In Vivo Topographic Analysis of Lumbar Facet Joint Space Width Distribution in Healthy and Symptomatic Subjects

Abstract

Study Design In vivo three-dimensional facet joint space width measurement. Objective To determine lumbar facet joint space width within clinically relevant topographical zones in vivo and its correlations with age, level and presence of lower back pain symptoms. Summary of Background Data Narrowing of the facet joint gap, articular cartilage thinning, and subarticular cortical bone hypertrophy are frequently observed age-related changes. Facet joint space width is a well-defined parameter to evaluate osteoarthritis. To the best of our knowledge, there is no other study that quantifies three-dimensional facet joint space width distribution in vivo. Methods Three-dimensional measurement to quantify facet joint space width distribution based on five clinically relevant topographic zones in a cohort of healthy and symptomatic low-back-pain volunteers using subject-based three-dimensional CT models with respect to spinal level, subject age, gender and presence/absence of lower back pain. Results Facet joint space width was 1.93±0.51 (mean ± standard deviation) mm for the central zone, 1.75±0.48 mm for the superior zone, 1.63±0.49 mm for the inferior zone, 1.48±0.44 mm for the medial and 1.65±0.48 mm for the lateral zone, respectively. There were no significant differences between right and left facet joints. Males showed larger space width than females. Overall, space width of symptomatic subjects was significantly narrower when compared against the asymptomatic group. Facet joints in the peripheral zones were narrower than in the central zone. Age-group comparisons showed local narrowing occurring as early as in the third decade at the inferior zone of L5/S1 with all the remaining zones implicated after the fourth decade. Conclusions This in vivo study shows variations in facet joint space width narrowing with spinal level and region within the facet joint and in vivo evidence of localized, age-influenced facet cartilage thinning. Techniques developed in this study may be applied in the detection of early osteoarthritis-related changes in the facet joints.

Presence and extent of severe facet joint osteoarthritis are associated with back pain in older adults

“…Earlier studies, including work from our group conducted in another sample of Framingham participants[10], used thresholds of mild or moderate facet joint OA[8, 9]. This is likely inappropriate, since mild facet joint OA is essentially ubiquitous by middle age[32-34], and moderate facet joint OA is nearly so[10, 34]. Third, our study used a well-characterized and reliable scale for facet joint OA, in contrast to some earlier studies[8, 9].…”

Glenoid subchondral bone density distribution in male total shoulder arthroplasty subjects with eccentric and concentric wear

“…Particular care was taken to identify and exclude osteophyte formations from the joint surface. The tracing methodology was previously described by Otsuka et al 9 and Simon et al 11 and consisted of extracting the 3D position of every pixel that constitutes the edge of the glenoid surface and its corresponding gray level expressed in Hounsfield units (HU). HU values were recorded for every pixel within individual DICOM images at every point on the glenoid surface and, subsequently, every point beneath the surface up to a depth of 5 mm (Fig.…”

“…2) were ascribed in analogous fashion based on a previously published zoning algorithm developed for the facet joint. 11 Cartesian coordinates for each point-cloud data point were converted to spherical coordinates with the origin set at each glenoid surface model's center of area. The outer margin of the glenoid surface was defined by the points farthest from the origin.…”

Osteoarthritis of the spine: the facet joints

“…50 Joint-space narrowing results from progressive cartilage thinning. 51 Chondrocyte clusters can be seen in early cartilage lesions, with the presence of foci of fibrocartilage suggesting attempts at repair. 52 Early on, the joint capsule might show fibrosis and increased vascularization, with the presence of inflammatory cells.…”