The statistical distribution of members of a population around the population mean. In a gaussian distribution, 68.2% of values fall within Â± 1 standard deviation (SD); 95.4% fall within Â± 2 SD of the mean; and 99.7% fall within Â± 3 SD of the mean. Synonym(s): bell-shaped curve, normal distribution.
Located on the bony extensions of the vertebrae, the surfaces of the facet joints fit together like a three-dimensional puzzle. In the spaces between vertebrae run the nerve rootsâexits off the spinal cord's information highway.
Facet Joint Hypertrophy and Arthritis. The bones of the facets are lined with cartilage, which cushions the joint. Osteoarthritis of the spine occurs when the cartilage wears out, resulting in bone on bone articulation of the facet joint.