Avascular necrosis is a complication of –
**Core Concept**
Avascular necrosis refers to the death of bone tissue due to a lack of blood supply, leading to bone collapse and potential joint destruction. This condition can arise from various causes, including trauma, steroid use, and certain medical conditions that affect blood flow to the bone.
**Why the Correct Answer is Right**
Avascular necrosis occurs when the blood supply to the bone is interrupted, leading to tissue death. This can happen due to various reasons such as trauma, which can cause a physical blockage in the blood vessels supplying the bone. **Option C** is a common cause of avascular necrosis, as steroid use can lead to the coagulation of blood, causing a physical blockage in the blood vessels and subsequent tissue death.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is not a known cause of avascular necrosis. While certain infections can cause bone damage, they are not typically associated with avascular necrosis.
**Option B:** This option is incorrect as it is more commonly associated with bone growth or bone tumors rather than avascular necrosis.
**Option D:** This option is incorrect as it is not a known cause of avascular necrosis. While certain conditions can affect blood flow to the bone, they are not typically associated with avascular necrosis.
**Clinical Pearl / High-Yield Fact**
Avascular necrosis is often seen in the femoral head and hip joint, leading to significant morbidity and potential disability. It is essential to diagnose and treat avascular necrosis promptly to prevent long-term consequences.
**Correct Answer:** C. Steroid use is a well-known risk factor for avascular necrosis, particularly in the femoral head and hip joint.