Co-existence of spina bifida occulta and lumbosacral transitional vertebra in patients presenting with lower back pain.

Lower back pain is a common symptom, which is managed by various specialties including neurology, orthopedics, general medicine, and rheumatology. Lumbosacral transitional vertebra (LSTV) is an important cause of back pain, about which many clinicians are unfamiliar. It is a congenital malformation of the spine, which results from abnormal fusion of the sacrum with the vertebra above, to a variable extent. An extra joint is formed between the ala of sacrum and the elongated transverse process of the vertebra above on one or both sides. It leads to altered rotational movement of the lower spine, which gives rise to back pain. Spina bifida occulta (SBO) is another congenital malformation of the spine, which is detected incidentally because it does not cause any symptoms. We observed frequent co-existence of SBO and LSTV in patients attending our rheumatology clinic for lower back pain.