Distribution of lumbosacral transitional vertebrae subtypes and functional disability in patients with low back pain: A single-center retrospective study

Background Lumbosacral transitional vertebrae (LSTV) are a common congenital anomaly that often remain underrecognized in patients with low back pain (LBP), potentially leading to inappropriate management and disability. Objective To determine the prevalence and distribution of LSTV subtypes in a large LBP cohort and to evaluate functional disability and healthcare utilization in patients with LSTV. Methods In this single-center retrospective observational study, electronic records of 20,395 patients presenting with LBP between January 1, 2018 and January 1, 2024 were reviewed. Lumbar and lumbosacral imaging was evaluated and LSTV were classified according to the Castellvi system. Functional disability was assessed using the Oswestry Disability Index (ODI) in patients with LSTV. Associations between ODI scores, age, sex, Castellvi subtype and number of outpatient visits were analyzed. Results LSTV were identified in 405 patients (prevalence 1.98%; mean age 52.9 ± 15.2 years; 63% female). Castellvi Type 2a was the most frequent subtype (25.7%). More than half of the patients reported pain duration of 1–5 years and 67.7% had multiple outpatient visits. Patients with multiple visits had significantly higher ODI scores than those with a single visit (42.65 ± 17.30 vs. 29.53 ± 18.05, p < 0.001) whereas ODI scores did not differ significantly across LSTV subtypes (p > 0.05). Conclusion In patients with LBP, LSTV were present in approximately 2%. Patients with LSTV demonstrated substantial disability and frequent healthcare utilization. Prospective controlled studies are needed to determine whether these findings are specifically attributable to LSTV and to clarify potential causal relationships.