Study design: An anatomic, epidemiologic study of facet arthrosis in cadaveric lumbar spines.
Objective: To define the prevalence of lumbar facet arthrosis in a large population sample and to examine its association with age, sex, and race.
Summary of background data: Arthrosis of lumbar facet joints is a common radiographic finding and has been linked to low back pain. However, no population studies have specifically defined the prevalence of facet arthrosis in the lumbar spine in relation to age, sex, and race.
Methods: A total of 647 cadaveric lumbar spines were examined by a single examiner for evidence of lumbar facet arthrosis. Information on race, age, and sex were collected. Arthrosis at each facet was graded from 0 to 4 on a continuum from no arthritis to complete ankylosis.
Results: Facet arthrosis was present in 53% (L1-L2), 66% (L2-L3), 72% (L3-L4), 79% (L4-L5), and 59% (L5-S1). By decade, facet arthrosis was present in 57% of 20- to 29-year-olds, 82% of 30- to 39-year-olds, 93% of 40- to 49-year-olds, 97% in 50- to 59-year-olds, and 100% in those >60 years old. Fisher exact test and t test demonstrated that men had a greater prevalence and degree of facet arthrosis than women at all lumbar levels (P < 0.001). The lumbar level with the highest prevalence and degree of arthrosis was the L4-L5 level, as compared with each of the other levels (P < 0.001). There was no difference in arthrosis between right versus left facet joints (P > 0.5).
Conclusion: Facet arthrosis is a universal finding in the human lumbar spine. Evidence of arthrosis begins early, with more than one half of adults younger than 30 years demonstrating arthritic changes in the facets. The most common arthritic level appears to be L4-L5. Men have a higher prevalence and degree of facet arthrosis than women.