Ankylosing spondylitis and the shoulder: commonly involved but infrequently disabling

To undertake 2 independent studies of shoulder involvement in patients with ankylosing spondylitis (AS) and assess the frequency of shoulder pain, stiffness, and loss of movement and function. To evaluate and correlate shoulder symptoms, function, range of movement, and radiology.

A cross sectional design was used in both studies. In Study A, a self-administered questionnaire was sent to members of the National Ankylosing Spondylitis Society of the UK and patients attending the Royal National Hospital for Rheumatic Diseases. In Study B, a clinical assessment of 88 patients with AS was undertaken that included a radiological assessment of 26 consecutive patients.

In Study A, 15.2% and 13.8% of subjects had severe/very severe shoulder pain or stiffness, respectively. In Study B the corresponding findings were 9.6% and 17.6%. Patient reported disability associated with shoulder involvement was uncommon. Study A revealed that patients with severe/very severe shoulder pain were more likely to have significant hip and knee involvement. Significant shoulder involvement appears to be as common as involvement of the hip joint. In Study B radiological changes were common, being present in 31% of patients, but were often minor. There was a significant correlation between the sum of the stiffness, abduction, and flexion scores for both shoulders and the total radiological score (r = 0.87; p<0.001).

The results suggest that shoulder symptoms and loss of shoulder mobility are common in patients with AS, and correlate with higher pain scores and influence of AS on their lives as assessed by the Arthritis Impact Measurement Scale, but are rarely disabling. Involvement of the shoulder joint in AS correlates with involvement of other peripheral joints as well as the extent of radiographic change on shoulder radiographs.