The Assessment of Fusion Following Sacroiliac Joint Fusion Surgery

Abstract

Sacroiliac joint fusions (SIJF) have been the subject of many research studies. The technical success of an SIJF is in part determined by whether osseous bridging occurs across the sacroiliac joint (SIJ). However, no validated SIJF assessment method has been described. Our objective was to document previously described SIJF assessment methods and define and validate a detailed assessment system for SIJF. Our results are only intended to establish computed tomography (CT)-based guidelines for SIJF to be used in a subsequent large clinical study to correlate them with clinical outcomes.The SIJF literature was reviewed to document previous descriptions of SIJF assessments. A detailed system was then developed for assessing SIJF from CT exams. To provide data that can be used to address a range of research questions, the system included assessing bridging bone relative to the SIJ anatomy, bridging bone immediately adjacent to the threaded implants crossing the joint, as well as bridging bone close to but not immediately adjacent to the implants. The system was applied to assessing SIJF from thin-slice CT exams in 19 patients 12 months following surgery. Two experienced radiologists implemented the assessment system, and in the event of a disagreement, an adjudicator was used.Most prior studies provide very little detail about how SIJF was assessed. Using the new assessment system, the agreement between the primary readers was substantial (0.67 using Gwet’s AC1 statistic). Bridging bone representing a fusion of the SIJ was identified in most patients both immediately adjacent to the threaded implants crossing the joint, as well as distant to the implants.A detailed radiographic assessment system proved to be applicable to SIJF. The assessment system includes explicit language describing the location and extent of bridging bone across the SIJ. Standardization of the assessment of the SIJFs may allow for a more meaningful comparison of data between studies.

Sacroiliac Joint Fusion – Impact of a New Image-Guidance Protocol on Safety and Complications

“…Previous studies have quoted fusion rates at 1-2 years postoperative in the range of 80-97%. 15,17,19 Two of our patients had documented symptomatic pseudarthrosis requiring revision, both in the fluoroscopy group. However, overall statements regarding solid fusion across the SI joint are difficult to generate with our data given the lack of protocolized follow-up CT imaging.…”

“…Complications such as pseudarthrosis and neural injuries, while rare, are often associated with need for revision surgery and poorer outcome. 18,19 The transition to CT-based image-guidance aims to reduce such complications. The purpose of this study is to review our series of minimally invasive sacroiliac fusion with a focus on safety and complications, and to review differences in these parameters between patients undergoing fluoroscopic technique versus CT-based image-guidance.…”

Clinical results following robotic navigation guidance for sacroiliac joint fusion in 36 patients

“…Fusion rates for MIS sacroiliac fusion from other studies with dedicated radiographic imaging have been reported from 87% to 97%. 21,22 Beck et al reported a fusion rate of 96.9% in 20 patients after using INFUSE bone graft consisting of rhBMP-2 in conjunction with a single-threaded titanium cage (INTER FIX, Medtronic), with a mean follow-up of 27 months. 23 The current study reports a progressive fusion trend over 12 months of follow-up.…”

Editor's Introduction: Update on Current Sacroiliac Joint Fusion Procedures: Implications for Appropriate Current Procedural Terminology Medical Coding

“…The safety and effectiveness has been demonstrated in randomized controlled trials, 1,2 a large multicenter trial, 9 and many case series. 8,[10][11][12][13][14][15][16] The durability 3,17 and economic benefit 18 of the iFuse (SI-BONE, Santa Clara, California) lateral device have been described. Collectively, nearly 100 peer-reviewed publications describe the extensive clinical experience with the lateral transiliac approach with placement of transfixing devices.…”