Incidence of lumbar disc surgery. A population-based study in Olmsted County, Minnesota, 1950-1979.

Age- and sex-specific incidence rates of operation for suspected lumbar disc prolapse were determined for residents of Olmsted County, Minnesota, for the 30-year period 1950 through 1979. The incidence rate (adjusted to the age and sex distribution of the United States white population in 1980) was 52.3 per 100,000 person-years for all such operations and 46.3 per 100,000 person-years for initial operations. These rates remained fairly constant over the study period. A distinction was made between surgically proven and unproven cases of lumbar disc prolapse. Patients with a surgically proven lumbar disc prolapse had about 10 times the risk of another operation for disc prolapse within 10 years after the first operation compared with the general population.