A longitudinal study of disc height narrowing and facet joint osteoarthritis at the thoracic and lumbar spine, evaluated by computed tomography: the Framingham Study

Abstract

Background context: Prevalence and progression of disc height narrowing (DHN) and facet joint osteoarthritis (FJOA) in the thoracic and lumbar regions in non-clinical populations are not well established.

Purpose: The present study aimed to use computed tomography (CT) images to determine the prevalence and progression of DHN and FJOA according to age, sex, and spinal region.

Study design: This is a 6-year longitudinal study.

Sample: A total of 1,195 members of the Framingham Study (mean baseline age 61±9 years) were included in the study.

Outcome measures: We compared the prevalence and progression (new or worsening) of moderate-to-severe DHN and FJOA by age, sex, and spinal region.

Methods: A musculoskeletal radiologist evaluated DHN and FJOA from T4/T5 to L4/L5 on baseline and follow-up CT images using a semi-quantitative scale: 0=normal, 1=mild, 2=moderate, and 3=severe.

Results: One-third or more of women and men ages 40-59 years at baseline had imaged-based evidence of prevalent DHN, more than half had prevalent FJOA, and DHN and FJOA prevalence increased approximately two- to fourfold in those age 60-69 and 70-89 years at baseline, respectively (p<.01). Progression of DHN and FJOA occurred more frequently at the lumbar than at the thoracic spine and more in women than in men (DHN: odds ratio [OR]=1.42, 95% confidence interval [CI]=1.07, 1.88; FJOA: OR=1.70, CI=1.33, 2.17).

Conclusions: Prevalence and progression of moderate-to-severe DHN and FJOA are common in non-clinical populations of older adults. The high frequency of spinal degeneration observed on CTs in this community-based study may contribute to challenges in interpreting the clinical significance of imaging evidence of DHN and FJOA. Future studies investigating the association of CT-based spinal degenerative features with pain and functional impairments in population-based samples are needed to help determine the clinical significance of imaged-based findings of DHN and FJOA.

Keywords: Aging spine; Disc height; Epidemiology; Facet joint; Longitudinal study; Osteoarthritis.