Increased Proportion of Fusion Surgery for Degenerative Lumbar Spondylolisthesis and Changes in Reoperation Rate A Nationwide Cohort Study With a Minimum 5-Year Follow-up

Study Design. A retrospective cohort study. Objective. The objectives of the present study were to examine the changes in the number of surgeries, surgical methods selected, and reoperation rates between the years 2003 and 2008. Summary of Background Data. The selection of the appropriate surgical method between decompression-only (D) and decompression plus fusion (DF) represents a challenging clinical dilemma in patients with degenerative lumbar spinal spondylolisthesis. DF is selected in greater than 90% of patients, mostly due to the associated low reoperation rate. However, the outcomes of D have been improved with minimally invasive decompression surgery techniques. Methods. The Health Insurance Review and Assessment Service database was used to create cohorts of all Korean patients who underwent surgery for degenerative lumbar spinal spondylolisthesis in 2003 (2003 cohort, n = 5624) and 2008 (2008 cohort, n = 11,706). All patients were followed up for at least 5 years. Reoperation was defined as the occurrence of any type of second lumbar surgery during the follow-up period. The probabilities of reoperation were calculated using the Kaplan-Meier method. Results. The number of surgeries increased 2.08-fold in 2008. Patients older than 60 years comprised 38.6% of the 2003 cohort and 52.4% of the 2008 cohort. The proportion of DF surgery was 31.13% in the 2003 cohort but 91.54% in the 2008 cohort. However, the high proportion of fusion surgery failed to reduce the reoperation probability in the 2008 cohort (8.1%) compared with that in the 2003 cohort (6.2%). The cost of DF was US$ 5264 and that of D was $ 2719 in 2008. DF decreased the reoperation probability by 1% at the cost of $ 421/patient in the 2008 cohort. Conclusion. The increased proportion of fusion surgery without improvement in reoperation probability in an aging society may be cautiously addressed in deciding future health policies.