EVALUATION OF DIAGNOSIS CRITERIA FOR DIFF USE IDIOPATHIC SKELETAL HYPEROSTOSIS IN A SERIES OF SKELETONS

Three sets of diagnostic criteria for diffuse idiopathic skeletal hype rostosis were evaluated in 78 medieval skeletons from subjects aged 30 years or more at the time of death. Prevalence of the disease ranged from 7.6 to 11.5% according to the criteria used. Gross examination of skeletons was consistent with hyperostosis in 16.6% of cases. The les ions observed are described. A new set of criteria is suggested: 1) in volvement of three vertebras (bridging of two intervertebral spaces) a t the lower thoracic spine; 2) involvement of four vertebras (bridging of three intervertebral spaces) at any level; 3) flowing ossification along the anterolateral aspect of at least two contiguous vertebras; 4) enthesopathies without remodeling of the cortex symmetrically invol ving the posterior calcanei, olecranons, and upper patellas. Decreased disk height in elderly subjects and para-articular bony bridging of t he sacroiliac joints do not rule out the diagnosis. The diagnosis is d efinite in patients with criteria 1 or 2, probable in patients with cr iteria 3 and 4, and possible in patients with criterion 3 or criterion 4.