Neck of Femur Classification (http://www.oxfordmedicaleducation.com/)

Definition: Fracture in the proximal femur, between the lesser trochanter and greater trochanter.

Mechanism 

  • Elderly: > 90% are from a low energy fall (Egol 2010)
  • Young: Typically a high-energy trauma, such as a motor-vehicle accident or fall from a height

Epidemiology

  • Intertrochanteric fractures account for about 50% of proximal femur fractures (Egol 2010)
  • Female to male ratio is 3:1, likely due to bone density changes in post-menopausal women (UptoDate 2017)

Hip Fracture Physical Exam (image.wikifoundry.com)

Physical Exam

  • Non-displaced fracture
    • Patients may have minimal pain
    • Patients may be ambulatory despite presence of fracture
  • Displaced fractures
    • Pain in lower extremity
    • Non-ambulatory
    • Affected leg is shortened and externally rotated

Fracture Types

  • Stable vs Unstable
    • Stable
      • Posteromedial cortex is intact or minimal comminution
      • When load is applied, intact cortex will prevent external rotation and varus displacement
    • Unstable
      • Disruption of posteromedial cortex
      • Comminution of posteromedial cortex
      • Subtrochanteric extension
      • Reverse obliquity fracture: fracture line proximally from medial cortex distally to lateral cortex
  • Occult Fracture
    • Fracture not visible on plain X-rays
    • Requires advanced imaging to diagnose

Evans Classification (https://image.slidesharecdn.com)

Intertrochanteric Fracture AP X-ray (Case courtesy of Dr M Osama Yonso, Radiopaedia.org. From the case rID: 16317)

Diagnostic Imaging

  • X-Ray
    • Required views: AP Pelvis, AP and cross table lateral Hip, AP Femur
    • Will demonstrate fracture between the greater and lesser trochanter, with/out extension into the subtrochanteric region
    • Occult Fractures
      • X-rays will miss about 10% of hip fractures
      • Of all hip fractures, 8% are identified by CT scan but missed on X-ray
      • About 2% of all hip fractures are missed on X-rays and CT scan, but seen on MRI
  • Advanced Imaging (CT and MRI)
    • Consider if X-Rays are negative but patient is unable to bear weight or physical exam is concerning for fracture

Hip Fracture Imaging Algorithm

ED Management

  • Analgesia
    • Femoral nerve block
      • Pros
        • Easy to perform by landmark or ultrasound technique
        • Provides analgesia without systemic effects
      • Cons: Does not provide analgesia to lateral thigh
    • Fascia iliaca compartment block
      • Pros
        • Injection away from nerve and artery reducing complications
        • Provides analgesia to lateral thigh
      • Cons: Requires larger volume of anesthetic
    • Systemic analgesia typically provided with opiates/opioids
  • Assess for secondary injuries
    • Assess for additional fractures
    • Consider head and cervical spine trauma in all patients
    • Consider complications from fall (i.e. prolonged immobility on ground)
  • Investigate cause of fall (i.e. mechanical fall vs. syncope)
  • Monitor blood loss
    • About 40% of patients with hip fractures require blood transfusions (Desai 2014)
    • Patients with intertrochanteric fractures are twice as likely to need blood transfusion as those with a femoral neck fracture
  • Non-operative
    • Pursued for patients at very high-risk of perioperative mortality or non-ambulatory at baseline
    • Non-weight bearing
    • Goal: Early bed to chair mobilization to prevent complications such as pneumonia, VTEs, ulcers
  • Operative
    • Stable: Sliding hip screw
    • Unstable: Intramedullary hip screw or arthroplasty

Prognosis

  • 1 year mortality: 20-30%¬†(Brauer 2009)
  • Mortality higher than in femoral neck fracture (Haentjens 2007)
  • Increased mortality associated with
    • Age over 85
    • Pre-existing medical conditions or ASA classification III and IV
    • Male
    • Operative delay for more than 2 days
  • Low rates of non-union and malunion, because of extensive blood supply

Take Home Points

  • Occult fractures are common. A negative X-ray with a high clinical suspicion should be followed by a CT and/or MRI
  • Do not forget to assess for secondary injury and monitor blood loss
  • Provide adequate analgesia with a regional nerve block or opioids
  • It is important to diagnose hip fractures early because there is a high mortality rate with delay in operative management

Read More

Orthobullets: Intertrochanteric Fractures

UptoDate: Hip Fractures in Adults

Highland EM Ultrasound: Femoral Block

Ultrasound Podcast: Lower Extremity Nerve Block Mastery with Mike Stone!

References

Egol KA et al. Handbook of Fractures. Lippincott Williams & Wilkins; 2010. Link

Desai SJ et al. Factors affecting transfusion requirement after hip fracture: can we reduce the need for blood?. Can J Surg. 2014;57(5):342-8. PMID 25265109

Brauer CA et al. Incidence and mortality of hip fractures in the United States. JAMA. 2009;302(14):1573-9. PMID 19826027

Haentjens P et al. Survival and functional outcome according to hip fracture type: a one-year prospective cohort study in elderly women with an intertrochanteric or femoral neck fracture. Bone. 2007;41(6):958-64. PMID 17913614