A. Sequence of ossification at joints (e.g., elbow)

B.  Physiologic radiolucencies

C.  Bone island (enostosis)

D.  Vascular channels 
   1.  Nutrient canal in phalanx or long bone cortex 
   2.  Vertebral body 
   3.  Scapula 
   4.  Iliac bone

E.  Normal sulci 
   1.  Preauricular sulcus (paraglenoid fossa) 
   2.  Rhomboid fossa

F.  Supracondylar process

G.  Dorsal defect of patella

H.  Epiphyseal ossification from multiple centers (e.g., bipartite patella)

I.  Irregular epiphyseal ossification (e.g., Meyer dysplasia)

J.  Periosteal reaction of infancy

K.  Physiologic bowing

L.  Transverse (growth) line

M.  Vacuum joint