Necrosis of the Femoral Head: A Silent Yet Dangerous Disease

Necrosis of the femoral head is a condition that can rapidly progress, often masquerading as other ailments. It poses a significant threat, leading to disability for those affected, but its symptoms remain subtle and easily mistaken for different health issues.

1. Understanding Femoral Head Necrosis

The femoral head, constituting two-thirds of the hip joint, is a spherical structure that points upward and inward. Femoral head necrosis, also known as avascular necrosis, arises due to insufficient blood supply, leading to the death of bone and cartilage tissue. In the initial stages, the bone head gradually thins, forming defects, followed by subchondral fractures, ultimately causing the collapse of the femoral head and loss of hip joint function, resulting in disability. This condition is not caused by bacteria, hence it is also referred to as aseptic necrosis of the femoral head.

2. Causes and Risk Factors

• Hip injuries, dislocations, or fractures of the femoral neck
• Excessive alcohol and tobacco consumption, damaging blood vessels and leading to chronic vasculitis, which obstructs the capillaries supplying the femoral head
• Autoimmune diseases such as rheumatoid arthritis, lupus erythematosus, etc.
• Prolonged use of corticosteroid-containing medications
• Hypercoagulable conditions and spontaneous embolism
• Occupational hazards, e.g., miners, divers

• The risk of this disease increases with age
• More commonly observed in men
• Associated with chronic conditions like diabetes, hypertension, lipid metabolism disorders, and high uric acid levels

3. Symptoms of Femoral Head Necrosis

Femoral head necrosis is often a silent disease with limited symptoms, which may include:

• Hip pain, mainly felt on the inner side of the groin, radiating to the inner thigh or buttocks. Some patients may experience knee joint pain, leading to misdiagnosis.
• Pain may occur on one or both sides of the hip joint and worsens while walking or standing for extended periods, typically relieved by rest.
• Restricted hip mobility, especially during internal rotation, external rotation, abduction, and adduction. Squatting may become difficult or impossible.
• In advanced stages, the pain intensifies, severely limiting hip movements, including flexion and extension.

4. Diagnostic Measures

Diagnosis is based on clinical manifestations, taking into account risk factors such as age, history of hip injury, alcohol and tobacco use, and chronic medical conditions like diabetes and hypertension. Definitive diagnosis may involve:

• X-ray imaging, which reveals bone thinning and varying degrees of femoral head collapse, and even partial or complete loss of the femoral head.
• MRI scans when X-rays are inconclusive, providing early and accurate diagnosis of femoral head necrosis.

5. Precautions

To reduce the risk of femoral head necrosis, individuals should:

• Limit alcohol consumption, quit smoking, and adopt a diet rich in green vegetables and fruits while minimizing fat intake.
• Effectively manage medical conditions, including blood pressure, blood sugar, and lipid levels.
• Exercise caution with medications containing corticosteroids, following medical staff instructions.