Association between lumbar discectomy and subsequent cervical discectomy.

BACKGROUND: Lumbar discectomy (LD) is one of the most common spinal surgical procedures. However, the remote effect of the cervical spine has seldom been discussed. The comparative incidence of cervical discectomy with or without a previous LD is an essential feature in predicting this effect. METHODS: A cohort comparative study was conducted from the National Health Research Institute, Taiwan, over the period from 1996 to 2010. Patients who received LDs and patients who did not receive LDs in the same period were randomly selected to serve as samples for comparison. A total of 14 480 patients who did not undergo LD surgery and 3620 patients who received LDs were enrolled in this study. The incidence rates of discectomy-cervical in both groups were calculated from the follow-up period until the end of 2010. The baseline comorbidity history was determined for each patient. Comorbidities included facture and osteoporosis. RESULTS: During the follow-up period, the overall incidence rate of CD was significantly higher in patients who were treated with LD than in those who were not (24.7 vs. 2.73 per 10 000 person years). The risk of CD in the LD-treated cohort was ∼9-fold greater than that of the non-LD-treated cohort (HRs = 8.58, 95% CI = 5.38-13.7). CONCLUSION: Patients who have undergone LDs are at A greater risk of subsequent CDs, an increased risk that is evident in all patients regardless of demographics or the presence of fracture or osteoporosis.