Study Design. Randomized double blind controlled clinical trial.
Objective. To evaluate the pain relief effect of locally injected corticosteroid treatment in women with long-lasting sacral low back pain with onset during pregnancy.
Summary of Background Data. Pregnancy-related low back pain is a global problem. Almost 1 of 10 women still experienced disabling daily back pain 2 years after childbirth with high impact on the individual, family, and society. On spite of this, the sources of pain and effective treatment are uncertain.
Methods. Thirty-six women were allocated to injection treatment, with slow-release triamcinolone and lidocaine or saline and lidocaine, given at the sacrospinous ligament insertion on the ischiadic spine bilaterally with 4 weeks follow-up time. Primary outcome measure was reported pain intensity on visual analogue scale and secondary outcome measures number of pain-drawing locations and pain-provoking test results.
Results. The triamcinolone treatment group had significantly reduced pain intensity, number of pain locations, and pain-provoking test results between baseline and follow-up as compared with the saline treatment group. The absolute median change of visual analogue scale score in the triamcinolone treatment group was −24 mm and in the saline group +4.5 mm (P < 0.05). A reduced number of pain drawing locations was reported by 16 of 18 women in the triamcinolone group as compared with 10 of 18 in the saline group (P < 0.05). In the triamcinolone treatment group, 17 of 18 women had an improved pain provocation test result as compared with 9 of 18 in the saline treatment group (P < 0.01).
Conclusion. The anatomic region around the sacrospinous ligament insertion on the ischial spine is suggested to be one source of long-lasting sacral low back pain with onset during pregnancy. The pain was relieved by slow-release corticosteroid injection treatment to the ischial spine.