The accuracy of oblique radiographs for use in assessment of osteoarthritis of the facet joints

Two independent observers blindly graded facet joint arthritis on oblique radiographs and CT scans in 50 patients. The L3-4, L4-5, and L5-S1 facet joints were evaluated. Sixty-eight percent of facet joints were abnormal, with 28% exhibiting moderate or severe disease. Interobserver agreement was high for conventional radiography (perfect agreement, 57%; within one grade, 39%; κ = .26) and CT (perfect agreement, 63%; within one grade, 35%; κ = .46). Receiver operating characteristic curve analysis indicated maximal combined sensitivity (55%) and specificity (69%) in distinguishing presence form absence of disease. Pathologic correlation with radiography, CT, and MR imaging findings was performed