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Updated: Oct 8 2023

Femoral Shaft Fractures

Images
https://upload.orthobullets.com/topic/1040/images/key image.jpg
https://upload.orthobullets.com/topic/1040/images/anterior bow.jpg
https://upload.orthobullets.com/topic/1040/images/type 0 femoral shaft radiograph.jpg
https://upload.orthobullets.com/topic/1040/images/type 1 radiograph.jpg
https://upload.orthobullets.com/topic/1040/images/type 4 femur fracture radiograph.jpg
  • 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
          • 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
          • begin with 8.5 to 9 mm reamer
            • increase by 0.5 mm increments
          • reamed nailing superior to unreamed nailing, with:
            • 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 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
        • allows for addressing other injuries surgically without changing patient position
        • 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
        • 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
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