II. Epidemiology

  1. Incidence: 20,000/year in United States
  2. Most common in men ages 30-50 years old
  3. Leg-Calve-Perthes Disease is idiopathic osteonecrosis of the femoral head in children ages 2-12 years old

III. Risk Factors (compromise femoral head blood supply further)

  1. Most significant common cases denoted (*)
    1. Pregnancy
    2. Chemotherapy
    3. Radiation Therapy
    4. Sickle Cell Anemia
  2. Hematologic Causes
    1. Coagulopathy
    2. Sickle Cell Disease (*)
  3. Gastrointestinal Causes
    1. Chronic Liver Disease
    2. Chronic Pancreatitis
  4. Rheumatologic Causes
    1. Gout
    2. Systemic Lupus Erythematosus
  5. Medication, substances and exposures
    1. Chemotherapy (*)
    2. Radiation Therapy (*)
    3. Alcohol Abuse
    4. Systemic Corticosteroids
    5. Tobacco Abuse
  6. Lipid Disorders
    1. Hyperlipidemia
    2. Gaucher Disease
  7. Miscellaneous Causes
    1. Diabetes Mellitus
    2. Pregnancy (*)

IV. Pathophysiology

  1. Femoral head subchondral bone with irreversible anoxia
    1. Results in secondary osteocyte death
    2. Osteoblasts are active in surrounding bone
  2. Subchondral trabeculae fails and result in collapse of Hip Joint space

V. Symptoms

  1. Progressive Groin Pain or Hip Pain, gradually increasing over weeks to months
  2. Starts unilaterally (but ultimately bilateral in over 70% of cases)
  3. Radiation into medial thigh
  4. Provoked with weight bearing (especially while standing with all weight on affected leg)
  5. Pain at rest suggests advanced avascular necrosis

VI. Signs

  1. Hip Range of Motion
    1. Normal initially
    2. Later significantly limited active and passive range of motion due to joint destruction and collapse

VII. Differential Diagnosis

  1. See Hip Pain

VIII. Diagnosis

  1. Typically delayed diagnosis until advanced stages (due to insidious, gradual presentation)

IX. Imaging

  1. MRI Hip (preferred)
  2. CT Hip
  3. XRay Hip (first-line, initial study)
    1. Stage 0 and 1: Normal XRay
    2. Stage 2: Hip sclerosis, bone cysts and Osteopenia
    3. Stage 3: Crescent sign
      1. Femoral head flattening of the superior aspect
      2. Subchondral Fracture parallel to articular surface
    4. Stage 4: Femoral head collapse
    5. Stage 5-6: Joint destruction

X. Management

  1. Orthopedic referral
  2. Non-Sickle Cell patients
    1. Hip replacement in nearly all cases
  3. Sickle-Cell patients
    1. Conservative management with focus on pain relief and mobility, physiotherapy
    2. Surgery is rarely indicated in Femoral Head AVN in Sickle Cell Anemia

XI. Prognosis

  1. Responsible for 12% of all hip replacements in the United States

XII. References

  1. Shahideh (2013) Crit Dec Emerg Med 27(9):10-18
  2. Welsh and Welsh (2016) Crit Dec Emerg Med 30(11): 15-23

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Related Studies

Ontology: Avascular Necrosis of Femur Head (C0410480)

Concepts Pathologic Function (T046)
MSH D005271
SnomedCT 203476003
English AVASCULAR NECROSIS FEMORAL HEAD, Avascular necrosis, head-femur, Avascular necrosis of femoral head, AVASCULAR NECROSIS OF FEMORAL HEAD, PRIMARY, ISCHEMIC NECROSIS OF FEMORAL HEAD, FEMORAL HEAD, AVASCULAR NECROSIS OF, OSTEONECROSIS OF FEMORAL HEAD, ANFH, Avascular Necrosis of Femur Head, avascular necrosis femoral head, avascular femoral heads necrosis, femoral head avascular necrosis, avascular femoral head necrosis, Avascular necrosis of the femoral head, FEMORAL HEAD, ASEPTIC NECROSIS OF, Ischemic Necrosis Of Femoral Head, Femoral Head, Avascular Necrosis Of, Avascular Necrosis Of Femoral Head, Primary, Avascular necrosis of the head of femur, Avascular necrosis of the head of femur (disorder), Avascular Necrosis of Femoral Head, Necrosis, Avascular, of Femur Head, Avascular necrosis femoral head
Dutch avasculaire necrose van femurkop, Femurkopnecrose, avasculair, Necrose, avasculair, van femorkop
German aseptische Nekrose des Femurkopfs, Nekrose, avaskuläre, des Femurkopfes, HUEFTKOPFNEKROSE NICHT GEFAESSBED, Avaskuläre Nekrose des Femurkopfes
Italian Necrosi avascolare della testa femorale, Necrosi avascolare della testa del femore
Portuguese Necrose avascular da cabeça femural, NECROSE AVASCULAR DA CABECA DO FE, Necrose Avascular da Cabeça do Fêmur
Spanish Necrosis avascular de la cabeza del fémur, Necrosis Avascular de la Cabeza Femoral, NECROSIS AVASCULAR CABEZA FEMUR, Necrosis Avascular de la Cabeza del Fémur, necrosis avascular de la cabeza del fémur (trastorno), necrosis avascular de la cabeza del fémur
French Nécrose avasculaire de la tête fémorale, NECROSE DE LA TETE FEMORALE, Nécrose ischémique de la tête fémorale, Nécrose ischémique de la tête du fémur, Nécrose avasculaire de la tête du fémur
Czech Avaskulární nekróza hlavičky femuru, femur - nekróza hlavice avaskulární, femur - nekróza hlavice ischemická
Hungarian Avascularis necrosis a femur fejben
Japanese ダイタイコツトウキョケツセイエシ, ダイタイコットウキョケツセイエシ, 大腿骨頭虚血性壊死
Norwegian Avaskulær lårbenshodenekrose, Avaskulær caputnekrose femur, Avaskulær lårbeinshodenekrose, Lårbenshodenekrose, avaskulær, Lårbeinshodenekrose, avaskulær