An International Multicenter Study Assessing the Role of Ethnicity on Variation of Lumbar Facet Joint Orientation and the Occurrence of Degenerative Spondylolisthesis in Asia Pacific: A Study from the AOSpine Asia Pacific Research Collaboration Consortium

Abstract

Study Design A multinational, multiethnic, cross-sectional image-based study was performed in 33 institutions, representing 10 countries, which were part of the AOSpine Asia Pacific Research Collaboration Consortium. Objective Lumbar facet joint orientation has been reported to be associated with the development of degenerative spondylolisthesis (DS). The role of ethnicity regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide-ranging population base to assess the role of ethnicity in facet joint orientation in patients with DS in the Asia Pacific region. Methods Lateral standing X-rays and axial magnetic resonance imaging scans were obtained for patients with lumbar DS. The DS parameters and facet joint angulations were assessed from L3–S1. Sex, age, body mass index (BMI), and ethnicity were also noted. Results The study included 371 patients with known ethnic origin (mean age: 62.0 years; 64% males, 36% females). The mean BMI was 25.6 kg/m2. The level of DS was most prevalent at L4–L5 (74.7%). There were 28.8% Indian, 28.6% Japanese, 18.1% Chinese, 8.6% Korean, 6.5% Thai, 4.9% Caucasian, 2.7% Filipino, and 1.9% Malay patients. Variations in facet joint angulations were noted from L3 to S1 and between patients with and without DS (p < 0.05). No differences were noted with regards to sex and overall BMI to facet joint angulations (p > 0.05); however, increasing age was found to increase the degree of angulation throughout the lumbar spine (p < 0.05). Accounting for age and the presence or absence of DS at each level, no statistically significant differences between ethnicity and degree of facet joint angulations from L3–L5 were noted (p > 0.05). Ethnic variations were noted in non-DS L5–S1 facet joint angulations, predominantly between Caucasian, Chinese, and Indian ethnicities (p < 0.05). Conclusions This study is the first to suggest that ethnicity may not play a role in facet joint orientation in the majority of cases of DS in the Asia-Pacific region. Findings from this study may facilitate future comparative studies in other multiethnic populations. An understanding of ethnic variability may assist in identifying those patients at risk of postsurgical development or progression of DS. This study also serves as a model for large-scale multicenter studies across different ethnic groups and cultural boundaries in Asia.

Multidimensional vertebral endplate defects are associated with disc degeneration, modic changes, facet joint abnormalities, and pain

“…The facet joints were found to be increasingly irregular, flat and significantly narrowed as the dimensions of the endplate defects increased. Facet joints are the point of contact between adjacent neural arches of the vertebral bodies and small changes in postural angle can lead to high stress concentration . It may be possible that endplate damage and resulting uneven stress distribution and disc degeneration cause much of the compressive stress to pass through the neural arch affecting the facet joints .…”

Traumatic bilateral L4-5 facet fracture dislocation: a case presentation with mechanism of injury

“…It has been shown that the facet angle consistently increased from L2-L3 to L5-S1 with regards to the sagittal plane [7]. However, it has also been demonstrated that the L4-5 and L5-S1 facet joints have high variations in facet angle depending on ethnicity [8][9][10][11].…”

The Variation in the Lumbar Facet Joint Orientation in an Adult Asian Population and Its Relationship with the Cross-Sectional Area of the Multifidus and Erector Spinae

“…Therefore, the difference in the results for the facet joint orientation at the L5–S1 in the healthy population between our study and Grobler's might be explained by the difference in age of the two study populations. Williams et al [8] reported an average facet joint orientation at the L5–S1 of 43.3°±13.0° for the left and 43.1°±12.5° for the right lumbar facet joints in patients with degenerative spondylolisthesis in a multicenter study in the Asia-Pacific region. The difference in the results for the facet joint orientation at the L5–S1 between our study and Williams et al's might be explained by the presence of degenerative spondylolisthesis and difference in the age of the two study populations.…”

“…Facet joint orientation in the sagittal plane has been reported to be from 150° to 170° from the vertical axis with no differences between each lumbar level [2]. In contrast, facet joint orientation in the horizontal plane has been reported as having 10° to 15° of standard deviation in Caucasian and African–American bone models [2] and patients with spondylolisthesis in Asia-Pacific legion [8], which suggests a wide variation between individuals. Furthermore, facet joint orientation in the horizontal plane changes toward the sagittal direction with aging [69].…”

“…Furthermore, facet joint orientation in the horizontal plane changes toward the sagittal direction with aging [69]. Several studies have reported that lumbar pathologies, such as lumbar spondylolysis and degenerative spondylolisthesis, were related to the facet joint orientation at the lower lumbar level [3810]. However, the data regarding variations in the facet joint orientation in asymptomatic subjects have not been well documented, and additional asymptomatic subject data is important for understanding the normal variation in the facet joint orientation.…”