[Epidemiology of narrow spinal canal]

During a period of 4.5 years, 199 patients have been operated on by laminectomy because of narrow lumbar canal. The incidence in Geneva is about 11.5 case/100000/year and the ratio between male and female is 1.28. The disease is strongly related to aging, but men are affected earlier in their life than women. Heavy work, particularly for men, has a part to play in the genesis, like the body mass calculated by BMI (Body Mass Index). A comparison between the epidemiology of lumbar disc prolapse and lumbar stenosis shows the differences.