Lumbar Spondylolisthesis More Common in Men Than Thought
Lumbar spondylolisthesis occurs when one of the vertebrae (bones) in the spine slips forward over the one below it. Doctors believe there are two main causes of spondylolisthesis: spondylolytic (a defect) or degenerative (break down over time), often caused by arthritis. The first kind shows as chronic tiny fractures in the bone, beginning in childhood. The second is a slip that isn't associated with any obvious defect.
Up to 300,000 lumbar (lower back) spinal fusions are done every year in the United States, many for this condition. But, even though so many surgeries are being done, there is not yet a clear understanding among doctors about the epidemiology, basis, of spondylolisthesis. What doctors and researchers do know is that it affects women three times more often than men and it increases with age. There are very few studies that look at men with spondylolisthesis. The authors of this article conducted a study using x-rays of the spine and data obtained from the Osteoporotic Fractures in Men Study. This study looked at these types of fractures among men in the United States, aged 65 to 100 years old.
There were 5,995 participants in the osteoporotic fracture study. Researchers randomly chose 300 study participants, obtaining their baseline and follow-up visit x-rays of their lumbar spine. Five had x-rays that were unreadable, leaving a total of 295 subjects. By the second visit of the study, 32 men had died, two had withdrawn, leaving 261 subjects. Because of other reasons, such as failure to complete questionnaires, the researchers had 190 final participants, who were an average age of 74 years (ranging from 68 to 80 years).
Upon examining the information and the x-rays, the researchers found that the average time between x-rays (baseline and follow-up) was 4.6 years, give or take three months. One quarter of the study group was obese, 60 percent either smoked or were former smokers. Many had either diabetes or heart disease, or both. Lumbar spondylolithesis was found in 31 percent of the men, seen at the L3/4, L4/5 and L5/S1 levels. These are the third and fourth lumbar vertebrae, the fourth and fifth, and then the fifth lumbar vertebrae and the first sacral vertebrae, the section of the back below the lumbar area.
The spondylolysthesis progressed between visits in 12 percent of the men and the increase in the slip of the vertebrae ranged from 5 percent to 10 percent. One hundred thirty three men did not have the condition at the baseline visit and among them, 12 percent showed signs of it at the second visit, mostly at the L3/L4 and L4/L5 levels.
The authors concluded that the incidence of spondylolisthesis increased with age among the men and may be more prevalent than first thought. However, it did not seem to have any connection between the men's height, weight, or smoking history, nor did it with any history of diabetes or heart disease. There did seem to be a connection between the condition and the number of men who reported the highest levels of leisure physical activity, however.
Patrick J. Denard, MD, et al. Lumbar Spondylolisthesis Among Elderly Men. In Spine. May 1, 2010. Vol. 35, No. 10. Pp. 1072-1078.