Understanding Avascular Necrosis (AVN) of the Hip

Avascular necrosis (AVN), also known as osteonecrosis, is a condition where the blood supply to the femoral head (the ball of the hip joint) is compromised, leading to bone cell death and eventual joint collapse. If untreated, it can result in debilitating pain and loss of mobility. While AVN has traditionally been linked to factors like trauma, excessive steroid use, alcoholism and clotting disorders, there has been a noticeable rise in cases following the COVID-19 pandemic.

Why is AVN Occurring Post-COVID?

Since the emergence of COVID-19, several post-recovery complications have been observed, with AVN being one of the more concerning orthopedic issues. Here’s why:

• Steroid Use During COVID-19 Treatment

Corticosteroids, such as dexamethasone, were widely used in managing severe COVID-19 cases, particularly in patients requiring oxygen or ventilator support. However, long-term or high-dose steroid use is a well-documented risk factor for AVN, as it can disrupt blood flow to bones.

• COVID-Induced Blood Clotting (Microvascular Thrombosis)

COVID-19 is known to cause vascular complications, including microvascular thrombosis (tiny blood clots in small blood vessels). These clots can reduce blood supply to bones, increasing the risk of AVN.

• Prolonged Immobility

Many COVID-19 patients experienced extended periods of bed rest due to severe illness, hospitalization, or post-recovery fatigue. Reduced movement can contribute to poor circulation, leading to AVN in susceptible individuals.

• Pre-Existing Health Conditions

Individuals with diabetes, obesity, autoimmune disorders, or cardiovascular diseases—conditions that were often exacerbated during COVID-19—are already at a higher risk for AVN. The combination of COVID-19 and these conditions further increases susceptibility.

Recognizing Symptoms of Post-COVID AVN

The symptoms of AVN often develop gradually but worsen over time. Common signs include:Persistent hip pain, particularly in the groin, thigh, or buttocks Pain that worsens with weight-bearing activities such as walking or climbing stairs Stiffness and restricted range of motion in the hip joint Limping or difficulty walking

If you’ve had COVID-19 and are experiencing any of these symptoms, it’s crucial to seek medical evaluation immediately.

Diagnosing AVN: The Role of Imaging

Timely diagnosis is critical for effective treatment. Doctor’s may use the following diagnostic tools:

X-ray: Can detect bone collapse or structural damage in later stages.

MRI: The most sensitive method for detecting early-stage AVN before visible damage occurs.

CT scan: Helps assess the extent of bone damage and joint involvement.

Treatment Options for Hip AVN Post-COVID

The treatment approach depends on the severity and stage of the disease:

Early-Stage AVN (Before Bone Collapse)

• Medications: Drugs like bisphosphonates, anticoagulants, or vasodilators may be prescribed to slow bone deterioration and improve circulation.
• Lifestyle Modifications: Avoiding high-impact activities and prolonged standing can help reduce stress on the hip joint.
• Physical Therapy: Strengthening exercises and low-impact activities such as swimming or cycling can maintain joint function.
• Core Decompression Surgery: A minimally invasive procedure to relieve pressure inside the bone and stimulate new blood vessel growth.

Advanced AVN (Bone Collapse and Joint Damage)

• Total Hip Replacement (THR): If the femoral head has collapsed, hip replacement surgery may be the best option for restoring mobility and reducing pain.
• Osteotomy (Bone Realignment Surgery): In certain cases, realigning the affected bone may help delay joint replacement.

Preventing AVN After COVID-19

Given the increasing reports of AVN among post-COVID patients, preventive measures are essential:

✅ Limit steroid use where possible – Only take corticosteroids when prescribed and under strict medical supervision.

✅ Monitor symptoms – Any unusual hip pain after COVID recovery should be reported to a doctor.

✅ Maintain a healthy lifestyle – Avoid excessive alcohol consumption and smoking, both of which increase AVN risk.

✅ Stay active – Regular low-impact exercises improve blood circulation and reduce the risk of bone damage.

✅ Early screening – Those with high-risk factors should undergo regular check-ups, including MRI scans, if necessary.

Conclusion

Hip Avascular Necrosis is emerging as a serious post-COVID complication, largely due to the effects of steroid therapy, vascular issues, and prolonged immobility. Early detection and timely intervention are key to managing AVN effectively. If you or someone you know is experiencing persistent hip pain after recovering from COVID-19, seeking medical attention at the earliest can help prevent further joint damage and improve long-term outcomes.