ABSTRACT
Spinal stenosis is an anatomical term used to describe a small spinal canal. The canal reaches maturity in early life (Figure 12.1) and, if it fails to reach adequate size by 5 years of age, it will remain small throughout life. A trefoil shaped canal is more troublesome than an oval-shaped canal. About 15% of adult spines have small trefoil-shaped spinal canals (Figure 12.2).
