A report on the strangeways collection of rheumatoid joints in the museum of the royal college of surgeons. Part II. Some natural features and histological peculiarities of osteo-arthritis and rheumatoid arthritis

Abstract

1. The Development of an Osteophyte.-The present view of the origin of an o\tcophyte is that it is due t o excitation of the adjacent rncdulltt. Vascular cellulo-conncrtivc tissue, supposed t o be a n extension from thc medulla," appears in patches of softening, or in spaces arising from them, in the deep parts of the articular cartilage. The cartilage becomes honeycombed with these spaces, and the intervening cartilage is converted into bone by rnct a 131 asia .There is no question that in an osteo-arthritic joint spaccs filled with vascular cellulo-connec.tivc tissue appear in thc deep layers of the articular cm-tilage, but the contents arise from proliferation of the connective-tissue hasi.; of the cartilage and a reversion of the cartilagc cdls to the connectibctissue type. After the formation of these spacrs thc evolution of the osteophytr begins.u. The cartilagc bordcring the spaces may undergo more or less calrification, and bone is dcveloped in the cartilage or in the calcified parts of it by mctaplasia.b. Thc adjacent cartilage lose4 its cartilaginous appearance, changing into fibrocnrtilagr or fibro-connective tisuc, and additional spaces arc outlined in it a\ calcification and ossification advance €rom the periphery of the dcreloping osteophyte.Q There is but little justitication for this idea, for the adjacent medullary spaces are i n some (:ascs fillrtl with fat only, and in others besidrs the fat therc may be only a sniall tlrveloprnent of proliferated connective tissur. Jlorcover? in sonic instances where the section is successful in derrioristrating itn aperturc in the subchondral bone lamina coniiecting i i rncdullary space with the spaces of a forming ostcophyte, the changc from fat rneditlla. t o t h e proliferated connectivc-tissue contents of the ostcophyte spares is a p t t o take place almiptly in the gap, which suggests that pcrforatioii has been effected from the osteophyte.