Summary Femoral shaft fractures are high energy injuries to the femur that are associated with life-threatening injuries (pulmonary, cerebral) and ipsilateral femoral neck fractures. Diagnosis is made radiographically with radiographs of the femur as well as the hip to rule out ipsilateral femoral neck fractures. Treatment generally involves intramedullary nailing which is associated with >95% union rates. Epidemiology Incidence common 37.1 per 100,000 person annually Etiology Mechanism traumatic high-energy most common in younger population often a result of high-speed motor vehicle accidents low-energy more common in elderly often a result of a fall from standing gunshot Fracture patterns transverse pure bending moment spiral rotational moment oblique uneven bending moment segmental 4-point bending moment comminuted high-speed crush or torsion mechanism Associated conditions orthopaedic ipsilateral femoral neck fracture 2-6% incidence often basicervical, vertical, and nondisplaced lack of displacement due to majority of energy dissipated through femoral shaft missed 19-31% of time bilateral femur fractures significant risk of pulmonary complications increased rate of mortality as compared to unilateral fractures ipsilateral tibial shaft fractures ipsilateral acetabular fracture thoracic pulmonary injury early surgical treatment of femur fracture can lead to ARDS approximately 2% of cases treatment can proceed when patient is appropriately resuscitated cerebral hemorrhage, subdural hemorrhage early surgical treatment can exacerbate neurologic injury intraoperative hypotension can decrease brain perfusion Anatomy Osteology largest and strongest bone in the body femur has an anterior bow linea aspera rough crest of bone running down middle third of posterior femur attachment site for various muscles and fascia acts as a compressive strut to accommodate anterior bow to femur Muscles 3 compartments of the thigh anterior sartorius quadriceps posterior biceps femoris semitendinosus semimembranosus adductor gracilis adductor longus adductor brevis adductor magnus Biomechanics musculature acts as a deforming force after fracture proximal fragment abducted gluteus medius and minimus abduct as they insert on greater trochanter flexed iliopsoas flexes fragment as it inserts on lesser trochanter distal segment varus adductors inserting on medial aspect of distal femur extension gastrocnemius attaches on distal aspect of posterior femur Classification Winquist and Hansen Classification Type 0 No comminution Type I Insignificant amount of comminution Type II Greater than 50% cortical contact Type III Less than 50% cortical contact Type IV Segmental fracture with no contact between proximal and distal fragment AO/OTA Classification 32A - Simple A1 - Spiral A2 - Oblique, angle > 30 degrees A3 - Transverse, angle < 30 degrees 32B - Wedge B1 - Spiral wedge B2 - Bending wedge B3 - Fragmented wedge 32C - Complex C1 - Spiral C2 - Segmental C3 - Irregula Presentation Initial evaluation Advanced Trauma Life Support (ATLS) should be initiated adequate resuscitation normal vital signs HR < 100 bpm SBP >100 mm Hg DBP >70 mm Hg normothermia (> 35° C) adequate urine output 0.5 - 1.0 mL/kg/hr (30 mL/hr) labs lactate <2.5 mmol/L base deficit within -2 and +2 IL-6 levels <500 pg/dL gastric mucosal pH >7.3 compensated shock commonly missed normotensive tachycardia without fever cool extremities narrowing pulse pressure weak peripheral pulses delayed capillary refill Symptoms pain in thigh Physical exam inspection tense, swollen thigh blood loss in closed femoral shaft fractures is 1000-1500ml for closed tibial shaft fractures, 500-1000ml blood loss in open fractures may be double that of closed fractures affected leg often shortened tenderness about thigh motion examination for ipsilateral femoral neck fracture often difficult secondary to pain from fracture neurovascular must record and document distal neurovascular status Imaging Radiographs recommended views AP and lateral views of entire femur AP and lateral views of ipsilateral hip important to rule-out coexisting femoral neck fracture AP and lateral views of ipsilateral knee CT indications may be considered in midshaft femur fractures to rule-out associated femoral neck fracture Ipsilateral femoral neck rule-out protocol dedicated 10° internal rotation AP hip radiographs placed femoral neck in profile fine-cut CT of the hip 2 mm cuts CT Capsular Sign a difference of >1mm capsular distension between injured and uninjured sides on the axial soft tissue window intraoperative fluoroscopic exam of the ipsilateral hip dedicated post-operative radiographs of the affected while patient is still in operating room Labs Septic nonunion ESR CRP most sensitive to the presence of a occult infection CBC WBC Adequate resuscitation IL-6 less than 500 pg/dL serum lactate less than 2.5 mmol/L base deficit within -2 or +2 Treatment Nonoperative long leg cast or hip spica cast indications nondisplaced femoral shaft fractures in patients with multiple medical comorbidities pediatric patients Operative antegrade intramedullary nail indications gold standard for treatment of diaphyseal femur fractures outcomes stabilization within 24 hours is associated with decreased pulmonary complications (ARDS) decreased thromboembolic events improved rehabilitation decreased length of stay and cost of hospitalization exception is a patient with a closed head injury critical to avoid hypotension and hypoxemia consider provisional fixation (damage control) retrograde intramedullary nail indications ipsilateral femoral neck fracture floating knee (ipsilateral tibial shaft fracture) use same incision for tibial nail ipsilateral acetabular fracture does not compromise surgical approach to acetabulum multiple system trauma bilateral femur fractures avoids repositioning morbid obesity avoids difficult of antegrade start point with obesity pregnancy (especially 1st trimester) low radiation exposure to uterus contraindications skeletal immaturity history of knee sepsis soft tissue injury surrounding knee outcomes results are comparable to antegrade femoral nails immediate retrograde or antegrade nailing is safe for early treatment of gunshot femur fractures external fixation with conversion to intramedullary nail within 2-3 weeks indications unstable polytrauma victim vascular injury severe open fracture outcomes no difference in union rates and infections rates with acute nailing infection rate does increase if ex-fix left in place >28 days reduced risk of ARDS and fat embolism sydnrome open reduction internal fixation with plate indications ipsilateral neck fracture requiring screw fixation fracture at distal metaphyseal-diaphyseal junction inability to access medullary canal outcomes inferior when compared to IM nailing due to increased rates of: infection nonunion hardware failure Techniques Long leg cast or hip spica cast hip spica casting typically used in pediatric patients <5 years of age with length stable fractures long leg casting can be used in adult patients who are not surgical candidates need frequent follow-up for skin checks Antegrade intramedullary nail approach 3 cm incision proximal to the greater trochanter in line with the femoral canal technique positioning supine on fracture table perineum well seated against post nonopearative leg in lithotomy bolster important to ensure adequate postioning to allow C-arm maneuvering during case "sloppy" lateral position radiolucent jackson table large bumps placed underneath operative hip places patient in partial decubitus position starting points piriformis entry pros colinear trajectory with long axis of femoral shaft cons starting point more difficult to access, especially in obese patients causes the most significant damage to abductor muscles and tendons may result in abductor limp blood supply to the femoral head may result in AVN in pediatric patients trochanteric entry pros minimizes soft tissue injury to abductors easier starting point than piriformis entry nail cons not colinear with the long axis of femoral shaft must use nail specifically designed for trochanteric entry use of a straight nail may lead to varus malalignment too lateral starting point can result in varus malalignment ideal starting point is dependent on the relative position of the greater trochanter to the long axis of the femur just lateral to the long axis of the femur entry reamer with soft tissue protector or awl pass ball-tip guidwire to desired depth/length of nail reaming beging with 8.5 to 9 mm reamer increase by 0.5 mm increments reamed nailing superior to unreamed nailing, with: increased union rates decreased time to union no increase in pulmonary complications indications for unreamed nail consider for patient with bilateral pulmonary injuries femoral rod insertion insert femoral nail with 90° of internal rotation leverages the anterior bow of the nail to direct the tip of the nail into the canal avoids medial comminution with nail contact along medial cortex careful mallet nail to appropriate depth after crossing fracture site interlocking screws technique computer-assisted navigation for screw placement decreases radiation exposure perfect circles technique obtain perfect trajectory of interlock holes with C-arm transducer use the angle of the transducer to guide trajectory of drill widening/overlap of the interlocking hole in the proximal-distal direction correct with adjustment in the abduction/adduction plane widening/overlap of the interlocking hole in the anterior-posterior plane correct with adjustment in the internal/external rotation plane reamed nailing has been associated with higher union rates compared to unreamed nailing reaming disrupts endosteal blood supply, but stimulates soft tissue and periosteal blood supply to fracture periosteal and soft tissue blood supply is predominate source after fracture reaming extrudes medullary contents into fracture site autologous bone grafting increased micro emboli to lungs with reaming intraoperative echocardiogram studies have not demonstrated this to be significant mild increases in marrow pressure with reaming greatest increase occurs with nail insertion can be decreased with fluted nails allows canal contents to extrude around the nail reaming allows are a larger diameter nail to be placed larger nail is stiffer and is related to the diameter to the 4th power increases the area of isthmic contact with nail no increase in infection rates after reaming open fractures postoperative care weight-bearing as tolerated range of motion of knee and hip is encouraged pros 98-99% union rate low complication rate infection risk 2% cons not indicated for use with ipsilateral femoral neck fracture increased rate of HO in hip abductors with antegrade nailing increased rate of hip pain compared with retrograde nailing mismatch of the radius of curvature of the femoral shaft and intramedullary nails can lead to anterior perforation of the distal femur Retrograde intramedullary nail approach 2 cm incision starting at distal pole of patella medial parapatellar versus transtendinous approaches nail inserted with knee flexed to 30-50 degrees technique positioned supine on radiolucent table bump under operative hip radiolucent triangle useful for eliminating extension moment of gastrocnemius in distal fragment entry point intercondylar starting point center of intercondylar notch on AP view extension of Blumensaat's line on lateral posterior to Blumensaat's line risks damage to cruciate ligaments trajectory in line with the canal on AP and lateral views medial condylar starting point preserves articular surface requires a curves nail to prevent valgus malalignment entry reamer with soft tissue protecting sleeve pass ball-tip guidewire should end proximal to lesser trochanter ream femoral canal fracture must be reduced to avoid eccentrically reaming the cortex F-tool bumps joysticking with Schanz pins manual traction start with 8.5 mm reamer increase in size by increments of 0.5 mm ream canal 1 to 1.5 mm greater than size of intended implant insert femoral nail should seat ~1 cm deep to articular surface to prevent patellofemoral symptoms place interlocking screws aiming arm used for distal lockings can place first and then mallet the nail to gain compression at fracture with transverse patterns perfect circles technique for proximal interlocks femoral neurovascular bundle safe if screws placed proximal to lesser trochanter postoperative care weight-bearing as tolerated range of motion of knee and hip is encouraged pros technically easier faster operative times quicker OR set-up allows for addressing other injuries surgically without changing patient position less blood loss than antegrade nailing allows for direct comparison of rotation and leg length to nonoperative extemity union rates comparable to those of antegrade nailing no increased rate of septic knee with retrograde nailing of open femur fractures cons knee pain increased rate of interlocking screw irritation cartilage injury cruciate ligament injury with improper starting point External fixation with conversion to intramedullary nail within 2-3 weeks technique safest pin location sites are anterolateral and direct lateral regions of the femur 2 pins should be used on each side of the fracture line pros prevents further pulmonary insult without exposing patient to risk of major surgery may be converted to IM fixation within 2-3 weeks as a single stage procedure cons pin tract infection knee stiffness due to binding/scarring of quadriceps mechanism Open reduction and internal fixation with plate technique submuscular plating less soft tissue stripping than with direct lateral approach preserves periosteal blood supply to fracture direct lateral approach lateral incision in line with femoral shaft incision iliotibial band fascia elevate vastus lateralis from ITB fascia and posterior septum place chandler over anterior cortex to expose lateral femur reduce fracture with traction and reduction forceps fracture fixation can place interfragmentary screw for simple fracture patterns comminuted fractures will require bridge plate Special considerations ipsilateral femoral neck fracture priority goes to fixing femoral neck because anatomic reduction is necessary to avoid complications of AVN and nonunion technique preferred methods usually two-construct fixation screws for neck with retrograde nail for shaft screws for neck and plate for shaft compression hip screw for neck with retrograde nail for shaft single constuct fixation is associated with femoral neck fracture displacement and loss of reduction less preferred methods antegrade nail with screws anterior to nail technically challenging usually done if neck fracture is identified after the femoral shaft fracture has been addressed Complications Heterotopic ossification incidence 25% treatment rarely clinically significant Pudendal nerve injury incidence 10% when using fracture table with traction Femoral artery or nerve injury incidence rare femoral artery is medial to femur if proximal locking screw is placed proximal to lesser trochanter in retrograde nails cause can occur when inserting proximal interlocking screws during a retrograde nail Malunion and rotational malalignment most accurately determined by the Jeanmart method angle between a line drawn tangential to the femoral condyles and a line drawn through the axis of the femoral neck femoral rotation = β - α anterversion and external rotation are positive values for equation retroversion and internal rotation are negative values for equation R(β - α) - L(β - α) = relative alignment malrotation up to 15 degrees is usually well tolerated incidence proximal fractures 30% distal fractures 10% risk factors use of a fracture table increases risk of internal rotation deformities when compared to manual traction fracture comminution night-time surgery treatment if noticed intraoperatively, remove distal interlocking screws and manually correct rotation if noticed after union, osteotomy is required Delayed union treatment dynamization of nail with or without bone grafting Nonunion incomplete healing within 9 months of injury or no evidence of healing on successive radiographs over 3 months incidence <10% risk factors postoperative use of nonsteroidal anti-inflammatory drugs smoking is known to decrease bone healing in reamed antegrade exchange nailing for atrophic non-unions broken distal interlock screws can be seen on radiographs race between healing and implant failure is lost distal interlock screws are exposed to the greatest stresses undergo 4-point bending stress results in fracture of the interlock screw in the region inside the nail treatment reamed exchange nailing works by increasing construct stiffness, enhanced isthmic fit, and extrusion of reaming contents to nonunion site plate augmentation with nail retention some studies have demonstrated higher union rates than exchange nailing enables full weight bearing compression plating allows compression of the fracture site bone grafting removal of interposed fibrous material Infection incidence < 1% treatment removal of nail and reaming of canal external fixation used if fracture not healed Weakness quadriceps and hip abductors are expected to be weaker than contralateral side Iatrogenic fracture etiologies risk factors antegrade starting point 6mm or more anterior to the intramedullary axis however, anterior starting point improves position of screws into femoral head increased cortical hoop stresses with anterior starting points using an anterior start point for a piriformis nail can result in a proximal femur fracture failure to overream canal by at least .5 mm Mechanical axis deviation (MAD) lengthening along the anatomical axis of the femur leads to lateral MAD shortening along the anatomical axis of the femur leads to medial MAD Anterior cortical penetration due to mismatch of the radius of curvature of the nail to the radius of curvature of the femur average radius of curvature of human femur is 120 +/- 36 cm starting points that are too posterior (especially piriformis start points) with relatively straight nails