The possible role of locally produced cytokines in the pathogenesis of peritrochanteric fractures in the elderly

Sixteen patients with intertrochanteric femoral fractures were studied for possible involvement of the cytokines interleukin-6 (IL-6), interleukin-1 b eta (IL-1 beta), tumor necrosis factor-alpha, and the disease activity fact ors C-reactive protein and alpha(1)-antitrypsin as local bone-resorbing age nts. Cytokine and disease activity factor levels were measured in gluteus m edius muscle and serum samples and were compared to sera obtained from age- and sex-matched healthy controls. Interleukin-6 and IL-1 beta levels were significantly higher (P=.0024 and P =.036, respectively) in the muscle samples from the fractured side than in the samples from the contralateral unaffected side. Levels of IL-6 and IL-1 beta also were significantly higher in patients' sera than in the sera of healthy controls. These results support a new hypothesis that may contribut e to the pathogenesis of fractures in the elderly: unilaterally locally ove rproduced IL-6 and IL-1 beta may lead to local bone resorption in the inter trochanteric region, which subsequently weakens the femoral bone and increa ses the risk of unilateral peritrochanteric fractures.