THE GROWING OSTEOPHYTE - A MODEL SYSTEM FOR THE STUDY OF HUMAN BONE-DEVELOPMENT AND REMODELING IN-SITU

There is a clear need for human model systems to enable in situ research into the complex cell-cell and cell-matrix interactions associated with the development of human bone and its subsequent turnover and maintenance. One possibility is the rapidly developing osteophyte, the highly characteristic bony outgrowth associated with osteoarthritis of large joints. The ability to section fresh, unfixed undecalcified human adult bone by suitably modified cryostat microtomy enabled a detailed histological study of this tissue at precise stages of bone development. The tissue presented numerous advantages: by suitable orientation of the tissue, each individual osteophyte clearly encompassed all aspects of bone development and turnover in a well organized sequence of events that was related to the age of the osteophyte. Two distinct bone formation processes ensued concurrently, namely intramembranous bone formation and endochondral ossification. Thus the developing osteophyte provides an excellent system for studying human bone cell differentiation and function in situ.