Synovial fluid from loose hip arthroplasties inhibits human osteoblasts

Aseptic loosening of prosthetic components in patients who have undergone t otal hip arthroplasty is a major clinical problem. Earlier studies on this topic have focused mainly on different aspects of bone resorption, The curr ent study investigated the influence of synovial fluid from patients who un derwent revision surgery because of aseptic loosening and synovial fluid fr om patients with osteoarthritis on the proliferation of primary cultures of human osteoblasts. Incubation of cells with 10% synovial fluid from patien ts who had revision surgery significantly inhibited [H-3]thymidine incorpor ation into deoxyribonucleic acid in human osteoblasts compared with control conditions, whereas 10% synovial fluid from patients with osteoarthritis h ad a significant stimulatory effect. These findings correlate well with cli nical features seen in these diseases, such as increased net bone resorptio n around the prosthesis in patients with loosening, and increased periartic ular hone formation in patients with osteoarthritis.