Effectiveness of intra-articular analgesia in reducing postoperative pain after minimally invasive sacroiliac joint fusion: a double-blind randomized controlled trial

During the first postoperative days following minimally invasive sacroiliac joint fusion (MISJF), patients often report serious pain, which contributes to high utilization of painkillers and prevention of early mobilization. This prospective, double-blind randomized controlled trial investigates the effectiveness of intraoperative SIJ infiltration with bupivacaine 0.50% versus placebo (NaCl 0.9%) in 42 patients in reducing postoperative pain after MISJF. The primary outcome was difference in pain between bupivacaine and placebo groups, assessed as fixed factor in a linear mixed model. Secondary outcomes were opioid consumption, patient satisfaction, adverse events, and length of hospital stay. We found that SIJ infiltration with bupivacaine did not affect postoperative pain scores in comparison with placebo, neither as group-effect (p = 0.68), nor dependent on time (group*time: p = 0.87). None of the secondary outcome parameters were affected in the postoperative period in comparison with placebo, including opioid consumption (p = 0.81). To conclude, intra-articular infiltration of the SIJ with bupivacaine at the end of MISJF surgery is not effective in reducing postoperative pain. Hence, we do not recommend routine use of intraoperative SIJ infiltration with analgesia in MISJF.