Femoral Shaft Fracture

Femoral Shaft Fracture

Femoral shaft fractures are fractures of the diaphysis of the femur. They have a bimodal distribution with high-energy mechanisms in young individuals and low-energy mechanisms in older osteoporotic patients. Closed fractures can lose 1000 – 1500 ml of blood, while open fractures lose 2000 – 3000 ml of blood. They carry a high risk of fat embolism (especially bilateral femur fractures) and are often associated with other life-threatening injuries. Open femoral shaft fractures are an orthopaedic EMERGENCY and require surgical treatment within 6 hours. Most femoral shaft fractures are managed operatively unless the patient is too sick to be operated on or refuses surgery.

Winquist and Hansen Classification: historical classification used to determine whether the femoral shaft fracture required locking, weight-bearing status post-op and prognosis, e.g. degree of malunion. It is not useful nowadays due to the full locking capabilities of implants and full post-op weight bearing with IM nails.

• Anatomy
  • The femoral shaft has an anterior bow with an isthmus (narrowest part of the intramedullary canal)
  • It has a linea aspera in the posterior cortex that acts as a compressive strut against the anterior bow
  • The medial cortex is under compression while the lateral cortex is under tension
  • The thigh has 3 compartments – anterior posterior and adductor compartment
    • Anterior compartment includes sartorius and quadriceps
    • Posterior compartment concists biceps femoris, semitendinosus and semimembranosus
    • Adductor compartments consists of gracilis, adductor longus, adductor brevis and adductor magnus
  • The 2 major arteries include the:
    • Profunda femoris: disruption leads to hemorrhage
    • Superficial femoral: disruption leads to distal ischemia since it enters the distal extremity as the popliteal artery
  • Significant nerves include the sciatic, femoral and obturator nerve. Sciatic nerve damage is most concerning
• Deforming forces
  • Proximal flexion by the iliopsoa
  • Proximal abduction by the gluteus minimus and medius
  • Distal adduction by adductors
  • Distal flexion by the gastrocnemius
• Mechanisms
  • High-energy mechanism
    • High-speed MVA (most common mechanism)
  • Low-energy mechanism
    • Fall from standing height
    • Gunshot
• Associated injuries
  • Ipsilateral femoral neck fracture (2 – 6%, vertically oriented non-displaced basicervical, easy to miss)
  • Bilateral femoral shaft fracture (significant risk of pulmonary embolism and increased mortality)
  • Ipsilateral tibia shaft fracture
  • Ipsilateral acetabular fracture
• Signs and symptoms
  • Severe thigh pain
  • Tenseness
  • Tenderness and swelling
  • Limb length shortening
  • External rotation (not all the time)
• Physical examination
  • Swollen thigh
  • Thigh tenderness
  • Shortening of the affected limb
  • Neurovascular examination
• Investigations
  • X-ray: AP and lateral view of the hip-joint, full-length femur and knee joint
    • AP internal rotation 15 – 20 degreees hip X-ray
  • CT-scan fo the hip: to rule out associated femoral neck fracture
    • 1 mm capsular distension between injured and uninjured sides on the axial soft tissue window (capsular sign)
  • CBC, ESR, CRP
• Imaging to rule out ipsilateral femoral neck fracture
  • 10 degrees internal rotation AP hip radiograph (femoral neck is placed in profile)
  • Fine-cut CT-scan of the hip
  • Intra-operative AP and lateral fluoroscopy of the ipsilateral hip
  • Post-operative hip x-rays
• Initial management of femoral shaft fracture
  • Thomas splint
  • Skeletal traction
    • 15% of patient body weight to pins
    • Distal femur pin (medial to lateral to avoid injuring the femoral artery), or
    • Proximal tibia pin ( 2 cm posterior and 2cm inferior of the tibial tuberosity lateral to medial to avoid injury to the common peroneal nerve)
  • Cutaneous traction (Bucks traction)
• Non-operative treatment of femoral shaft fractures
  • Long-leg cast or hip spica for paediatric patients or non-operative candidates
• Operative treatment
  • External fixator: temporary stabilization for damage control orthopaedics. Converted to nail in 2 – 3 weeks
  • Open reduction internal fixation (ORIF) with plate: has an increased risk of infection, non-union and failure
  • Locked Intramedullary (IM) nail: preferred mode of treatment. Rate of malunion increased when the starting point is opposite the fracture site e.g. antegrade nail for a distal femoral shaft fracture. Reaming increases union, decreases time to union with no change in pulmonary complications
    • Antegrade, reamed, locked IM nail is gold standard
    • Dynamic lock for transverse fracture
    • Static lock for all other fracture patterns
    • Antegrade nail can be placed via piriformis or trochanteric entry point
    • Retrograde nail is placed intercondylar anterior to Blumensaat’s line or medial condylar
• Complications of antegrade nails
  • Hip pain
  • Abductor or quadricep weakness
  • Reduced hip range of motion
  • Heterotopc ossification
  • Iatrogenic femoral neck fracture
• Complications of retrograde nails
  • Knee pain
  • Cartilage injury
  • Cruciate ligament injury if starting posterior to Blumensaat’s line
• Complications of femoral shaft fracture
  • Shock
  • Fat embolism
  • Deep venous thrombosis
  • Pulmonary embolism
  • Heterotopic ossification
  • Avascular necrosis
  • Pudendal nerve injury (10%, excessive traction on fracture table, presents with erectile dysfunction)
  • Peroneal nerve injury
  • Compartment syndrome (non-injured legs in hemilithotomy position, more common in ballistic injuries compared to blunt injury)
  • Femoral artery or nerve injry
  • Anterior perforation of distal femur if there is a nail/femur radius of curvature mismatch
  • Iatrogenic femoral neck fracture
  • Delayed-union
  • Aseptic non-union
  • Septic non-union
  • Malunion
  • Implant failure
  • Hip pain or limp from antegrade nail
  • Knee pain or retro-patellar arthritis from a retrograde nail