The radiographic effects of ketorolac on patients with spondylolisthesis

Abstract Background: Low back pain may inhibit patients’ spinal range of motion during radiography. Little is known about the dynamic changes of measurement variables and diagnosis of unstable segments in flexion/extension radiographs before and after analgesic injections. We hypothesise that pain control with intramuscular (IM) ketorolac could reveal more radiographic instability segments currently masked by low back pain. Methods: One hundred patients with symptomatic spondylolisthesis from outpatient clinics were recruited. Standing flexion-extension radiographs before and after analgesic injections (IM ketorolac 30 mg) were examined. The visual analog scale (VAS) score and the parameters of segmental instability, including dynamic lumbar lordosis (º; DL), dynamic segmental angulation (º; DA), dynamic segmental translation (mm; DT), and slip percentage (dynamic translation divided with vertebral body width; SP) (%), before and after ketorolac injection were measured. In addition, newly diagnosed unstable segments by different instability criteria were recorded. Pre-post changes between the two groups were analysed using paired t-tests.Results: The VAS score decreased significantly after analgesic injections (66.9 ± 0.97 vs. 32.2 ± 13.1 mm, P < 0.001). DL, DA, DT, and SP were significantly increased (P < 0.001) after providing analgesia compared to pre-analgesia. More unstable segments were found from radiography after ketorolac injection.Conclusion: Ketorolac 30 mg injections provided effective analgesia. The radiographic change and diagnosis of instability segments, which might be masked by back pain, significantly changed after IM Ketorolac in patients with symptomatic spondylolisthesis.