Avascular necrosis of the hip causes symptoms treatment and how to protect yourself

Avascular hip necrosis is one of those conditions that can begin quietly, without the patient noticing any clear symptoms at first. However, over time, it can develop into a serious problem that significantly affects mobility and overall quality of life.This condition occurs due to reduced or interrupted blood flow to the head of the femur (thigh bone), which gradually leads to the death of bone tissue. If left untreated, it may progress to the collapse and complete degeneration of the hip joint.What makes this condition particularly concerning is that it can affect people of all ages, including young adults. This is why awareness of its causes, early symptoms, diagnostic methods, and treatment options is extremely important. we will cover everything you need to know about avascular hip necrosis: why it happens, how it can be detected early, and the latest treatment options that can help preserve the joint and prevent further deterioration.

What is Avascular Necrosis of the Hip (Femoral Head Osteonecrosis)?

Avascular necrosis of the hip is a painful condition that occurs when blood flow to the head of the femur (thigh bone) is reduced or completely interrupted. As a result of this lack of blood supply, bone cells begin to die gradually. If the condition is not treated early, it may lead to collapse of the joint surface and severe hip arthritis.

⚠️ Is avascular necrosis of the hip serious?

Yes, it can be a serious condition if left untreated. Over time, it may progress to significant damage of the hip joint and advanced osteoarthritis. However, its severity is greatly reduced when it is diagnosed early and managed properly.

Can the patient walk normally?

In the early stages, patients may walk normally or experience only mild pain. As the condition progresses, limping may appear and movement becomes more difficult. In advanced stages, the patient may need a walking aid such as a cane.

Can it occur at a young age?

Yes, it can affect young people as well. Common risk factors include long-term corticosteroid use, blood disorders, or trauma to the hip area.

Is exercise beneficial?

Yes, exercise can be helpful, but only if it is low-impact and safe. Recommended activities include swimming and physiotherapy exercises, as they help maintain joint flexibility and strengthen surrounding muscles without putting excessive stress on the femoral head.

On the other hand, high-impact activities such as running, jumping, or intense workouts should be avoided, as they may accelerate joint damage.

⏱️ Does the disease progress quickly?

The progression rate varies from one person to another depending on the cause and stage at diagnosis. In most cases, it progresses gradually over months or even years. Therefore, early detection and regular medical follow-up are essential to slow down disease progression and reduce complications.

Stages of Avascular Necrosis of the Hip (Femoral Head Osteonecrosis)

The stages of avascular necrosis are determined by the degree of damage to the femoral head and its ability to bear weight. These stages are crucial in deciding the appropriate treatment plan.

Stage 1

No visible changes on standard X-rays
Diagnosis is mainly confirmed using MRI
The bone still looks normal in shape
Pain may be present, but no structural collapse has occurred

This is the most important stage because treatment is most effective here.

Stage 2

Mild changes in bone density begin to appear
Reduced blood supply becomes more evident
No collapse or flattening of the femoral head yet
Pain increases, especially during walking or weight-bearing

Stage 3

Partial collapse of the femoral head begins (flattening of the surface)
Loss of normal joint shape
Persistent and more noticeable pain
Reduced range of motion
Early signs of osteoarthritis may appear

Stage 4

Severe destruction of the femoral head
Advanced hip arthritis develops
Direct bone-on-bone friction occurs
Severe pain even at rest
Significant difficulty in walking and movement

In most cases, surgical intervention such as hip replacement is required.

Causes of Avascular Necrosis of the Hip

Avascular necrosis occurs due to reduced or interrupted blood supply to the femoral head, leading to gradual bone cell death. Over time, this may result in joint damage, severe pain, and limited mobility.

Main causes include:

1. Hip injuries or fractures

One of the most common causes. Fractures or severe dislocations near the hip joint can disrupt blood flow to the femoral head.

2. Long-term corticosteroid use

High doses or prolonged use of steroids (for allergies or autoimmune diseases) can affect blood circulation within the bone.

3. Excessive alcohol consumption

Alcohol can disrupt fat metabolism and damage small blood vessels, leading to reduced blood supply to bone tissue.

4. Blood disorders

Conditions such as sickle cell anemia or clotting disorders can block small blood vessels and reduce oxygen delivery to the bone.

5. Chronic and autoimmune diseases

Diseases like systemic lupus erythematosus may affect circulation and increase the risk of necrosis.

6. Unknown causes (idiopathic cases)

In some cases, no clear cause can be identified.

7. Increased intra-bone pressure

Elevated pressure inside the femur may gradually reduce blood flow, leading to bone cell death.

Main Symptoms of Avascular Necrosis of the Hip (Femoral Head Osteonecrosis)

1. Hip pain

This is the most common and primary symptom. It usually starts mildly and gradually worsens over time.
The pain may also radiate to the thigh or the groin area.

2. Increased pain with movement

Pain becomes worse during walking, running, or standing for long periods.
In early stages, pain may improve with rest, but it can become constant as the condition progresses.

3. Hip stiffness

Patients may experience difficulty moving the hip joint normally, especially when rotating the thigh or moving it inward.

4. Limping

A noticeable limp develops gradually due to pain and reduced joint function.

5. Reduced range of motion

The ability to fully bend or extend the leg decreases, and the joint may feel tight or restricted.

6. Pain during sleep (advanced stages)

Pain may occur even at rest, especially when lying on the affected side, causing significant discomfort.

7. Gradual worsening of symptoms

Symptoms are usually mild at first but progressively worsen over time if untreated, becoming more severe and persistent.

Diagnosis of Avascular Necrosis of the Hip (Femoral Head Osteonecrosis)

Diagnosis is based on clinical evaluation and imaging tests, as early stages may not appear on standard X-rays.

1. Clinical examination

The doctor evaluates:

Location of pain (often in the groin or thigh)
Range of motion of the hip joint
Presence of limping
Whether pain worsens with movement or occurs at rest

However, clinical examination alone is not enough for a definitive diagnosis.

2. X-ray (Radiography)

This is usually the first imaging test.

May appear completely normal in early stages
In advanced stages, it may show:
- Flattening of the femoral head
- Joint degeneration
- Signs of osteoarthritis

However, its main limitation is that it cannot detect early disease.

3. MRI (Magnetic Resonance Imaging)

This is the most accurate and important diagnostic tool.

Detects the disease in very early stages before X-ray changes appear
Shows reduced or interrupted blood supply to the bone
Identifies early bone cell death and structural changes

It is considered the gold standard for early diagnosis.

4. CT scan

Provides a detailed view of bone structure
Helps assess the degree of collapse of the femoral head
Less sensitive than MRI in early stages

5. Laboratory tests (in selected cases)

These do not diagnose the condition directly but help identify underlying causes, such as:

Blood clotting disorders
Sickle cell anemia
Liver function tests
Corticosteroid levels (if long-term use is suspected)
Autoimmune disease markers

Complications of Avascular Necrosis of the Hip (Femoral Head Osteonecrosis)

Complications usually occur when diagnosis or treatment is delayed, leading to progressive damage of the femoral head and hip joint.

⚠️ Main complications:

1. Femoral head collapse

Reduced blood supply weakens the bone, leading to flattening or collapse of the femoral head, which severely affects joint function.

2. Severe hip osteoarthritis

Progressive cartilage damage leads to bone-on-bone friction, resulting in advanced arthritis and chronic pain.

3. Chronic severe pain

Pain may become constant and persist even at rest, affecting sleep and daily life.

4. Severe joint stiffness

Hip movement becomes significantly limited, making bending or rotating the leg difficult.

5. Limping and difficulty walking

Due to pain and joint deterioration, patients may require assistive devices such as a cane.

6. Complete joint destruction (advanced cases)

Severe stages may lead to near-total destruction of the femoral head, often requiring hip replacement surgery.

7. Muscle weakness and atrophy

Reduced movement and chronic pain can cause muscle wasting around the hip and thigh, further limiting mobility.

Medical Treatment of Avascular Necrosis of the Hip

Drug therapy does not completely cure the condition in all stages, but it helps reduce pain, improve blood flow, and slow disease progression—especially in early stages.

1. Pain relievers and anti-inflammatory drugs

Examples:

Ibuprofen
Diclofenac
Naproxen

Benefits:

Reduce pain
Decrease inflammation
Improve mobility

⚠️ Should be used carefully in patients with stomach or kidney problems.

2. Drugs that improve blood circulation

These aim to enhance blood flow to the femoral head, such as vasodilators (as prescribed by a doctor).

Goals:

Improve bone blood supply
Slow bone cell damage

In some cases, blood-thinning medications may be used under strict medical supervision.

3. Lipid-lowering drugs

Example:

Statins

Benefits:

Reduce fat-related vascular blockage
May improve microcirculation in some patients

4. Bone-strengthening medications

Examples:

Bisphosphonates

Role:

Reduce bone breakdown
Slow femoral head collapse
Help preserve bone structure in early stages

5. Vitamins and supplements

Examples:

Vitamin D
Calcium

Purpose:

Support bone health
Improve bone density
Reduce fragility

6. Treating the underlying cause (if present)

Treatment is directed at the root cause, such as:

Reducing or adjusting corticosteroid use
Treating sickle cell anemia
Managing autoimmune diseases
Treating clotting disorders

Surgical Treatment of Avascular Necrosis of the Hip

Surgery is the main option for moderate to advanced stages, or when medication is no longer effective. The goal is either to preserve the femoral head or replace the joint entirely, depending on disease severity.

1. Core decompression (pressure relief surgery)

Concept:
Reducing pressure inside the femoral head to improve blood flow.

Procedure:

Drilling small channels into the femoral head
Removing dead or damaged bone tissue
Reducing internal bone pressure
Sometimes injecting stem cells or bone grafts

Goals:

Improve blood circulation
Reduce pain
Slow or stop disease progression

Best suited for:
Stage 1 and Stage 2

2. Bone grafting

1. Non-vascularized bone graft

Procedure:

Removal of damaged bone from the femoral head
Replacement with healthy bone (from the patient or a donor)

Goal:

Support the structure of the femoral head
Reduce the risk of collapse

2. Vascularized Fibular Graft

Procedure:

A segment of the fibula bone is harvested along with its blood vessels.
The small blood vessels are microsurgically connected in the hip area.
The graft is inserted and fixed into the femoral head.

Advantages:

Direct improvement of blood supply
Higher success rate compared to traditional bone grafting

Suitable for:

Moderate cases before complete collapse of the femoral head.

3. Osteotomy (Pelvic or Femoral Bone Cutting)

Concept:

Redistributing weight and pressure away from the damaged part of the joint to a healthier area.

Procedure:

A section of the femur or pelvis is surgically cut
The bone angle is adjusted to reduce pressure on the affected area
The bone is fixed using plates and screws

Goal:

Reduce stress on the damaged femoral head
Delay joint deterioration

Suitable for:

Selected moderate cases.

4. Total Hip Replacement

Concept:

Complete replacement of the hip joint with an artificial implant.

Procedure:

Removal of the damaged femoral head
Preparation of the acetabulum (hip socket)
Implantation of an artificial joint made of metal or ceramic with a medical-grade plastic lining

Goal:

Permanent pain relief
Restoration of mobility

Suitable for:

Stage 4 (severe collapse and advanced osteoarthritis)

5. Hip Resurfacing

Concept:

A partial alternative to total hip replacement that preserves more of the natural bone.

Procedure:

Removal of the damaged surface layer of the femoral head
Placement of a metal cap instead of removing the entire head

Advantages:

Preserves more natural bone
Suitable for some younger patients

Treatment of Avascular Necrosis of the Hip with Exercise

Exercise does not cure avascular necrosis, but it is an important part of the treatment plan. It helps reduce pain, improve joint flexibility, strengthen surrounding muscles, and slow disease progression, especially in early and moderate stages.