[Polymorphonuclear leucocytes and the production of reactive oxygen species after total hip and knee replacement]

Aseptic loosening of the prosthesis is caused by the mechanical instability of it's components or it depends on direct tissue reaction--foreign body reaction to implant's wear debris. Former studies showed a significant role of macrophages in the process of the chronic inflammation leading to the aseptic loosening. There are few studies concerning the early reaction against the implant and concerning in this process the role of neutrophils--the cells which form the primary defence of the body and are activated during contact with the foreign body. The examined group consisted of 33 patients aged 59-79 with implanted cemented hip or knee endoprosthesis due to the primary osteoarthritis. The count of granulocytes, production of the nitric oxide and hydrogen peroxide with Pick's and Market's method was evaluated in samples collected before the surgery, 2 months and 3 years after the operation. 3 years postoperatively 8 patients reported pain of the operated joint and in two cases aseptic loosening was recognized. In this group the level of production of the nitric oxide and hydrogen peroxide by the neutrophils 2 months postoperatively was significantly higher in comparisons to the levels in the patients without pain and the control group. In patients without pain the production of nitric oxide and the hydrogen peroxide did not change significantly after the surgery. The presented results suggest the neutrophil's activation by the cytokines, which appear as a result of a local response to a foreign body, may be a factor initiating a chronic inflammation around the implant leading to the aseptic loosening.