Objective: To study the association of facet joint angulation and joint tropism with Degenerative Spondylolisthesis (DS) and compare it with a matched control group. Methods: This radiographic study was carried out in two groups of 45 patients each; Group A with single level DS and Group B with similar age and degeneration, who were operated for disc prolapse or lumbar stenosis but without DS, as control. DS was diagnosed with 3mm or greater translation in standing lateral radiograph. Axial MRI from L3-S1 were utilized to assess angulation of facet joints in relation to the coronal plane, a difference of 8° or more was taken as tropism. Results: Among 45 patients with DS, 15 were males and 30 females. Mean age was 62.2 years. Facet tropism was identified in 20/45 patients at the level of DS, 12 patients at level proximal to DS, and 15 patients at level distal to the DS. Among 45 patients in the control group, facet tropism was found in 7 patients.. In Group A, we observed a significantly higher prevalence of multi-level facet tropism as well as facet tropism at levels adjacent to DS level. Conclusions: The present study shows a statistically significant relationship between facet tropism and DS. An increased prevalence of facet tropism was found in the spondylolisthesis group at non-DS levels also, which is a new observation. This finding supports the argument of facet tropism being a pre-existing morphology contributing to development of DS; and not a result of secondary remodelling.
Objective: To study the association of facet joint angulation and joint tropism with Degenerative Spondylolisthesis (DS) and compare it with a matched control group. Methods: This radiographic study was carried out in two groups of 45 patients each; Group A with single level DS and Group B with similar age and degeneration, who were operated for disc prolapse or lumbar stenosis but without DS, as control. DS was diagnosed with 3mm or greater translation in standing lateral radiograph. Axial MRI from L3-S1 were utilized to assess angulation of facet joints in relation to the coronal plane, a difference of 8° or more was taken as tropism. Results: Among 45 patients with DS, 15 were males and 30 females. Mean age was 62.2 years. Facet tropism was identified in 20/45 patients at the level of DS, 12 patients at level proximal to DS, and 15 patients at level distal to the DS. Among 45 patients in the control group, facet tropism was found in 7 patients.. In Group A, we observed a significantly higher prevalence of multi-level facet tropism as well as facet tropism at levels adjacent to DS level. Conclusions: The present study shows a statistically significant relationship between facet tropism and DS. An increased prevalence of facet tropism was found in the spondylolisthesis group at non-DS levels also, which is a new observation. This finding supports the argument of facet tropism being a pre-existing morphology contributing to development of DS; and not a result of secondary remodelling.