Myelomeningocele most commonly involves which region of spine:

c. Lumbosacral(Ref: Nelson's 20/e p 2802-2803)Myelomeningocele involves lumbosacral region (75% of cases)Appearance: a sac-like cystic structure with remnants of neural tissue visible beneath the membrane, which occasionally ruptures and leaks CSF or an exposed flat neural placodeHydrocephalus with a type II Chiari malformation develops in 80% of patients with MMCThe lower the deformity in the neuraxis, the less likely is the risk of hydrocephalus.