New clinical and radiographic features of ankylosing spondylitis.

This article reviews new classification criteria for spondyloarthropathies and describes ankylosing spondylitis-like features in nonhuman primates. It describes the literature in general and analyzes specific papers on clinical assessment, outcome measurements, and standardization procedures. The extra-articular manifestations of ankylosing spondylitis and recent papers dealing with the clinical associations and differential diagnosis of ankylosing spondylitis are reviewed. The normal appearance of sacroiliac joints with magnetic resonance imaging and the value of different imaging techniques in the diagnosis of sacroiliitis, are discussed.