α-CALCIUM SULPHATE HEMIHYDRATE AS BONE SUBSTITUTE

A b s t r a c t The use of calcium sulphate externally on the human body in the form of Plaster of Paris (PoP) has been well established, but its possible use inside the human body as bone void filler is a recent phenomenon. It has been realized that the quality of the calcium sulphate and its physical characteristics are the key factors for its reproducible performance inside human body, and most commercial powders may not be suitable. Controlling the size and shape of the calcium sulphate hemihydrate/bihydrate crystals is necessary to obtain a product, which will get resorbed in human body at a rate consistent with the new bone growth. It has been realised that α-hemihydrate form of calcium sulphate is a more suitable material for such applications. Hence α-hemihydrate of calcium sulphate was prepared in the laboratory and ceramic shapes with requisite porosity and strength were fabricated. The powders and pellets were characterised for their morphology and microstructure respectively. These shapes after radiation sterilisation have been used in certain test cases for orthopaedic surgery patients with bone defects. These trials have met with considerable success. Results obtained during the actual trials at L.T.M.G. Hospital, Mumbai, are described below.