The Effects of Ketorolac Injected via Patient Controlled Analgesia Postoperatively on Spinal Fusion

Abstract

Lumbar spinal fusions have been performed for spinal stability, pain relief and improved function in spinal stenosis, scoliosis, spinal fractures, infectious conditions and other lumbar spinal problems. The success of lumbar spinal fusion depends on multifactors, such as types of bone graft materials, levels and numbers of fusion, spinal instrumentation, electrical stimulation, smoking and some drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs). From January 2000 to December 2001, 88 consecutive patients, who were diagnosed with spinal stenosis or spondylolisthesis, were retrospectively enrolled in this study. One surgeon performed all 88 posterolateral spinal fusions with instrumentation and autoiliac bone graft. The patients were divided into two groups. The first group (n=30) was infused with ketorolac and fentanyl intravenously via patient controlled analgesia (PCA) postoperatively and the second group (n=58) was infused only with fentanyl. The spinal fusion rates and clinical outcomes of the two groups were compared. The incidence of incomplete union or nonunion was much higher in the ketorolac group, and the relative risk was approximately 6 times higher than control group (odds ratio: 5.64). The clinical outcomes, which were checked at least 1 year after surgery, showed strong correlations with the spinal fusion status. The control group (93.1%) showed significantly better clinical results than the ketorolac group (77.6%). Smoking had no effect on the spinal fusion outcome in this study. Even though the use of ketorolac after spinal fusion can reduce the need for morphine, thereby decreasing morphine related complications, ketorolac used via PCA at the immediate postoperative state inhibits spinal fusion resulting in a poorer clinical outcome. Therefore, NSAIDs such as ketorolac, should be avoided after posterolateral spinal fusion.

Acupuncture for analgesia in the emergency department: a multicentre, randomised, equivalence and non‐inferiority trial

“…In one study of 88 patients, 30 of whom were given ketorolac after spinal fusion, the incidence of incomplete union or non-union was higher in those given ketorolac; the relative risk was approximately six times higher than control group of patients who did not receive an NSAID and smoking was said to have had no effect on the spinal fusion outcome (Park et al, 2005 Level III-2). In another study of 405 patients, 228 of whom were given ketorolac after similar surgery, there was no significant difference in the non-union rates between the two groups; in this study there were no patients who smoked (Pradhan et al, 2008 Level III-3).…”

Methodological aspects of outcomes research

“…Confounding can mask the observed statistical association between treatment and outcome, either inflating the estimate or diminishing it. For example, in a study comparing opioid patient controlled analgesia with non-steroidal analgesia (NSAIDs) following lumbar fusion surgery, Park et al found that individuals infused with a combination of ketorolac and fentanyl were more likely to have delayed fusion than those using fentanyl alone, and concluded that NSAIDs were responsible for the delayed recovery [43]. However, in Park et al study, individuals using NSAIDs were far more likely to smoke cigarettes than those taking opioids.…”

High-Dose Ketorolac Affects Adult Spinal Fusion

“…[20][21][22][23][24][25][26]28 Three studies were further excluded for the following reasons: (1) no detailed information about the dose of NSAIDs that those patients had received, 20 (2) patient population including not only nonunion but also infection or other reasons for reoperation, 22 (3) paper retracted by the journal 25 (Figure 1). In 1 study, 26 a group of patients who underwent the surgery by 1 surgeon before November 1989 (before the introduction of ketorolac) had a signifi cantly higher nonunion rate than the others without any detailed explanation.…”

“…Several studies involving animal models have documented evidence supporting this hypothesis. [15][16][17][18][19] And several clinical trials have also evaluated the effect of NSAIDs on spinal fusion, [20][21][22][23][24][25][26][27][28] but most of them included relatively small cohorts of patients and thus their results lacked statistical strength. The aim of this metaanalysis was to determine the effects of postoperative NSAIDs on spinal fusion.…”