Hip disease in ankylosing spondylitis

Hip disease occurs in about one-third of patients with ankylosing spondylitis (AS) and can often be disabling, necessitating total hip replacement in young adults. There have been recent articles on a number of aspects of this problem, including the epidemiology and pathology. The most recent studies on diagnosis, prognosis and therapeutic management are reviewed here.Several large studies have evaluated the prevalence and outcome of hip involvement in AS. Hip involvement can be diagnosed clinically, radiologically, by MRI or by ultrasonography. These examinations highlight different aspects of hip disease in AS. Hip disease is more prevalent in patients with a younger disease onset and seems to be associated with more severe axial disease. Antitumour necrosis factor (TNF) agents are helpful for pain relief and improvement of function in patients with active axial and active hip disease. However, it is not clear whether this treatment option can prevent progression of structural damage. In case of end-stage hip disease, total hip replacement should be considered.In patients with AS, the hips should be routinely assessed, at least by clinical examination. Anti-TNF therapy should be considered in patients with NSAID-resistant active axial disease who have concomitant hip disease.