Although bone marrow edema and HLA-B27 predict poor prognosis in axial spondyloarthritis (SpA), a study in 44 patients with SpA-related oligoarthritis involving the knees (mean disease duration at baseline 9.75 months), 26 of whom were followed up after 10 years, found that neither of these factors was significantly predictive of subsequent knee morbidity. Of the parameters measured, only the presence of psoriasis at baseline predicted worse 10-year outcome in this SpA subtype.