Ankylosing spondylitis: Yesterday and Today

ANKYLOSING SPONDYLITIS is one of the diseases at the forefront of medical interest at the present time.This renewed interest is largely due to the exciting discovery that approximately ninety-five per cent of individuals with ankylosing spondylitis possess a human leucocyte associated antigen (HLA antigen) shown as HLA-B27.1,2We considered that a critical evaluation of the literature of spinal lesions both in prehistoric and modern animals together with the palaeopathological evidence for the existence of spondylitis in ancient man would be of interest to the modern-day study of the disease.The existence of disease of the spine causing ankylosis has been described in two crocodiles, one from Egypt and the other from Cuba, dating from the Miocene and Pliocene periods respectively.3'4Ruffer3 stated that "the changes due to spondylitis in human dorsal vertebrae show a great resemblance between the lesions of this disease in man and those seen in our crocodile."From examining the illustrations of the crocodile's vertebrae in Ruffer's paper3 it is clearly evident that there is spinal fusion, but unfortunately only a few vertebrae are illustrated and no radiographs are provided.Numerous other prehistoric animals have been described with spinal lesions similar to human ankylosing spondylitis.4'5,6These animals consisted of many different species, which are now extinct such as the dinosaurs4'5'6 Diplodocus and Polacanthusfoxi, the cave bear Ursus spelaeus,3 and the sabre-toothed tiger Smilodon californicus.4However, whether these lesions are developmental or pathological, and if pathological