5 Interesting Facts of Osteonecrosis
1. Osteonecrosis (ON) most commonly involves the femoral head.
2. The most common risk factors for ON are glucocorticoid (GC) use and alcohol abuse.
3. If you have sufficient clinical suspicion of ON and x-rays are normal, magnetic resonance imaging (MRI) must be performed.
4. Nonoperative therapy for early disease includes protected weight-bearing, bisphosphonates, statins, and anticoagulants.
5. Operative therapy includes core decompression with or without grafting and total joint replacement.
Synonyms for Osteonecrosis
- Avascular necrosis,
- aseptic necrosis,
- atraumatic necrosis, and
- ischemic necrosis
How is Osteonecrosis defined?
ON refers to death of the cellular component of bone (osteocytes) and contiguous bone marrow resulting from ischemia. Although inciting factors for such ischemia are varied, their end results are clinically indistinguishable.
What skeletal regions are predisposed to developing Osteonecrosis?
Bones are most vulnerable in those areas having both limited vascular supply and restricted collateral circulation, which are areas that are also typically covered by articular cartilage.
The area most frequently affected is the femoral head. At-risk areas include femoral head, carpal bones (scaphoid, lunate), humeral head, talus, femoral condyles, tarsal navicular, proximal tibia, and metatarsals.