Titanium as a Biomaterial for Implants

Abstract

Aseptic loosening is the most serious long-term complication after total hip arthroplasty. The role of wear debris in the process of loosening is well established. However, debate continues about the pathogenesis of the process. Some researchers implicated that free radicals may be involved in the induction and maintenance of chronic inflammation with resulting periprosthetic bone resorption. We have therefore investigated the levels of oxidative stress in pseudosynovial fluid from loose hip arthroplasties. We studied 18 consecutive revision hip arthroplasties performed for aseptic loosening. Pseudosynovial fluid was collected at surgery and immediately deep frozen until analysis. Malondialdehyde (MDA) was assayed as a marker of lipid peroxidation in the 18 loose hips and in 18 controls. Linear wear was measured and periprosthetic osteolysis was graded. Fluorometric investigation of pseudosynovial fluid from the 18 loose hips showed significantly higher oxidative stress measured by the level of MDA (27.46 nmol/L, range, 13.47 to 82.9, SD +/- 17.55) compared to controls (14.86 nmol/L, range, 10.66 to 28.9, SD +/- 4.45). MDA level correlated nonsignificantly with linear wear and grade of femoral osteolysis. Our results provide further evidence that elevated oxidative stress is involved in aseptic loosening of hip arthroplasty. Whether elevated oxidative stress is a cause for or result of aseptic loosening is a question of further research. This study may help introducing new strategies for prevention and treatment of aseptic loosening.