Avascular Necrosis Of The Hip: Causes, Stages, And What To Do About It

Avascular necrosis (AVN) of the hip, also called osteonecrosis, is a condition that destroys the hip joint from the inside, and it does so most often in people who are not old. The average patient with AVN of the hip in India is between 25 and 50 years of age. That fact alone separates it from most other reasons for hip surgery and demands a different approach to management.

If you or someone you know has been diagnosed with AVN of the hip in Noida or Greater Noida, this guide will help you understand what is actually happening inside the joint, what the staging system means, and what your treatment options are at each stage.

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What Is Avascular Necrosis of the Hip?

The femoral head — the ball at the top of the thigh bone — is kept alive by a network of small blood vessels. AVN occurs when this blood supply is disrupted or significantly reduced. Without adequate blood flow, the bone cells in the femoral head begin to die. The weakened bone then loses its structural integrity and, over time, collapses under the weight it is designed to support.

The hip is a ball-and-socket joint. When the ball (femoral head) collapses, the smooth cartilage surface that allows pain-free movement is destroyed, and the joint becomes arthritic. This is why AVN, if not treated early, almost inevitably leads to severe hip pain and eventual need for hip replacement.

What makes AVN particularly difficult is that early stages are often painless or produce only mild groin discomfort. By the time pain becomes significant, the bone has often already begun to collapse — making joint preservation far more challenging.

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What Causes AVN of the Hip?

Corticosteroid Use

This is the most common non-traumatic cause of AVN in India, and it deserves specific attention. High-dose corticosteroids — used for conditions like rheumatoid arthritis, lupus, asthma, nephrotic syndrome, and increasingly for managing COVID-19 complications — can disrupt the fat metabolism in bone marrow, leading to fatty deposits that block the small blood vessels supplying the femoral head.

The risk is dose-dependent and cumulative. Patients who received high-dose steroids during COVID-19 management have shown a notable increase in AVN presentations across India over the past few years. If you received prolonged steroid treatment and have since developed groin or hip pain, AVN must be considered and investigated promptly.

Excessive Alcohol Consumption

A significant risk factor. Chronic heavy alcohol intake causes fat accumulation in the blood vessels of bone, leading to vascular obstruction similar to steroid-induced AVN.

Hip Trauma

A fracture of the femoral neck or a hip dislocation can physically disrupt the blood vessels supplying the femoral head. This is why fracture management in the hip region must be precise and timely — delay in treating displaced femoral neck fractures dramatically increases AVN risk.

Other Causes

Blood clotting disorders, sickle cell anaemia, Gaucher's disease, decompression sickness (divers), and radiation therapy are all associated with AVN. In a proportion of cases — particularly in younger patients — no obvious cause is identified (idiopathic AVN).

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Staging of AVN: The ARCO System

The most widely used staging system for AVN is the ARCO (Association Research Circulation Osseous) classification, which runs from Stage I to Stage IV:

Stage I: Early AVN. The femoral head appears normal on X-ray. MRI is required for diagnosis — it shows early oedema and signal changes that indicate compromised blood supply. The bone is structurally intact at this stage.

Stage II: The bone shows changes visible on X-ray — sclerosis, cyst formation, or density changes — but the femoral head has not collapsed. The spherical shape is preserved. This is still a stage where joint preservation is possible.

Stage III: The femoral head begins to collapse. A "crescent sign" may be visible on X-ray — a thin line of bone separation just beneath the cartilage surface as the subchondral bone gives way. The cartilage above may still be intact. This is the critical transition point.

Stage IV: Advanced collapse. The femoral head has lost its spherical shape. The joint space narrows as the collapsed head grinds against the socket, causing secondary arthritis. This stage almost always requires hip replacement.

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Treatment Options by Stage

Stage I and Early Stage II: Joint Preservation

The goal at early stages is to restore blood flow to the femoral head, stimulate bone healing, and prevent collapse. Options include:

Core Decompression: A minimally invasive procedure where one or more channels are drilled into the femoral head to relieve the elevated pressure within the bone and create pathways for new blood vessel growth. This is the most established joint-preserving intervention. Outcomes are best when performed at Stage I or early Stage II before collapse begins.

Core Decompression with Bone Grafting: The channel created by decompression is filled with a bone graft (autologous or synthetic) to provide structural support and stimulate healing. Adds structural stability compared to decompression alone.

Medications: Bisphosphonates (alendronate, zoledronic acid) have been studied as adjuncts to surgical treatment, with evidence suggesting they may slow progression and reduce the need for joint replacement in selected patients, particularly at early stages.

Activity Modification: Reducing weight-bearing load on the affected hip during the healing phase, typically using crutches for a period. Crutch use alone is not a treatment for AVN, but it reduces mechanical stress during the biological recovery phase after joint-preserving surgery.

Late Stage II and Stage III: The Decision Point

Stage III represents the most complex decision territory. If the area of collapse is small and the femoral head retains reasonable structural integrity, joint-preserving procedures combined with careful monitoring may still be appropriate — particularly in younger patients where every year of hip preservation matters.

For larger collapses or where Stage III has advanced significantly, hip replacement becomes the more reliable option for pain relief and restored function.

Stage IV: Hip Replacement

At Stage IV, the joint surface is destroyed, and secondary arthritis is established. Hip replacement surgery — total hip arthroplasty — is the definitive treatment. Modern hip replacement in younger AVN patients is performed with implants designed for high durability and activity, and when performed with robotic assistance, positioning is optimised for long-term implant performance.

For patients in their 30s and 40s with Stage IV AVN, the goal is an implant that performs well for decades — making surgical precision especially important.

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Why Early Diagnosis Matters So Much

The difference between Stage I/II and Stage III/IV is the difference between potentially preserving your own hip and needing a replacement. That gap can be as little as months in aggressive disease, or it can span years in slow-progressing cases — but it cannot be predicted without imaging.

If you have received corticosteroid treatment in the past one to three years and have developed groin or hip pain — even mild pain that comes and goes — an MRI should be requested. X-rays are unreliable at early stages. An MRI showing normal findings is reassuring; an MRI showing early oedema allows intervention before collapse occurs.

Do not wait for the pain to become severe before seeking evaluation.

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AVN Hip Treatment at Dr. Ankur Singh's Clinic in Noida

Dr. Ankur Singh manages avascular necrosis of the hip at all stages — from early joint-preserving core decompression to robotic total hip replacement for advanced disease. His clinical approach prioritises preservation whenever clinically viable, and replacement when preservation is no longer a realistic option.

Patients from across Noida, Greater Noida, and the Delhi-NCR region have access to this specialist care at KDSG Superspeciality Hospital without needing to travel to central Delhi.

If you have been diagnosed with AVN of the hip, or if you have risk factors (steroid use, alcohol, prior hip trauma) and have developed hip or groin pain, a specialist consultation with Dr. Ankur Singh is the right next step.

To book a consultation, call the number listed on this website.

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Frequently Asked Questions

Can AVN of the hip be treated without surgery?

At Stage I, conservative measures with close monitoring are an option in carefully selected cases. Most orthopedic specialists recommend core decompression at Stages I–II to actively promote healing and prevent progression. Stage IV invariably requires hip replacement.

Is AVN more common after COVID-19 treatment?

Yes. The widespread use of high-dose corticosteroids during COVID-19 management has led to a documented increase in AVN cases across India. Anyone who received prolonged steroid therapy during or after COVID-19 and has since developed hip or groin pain should be evaluated for AVN.

Does AVN affect both hips?

Frequently, yes. AVN is bilateral (affects both hips) in approximately 40–80% of cases, though both hips may not present at the same stage simultaneously.

Is hip replacement available for young patients with AVN in Noida?

Yes. Dr. Ankur Singh performs total hip replacement for AVN patients at KDSG Superspeciality Hospital in Greater Noida, with implant selection and surgical approach tailored to the patient's age, activity level, and long-term goals.

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Dr. Ankur Singh | Best Orthopedic Surgeon in Noida | Avascular Necrosis Hip Treatment | Hip Replacement for AVN | KDSG Superspeciality Hospital, Greater Noida