Psoriatic Spondylitis: A Clinical and Radiological Description of the Spine in Psoriatic Arthritis

Abstract

In a review of 130 patients with psoriatic arthritis, spondylitis was noted in 40 per cent. Sacro-iliitis was observed in 21 per cent and was present either when axial disease was predominant (seven patients) or in association with peripheral polyarthritis (15 patients). The groups differed in that most of those with axial disease were males who had developed psoriasis later in life. In those with disease of the axial skeleton, nail dystrophy was less common, and iritis, chronic back pain and restriction of spinal mobility were more common. They had higher values of E.S.R. In both there was a high incidence of the histocompatibility antigen B27. The axial group resembled idiopathic ankylosing spondylitis and the New York criteria were fulfilled by 86 per cent compared with 27 per cent of those who had peripheral arthritis as well. This latter group was frequently without symptoms or signs of spondylitis. Syndesmophytes are accepted as a radiological manifestation of spondylitis. They were noted in 25 per cent of patients and in 60 per cent of these the sacroiliac joints were normal radiologically. Anterior syndesmophytes alone were found only in the cervical spine and were more common in patients without sacro-iliitis. Lateral syndesmophytes were most commonly found in the lumbar and lower dorsal vertebrae and were slightly less common in patients without sacro-iliitis. Patients with syndesmophytes and normal sacro-iliac joints had a small male preponderance. They were no more likely to have symptoms or signs of spinal disease than those with normal spine radiographs.