Avascular necrosis, also called osteonecrosis, is a painful condition caused by the lack of blood supply to the bone. Blood supply to any bone is essential, so when this happens, it leads to the destruction of the bone, collapsing of the joint and severe arthritis. While avascular necrosis can occur in any bone, it commonly affects the top of the thighbone, in the hip joint.
Avascular necrosis commonly affects people over the age of 40, for those with a previous dislocation or fracture to the thighbone, or those with chronic corticosteroid use. Excessive alcohol intake, diabetes, autoimmune disease, artery disease or conditions that cause blood clots and inflammation are also known risk factors for osteonecrosis.
Since osteonecrosis causes the disruption of blood supply to the thighbone, leading to the slow destruction of the bone and the hip joint pain in the hip is typically the first symptom. This may be experienced as:
- A dull ache or shape pain in the groin, buttock, thigh or hip
- Pain when weight is put onto the hip
While non-surgical treatments such as lifestyle modifications and anti-inflammatory medications may relieve pain for some, for others, surgery may be necessary. Surgical treatment for avascular necrosis in the hip is most successful when caught in the early stages. In these cases, hip preservation surgery may be used. This may involve bone and cartilage grafts to replace the damaged bone and support healthy cartilage, osteotomy to repair alignment in the hip and relieve stress on the joint or core decompression to allow new blood vessels to form by removing the inside part of the thighbone.
In cases where the osteonecrosis is more far along, a total hip replacement may be advised instead. This involves the replacement of both the head of the femur and the socket with artificial components to restore the function of your hip.