BACKGROUND

Low back pain (LBP) emanating from the sacroiliac joint (SIJ) is a common finding. Devices to fuse the SIJ are now commercially available, but high-quality evidence supporting their effectiveness is limited.

OBJECTIVES

To compare the safety and effectiveness of conservative management (CM) to minimally invasive sacroiliac joint fusion (SIJF) in patients with chronic LBP originating from the SIJ.

STUDY DESIGN

Prospective, multicenter randomized controlled trial.

SETTING

One hundred three adults in spine clinics with chronic LBP originating from the SIJ.

METHODS

Patients were randomly assigned to CM (n = 51) or SIJF using triangular titanium implants (n = 52). CM consisted of optimization of medical therapy, individualized physiotherapy, and adequate information and reassurance as part of a multifactorial treatment. The primary outcome was the difference in change in self-rated LBP at 6 months using a 0 - 100 visual analog scale (VAS). Other effectiveness and safety endpoints, including leg pain, disability using Oswestry Disability Index (ODI), quality of life using EQ-5D, and SIJ function using active straight leg raise test (ASLR), were assessed up to 12 months.

RESULTS

At 12 months, mean LBP improved by 41.6 VAS points in the SIJF group vs. 14.0 points in the CM group (treatment difference of 27.6 points, P < 0.0001). Mean ODI improved by 25.0 points in the SIJF group vs. 8.7 points in the CM group (P < 0.0001). Mean improvements in leg pain and EQ-5D scores were large after SIJF and superior to those after CM. CM patients were allowed to crossover to SIJF after 6 months. Patients who crossed to surgical treatment had no pre-crossover improvement in pain and ODI scores; after crossover, improvements were as large as those originally assigned to SIJF. One case of postoperative nerve impingement occurred in the surgical group. Two SIJF patients had recurrent pain attributed to possible device loosening and one had postoperative hematoma. In the CM group, one crossover surgery patient had recurrent pain requiring a revision surgery.

LIMITATIONS

The primary limitation was lack of blinding and the subjective nature of self-assessed outcomes.

CONCLUSIONS

For patients with chronic LBP originating from the SIJ, minimally invasive SIJF with triangular titanium implants was safe and more effective than CM in relieving pain, reducing disability, and improving patient function and quality of life. Our findings will help to inform decisions regarding its use as a treatment option in this patient population.Key words: Sacroiliac joint dysfunction, pelvic girdle pain, randomized controlled trial, quality of life, spine implants.