Sacroiliac Joint Dysfunction in Patients With Low Back Pain

Treatment

Nonoperative management of SIJ dysfunction includes exercise programs, physical therapy, manual manipulation therapy, sacroiliac belts, and periodic articular injections. Efficacy of these methods is variable, and analgesics often do not significantly benefit this type of pain. Another nonoperative approach is radiofrequency ablation (RFA) of the lumbar dorsal rami and lateral sacral branches, which can vary based on the number of rami treated as well as the technique used. About two-thirds of patients report pain relief after RFA.2 When successful, pain is relieved for 6 to 12 months, which is a temporary yet effective option for patients experiencing SIJ dysfunction.^14,20

Fusion Surgery

Cadaver studies show that biomechanical stabilization of the SIJ leads to decreased range of motion in flexion/extension, lateral bending, and axial rotation. This results in a decreased need for periarticular muscular and ligamentous support, therefore facilitating load transfer across the SIJ.^21,22 Patients undergoing minimally invasive surgery report better pain relief compared with those receiving open surgery at 12 months postoperatively.²³ The 2 main SIJ fusion approaches used are the lateral transarticular and the dorsal approaches. In the dorsal approach, the SIJ is distracted and allograft dowels or titanium cages with graft are inserted into the joint space posteriorly through the back. When approaching laterally, hollow screw implants filled with graft or triangular titanium implants are placed across the joint, accessing the SIJ through the iliac bones using imaging guidance. This lateral transiliac approach using porous titanium triangular rods currently is the most studied technique.²⁴

A recent prospective, multicenter trial included 423 patients with SIJ dysfunction who were randomized to receive SIJ fusion with triangular titanium implants vs a control group who received nonoperative management. Patients in the SIJ fusion group showed substantially greater improvement in pain (81.4%) compared with that of the nonoperative group (26.1%) 6 months after surgery. Pain relief in the SIJ fusion group was maintained at > 80% at 1 and 2 year follow-up, while the nonoperative group’s pain relief decreased to < 10% at the follow-ups. Measures of quality of life and disability also improved for the SIJ fusion group compared with that of the nonoperative group. Patients who were crossed over from conservative management to SIJ fusion after 6 months demonstrated improvements that were similar to those in the SIJ fusion group by the end of the study. Only 3% of patients required surgical revision. The strongest predictor of pain relief after surgery was a diagnostic SIJ anesthetic block of 30 to 60 minutes, which resulted in > 75% pain reduction.^21,25 Additional predictors of successful SIJ fusion include nonsmokers, nonopioid users, and older patients who have a longer time course of SIJ pain.²⁶

Another study investigating the outcomes of SIJ fusion, RFA, and conservative management with a 6-year follow-up demonstrated similar results.²⁷ This further confirms the durability of the surgical group’s outcome, which sustained significant improvement compared with RFA and conservative management group in pain relief, daily function, and opioid use.

HCPs should consider SIJ fusion for patients who have at least 6 months of unsuccessful nonoperative management, significant SIJ pain (> 5 in a 10-point scale), ≥ 3 positive provocation tests, and at least 50% pain relief (> 75% preferred) with diagnostic intra-articular anesthetic injection.¹⁴ It is reasonable for primary care providers to refer these patients to a neurosurgeon or orthopedic spine surgeon for possible fusion. Patients with earlier lumbar/lumbosacral spinal fusions and persistent LBP should be evaluated for potential SIJ dysfunction. SIJ dysfunction after lumbosacral fusion could be considered a form of distal pseudarthrosis resulting from increased motion at the joint. One study found its incidence correlated with the number of segments fused in the lumbar spine.²⁸ Another study found that about one-third of patients with persistent LBP after lumbosacral fusion could be attributed to SIJ dysfunction.²⁹