Although inciting events are commonly reported by patients with lumbosacral radiculopathy, these may not be associated with outcomes following epidural steroid injection, according to a study published in Pain Medicine.
Lumbosacral radiculopathy accounts for more than one-third of cases of low back pain, the leading cause of disability worldwide. Researchers analyzed the data from a chronic pain clinic on etiologies for lumbosacral radiculopathy reported by patients between January 2007 and December 2015. The medical records of 1242 patients with lumbosacral radiculopathy who received epidural steroid injections were reviewed. A positive outcome was defined as ≥30% pain relief sustained for ≥6 weeks without further intervention. Multivariable logistic regression was used to analyze factors associated with injection outcomes.
In this cohort, 50.7% of patients reported that their low back pain was the result of an inciting event, and 59.9% reported experiencing a positive outcome for epidural steroid injections. Falls were the most commonly reported cause for low back pain, with a 13.1% incidence, followed by motor vehicle collisions (10.7%), and lifting (7.8%). Patients with herniated discs (56.3%) were more likely to report that an inciting event had resulted in low back pain compared with patients with stenosis or degenerative discs (44.7% and 47.8%, respectively; P =.012). Outcomes of epidural steroid injections were not found to be predicted by the occurrence of inciting events. Factors that were associated with negative treatment outcomes included opioid consumption (odds ratio [OR], 0.61; 95% CI, 0.39-0.95; P =.027), secondary gain (OR, 0.69; 95% CI, 0.50-0.96; P =.030), and baseline pain score (OR, 0.90; 95% CI, 0.84-0.97; P =.006). An association was found between the number of levels injected and a positive outcome (OR, 2.72; 95% CI, 1.28-6.47; P =.008).
“There was no association between patient-reported inciting events, which occurred in a little over half the patients, and treatment outcome. However, characteristics of opioid consumption, secondary gain, and baseline pain score could provide value to personalizing pain management to optimize treatment outcomes. Future areas of investigation should explore new and existing preclinical and experimental models that seek to determine whether specific events can in fact precipitate [lumbosacral radiculopathy] and, if so, identify preventive measures that can be undertaken in high-risk individuals,” concluded the study authors.
One author reports being a consultant for Semnur, which is working to develop a US Food and Drug Administration–approved corticosteroid for epidural injection.
Engle AM, Chen Y, Marascalchi B, et al. Lumbosacral radiculopathy: inciting events and their association with epidural steroid injection outcomes [published online May 17, 2019]. Pain Med. doi: 10.1093/pm/pnz097