Core decompression of the hip is a surgical technique in which a doctor drills one large hole or several smaller holes through the head of the femur at the hip joint to relieve pressure and create passages for blood vessels to the hip, notes the American Academy of Orthopaedic Surgeons. Doctors use the technique to treat osteonecrosis of the hip, a condition in which bone cells die due to a lack of blood supply.
Core decompression is effective in stopping the progression of osteonecrosis in between 25 percent and 85 percent of cases, depending on how much bone has been damaged, states the American Academy of Orthopaedic Surgeons. The chances of a successful surgery are higher when the osteonecrosis is in its early stages, giving the bone more time to regain its blood supply and heal. If the femoral head has already collapsed, the patient should have a total hip replacement rather than a core decompression.
A doctor is likely to perform a bone graft at the same time as a core decompression to help support the hip joint cartilage and regenerate healthy bone, notes the American Academy of Orthopaedic Surgeons. The surgeon may use a bone from another part of the patient's body or bone from a cadaver to graft onto the affected area. The doctor may choose to conduct a vascularized fibula graft, in which a piece of bone, an artery and a vein are taken from a fibula and grafted into the hole created in the femoral neck and head during the core decompression.