Are facet joint bone marrow lesions and other facet joint features associated with low back pain? A pilot study

To determine the frequency of facet joint (FJ) bone marrow lesions, high FJ periarticular signal intensity, and FJ effusions in a convenience sample of patients with axial low back pain (LBP).

A cross-sectional pilot study with retrospective data collection.

Outpatient spine clinics.

Sixty-four adults with axial LBP scheduled to receive an FJ intra-articular corticosteroid injection.

Clinical data were abstracted from the medical record by 1 physician, who was blinded to results of the magnetic resonance imaging evaluations. A musculoskeletal radiologist blinded to clinical information performed standardized assessments of the L1-S1 spinal levels for FJ bone marrow lesions, effusions, and high periarticular signal intensity on lumbar magnetic resonance imaging, including short tau inversion recovery sequences. We calculated the frequency of these FJ features and used generalized estimating equations to examine side-specific associations between the location of FJ features and the side on which LBP was experienced.

The sample included 64 participants with a mean (standard deviation) age of 59.9 ± 14.5 years. FJ bone marrow lesions were present in 64.1%, effusions in 70.3%, and high periarticular signal intensity in 65.6% of participants. All the features were most common at the L4-L5 level. These FJ features showed significant associations with the side on which LBP was experienced or statistical trends toward an association, with or without adjustment for age, gender, and body mass index. The strongest side-specific associations were seen for the number of bone marrow lesions (odds ratio [OR] 1.60 [95% confidence interval {CI},1.05-2.43]), any FJ effusion (OR 2.23 [95% CI, 1.02-4.85]), and the number of joints with high periarticular signal intensity (OR 1.75 [95% CI, 1.16-2.63]).

FJ bone marrow lesions, effusions, and high periarticular signal intensity were common in this sample of patients with axial LBP and substantially more frequent than in prior reports from unselected samples of patients with or without radicular pain. These FJ features demonstrate side-specific associations with LBP. Further study of associations between these FJ features and LBP are warranted.