Objectives: To examine the association between radiographic lumbosacral (LS) osteoarthritis (OA) and lumbar flexibility in elders without back pain or known spinal pathology and to develop a reliable grading system for osteoarthritis of the lumbosacral spine.
Design: Cross-sectional study.
Setting: Durham VA and Duke University Medical Center Department of Radiology.
Participants: 35 volunteers aged 64-90 (nursing home residents and community dwellers). Exclusion criteria were known spinal pathology, back pain, inability to stand independently for 1 minute, and > 150% of ideal body weight.
Interventions: All subjects underwent LS spine radiographs and flexibility measures (forward flexion, extension, lateral flexion, and axial rotation).
Main outcome measures: Reliability of ordinal OA X-ray grading system, tested using intraclass correlations (ICCs); stability of flexibility measures, using ICCs; and association of disc or facet summary scores (sum of all levels, T12 thru S1) with flexibility measures, using Pearson correlations.
Results: ICCs for interest flexibility measures ranged from 0.72 to 0.94. ICCs for interobserver X-ray scores were 0.85 for facet disease and 0.93 for disc disease. The correlation of facet disease with forward lumbar flexion was 0.29. The correlation of disc disease with flexibility showed modest correlation for forward (r = 0.34), right lateral (r = 0.36), and left lateral (r = 0.35) flexion. None of the correlations was influenced by age.
Conclusions: We have developed a reliable radiographic scoring instrument for assessing radiographic OA of the LS spine. It appears that painless LS disc OA is one factor that influences spinal motion.