Basic Fibroblast Growth Factor (bFGF) in the Synovial-like Membrane around Loose Total Hip Prostheses

Abstract

The aim of this investigation was to examine the eventual presence of bFGF in the synovial-like membrane of the interface and pseudocapsular tissue of loose total hip replacement (THR) and compare it to control knee synovial membrane. bFGF was demonstrated using specific antibodies in avidin-biotin-peroxidase complex (ABC) staining and quantitated using a semiautomatic VIDAS image analysis system. bFGF was found in fibroblasts, in vascular endothelial cells and in particular in macrophages in a characteristic pattern. The number of bFGF positive cells per one mm² was increased in interface (1693 ± 291; n= 10; p < 0.01) and pseudocapsular tissue (1954±256; n= 10; p < 0.01), compared to the knee joint synovial membrane (1009 ± 133; n = 10). These findings suggest that bFGF is involved in the enhanced tissue remodelling of the synovial-like membrane around loose total hip prostheses. Codistribution of metallosis and bFGF positive macrophages suggests a chronic foreign body type reaction as the driving stimulus.

Key Words:

• total hip replacement (THR)
• basic fibroblast growth factor (bFGF)
• aseptic loosening
• macrophage
• fibroblast
• bone resorption
• immunohistochemistry