weight needed should suspend the buttocks 1 cm from the bed. The patient should be frequently checked to assess for allergic reactions to the adhesive material, blister formation or pressure sores from slipping straps, compartment syndrome, or peroneal nerve palsy. Adjustments should be made if concerns for any of the aforementioned arise ( Fig. 14-4 ).
Pavlik Harness
The Pavlik harness makes care of femoral fractures in infants very easy. The ease of application and adjustability, reduced hospital stay and cost, and significant improvement in perineal care all contribute to the attractiveness of this treatment modality. Few studies have evaluated the long-term efficacy, but the short-term results are equal to those of hip spica casting.
Technique
Placement of the Pavlik harness does not require anesthesia, and oral pain medication usually suffices during application and subsequent care. Traction is applied to the affected limb while an assistant places the shoulder straps, chest band, and the normal limb in the stirrup. The affected limb is then placed in the stirrup with the hip flexed approximately 80° and abducted 45°. Blankets or towels can be placed to support the lateral aspect of the affected leg as needed for patient comfort. The patient is then seen weekly in the clinic until the fracture is healed. This usually takes 3 to 4 weeks in the young infant. Adjustments are made during this time based on standard AP and lateral radiographs obtained at each visit.
Hip Spica Casting
Application of a hip spica cast is a technique requiring thorough instruction. Although often relegated to the junior resident at most academic institutions, the appropriate application is challenging. Adequate sedation, assistance for reduction maintenance, and appropriate cast application and molding are crucial. Several different ways to apply a hip spica cast have been documented in the literature. These methods differ in the sequence of body parts casted, position of the hip and knee, incorporation of the foot or contralateral limb, casting material, and surface to which the cast is applied. The hammock suspension technique for hip spica cast application in children uses a classic suspension system to support infants during application. The suspension system is simple and safe and requires only readily available materials. Waterproof cast liners have been used at different centers. The reported benefit is decreased skin breakdown. Closed treatment with use of the hip spica cast allows the potential for remodeling in young children. Any resultant angular deformity remodels significantly in children younger than 5 years but does so less reliably in those 5 to 10 years of age. Remodeling is unlikely to be substantial in children older than 10 years. However, remodeling will not correct significant rotational malunion. Additionally, overgrowth of 1 cm to 1.5 cm must be anticipated in younger children, and this must be considered when the cast is applied.
Technique
The authors prefer using a spica table in the operating room with general anesthesia. A long leg cast is applied first. While the knee is maintained in 45° to 60° of flexion and the hip is maintained in 45° of flexion, the stockinette and cast padding are rolled onto the extremity. The foot is included in neutral position or left out. Adhesive-backed foam can be applied over bony prominences to further reduce skin compromise. Maintenance of these positions throughout the application of the different materials ensures that no bunching of the padding or creases of the cast material occur. The fiberglass, which is the material of choice because of weight and ease of care, is then applied. It is soaked in room temperature water and then rolled with use of the stretch–relax technique to avoid excessive skin pressure. Assistants should be advised to use the flats of their hands to support the limb during cast application. This prevents indentations in the cast that may cause pressure points and subsequent sores.
Finally, the long leg cast can be incorporated into the torso. It is critical that the hip position at this juncture be maintained. If required, slabs can be started across the hip joint before unrolling the remainder of the cast material, creating a stronger strut ( Fig. 14-5 ).
Trimming the cast is very important. A good guideline is to leave enough room posteriorly that a caudal block can be given. Caudal blocks are administered in the anatomic region that creates an equilateral triangle pointing caudally with a horizontal line drawn between the posterior superior iliac spine, which courses over the sacral cornu. The distal point is the sacral hiatus. This is always above the intergluteal fold. The perineal area must be trimmed so that adequate room exists for double diapering. The diapering must be performed shortly after completion of the cast because soiling often occurs as patients are emerging from anesthesia.
Hip spica casts can be augmented with a connecting bar. This may be beneficial in preventing mechanical failure of the cast, as well as providing a useful way to transfer and carry the patient.
Although considered by many to be a conservative means of treatment, spica casting is not without complications. It is important to leave adequate space for abdominal expansion. This can be accomplished by placement of a towel between the skin and the cast padding and casting material. Additionally, a window can be cut in the abdominal area for decompression or examination purposes. Great care must be taken in padding and molding the cast appropriately. Compartment syndrome and Volkmann contracture are devastating complications that have occurred with 90/90 casting. Wedging of casts must be done with care. In particular, one must be conscientious of injuries to the peroneal nerve.
A good rule of thumb regarding length of time for cast treatment is the patient’s age in years plus 2 weeks, for a maximum of 12 weeks. The patient is seen every 2 to 3 weeks and is carefully monitored for skin problems and adequate room for growth. The latter can be an issue in the young child. During a growth spurt, the child can quickly outgrow a hip spica cast.
Skeletal Traction
Generally reserved for older children with isolated fractures, skeletal traction is often only a temporary measure until definitive treatment can be applied. The specific technique of skeletal traction varies. Distal femoral or proximal tibial sites are most frequently used for pin placement. The choice of bone depends on four considerations: (1) status of the knee ligaments and local soft tissues, (2) level of the femoral shaft fracture, (3) ipsilateral extremity trauma, and (4) the child’s age.
Proximal tibial pins are not recommended in children younger than 10 years because of the potential for proximal tibial physeal injury. A distal femoral traction pin is used when the knee joint is injured or its stability is unknown. Likewise, an ipsilateral tibial fracture usually precludes placement of a proximal tibial traction pin. A femoral shaft fracture is more easily controlled with a femoral pin ( Fig. 14-6 ).
Technique
The pin is placed with aseptic technique and guided by fluoroscopic imaging so that the physes is avoided. The anesthetic chosen may be local, regional, or general. Liberal local anesthesia should include the periosteum and skin at the point of exit. In younger and less cooperative patients, adequate sedation should supplement the local anesthetic.
The pin size, location, and orientation should all be carefully planned before pin insertion begins. Pin placement is critical for optimizing the vector of traction pull and for avoiding growth plate injury. Pin size depends on the type of traction bow to be used. A narrow-diameter pin that is adequately tensioned (Kirschner bow) is more effective than a larger pin placed in a neutral bow (Böhler bow). The pin may be smooth or threaded. Smooth pins tend to loosen within the bone over a prolonged period.
The local anatomy should be carefully considered before insertion of the pin. The proximal end of the tibia has an unusual apophysis that can easily be injured by errant pin placement. Proximity to the physis should be avoided during insertion, and the pin should be inserted slowly with a hand drill. Heat generated during rapid pin advancement results in thermal injury to the pin tract and adjacent physis and will cause the development of a ring sequestrum or a physeal bar, which should both be avoided.
The orientation of the pin helps correct angular deformity if properly planned. The point of insertion should be carefully controlled so that pin bending does not occur, especially when narrow-diameter pins are used. Bending may cause the pin to exit the bone in a potentially dangerous area. For this reason, a distal femoral pin should be inserted medially and should exit laterally. Medial insertion avoids popliteal vascular damage. The opposite holds true with a proximal tibial pin. The peroneal nerve is most at risk, so the pin should be inserted laterally and should exit medially.
Fluoroscopic imaging during pin placement helps to establish a safe physeal margin and detects misdirection. Biplanar radiographs confirm the pin’s location. Pin sites should be treated with frequent cleansing and antiseptic dressings so that infection does not occur.
The initial traction weight should be enough to slightly elevate the ipsilateral buttock from the mattress when added to the traction apparatus. The amount of shortening at the fracture site is monitored with serial lateral plain radiographs. AP images are inaccurate in assessing length because of the usual anterior bowing in the femur and the technical difficulty in obtaining a true AP image. The traction weight is adjusted according to the findings on these serial radiographs, which are usually obtained every third or fourth day during the first 10 to 14 days of treatment. Once a callus is present, radiographs can be obtained less frequently. If distraction of the fracture site is avoided, pain can be eliminated and neurovascular injury will be prevented.
Surgical Treatment
External Fixation
External fixation historically has been recommended for operative management of pediatric femoral shaft fractures. With the advent of flexible nails, the enthusiasm for external fixation has waned. Studies comparing the two methods have demonstrated improved outcomes with flexible nailing. Despite these limitations, external fixation can be used in patients with open fractures and fractures associated with neurovascular injury and in polytrauma patients. Most authors report good results with a variety of external frame constructs, although there is some evidence that dynamic external fixation is superior to static external fixation.
Anatomic concerns of frame placement must be addressed. The quadriceps muscle mass is minimally violated when the frame is applied laterally as opposed to when multiplanar constructs are used. Lateral half-pin frames allow for control of the fracture and mobilization of both the hip and knee joints.
Many external fixation systems with multiplane adjustment are now available, are simple to apply, and have few parts. An advantage to external fixation is the ability to perform serial adjustments if an adequate initial reduction was not obtained. Serial biplanar radiographs evaluate changes in the fracture, especially in a combative or restless patient, and remanipulation is preferably performed early. The connecting nuts should be tightened at intervals, which will prevent frame loosening.
Technique
The patient is positioned supine on a radiolucent table. If the fracture is open, débridement of the open wound should be performed first. Skin edges must be sharply excised, all debris removed, and the nonbleeding crushed or contaminated subcutaneous tissue and muscle débrided. The fractured bone ends are inspected and débrided. This step is followed by lavage with copious amounts of normal saline irrigant.
Fluoroscopy directs safe and strategic pin insertion, as well as manipulative reduction. The initial lateral pin is placed farthest from the fracture site (“caudal far” pin) in the longer of the two fracture fragments. The pin can be either a 5-mm standard adult pin or a 4-mm pin for smaller children. The pin is placed through a 1-cm stab wound with the use of a sleeve system that allows for saline-cooled predrilling of the bone. The length of connecting bar is then selected. A carbon fiber rod is preferred for its radiolucency. Two bars are appropriate for length-unstable fracture patterns. Two pin–bar clamps are placed on each bar.
One of the end clamps is attached to the caudal far pin, and manual traction is applied. The “cephalad far” pin is then placed through another end clamp into the shorter fracture fragment. The reduction is perfected, and the two end pin clamps are tightened to the connecting bars. The bar is positioned in line with the femoral shaft laterally and at least two fingerbreadths from the skin to allow for any thigh swelling. The near pins can then be placed through the remaining clamps. Such positioning is critical when two connecting bars are stacked because some clamps will not capture an angled pin. A short intermediate connecting bar can be added if one of the pins was placed at an angle. This configuration also allows for easier adjustment of the fracture reduction after the frame has been applied.
The soft tissues adjacent to the pins may need to be incised so that hip and knee range of motion is not restricted. Commonly, the most distal pin in the supracondylar region is entrapped by the iliotibial band, which results in limited knee motion. The surgeon should passively range the hip and knee and ensure that the skin and deep tissues are adequately released ( Fig. 14-7 ).
Related posts:
Outcomes Assessment of Fractures in Children
The Multiply Injured Child
Anesthesia and Analgesia for the Ambulatory Management of Children’s Fractures
Private: Fractures and Dislocations about the Hip and Pelvis
Private: Fractures around the Knee in Children
Private: Fractures and Dislocations of the Forearm, Wrist, and Hand
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