Steroid-Induced AVN: How It Happens

 For many people, steroids can feel like a lifesaver. They reduce inflammation, control autoimmune conditions, ease asthma symptoms, and even help cancer patients cope with side effects of treatment. But like most powerful medicines, steroids come with risks. One of the lesser-known yet serious side effects is Avascular Necrosis (AVN) a condition where bones slowly die due to loss of blood supply.

Steroid-induced AVN may not get as much attention as diabetes or weight gain caused by steroids, but it can be life-changing. Understanding how and why it happens is the first step in protecting yourself or your loved ones.

What Exactly Is AVN?

Avascular Necrosis, sometimes called osteonecrosis, is a disease where blood flow to a part of the bone gets disrupted. Without proper circulation, bone tissue weakens and eventually collapses. The hip joint is the most commonly affected site, though AVN can also develop in the shoulder, knee, or ankle.

When AVN happens, daily activities like walking, climbing stairs, or even sleeping can become painful. If left untreated, the condition often leads to arthritis and may require joint replacement surgery.

Why Are Steroids Involved?

Corticosteroids are commonly prescribed for conditions like:

• Asthma and chronic lung diseases

• Autoimmune disorders such as lupus or rheumatoid arthritis

• Post-organ transplant care (to prevent rejection)

• Cancer treatments

• Severe allergies or inflammation

They’re powerful because they reduce inflammation quickly. But the same steroids that control disease can also quietly damage bones.

How Steroid-Induced AVN Happens

The exact mechanism isn’t fully understood, but research and clinical observations point to several interconnected factors:

1. Fat buildup in bone marrow

Steroids can increase fat production in the body. When too much fat builds up inside the bone marrow, it compresses blood vessels. This makes it harder for blood to flow into the bone, essentially “starving” it.

2. Blood clotting changes

Steroids may make blood thicker and more prone to clotting. Tiny clots can form in the vessels that feed the bone, blocking circulation and leading to tissue death.

3. Weakening of bone structure

Long-term steroid use can interfere with bone-forming cells (osteoblasts). This makes bones weaker overall and less able to withstand stress.

4. Cumulative effect over time

It’s not always about one high dose. Even moderate doses over months or years can add up, slowly cutting off blood supply to critical areas like the hip joint.

Who’s at Risk?

Not everyone who takes steroids develops AVN. But certain factors raise the likelihood:

• High doses of steroids taken over a long period

• Prolonged treatment (months or years of therapy)

• Underlying health conditions like lupus or organ transplant recovery that require strong steroid regimens

• Alcohol use or smoking, which further reduce bone health

• Genetic susceptibility, as some people are simply more prone to AVN

For example, a patient with asthma who uses steroids occasionally during flare-ups is less at risk compared to someone with an autoimmune condition who needs daily steroid therapy for years.

The Silent Progression

One of the most dangerous aspects of steroid-induced AVN is how quietly it develops.

• In the early stages, patients often feel no pain.

• Gradually, a dull ache may appear in the hip or shoulder, often mistaken for simple muscle fatigue.

• As the disease progresses, pain intensifies, and mobility decreases.

By the time most patients seek medical help, the bone may already be collapsing limiting treatment options.

Real-Life Example

Consider a young woman in her 30s living with lupus. To manage her flares, she’s been on long-term steroid therapy. For months, she notices some stiffness in her hip but blames it on working from home and sitting too long. One day, climbing stairs becomes painful, prompting her to see a doctor. An MRI reveals early-stage AVN.

Her story highlights the importance of awareness: steroid users need to stay alert to even mild, persistent joint symptoms.

Can Steroid-Induced AVN Be Prevented?

While not every case can be avoided, there are steps to reduce risk:

• Use the lowest effective steroid dose under medical supervision.

• Regular monitoring with checkups and imaging if on long-term therapy.

• Bone health support through a nutrient-rich diet, calcium, vitamin D, and weight-bearing exercises.

• Avoid alcohol and smoking, both of which worsen blood supply and bone strength.

• Report early symptoms of joint stiffness or unexplained pain to your doctor immediately.

Doctors sometimes also prescribe steroid-sparing medications (other drugs that reduce inflammation without heavy steroid use) for patients at risk.

Treatment if AVN Develops

If diagnosed early, there are ways to manage steroid-induced AVN:

• Medications to support bone health and blood circulation

• Physiotherapy to maintain mobility

• Minimally invasive procedures like core decompression or stem cell therapy

• Surgical options, including joint replacement, in advanced stages

The goal is always to catch AVN before collapse, giving patients the best chance of preserving their natural joints.

Final Thoughts

Steroid-induced AVN is a reminder that while medicines can heal, they can also harm if not carefully managed. Steroids are lifesaving for millions of people, but their long-term impact on bones should never be ignored.

The good news? With awareness, regular monitoring, and early detection, the risks can be managed. Patients don’t need to fear steroids but they do need to respect their power and stay informed.

If you or someone you know is on long-term steroid therapy, don’t ignore subtle hip, knee, or shoulder discomfort. It may be your body’s quiet way of asking for help. And when it comes to AVN, listening early can make all the difference.