A prospective multicenter randomized controlled trial on safety and procedural competency in SI joint fusion performed by interventional pain physicians trained by a spine surgeon

Abstract

Background context: Sacroiliac joint (SIJ) fusion was traditionally performed exclusively by spine surgeons using a minimally invasive direct lateral approach. With advancements in technology, SIJ fusion has evolved into percutaneous techniques which have been adopted by interventional pain management (IPM) physicians due to their expertise in interventional techniques. However, this expansion has raised safety concerns among spine surgeons regarding "practice creep" and procedural competency gaps. Furthermore, the lack of uniform outpatient credentialing has created an environment where safety oversight may be inconsistent.

Purpose: To evaluate and compare the safety and procedural competency of percutaneous posterior-oblique SIJ fusions performed by trained IPM physicians using titanium screws plus a synthetic bioactive glass flowable biologics under direct spine surgeon supervision versus nonspine surgeon supervision.

Study design/setting: A prospective multicenter randomized controlled trial conducted across multiple ambulatory surgery centers between 2020 and 2022.

Patient sample: About 276 adult patients (mean age 56.7 years; 72.1% female) scheduled for SIJ fusion.

Outcome measures: The primary outcome measures were surgical complications, deviations, and revisions. These were assessed through medical records and radiographs for at least 6 months post operative.

Methods: About 276 patients were in this study and were randomly assigned to Group 1 or Group 2. Sixty-six patients (Group 1; spine surgeon supervised). Sixty-seven patients, clinical specialist supervised, plus 143 assigned to sales representatives/independent distributors supervised (Group 2; nonspine surgeon supervised). All primary procedures were performed by 47 IPM physicians who received structured training on the percutaneous posterior-oblique technique by a board-certified orthopedic spine surgeon. Surgical complications, deviations, and revisions were recorded, with follow-up data collected for at least 12 months.

Results: A total of 9 complications (3.3%), 4 deviations (1.4%), and 5 revision cases (1.8%) were observed. Group 1 experienced no complications, deviations, or revisions. In Group 2, 9 complications (4.3%) and 4 deviations (1.9%) occurred between the second and fifth operative days. 5 cases were revised (2.4%).

Conclusions: Spine surgeon training equipped IPM physicians to safely performed percutaneous posterior-oblique SIJ fusions with titanium screws plus biologics, achieving low complication and revision rates. These findings highlight the importance of incorporating standardized surgeon-led training and certification programs to bridge the competency gap and ensure safe adoption of interventional spine surgery practices by IPM physicians.

Keywords: Interventional pain medicine; NanoFuse biologics; Posterior-oblique; SI-bone; SIJ fusion; Sacrix®; Sacroiliac joint fusion; Titanium triangular implant; iFuse.