Lumbar spine radiographic features and demographic, clinical, and radiographic knee, hip, and hand osteoarthritis

Objective: To determine the prevalence of lumbar spine individual radiographic features (IRFs) of disc space narrowing (DSN), osteophytes (OST), and facet joint osteoarthritis (FOA); to describe the frequencies of demographic, clinical, and radiographic knee, hip, and hand osteoarthritis (OA) across lumbar spine IRFs; and to determine factors associated with lumbar spine IRFs.

Methods: We conducted a cross-sectional study of 840 participants enrolled in the Johnston County Osteoarthritis Project (2003-2004). Sample-based prevalence estimates were generated for each lumbar spine IRF. The associations between lumbar spine IRFs and demographic, clinical, and peripheral joint OA were determined with logistic regression models.

Results: Sample-based prevalence estimates were similar for DSN (57.6%) and FOA (57.9%) but higher for OST (88.1%), with significant differences across race and sex. Hand and knee OA frequencies increased across IRFs, whereas the effect was absent for hip OA. African Americans had lower odds of FOA (adjusted odds ratio [OR(adj) ] 0.45 [95% confidence interval (95% CI) 0.32-0.62]), while there was no racial association with DSN and OST. Low back symptoms were associated with DSN (OR(adj) 1.37 [95% CI 1.04-1.80]) but not OST or FOA. Knee OA was associated with OST (OR(adj) 1.62 [95% CI 1.16-2.27]) and FOA (OR(adj) 1.69 [95% CI 1.15-2.49]) but not DSN. Hand OA was associated with FOA (OR(adj) 1.67 [95% CI 1.20-2.28]) but not with DSN or OST. No associations were found with hip OA.

Conclusion: These findings underscore the importance of analyzing lumbar spine IRFs separately as the associations with demographic, clinical, and radiographic knee, hip, and hand OA differ widely.