Up to now, little has been known about the incidence of different types of tears found in degenerated discs. The authors of this study developed a method for recording the types of tears in each disc and reviewed them to find patterns of incidence.
Using freshly removed, intact, lumbar discs from 70 patients, aged from 13 to 79 years, the researchers divided the discs into three groups: those from patients aged 10 to 13 years (19), 31 to 50 years (21), and 51 to 80 years (30). These groups were chosen because of the degree of enlargement or swelling that can exist on the discs before they begin to dry out, around the age of 30 years. Then, at age 50 years, the discs can begin to break down.
The researchers found that posterior (from the back) concentric (central) tears were consistently the first ones to appear in the discs. This corresponds with a study done earlier that found similar “cracks” in patients as young as 15 years and were almost always present in patients over 30 years. Other tears, called rim lesions and transdiscal tears, appeared more often as the patients were older. In the even older group, many of the discs had tears that had blood vessels, which had nerves that transmitted pain.
The authors concluded that there is a change in the type of tears that appear in the lumbar discs from early on in life (13 years) to the elderly.