The importance of core decompression in treatment of osteonecrosis of the femoral head

Core decompression of the necrotic area for treatment of idiopathic osteone crosis of the femoral head was developed and published by Ficat and Arlet i n 1962 within the scope of their,Functional exploration of bone". The mode of action is attributed to a reduction of the intramedullary pressure in th e bony compartment of the femoral head. The possibilities of repair and bon e regeneration following core decompression are still discussed controversi ally. Core decompression is a common but not generally accepted procedure i n the treatment of idiopathic osteonecrosis of the femoral head. After firs t publications of positive mid- and long-term effects, some subsequent stud ies judged it as an ineffective and high-risk method. Analysis of the liter ature shows that the effectiveness of core decompression depends on the sta ge of osteonecrosis at the time of surgical intervention. Prognosis is infl uenced by the extent and location of the necrotic area, the presence and am ount of head depression, and continued risk factors - mainly corticoid medi cation. The best prognosis can be given for patients with a small, medial-c entrally located necrosis without head depression. The classification according to Ficat appears to be insufficient, as the ex tent and localization of the necrotic area are not assessed. Magnetic reson ance imaging has become a diagnostic gold standard, as radiographic diagnos is showed poor sensitivity and specificity, especially in the early stages of the disease. As an essential part, MRI was integrated into the new class ification of the "Association Internationale de Recherche sur la Circulatio n Osseuse" (ARCO). On account of the literature and our own experience, tre atment by core decompression can be recommended in cases of reversible earl y stages of osteonecrosis (ARCO 1), as well as in those cases of irreversib le early stages (ARCO 2) that show a medial or central location of the necr osis with an extent of less than 30% of the femoral head. Once the disease reaches the irreversible early stage, complete recovery cannot be expected, in these cases only reduction of pain and retardation of the natural cours e of the osteonecrosis are possible to gain time until total hip replacemen t is unavoidable.