The presence of alkaline phosphatase in the subchondral bone of the medial tibial condyle in the normal state and in osteoarthritis and rheumatoid arthritis.

A study has been carried out on the alkaline phosphatase activity in trabecular bone in the normal state, rheumatoid arthritis and osteoarthritis. Samples were taken from the subchondral bone of the medial tibial condyle in all cases. The reason for this study was to investigate whether changes in rheumatoid bone like trabecular microfractures and healing reactions were parallelled by a mineralization process which could be demonstrated by an increased alkaline phosphatase activity and compared to that in osteoarthritic and normal bone. This investigation disclosed that the alkaline phosphatase activity in rheumatoid bone did not differ much from either osteoarthritis or normal bone.