Article Text
Abstract
BACKGROUND The interfacial membrane between bone and implant has been shown to be a key tissue in the process of aseptic loosening of total hip arthroplasty. The cells within the interfacial membrane produce numerous inflammatory mediators which, through complex mechanisms, cause periprosthetic osteolysis and aseptic loosening. Both epidermal growth factor (EGF) and transforming growth factor α (TGFα) have similar biological functions. They have been found to stimulate bone resorption.
OBJECTIVE To investigate the presence, cellular localisation, and extent of expression of EGF and TGFα in interfacial membrane retrieved from revision total hip arthroplasty and compare it with that in synovial membrane from primary total hip arthroplasty.
METHODS Ten interfacial membranes and 10 synovial membranes were stained with avidin-biotin-peroxidase complex for EGF and TGFα. The staining process was done using the Lab Vision Autostainer. The results were measured by a semiautomatic VIDAS image analysis system.
RESULTS Immunoreactivity for both EGF and TGFα was found in the endothelial cells of blood vessels, macrophages, and fibroblasts, both in interfacial membranes and synovial membranes. However, the number of EGF (980 (370)) and TGFα (1070 (360)) positive cells per mm2 was greater in interfacial membranes than in the synovial membranes (220 (200), 270 (100); p<0.01).
CONCLUSION It is suggested that owing to their increased expression in interfacial membrane, EGF and TGFα may have an important pathogenetic role in stimulating periprosthetic bone resorption in aseptic loosening of total hip arthroplasty.
- epidermal growth factor
- transforming growth factor
- hip arthroplasty