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

Abstract

Sixteen patients with intertrochanteric femoral fractures were studied for possible involvement of the cytokines interleukin-6 (IL-6), interleukin-1 beta (IL-1beta), tumor necrosis factor-alpha, and the disease activity factors C-reactive protein and alpha1-antitrypsin as local bone-resorbing agents. Cytokine and disease activity factor levels were measured in gluteus medius muscle and serum samples and were compared to sera obtained from age- and sex-matched healthy controls. Interleukin-6 and IL-1beta 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-1beta also were significantly higher in patients' sera than in the sera of healthy controls. These results support a new hypothesis that may contribute to the pathogenesis of fractures in the elderly: unilaterally locally over-produced IL-6 and IL-1beta may lead to local bone resorption in the intertrochanteric region, which subsequently weakens the femoral bone and increases the risk of unilateral peritrochanteric fractures.