summary Proximal Femur Fractures in the pediatric poplulation are rare fractures caused by high-energy trauma and are often associated with polytrauma. Diagnosis can be made with plain radiographs of the hip. Treatment is usually operative with the technique depending on the age of the patient and the Delbet classification type of fracture. Epidemiology Incidence accounts for < 1% of pediatric fractures Demographics males more commonly affected 2.5:1 bimodal distribution children < 2-3 years old due to non-accidental trauma adolescents involved in motor vehicle accidents Etiology Pathophysiology mechanism of injury usually results from high-energy trauma (75-80%) can result from low-energy trauma if the patient has weakened bone (i.e. tumors, metabolic bone disease) Associated conditions 30-85% of patients will have associated traumatic injuries head or facial trauma splenic lacerations retroperitoneal hemorrhage perineal injury pelvic ring or acetabular fractures hip dislocation femur fractures associated complications AVN premature physeal closure Anatomy Osteology proximal femur develops from 2 centers of ossification proximal femoral epiphysis ossification begins at 4-6 months in girls and 5-7 months in boys responsible for metaphyseal growth of femoral neck rate of growth is 3 mm/year accounts for 13-15% of overall leg length accounts for 30% of overall femur length trochanteric apophysis ossification begins at 4 years in both girls and boys responsible for appositional growth of greater trochanter also makes small contribution to growth of femoral neck and intertrochanteric femur disordered growth injury to the GT apophysis leads to shortening of the GT and coxa valga overgrowth of the GT apophysis leads to coxa vara Blood supply medial femoral circumflex artery (MFCA) via the posterosuperior and posteroinferior retinacular branches at birth, contributes to the blood supply to the head with the LFCA and artery of ligamentum teres at 4 years old, becomes the main blood supply after regression of the LFCA and artery of ligamentum teres lateral femoral circumflex artery (LFCA) at birth, contributes to the blood supply to the head regresses in late childhood artery of the ligamentum teres at birth, contributes to the blood supply to the head diminishes after 4 years old metaphyseal vessels also contribute to blood supply to the head < 3 years old and after 14-17 years between 3 to 14-17 years, the physis blocks metaphyseal supply after 14-17 years, anastomoses between metaphyseal-epiphyseal vessels develop Neurovascular superior gluteal nerve (L4, L5, S1) gluteus medius gluteus minimus Presentation Symptoms severe pain in affected hip inability to bear weight Physical exam shortened, externally rotated lower extremity Classification Delbet Classification Description Incidence AVN Nonunion Type I Transphyseal (with or without epiphyseal dislocation) <10% 38%-100% Type II Transcervical 40-50% 28% 15% Type III Cervicotrochanteric (or basicervical) 30-35% 18% 15-20% Type IV Intertrochanteric 10-20% 5% 5% Imaging Radiographs recommended views AP cross-table lateral optional views bone survey if suspected non-accidental trauma findings break/offset of bony trabeculae near Ward triangle indicates nondisplaced or impacted fracture CT indications nondisplaced fractures and stress fractures MRI indications nondisplaced fractures and stress fractures (preferred over CT) pathologic fractures findings well-defined low-signal line and surrounding high-signal bone edema on T2-weighted images Ultrasound indications nondisplaced fractures in infants findings hemarthrosis difficult to differentiate from effusion due to inflammation or infection subtle epiphyseal mobility Differential Legg-Calve-Perthes disease Toxic synovitis Spontaneous hemarthrosis Infection Treatment Nonoperative closed reduction and spica abduction casting indications (rarely indicated) Type I without epiphyseal dislocation, II, III, IV IF nondisplaced/minimally displaced AND < 4 years old evaluate type I fractures for non-accidental trauma if young (< 2-3 years old) Operative emergent ORIF with capsulotomy (or joint aspiration) indications open hip fractures (rare) vessel injury where large vessel repair is required (rare) concomitant hip or epiphyseal dislocations (especially type I) fractures with significant displacement some data suggests this may decrease the rate of AVN closed reduction percutaneous pinning (CRPP) indications type I (without epiphyseal dislocation), II, III if displaced and/or > 4 years old fixation smooth pins may be adequate in young patients if postoperative spica casting performed cannulated screws in older patients and adolescents postop fracture brace or spica cast if there is concern that the long lever arm of the leg could contribute to loss of fixation of the fracture ORIF with pin/screw fixation indications type I II, III if unable to achieve closed anatomic reduction postop consider fracture brace or spica cast if concern for stability of fracture ORIF with sliding hip screw (DHS) indications type IV if displaced or > 4 years old Techniques Closed reduction and spica abduction casting timing of reduction early reduction (< 24h) may diminish risk of AVN by restoring blood flow through kinked vessels technique fracture table (preferred for most patients) can use radiolucent table for younger patients apply gentle longitudinal traction with abduction and internal rotation follow with weekly radiographs for 3 weeks to make sure reduction maintained acceptable alignment type II accept < 2mm cortical translation, < 5° of angulation, no malrotation type III and IV accept < 10° of angulation Emergent ORIF with capsulotomy (or joint aspiration) may decrease AVN technique aspiration with large bore needle through subadductor/anterior hip approach open capsulotomy through anterior incision Closed reduction and percutaneous pinning (CRPP) reduction technique see above instrumentation smooth or threaded pins/K wires indications type I without epiphyseal dislocation, II, III in patients < 4yrs cannulated screws indications type I without epiphyseal dislocation, II, III in patients > 4yrs technique pin/screw placement short of the physis indications patients < 4-6yrs most type III fractures less stable than transphyseal transphyseal indications older patients close to skeletal maturity (> 12yrs old) when there is little metaphyseal bone available where crossing the physis is necessary to achieve stable fixation it is easier to treat leg length discrepancy from premature physeal closure than nonunion place within 5mm of subchondral bone avoid anterolateral quadrant of epiphysis and posterior perforation of femoral neck to prevent injury to vasculature postop immobilization post-op spica casting (abduction and internal rotation) for 6-12 weeks if < 4yrs or pin/screw placement short of the physis long lever arm of the leg could contribute to loss of fixation of the fracture ORIF with pin/screw fixation approach anterolateral (Watson-Jones) instrumentation/technique see above ORIF with DHS approach lateral (Hardinge) instrumentation pediatric hip screw Complications AVN most common complication risk factors age risk increases 1.14 times for every year of increasing age fracture type highest risk with type I (transphyseal) fractures nearly 100% if epiphyseal dislocation delayed reduction > 24 hours inadequate/unstable reduction anatomic reduction is the most important factor in preventing subsequent osteonecrosis/AVN etiology kinking/laceration of vessels tamponade by intracapsular hematoma classification - Ratliff type I - involvement of whole head type II - partial involvement of head type III - area of necrosis in femoral neck from fracture line to physis treatment core decompression vascularized fibular graft Coxa vara (neck-shaft angle <120°) 2nd most common complication risk factors more common if fracture is treated non-operatively more common for type I, II and III fractures incidence 25% for type III treatment young patients (0-3 yrs) will remodel if neck-shaft angle > 110° surgical arrest of trochanteric apophysis indications mild coxa vara in < 6-8 yrs only works in younger patients subtrochanteric or intertrochanteric valgus osteotomy indications coxa vara with nonunion coxa vara with severe Trendelenburg limp or signs/symptoms of FAI older patients Coxa valga seen in type IV fractures involving GT in younger patients due to premature GT apophysis closure Nonunion can occur together with coxa vara (see above) etiology nonoperative treatment of type II or III fractures occult infection at fracture site malreduced fracture treatment ORIF and immobilization (spica cast if younger patient) subtrochanteric or intertrochanteric valgus osteotomy bone grafting if persistent Physeal arrest can lead to leg length discrepancy proximal femoral physis contributes to 15% of overall limb length (3 mm/yr) significant (> 2cm) leg length discrepancy is rare and only occurs in very young children risk factors penetration of physis by fixation devices AVN more common in patients with type II or III AVN Limb length discrepancy (LLD) significant LLD occurs in combined AVN and physeal arrest treatment shoe lift if projected LLD at skeletal maturity is < 2cm epiphysiodesis of contralateral distal femur ± proximal tibia if projected LLD at skeletal maturity is 2-5cm Chondrolysis usually associated with AVN etiology poor vascularity to femoral head cartilage penetration of hardware into joint presents as restricted hip motion, hip pain, radiographic joint space narrowing Malreduction common with subtrochanteric fractures deforming forces lead to proximal fragment in flexion, abduction, and external rotation Infection Prognosis Poor functional outcomes have been associated with head trauma amputation peripheral neurological damage AVN