Lumbosacral transitional vertebrae: An overlooked cause of back pain on MRI

To evaluate the frequency of lumbosacral transitional vertebrae (LSTV) on MRI in patients with backpain and clinically suspected sacroiliitis. Sacroiliac who had were suspicious for sacroiliitis between November 2021-March 2022 retrospectively analyzed from hospital database by two different radiologists. LSTV cases identified subgrouped according to Castellvi classification. Presence sacroiliitis, degeneration /or herniation cranial segment intervertebral disc, facet joint hypertrophy, coxarthrosis psoas atrophy recorded. In where radiologists conflict, consensus was made. Between 2022, 614 sacroiliac MRIs obtained 81 (13%) LSTV. Fifty-nine female (72.8%). Mean age 43.4. The most common type 1a (n=30, 10 right-sided, 20 left-sided). Sacroiliitis significantly more younger (p=0.04) males (p=0.009). Disc degeneration, disc herniation, hypertrophy increased (p=0.007, p=0.001, p=0.002 p=0.013 respectively). No correlation found gender or presence any LSTV.LSTV may present should be considered is suspected. a useful tool identify other accompanying pathologies these cases.