Dr Tarandeep Singh Gill — MS Ortho, MCh Ortho
Director – Joint Replacement & Robotic Surgery · RoboLens FT3D Pioneer · Max Super Speciality Hospital, Mohali
Avascular necrosis — also called osteonecrosis — is a condition most patients haven’t heard of until it’s affecting them. The femoral head (the ball of the hip joint) loses its blood supply, and without blood, the bone tissue begins to die. The femoral head then weakens, flattens, and eventually collapses — leading to severe hip pain and joint damage that, in advanced cases, requires total hip replacement.
It affects a younger demographic than typical hip arthritis. Many patients with AVN are in their 30s, 40s, or 50s. The causes include long-term steroid use (common in patients treated for autoimmune conditions or post-transplant), excessive alcohol use, trauma to the hip, sickle cell disease, and in some cases no identifiable cause at all (idiopathic AVN).
Stages and What They Mean
AVN is staged on a scale of 0 to 4 (Ficat classification or ARCO classification). The stage determines what treatment is appropriate:
- Stage 1–2 (pre-collapse): The femoral head is intact. MRI will show the characteristic signal changes even before X-ray changes appear. This is the window for joint-preserving treatment — core decompression (drilling channels into the femoral head to restore blood flow) sometimes combined with bone grafting or biological augmentation.
- Stage 3 (crescent sign / early collapse): The subchondral bone begins to fracture. Core decompression becomes less effective. Some patients at this stage are managed conservatively if the collapsed area is small and they’re not in severe pain.
- Stage 4 (collapse with joint involvement): The femoral head has collapsed significantly and the acetabulum is affected. Total hip replacement is typically the appropriate treatment at this stage.
Why Early Diagnosis Matters Significantly Here
More than most orthopedic conditions, AVN has a treatment window that closes. A patient diagnosed at stage 1 who undergoes core decompression has a reasonable chance of avoiding or substantially delaying hip replacement. A patient diagnosed at stage 4 doesn’t have that option.
If you’re a younger patient with unexplained hip pain — especially if you’ve had prolonged steroid use, trauma, or a known risk factor — an MRI-based assessment is worth doing promptly. X-rays can appear normal in early AVN while the disease is already progressing.
Dr. TS Gill at Max Hospital Mohali treats both early-stage AVN (core decompression) and advanced cases (total hip replacement) in the Chandigarh–Tricity area. Book a consultation if you have unexplained hip pain and want a specialist opinion.
