The four stages of Avascular Necrosis (AVN), also known as osteonecrosis, represent the progression of bone damage due to insufficient blood supply. Here's a breakdown:
Understanding AVN Progression
AVN develops in stages, with each stage indicating a greater degree of damage. Early diagnosis and treatment can sometimes slow or halt the progression.
The 4 Stages of AVN
The stages are primarily determined by X-ray findings, along with clinical symptoms.
| Stage | Description |
|---|---|
| Stage 1 | Primarily hip pain. This stage might not show any abnormalities on X-rays, making diagnosis challenging. |
| Stage 2 | Bone death can be seen on x-ray, but the femoral ball is intact. There are visible changes in bone structure indicating necrosis, but the overall shape is maintained. |
| Stage 3 | Shows bone death with collapse on x-ray, also shows signs of cartilage damage and osteoarthritis. The femoral head starts to collapse, leading to joint surface irregularities and early arthritis. |
| Stage 4 | Shows collapse of the femoral head with severe osteoarthritis. There is significant destruction of the joint, resulting in severe pain and limited range of motion. |
In summary, the stages progress from initial pain (Stage 1) to visible bone death (Stage 2), then to femoral head collapse and cartilage damage (Stage 3), and finally to severe osteoarthritis (Stage 4).
