Association of fracture configuration and callus formation with a concentration of proinflammatory cytokines in children with long bone fractures

Abstract

Background/Aim. The inflammatory response is of utmost importance in bone healing, but the precise role of cells and cytokines remains unclear. In our study, we examined the as-sociation between interleukin-1β (IL-1β), tumor necrosis fac-tors alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) concentrations, fracture configuration, and callus formation. Methods. Serum cyto-kine concentrations were determined in 78 non-obese chil-dren with long bone fractures (group 1), 10 children with fin-ger fractures (group 2), and 10 healthy controls (group 3). Blood samples were taken immediately after fracture upon hospital admission for groups 1 and 2. Differences in cyto-kine concentrations were analyzed among groups and catego-rized according to fracture configuration and callus for-mation. Results. IL-1β and TNF-α levels were lower in pa-tients that went on to produce incomplete callus compared with patients that formed complete callus. Surprisingly, the average IL-1β concentration was highest in the healthy con-trol group. The only significant correlation between IL-1β and TNF-α was in the group with moderate callus formation. MCP-1 level was slightly increased in all patient groups com-pared to controls, with no mutual difference. An average IL-8 level showed a clear decrease tendency from the group with incompletely formed callus toward the group with completely formed callus compared to controls, without significant dif-ference. Children with epiphysiolysis had the lowest concen-trations of cytokines compared with all other fracture types including transverse, oblique, and spiral. There were signifi-cantly lower concentrations of IL-1β and MCP-1 in patients with less fragment displacement compared with patients with greater fragment displacement. Conclusion. The systemic in-flammatory response is important in physiological bone heal-ing. High early production of IL-1β, TNF-α, and MCP-1 is associated with greater callus formation and better healing outcome, while increased IL-8 level is associated with poor callus formation and worse healing outcome. Our results in-dicate that epiphysiolysis and larger fragment displacement are associated with delayed fracture healing.

Keywords

• prognosis
• fractures, bone
• fracture healing
• child
• adolescent
• bony callus
• interleukin-1beta
• tumor necrosis factor-alpha
• monocyte chemoattractant protein-1
• interleukin-8
• prognosis