summary Femoral Shaft Fractures are one of the most common pediatric orthopedic fractures and are the most common reason for pediatric hospitalization due to orthopedic injury. Diagnosis is made with plain radiographs of the femur. Treatment may be palvic harness, spica casting or operative depending on the fracture pattern and age of the patient. Epidemiology Incidence 1.6-2% of all pediatric fractures bimodal distribution increased rate in toddlers age 2-4 years and adolescents most common reason for pediatric hospitalization due to orthopaedic injury Demographics males more commonly affected 2.6:1 Etiology Pathophysiology mechanism of injury fall is the most common cause < 10 years old motor vehicle accident is the most common cause > 10 years old correlated with age due to the increased thickness of the cortical shaft during skeletal growth and maturity Associated conditions high suspicion for child abuse required abuse must be considered if the child is < 3 years and especially if present in a patient before walking age femur fractures are one of the most common fractures associated with child abuse Transverse fractures more predictive of non-accidental trauma compared to spiral or oblique fractures hemodynamic instability should raise suspecion for associated injuries medical conditions and comorbidities osteogenesis imperfecta osteopenia secondary to neuromuscular disorders benign or malignant bone tumors Anatomy Osteology anterior bow to femur isthmus is the narrowest portion of the femur Muscles iliopsoas creates a flexion and external rotation force on the proximal fragment adductors create a shortening and varus force on the distal fragment Biomechanics femoral shaft cortical diameter and cortical thickness increase with age Classification Descriptive classification characteristics of the fracture transverse comminuted spiral others location of the fracture proximal, middle, or distal third integrity of the soft-tissue envelope open vs. closed fracture Stability stable fractures typically transverse or short oblique unstable fractures long spiral (fracture length > 2x bone diameter at that level) comminuted Presentation Symptoms thigh pain inability to walk report of deformity or instability Physical exam gross deformity shortening swelling of the thigh Imaging Radiographs AP and lateral of the femur allow for complete evaluation of the fracture location, configuration, and amount of displacement ipsilateral AP and lateral of knee and hip to rule out associated injuries Treatment Nonoperative Pavlik harness indications children < 6 months old any fracture pattern spica casting indications children 0-5 years old relatively contraindicated with polytrauma, open fractures and shortening > 2-3 cm traction + delayed spica casting indications younger patients with significant shortening rarely utilized Operative flexible intramedullary nails indications most length stable fracture patterns in children 5-11 years old weighing < 49kg (100 lbs) submuscular bridge plate fixation indications unstable fractures in children > 5 years old and > 49kg (100lbs) very proximal or very distal fractures severe comminution antegrade rigid intramedullary nail fixation indications in patients > 11 years old or approaching skeletal maturity unstable fractures fractures in patients weighing > 49kg (100 lbs) external fixation indications damage control orthopedics in a polytrauma patient open fractures associated vascular injuries requiring revascularization segmental or significantly comminuted fractures Treatment Table by Age < 6 months Any fracture pattern Pavlik harness Early spica casting 6 months - 5 years Stable fracture pattern Early spica casting Unstable fracture pattern Polytrauma, multiple/open fx Traction with delayed spica casting External fixator 5-11 years Length stable and <49kg Flexible titanium nail Length unstable fx (comminuted or spiral) Very proximal or distal fx Any weight ORIF with submuscular bridge plating Stainless steel Enders nails External fixation > 11 years Patient weighs > 49kg (100 lbs) Antegrade rigid intramedullary nail fixation Proximal or distal fx Severe comminution ORIF with submuscular bridge plating Techniques Pavlik harness technique avoids the need for sedation or anesthesia complications can compress femoral nerve if excessive hip flexion is used in presence of a swollen thigh identified by decreased quadriceps function Immediate spica casting technique applied with reduction under sedation or with general anesthesia single-leg spica or one-and-one-half spica (to control rotation) distal femoral buckle fracture may be treated with long leg cast alone (not spica) hips flexed 60-90° and approximately 30° of abduction external rotation is typically needed to correct a rotational deformity molded into recurvatum and valgus as the muscular forces will pull fracture into procurvatum and varus molds along the distal femoral condyles and buttocks help to maintain reduction acceptable limits are based on age the goal of reduction should include obtaining < 10° of coronal plane and < 20° of sagittal plane deformity with no more than 2cm of shortening or 10° of rotational malalignment a special car seat is sometimes needed for transport (often can use a regular car seat if single-leg spica is used) complications compartment syndrome be careful to apply with smooth contours in popliteal fossa, do not flex knee >90, and avoid excessive traction outcomes healing times vary from 4-8 weeks based on age Traction + delayed spica casting technique placed in distal femur proximal to distal femoral physis proximal tibial traction can cause recurvatum due to damage to the tibial tubercle apophysis used for 2-3 weeks to allow early callus formation spica casting then applied until fracture healing more complications than immediate spica casting Flexible intramedullary nails approach all distal approach 2cm incision medially and laterally at level of distal physis spread with hemostat to starting point 2cm proximal to physis distal and proximal approach 2cm incision laterally at level of distal physis and 2cm incision proximally at greater troch apophysis instrumentation nail size determined by multiplying the width of the isthmus of femoral canal by 0.4 the goal is 80% canal fill complications the most common complication is pain at insertion site near the knee in up to 40% of patients recommended that < 25mm of nail protrusion and minimal bend of the nail outside the femur are present increased rate of complications in patients 11 years or up or > 50 kg malunion increased rates with comminuted, shortened, or very proximal/distal fractures outcomes generally good outcomes time to union is typically 10-12 weeks removal of the nail can be performed at 1 year Submuscular bridge plate fixation approach laterally based incision and plating with minimal disruption of soft tissue envelope small proximal and distal incisions and plate is placed between periosteum and vastus lateralis on the lateral side of the femur fracture is provisionally reduced with closed or percutaneous techniques instrumentation typically use 12-16 hole 4.5mm narrow LC-DC plate with 3 screws proximal and 3 screws distal to the fracture plate may need to be bent to accommodate the natural bend of the femur contoured femur plates are also an option complications hardware removal refracture following hardware removal outcomes favorable time to union, weight bearing, hardware irritation, and limp outcomes Antegrade rigid intramedullary nail fixation approach trochanteric entry nail lateral entry nail avoid piriformis entry due to risk of injury to vascularity to femoral head soft tissue lateral incision proximal to the greater trochanter sharp or electrocautery through fascia lata to obtain starting point at the tip of the greater trochanter closed versus open reduction of the fracture instrumentation with fracture reduced follow steps to insert intramedullary nail with caution to not cross distal physis complications osteonecrosis risk is 1-2% with piriformis start in a patient with open proximal physes the exact risk of osteonecrosis with greater trochanter and lateral entry nails is unknown secondary deformities of the proximal femur can occur after greater trochanteric insertions narrowing of the femoral neck premature fusion of greater trochanter apophysis coxa valga hip subluxation outcomes decreased risk of angular malunion favorable outcomes in adolescents External fixation technique applied laterally avoid disruption and scarring of quadriceps 10-16 weeks of fixation is typically needed for solid union weight-bearing weight-bearing as tolerated can be considered with stiff constructs complications more complications than internal fixation pin tract infections are frequent as high as 50% of fixator related complications treated with oral antibiotics and pin site care higher rates of delayed union, nonunion and malunion increased risk of refracture (1.5-21%) after removal of fixator especially with varus malunion Complications Leg-length discrepancy overgrowth the most common complication in younger patients 0.7 - 2 cm is common in patients <10 years typically occurs within 2 years of injury shortening is acceptable if less than 2 - 3 cm because of anticipated overgrowth in young patients can be symptomatic if greater than 2 - 3 cm temporary traction or fixation used to prevent persistent shortening Osteonecrosis (ON) of the femoral head reported with both piriformis and greater trochanter entry nails femoral nailing through the piriformis fossa is contraindicated in adolescents with open physes because of the risk of osteonecrosis of femoral head main supply to femoral head is deep branch of the medial femoral circumflex artery branches into superior retinacular vessels that supply the femoral head vulnerable as it lies near the piriformis fossa Nonunion and malunion higher risk with load bearing devices external fixator or submuscular plates can occur after flexible intramedullary nailing in patients aged over 11 years old who weigh >49 kg (>108 lb) the typical deformity is varus + flexion of the distal fragment remodeling is greatest in the sagittal plane rotational malalignment does not remodel nearly 50% of fractures treated with flexible nails have 15 degrees of malalignment Refracture most common after external fixator removal with varus alignment Prognosis High rate of fracture union if appropriate treatment is selected based on patient age and fracture pattern Timing of surgical intervention early surgical intervention (< 24-48 hours) of femur fractures in the setting of a closed head injury leads to decreased length of hospital stay and is not associated with an increase in pulmonary complications