[The enthesopathic shoulder].

61 shoulders of rheumatoid diseases, 23 of ankylosing spondylo-arthritis, 22 of psoriatic rheumatism and 30 of hyperostoses (Forestier's disease) were analysed and compared. There is a very significant difference between rheumatoid disease, on the one hand, and the other diseases, on the other hand. In ankylosing spondylo-arthritis, psoriatic rheumatism and hyperostosis, enthesophytes are observed; it is not the case in rheumatoid disease (unless associated with hyperostosis). The most frequent entesophyte is the one at the acromial insertion of the acromio-coracoid ligament ("bearded acromion"). It is also the easiest to visualise on an AP X-Ray of the shoulders. The association of a bearded acromion and an ulceration of the supero-lateral area of the humeral head (sulcus) is characteristic of spondylo-arthropathies (ankylosing spondylo-arthritis, psoriatic rheumatism) and is not found in hyperostosis. The ulceration of the sulcus is, on the contrary, common to spondylo-arthropathies and rheumatoid disease. This ulceration does not seem to be the sign of an inflammatory enthesopathy but rather a synovitis.