Osteonecrosis of the femoral head most frequently affects 30 to 50 year olds, with 20,000-30,000 new cases diagnosed annually. Although the actual pathology behind femoral osteonecrosis is not yet understood, the disease typically follows a progression to eventual femoral collapse, which results in the need for a total hip replacement.
Osteonecrosis literally translates to bone death. There are several reasons why this can occur. Ischemia, or lack of blood flow, is one. This can happen from trauma, (like a hip dislocation or fracture), a blood clot blocking blood flow, or high blood pressure at the level of the bone tissue from excessive alcohol or corticosteroid use. Some genetic blood clot formation mutations have also been linked to femoral osteonecrosis. Disruption to the bone cells themselves by irradiation, chemotherapy, or the presence of excessive free radicals, also causes osteonecrosis. Primary risk factors include corticosteroid use, alcoholism, trauma, and coagulation disorders. They have found, however that a risk factor alone does not determine the onset of osteonecrosis, but that there must also be a genetic factor present.
The earlier the disease is diagnosed, the better the outcome. The most frequent symptom is deep groin pain that can radiate to the buttock or knee on the same side. The gold standard for femoral osteonecrosis detection is an MRI, which can give insight into the amount of bone death present, its location, and the amount of swelling in the bone. All of this information can help physicians treat the problem and predict whether or not the femoral head will “collapse.” which then means a need for a total hip replacement.
Nonsurgical treatment of femoral osteonecrosis is limited to smaller, symptom free lesions for a period of no weight bearing to see if symptoms do occur. Little evidence exists backing shockwaves and electromagnetic field treatment. Pharmacologic agents are also not strongly backed in the literature for prevention and treatment of femoral osteonecrosis.
Surgical treatment is the primary treatment option for femoral head osteonecrosis and consists of femoral head preserving procedures or total hip replacement. The type of femoral head preserving procedure is subject to debate and dependent on the extent and location of the bone death. Femoral head sparing procedures are also indicated for the younger patient.
Charalampos G. Zalavras, M.D. and Jay R. Lieberman, M.D. Osteonecrosis of the Femoral Head: Evaluation and Treatment. The Journal of American Academy of Orthopedic Surgery. July, 2014. Vol. 22, No. 7. Pp 455-464.
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