Hip
Avascular Necrosis of the Hip
Avascular necrosis is the bone at the top of the thigh bone dying because its blood supply has been cut off or reduced, not because it has worn out. Caught before the joint surface collapses it can sometimes be treated without a replacement; caught after, replacement is usually what restores the joint.
By appointment only, at Kharar (Mohali) or Solan. Your confirmation says which.
What causes it
In many people no clear cause is ever found. Where one is, the recognised risk factors are long-term or high-dose steroid use, significant alcohol intake, sickle cell disease, smoking, and a previous fracture or dislocation of the hip that disrupted the blood supply directly. It is also more common in India than in many other countries, for reasons that are not fully settled.
It typically affects people in their thirties to fifties, younger than the usual age for hip arthritis, and it is common for the other hip to be affected too, sometimes without yet causing symptoms, which is why the opposite hip is often imaged as well once one side is diagnosed.
When it needs seeing sooner
- Sudden inability to bear weight, which can mean the bone has acutely collapsed or there is an associated fracture
- The hip is hot and painful and you feel unwell or feverish
- A sudden, marked change in how the leg sits or moves
- Pain with fever, night sweats or unexplained weight loss
Short of those, groin pain with the risk factors above is worth a routine consultation rather than waiting to see if it settles, because how early it is caught genuinely changes what can be done about it.
How it gets assessed
Pain is usually felt in the groin and can travel down the front of the thigh towards the knee, similar to other hip joint pain, and can be present even at rest once it has progressed. The examination looks at rotation in particular, which is often the first movement to be affected.
X-rays are frequently normal in the early stages, which is the trap here: a normal X-ray does not rule this out if the story fits. An MRI is far more sensitive early on and is the test that actually catches it before the bone surface has started to collapse, which is the point at which treatment options are widest.
What treatment usually looks like
What is offered depends almost entirely on the stage at diagnosis, which is the central reason early imaging matters so much here.
Before the bone surface has collapsed, in carefully selected cases, procedures aimed at relieving pressure inside the bone or supporting the area can sometimes preserve the joint and delay or avoid a replacement. These options genuinely narrow, and can disappear, once collapse has begun, which is why watching and waiting is not a neutral choice in early disease the way it often is in ordinary arthritis.
Once the joint surface has collapsed or arthritis has set in, hip replacement is usually the option that reliably restores comfortable movement, and it works as well here as it does for any other cause of hip arthritis. The difference is that patients reaching this point are often younger than the typical hip replacement patient, which is a real part of that conversation rather than a reason to avoid it.
Common questions
Is avascular necrosis the same as arthritis?
No, though it can lead to it. Arthritis is the joint surface wearing out; avascular necrosis is the bone underneath it dying because its blood supply failed. Once the bone surface collapses under normal loading, arthritis often follows as a consequence, but the two are different diseases with different early treatment.
What actually causes the blood supply to fail?
Steroid use, heavy alcohol intake, sickle cell disease and a hip fracture or dislocation are the recognised causes, though in a real proportion of people none of these is present and no clear cause is ever identified.
Will my other hip be affected too?
It often is, sometimes without any symptoms yet. Because of that, the opposite hip is usually imaged once one side is diagnosed, so that if it is affected, it can be caught at an earlier and more treatable stage rather than waiting for it to become painful.
Can it be caught before the joint collapses?
Yes, and this is the single most important thing to know about this condition. An MRI can detect it well before an X-ray does and well before the bone surface has collapsed, which is the window in which joint-preserving treatment is possible. Groin pain with any of the risk factors above is worth imaging rather than waiting out.
Related procedures
Where an operation does turn out to be the right answer, these are the ones this problem most often leads to.
Not sure what is causing it?
That is what a consultation is for. Bring any imaging you already have, and any plan you have been given elsewhere.