Patient-reported outcomes after minimally invasive sacro-iliac joint surgery: a cohort study based on the Swedish Spine Registry.

BACKGROUND AND PURPOSE: There is conflicting evidence regarding treatment outcomes after minimally invasive sacroiliac joint fusion for long-lasting severe sacroiliac joint pain. The primary aim of our cohort study was to investigate change in patient-reported outcome measures (PROMs) after minimally invasive sacroiliac joint surgery in daily practice in the Swedish Spine Registry. Secondary aims were to explore the proportion of patients reaching a patient acceptable symptom score (PASS) and the minimal clinically important difference (MCID) for pain scores, physical function, and health-related quality of life outcomes; furthermore, to evaluate self-reported satisfaction, walking distance, and changes in proportions of patients on full sick leave/disability leave and report complications and reoperations. METHODS: Data from the Swedish Spine Registry was collected for patients with first-time sacroiliac joint fusion, aged 21 to 70 years, with PROMs available preoperatively, at 1 or 2 years after last surgery. PROMs included Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for low back pain (LBP) and leg pain, and EQ-VAS, in addition to demographic variables. We calculated mean change from pre- to postoperative and the proportion of patients achieving MCID and PASS. RESULTS: 68 patients had available pre- and postoperative data, with a mean age of 45 years (range 25-70) and 59 (87%) were female. At follow-up the mean reduction was 2.3 NRS points (95% confidence interval [CI] 1.6-2.9; P < 0.001) for LBP and 14.8 points (CI 10.6-18.9; P < 0.001) for ODI. EQ-VAS improved by 22 points (CI 15.4-30.3, P < 0.001) at follow-up. Approximately half of the patients achieved MCID and PASS for pain (MCID NRS LBP: 38/65 [59%] and PASS NRS LBP: 32/66 [49%]) and physical function (MCID ODI: 27/67 [40%] and PASS ODI: 24/67 [36%]). The odds for increasing the patient's walking distance to over 1 km at follow-up were 3.5 (CI 1.8-7.0; P < 0.0001), and of getting off full sick leave or full disability leave was 0.57 (CI 0.4-0.8; P = 0.001). In the first 3 months after surgery 3 complications were reported, and in the follow-up period 2 reoperations. CONCLUSION: We found moderate treatment outcomes after minimally invasive sacroiliac joint fusion when applied in daily practice with moderate pain relief and small improvements in physical function.

The effect of minimally invasive sacroiliac joint fusion compared with sham operation: study protocol of a prospective double-blinded multicenter randomized controlled trial.

Background and purpose - The sacroiliac joint is increasingly recognized as a cause of pain in 15-30% of patients with low back pain. Nonoperative management is not always successful and surgical treatment with fusion of the joint is increasingly recommended. According to the literature, minimally invasive fusion reduces pain and improves function compared with nonoperative treatment. It is, however, unclear to what extent the placebo effect influences these results. Patients and methods - The trial is designed as a prospective multi-center, double-blind, randomized shamsurgery controlled trial with 2 parallel groups. 60 patients with a suspected diagnosis of sacroiliac joint pain confirmed with sacroiliac joint injection are included according to the trial inclusion criteria. Patients are randomized with a 1:1 allocation into 2 groups of 30 patients each. The primary end-point is group difference in sacroiliac joint pain intensity on the operated side at 6 months postoperatively, measured by the Numeric Rating Scale. The main objective is to examine whether there is a difference in pain reduction between patients treated with a minimally invasive fusion of the sacroiliac joint compared with patients undergoing a sham operation. Results - Unblinding occurs after the completed 6-month follow-up. The primary analysis will be performed when all patients have completed 6 months' follow-up. Follow-ups are continued to at least 2 years postoperatively. Data from the different groups will be compared based on the "intention to treat" principle.

The effect of minimally invasive sacroiliac joint fusion compared to sham operation: a double-blind randomized placebo-controlled trial.

Background: Minimally invasive fusion of the sacroiliac joint as treatment for low back pain may reduce pain and improve function compared to non-operative treatment, although clear evidence is lacking. The aim of this trial was to evaluate the effect of minimally invasive sacroiliac joint fusion compared to sham surgery on sacroiliac joint pain reduction. Methods: In this double-blind randomized sham surgery-controlled trial patients with clinical diagnosis of sacroiliac joint pain confirmed with sacroiliac joint injection were included at two university hospitals in Sweden and Norway. Patients were randomized by the operating surgeon at each site to minimally invasive sacroiliac joint fusion or sham surgery. The primary endpoint was group difference in sacroiliac joint pain on the operated side at six months postoperatively, measured by the Numeric Rating Scale (0-10). Un-blinding and primary analysis were performed when all patients had completed six months follow-up. The trial is closed for new participants and was registered at clinicaltrials.gov: NCT03507049. Findings: Between September 1st, 2018 and October 22nd, 2021, 63 patients were randomized, 32 to the surgical group, 31 to the sham group. Mean age was 45 years (range 26-63) and 59 of 63 (94%) patients were female. The mean reduction in the operated sacroiliac joint from baseline to six months postoperative was 2.6 Numeric Rating Scale points in the surgical group and 1.7 points in the sham group (mean between groups difference -1.0 points; 95% CI, -2.2 to 0.3; p = 0.13). Interpretation: This double-blind randomized controlled trial could not prove that minimally invasive fusion of the sacroiliac joint was superior to sham surgery at six months postoperative. Funding: Sophies Minde Ortopedi supported a clinical research position for Engelke Marie Randers. Region Stockholm supported the cost for the Swedish ethical application and a clinical research appointment for Paul Gerdhem.