Anuj Singla, Scott Yang, Brian C. Werner, Jourdan M. Cancienne, Ali Nourbakhsh, Adam L. Shimer, Hamid Hassanzadeh and Francis H. Shen
Lumbar epidural steroid injections (LESIs) are performed for both diagnostic and therapeutic purposes for a variety of indications, including low-back pain, the leading cause of disability and expense due to work-related conditions in the US. The steroid agent used in epidural injections is reported to relieve nerve root inflammation, local ischemia, and resultant pain, but the injection may also have an adverse impact on spinal surgery performed thereafter. In particular, the possibility that preoperative epidural injections may increase the risk of surgical site infection after lumbar spinal fusion has been reported but has not been studied in detail. The goal of the present study was to use a large national insurance database to analyze the association of preoperative LESIs with surgical site infection after lumbar spinal fusion.
A nationwide insurance database of patient records was used for this retrospective analysis. Current Procedural Terminology codes were used to query the database for patients who had undergone LESI and 1- or 2-level lumbar posterior spinal fusion procedures. The rate of postoperative infection after 1- or 2-level posterior spinal fusion was analyzed. These study patients were then divided into 3 separate cohorts: 1) lumbar spinal fusion performed within 1 month after LESI, 2) fusion performed between 1 and 3 months after LESI, and 3) fusion performed between 3 and 6 months after LESI. The study patients were compared with a control cohort of patients who underwent lumbar fusion without previous LESI.
The overall 3-month infection rate after lumbar spinal fusion procedure was 1.6% (1411 of 88,540 patients). The infection risk increased in patients who received LESI within 1 month (OR 2.6, p < 0.0001) or 1–3 months (OR 1.4, p = 0.0002) prior to surgery compared with controls. The infection risk was not significantly different from controls in patients who underwent lumbar fusion more than 3 months after LESI.
Lumbar spinal fusion performed within 3 months after LESI may be associated with an increased rate of postoperative infection. This association was not found when lumbar fusion was performed more than 3 months after LESI.
Varun Puvanesarajah, Francis H. Shen, Jourdan M. Cancienne, Wendy M. Novicoff, Amit Jain, Adam L. Shimer and Hamid Hassanzadeh
Surgical correction of adult spinal deformity (ASD) is a complex undertaking with high revision rates. The elderly population is poorly studied with regard to revision surgery, yet senior citizens constitute a rapidly expanding surgical demographic. Previous studies aimed at elucidating appropriate risk factors for revision surgery have been limited by small cohort sizes. The purpose of this study was to assess factors that modify the risk of revision surgery in elderly patients with ASD.
The PearlDiver database (2005–2012) was used to determine revision rates in elderly ASD patients treated with a primary thoracolumbar posterolateral fusion of 8 or more levels. Analyzed risk factors included demographics, comorbid conditions, and surgical factors. Significant univariate predictors were further analyzed with multivariate analysis. The causes of revision at each year of follow-up were determined.
A total of 2293 patients who had been treated with posterolateral fusion of 8 or more levels were identified. At the 1-year follow-up, 241 (10.5%) patients had been treated with revision surgery, while 424 (18.5%) had revision surgery within 5 years. On univariate analysis, obesity was found to be a significant predictor of revision surgery at 1 year, while bone morphogenetic protein (BMP) use was found to significantly decrease revision surgery at 4 and 5 years of followup. Diabetes mellitus, osteoporosis, and smoking history were all significant univariate predictors of increased revision risk at multiple years of follow-up. Multivariate analysis at 5 years of follow-up revealed that osteoporosis (OR 1.98, 95% CI 1.60–2.46, p < 0.0001) and BMP use (OR 0.70, 95% CI 0.56–0.88, p = 0.002) were significantly associated with an increased and decreased revision risk, respectively. Smoking history trended toward significance (OR 1.37, 95% CI 1.10–1.70, p = 0.005). Instrument failure was consistently the most commonly cited reason for revision. Five years following surgery, it was estimated that the cohort had 68.8% survivorship.
For elderly patients with ASD, osteoporosis increases the risk of revision surgery, while BMP use decreases the risk. Other comorbidities were not found to be significant predictors of long-term revision rates. It is expected that within 5 years following the index procedure, over 30% of patients will require revision surgery.