The effect of lumbosacral transitional vertebra on lumbar spine degeneration and spondylolisthesis among patients with low back pain

Aim To examine the impact of lumbosacral transitional vertebra (LSTV) on lumbar spine degeneration, disc protrusion, and spondylolisthesis among patients with low back pain.Methods The records of the patients who had undergone anterioposterior lumbar radiographs and lumbar magnetic resonance imaging (MRI) for low back pain between November 2014 and September 2021 were extracted retrospectively and assessed for eligibility. Of the remaining patients, those with LSTV were assigned as "case group." Age- and sex-matched patients without LSTV were assigned as "control group." On digitalized lumbar MRIs, Modic degeneration (type I-III) and Pfirrman's disc degeneration (grade I-V) immediately cephalad to the transitional level were evaluated; intervertebral disc height (mm), disc protrusion (mm), and percentage of vertebral slippage (%) were measured.Results Of the 501 patients with low back pain, 128 ineligible patients were excluded; 113 patients with LSTV and 117 age- and sex-matched controls were included in the study. LSTV group revealed decreased intervertebral disc height, increased vertebral endplate degeneration, and slippage, as well as increased disc degeneration and protrusion when compared with controls (p < 0.001). Patients with type III LSTV had greater disc protrusion and higher percentage of slippage compared to those with type I LSTV (p = 0.008 and p = 0.009, respectively). Vertebral endplate degeneration, disc height, and disc degeneration did not differ across categories of LSTV type.Conclusion Lumbosacral transitional vertebra malformation is related to decreased intervertebral disc height, increased disc degeneration, vertebral endplate degeneration, disc protrusion, and slippage above the level of transition. Patients with type III LSTV revealed the highest percentage of slippage and disc protrusion.