Core decompression is a surgical procedure that involves surgical drilling into the area of dead bone near the joint. This reduces pressure allows increased blood flow and slows or stops bone and/or joint destruction. Core decompression is commonly performed to treat osteonecrosis. This procedure involves drilling one larger hole or several smaller holes into the femoral head to relieve pressure in the bone and create channels for new blood vessels to nourish the affected areas of the hip. When osteonecrosis of the hip is diagnosed early core decompression is often successful in preventing the collapse of the femoral head and the development of arthritis. Core decompression is often combined with bone grafting to help regenerate healthy bone and support cartilage at the hip joint.
Expectations from surgery
Core decompression prevents osteonecrosis from progressing to severe arthritis and the need for hip replacement in 25% to 85% of cases. This depends upon the stage and size of the osteonecrosis at the time of the procedure. Core decompression achieves the best results when osteonecrosis is diagnosed in its early stages before the bone collapses. In many of these cases, the bone heals and regains its blood supply after core decompression. It takes a few months for the bone to heal, and during this time, a walker or crutches will be needed to prevent putting stress on the damaged bone. Patients with successful core decompression procedures typically return to walking unassisted in about 3 months and have complete pain relief. When osteonecrosis is diagnosed after collapse of the bone, core decompression is not usually successful in preventing further collapse. In this situation, the patient is best treated with a total hip replacement, which relieves pain and restores function in 90% to 95% of patients.
The operation is an open procedure and the surgeon uses x-ray guidance to be able to clearly visualize the area. The surgeon takes a plug of bone out of the affected area and often places bone chips back into the area to provide an osteoinductive (bone forming) environment. As blood flow is restored to the area, the bone chips provide a scaffolding and stimulus for new bone to form.