Surgery for herniation of a lumbar disc in Sweden between 1987 and 1999. An analysis of 27,576 operations.

The National Inpatient Register and the Swedish Death Register were linked to determine the incidence of surgical intervention, the trends and characteristics of the patients, the death rate and the pre- and post-operative admissions for herniation of a lumbar disc based on comprehensive national data between 1987 and 1999. There were 27,576 operations which were followed cumulatively for 155,249 years, with a median of 6.0 years. The mean annual rate of operation was 24 per 100,000 inhabitants, the median age of the patients was 42 years. The 30-day death rate was 0.5 per 1000 operations. The rates of re-operation at one and ten years were 5% and 10%, respectively, decreasing significantly (40%) with time. The mean length of stay decreased from nine to five days. Patients who had been in hospital because of a previous spinal disorder had a significantly higher risk of readmission.