Ingrowth of blood vessels in disc degeneration. Angiographic and histological studies of cadaveric spines.

Angiograms were made of twenty-two cadaveric lumbar spines to determine the presence of any new blood vessels between adjacent lumbar vertebrae and corresponding discs. The annulus and adjacent longitudinal ligaments were also analyzed histologically. A total of 105 intervertebral spaces were studied. It was found that the normal anastomosing arteries in the posterior longitudinal ligament were significantly obliterated with advancing degeneration of the disc (p < 0.001), whereas several tiny tortuous arteries--often running between the osteophytic spurs--were seen in the anterolateral aspects of the intervertebral spaces connecting the adjacent vertebrae. Histological examination of the anterolateral part of the annulus showed that the vascularity of the annulus increased significantly with degeneration of the disc (p < 0.001), and most of the arteries had a vertical orientation. Regression analysis showed that vascular changes occurred before degeneration of the disc at every lumbar level, suggesting that disturbances in the nutritional supply may precede degeneration. The correlation coefficient was 0.77 (95 per cent confidence limit, 0.52 to 0.90) for the increase in annular vascularity with an increase in the age of the individual at the time of death and 0.86 (95 per cent confidence limit, 0.69 to 0.94) for the increase in degeneration of the disc with an increase in age.