Henry Ford Hospital Medical Journal


A histological study of fully mineralized bone sections was made on thirty joints surgically removed from patients with rheumatoid arthritis. The patterns of bone erosion fell into three groups: 1) that due to multinucleated osteoclasts; 2) areas of apparent bone erosion occupied exclusively by mononuclear cells; and 3) changes produced by an osteocyte which could either enlarge the lacuna space in which it resided or demineralize a region of bone in its immediate vicinity. Tissues taken from knee and hip specimens frequently showed all three cellular patterns of bone erosion, while the sections from finger joints rarely container multinucleated osteoclasts but often revealed mononuclear cells which occupied Howship's resorption lacunae. The presence of mononuclear cells on the bone surface in the earliest as well as the latest stages of erosive rheumatoid arthritis supports the concept that some mononuclear cells have osteoclastic capabilities. Different regions of the same specimen of the larger joints demonstrated low or high cellular activity (both osteoblastic and osteoclastic) which was independent of the degree of joint damage, duration of disease, and drug therapy.