A mnemonic to help recall the causes of basilar invagination is:
P: Paget disease of bone
F: fibrous dysplasia
R: rheumatoid arthritis, rickets
O: osteogenesis imperfecta, osteomalacia
C: Chiari I and Chiari II, cleidocranial dysostosis
Bone within a bone is a descriptive term applied to bones that appear to have another bone within them. There are numerous causes including:
thoracic and lumbar vertebrae (neonates and infants)
growth recovery lines (after infancy)
cortical splitting and new periostitis
sickle cell d...
A handy mnemonic to recall the roots of the lumbar plexus is:
2 from 1, 2 from 2, 2 from 3
2 nerves from 1 root: ilioinguinal (L1), iliohypogastric (L1)
2 nerves from 2 roots: genitofemoral (L1/L2), lateral femoral cutaneous (L2/L3)
2 nerves from 3 roots: obturator (L2/L3/L4), femo...