Coupon Accepted Successfully!


Avn Femur Head

It is aseptic (noninfectious) ischemic necrosis of bone.

  1. Etio — Pathogenesis
    1. Idiopathic (40% ≈ most common)
    2. Traumatic
    3. Infective
    4. Embolism
      Caison’s disease (N2)
    5. Vasculitis-SLE/Irradiation
  2. Thrombosis
    1. Haemoglobinopathies
      1. Sickle cell disease (SS)
      2. Hb SC
      3. Thalassemi
    2. Hypercoagulability & Coagulation disorders
      1. Anticoagulant deficiency - Thrombophilia - Toxic shock
      2. Nephrotic syndrome - Hypofibrinolysis – Hypolipoproteinemia
      3. Thrmbocytopenic purpura
    3. Conditions causing thromboplastin release
      1. Malignancy esp. hematological eg. leukemia, lymphoma, polycythemia
      2. Pregnancy - Inflammatory bowel disese - Pancreatitis
  3. Capillary Occlusion
    1. Steroid- Alcohol - Gaucher’s disease
    2. Hyperlipidemia eg Nephrotic syndrome
  4. Other
    1. Perthe’s disease - Endotoxin reaction, Toxic shock, Anaphylactic shock
    2. Renal transplant patients (16%)
    3. Brain / spinal surgery - Diabetes mellitus
  5. MRI is the investigation of choice
    1. Clinical Features
      1. High index of suspicion in patient with associated risk factor eg high dose/prologned steroid therapy, alcohol abuse
      2. Age 20-50 years with slight male preponderance
      3. Bilateral in 50% of idiopathic cases, and 80% of steroid induced cases.
      4. Limp with antalgic gait and positive Trendelenburg sign.
      5. Thigh wasting and 1-2cm shorting in late cases.
      6. Decreased range of motion especially internal rotation followed by abduction
      7. A characteristic sign is a tendency for hip to twist into external rotation during passive flexion; this corresponds to the ‘Sectoral sign’ in which, with the hip extended, internal rotation is almost full but with hip flexed it is grossly restricted.
      8. On x-ray there is crescent sign
      9. On MRI there is double line sign

Description: images-2

AVN with collapsed head

Crescent sign


Core decompression

Urbaniak vascularized fibular grafting

  1. Treatment early stages protected weight bearing
  2. Followed by core decompression that is drilling the avascular area increases the blood supply if not relieved by rest.
  3. Rotational osteotomy with vascular repair is done to rotate the avascular area of femoral head with normal sector of femoral head.
  4. In late stages when collapse occurs accompanied by arthritis – Arthroplasty.

Test Your Skills Now!
Take a Quiz now
Reviewer Name