Efficacy of core decompression of femoral head to treat avascular necrosis in intravenous drug users.

Core decompression (CD) of the femoral head is one of the effective treatments of avascular necrosis (AVN), especially in the early stages of the disease. To investigate further the value of CD in treating the AVN, this study was performed on patients with symptomatic AVN with different etiologies who were treated with CD. This study was carried out on 25 patients (with the total number of 37 femoral head) who were diagnosed AVN using X-Ray and MRI. The CD treatments for these patients were started soon after the diagnosis. The results were considered as a success if there was no progression of disease confirmed by X Ray or no subsequent operation was required. Modified Ficat staging was used to record changes before and 2 years after CD treatment. Twenty five patients were participated in this study in which 68% (n=17) were female, 32% (n=8) were male, and the average of the age of the patients were 29.58±4.58. Eight of these patients had systemic lupus erythematous (SLE) (32%), 4 rheumatoid arthritis (RA) (16%), 3 with kidney transplant (12%), 1 Takayasu's vasculitis (4%) and 1 Wegner vasculitis (4%). Eight of patients had a history of intravenous injection of Temgesic (32%). In patients using Temgesic the changes in Modified Ficat staging were significantly different before and after CD treatment (P=0.03) in comparison with other groups. And in all 8 Temgesic users AVN progressed to the stage 3 and 4 after CD treatment. This study demonstrated that CD treatment to prevent the changes in the femoral head has been more effective in patients with collagen vascular diseases and kidney transplant than patients using intravenous Temgesic. These patients, in spite of early operation, showed no benefit of CD to prevent the changes in the femoral head.