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.
Osteoarthritis is the wearing down of cartilage on joints, and when cartilage wears away, bones are left to rub directly on each other. Bone-on-bone rubbing of facet joints can inflame medial branch nerves, resulting in intense facet joint pain.