Background Epidural injection with corticosteroids is a common treatment option for patients with lower back pain or sciatica. It can be performed via the interlaminar/interspinous routes or via the sacral hiatus. US has shown its interest to guide steroid injection via the sacral hiatus with a high rate of injection success. However, it is thought that this route might be less well tolerated and more painful for the patient than the interspinous one. It has also been demonstrated that the shape of the sacral hiatus could lead to more difficult injections.
Objectives The goal of our study was to evaluate the pain during the injection, the acceptability of the procedure and to find clinical or anatomical factors associated with a painful procedure. We compared the pain during sacral hiatus epidural and interspinous injections.
Methods We performed a cross-sectional study. Patients undergoing an epidural steroid injection for the treatment of radicular pain due to a disc herniation were included. Epidural injection was performed under US guidance via the sacral hiatus. After a local anesthesia with 5 mL lidocaine, 1.5 mL of cortivazol followed by 18.5 mL sterile serum were slowly injected. Pain during the procedure was evaluated using VAS pain scale. US characteristics of the sacral hiatus was recorded. Acceptability was assessed by the question “If needed, would you accept to have the procedure again”. Association between pain and any clinical or anatomical characteristics of the hiatus were assessed by linear regression analysis. Pain during the procedure was compared to the pain during interspinous injection evaluated in one of our previous study (1).
Results There were 52 patients, 28 male (53%), with a mean age 52.5 years (±15). Mean BMI was 26.5 (±5). Radicular VAS pain before the procedure was 5.2 (±2.1). On US, sacral hiatus mean depth was 7.4 mm (±5.4). Intercornual distance was a mean 12.3 mm (±4) and the mean length of the sacrococcygien ligament was 22.8 mm (±7). Mean VAS pain during the procedure was 3 (±2.4) with no significant difference when compared to the interspinous route (mean VAS = 2.8±2.1; p=NS). No immediate complication was recorded. Forty-height patients (92%) would either be very likely or somewhat likely to a repeat procedure. Only one patient would be somewhat unlikely to have a new injection. Thirty-six (69%) patients would surely recommend this procedure to one of their friends. We found no significant association between the pain during the procedure and any of the clinical or anatomical parameters. Importantly, no association was found between the pain and the US shape of the sacral hiatus.
Conclusions US guided epidural injections through the sacral hiatus is a simple and well tolerated procedure. We found no difference of pain between the interspinous or the sacral hiatus routes. Most of the patients would accept to have this procedure again. We did not find any clinical or anatomical characteristic associated with a painful procedure.
Darrieutort-Laffite C, Bart G, Planche L, Glemarec J, Maugars Y, Le Goff B. Usefulness of a pre-procedure ultrasound scanning of the lumbar spine before epidural injection in patients with a presumed difficult puncture: A randomized controlled trial. Joint Bone Spine. 2015 Oct;82(5):356–61.
Disclosure of Interest None declared