Surgical Indications

• Subchondral decompression is employed in cases of osteonecrosis--deadening of the bones--or subchondral cysts--cavities that form in the bone under the cartilage--in the joints.
  
  

Purpose

• The surgery is intended to lessen the pressure that builds up in and around dying bone or cystic voids inside the bone.
  
  

Procedure

• Subchondral decompression involves using fluoroscopic (X-ray) images to guide a drill that makes a small hole or tunnel in the necrotic bone or cyst.
  
  

Effects

• A hole into the bone or cyst creates a vent that allows the pressure to be released. The procedure also sometimes has the effect of slowing the deadening of the bone.
  
  

Expert Insight

• Osteonecrosis or avascular necrosis is a primary cause of arthritis, which is actually not a specific disease but rather a general term for ailments or dysfunctions of the joints.