Long-Term Prospective Clinical And Radiographic Outcomes After Minimally Invasive Lateral Transiliac Sacroiliac Joint Fusion Using Triangular Titanium Implants

Sacroiliac joint dysfunction: anatomy, pathophysiology, differential diagnosis, and treatment approaches

The sacroiliac joints (SIJ) play a pivotal role in pelvic stability and load transmission. SIJ-related disorders can pose a diagnostic challenge because of complex anatomy, non-specific imaging findings, and overlapping symptomatology with other lower back conditions. Broadly, SIJ pathology can be divided into the following categories: infectious, inflammatory, degenerative, mechanical, traumatic, and neoplastic. On the spectrum of mechanical disorders is the entity of SIJ dysfunction, defined as pain localized to the SIJ due to non-inflammatory causes. This paper aims to enhance the understanding of SIJ dysfunction by exploring SIJ anatomy, pathophysiology, and differential diagnosis for SIJ pain. Etiologies, associations, and diagnostic physical examination maneuvers for SIJ dysfunction are reviewed. We will discuss the role of diagnostic imaging in SIJ dysfunction and propose imaging findings which may indicate the diagnosis. Finally, we will discuss therapeutic strategies to treat SIJ dysfunction. By delving into the complexities of SIJ anatomy and pathophysiology, this paper provides valuable discernment for the diagnosis and management of SIJ-related disorders.

Minimally invasive sacroiliac joint fusion secondary to lumbosacral fusion: Clinical and functional results at 2years of follow-up

INTRODUCTION

Degenerative sacroiliac (SI) joint syndrome is known to be more common after lumbosacral fusion. While this diagnosis is suspected based on various clinical criteria and diagnostic tests, it is confirmed with a diagnostic nerve block. If conservative treatment fails, SI joint fusion through a minimally invasive approach is a useful palliative approach for patients at a treatment crossroads. The aim of this study was to evaluate the clinical and functional results at 2years postoperative after minimally invasive SI joint fusion in patients with SI joint syndrome following lumbosacral fusion.

MATERIALS AND METHODS

We carried out a single-center retrospective study of patients operated between June 2017 and October 2020. Included were patients who had a confirmed diagnosis of SI joint syndrome after lumbosacral fusion surgery, who underwent SI joint fusion and had at least 2years' follow-up. The primary outcome was the improvement in lumbar and radicular pain on a numerical rating scale (NRS). The secondary outcomes were the functional scores (Oswestry and SF-12) along with the level of patient satisfaction. Our study population consisted of 54 patients (41 women, 13 men) with a mean age of 59years (27-88). Thirty-one of these patients were operated on both sides (85 fusions in all). The patients had undergone a mean of 3 lumbar surgeries (1-7) before the SI fusion.

RESULTS

The lumbar and radicular NRS were 8.4 (7-10) and 5.1 (2-10) preoperatively and 5.2 (0-8) and 3.0 (0-8) at 2years postoperatively, which was a reduction of 37% and 42% (p<0.001), respectively. The Oswestry score went from 69.4 (52-86) preoperatively to 45.6 (29-70) at 2years, which was a 33% improvement (p<0.001). Eighty-six percent of patients were satisfied or very satisfied with the surgery.

DISCUSSION

After minimally invasive SI joint fusion, the patients in this study had clear clinical and functional improvements. Previous publications analyzing the results of SI joint fusion found even more improvement, but those patients were relatively heterogenous; in our study, only patients who had a history of lumbosacral fusion were included.

CONCLUSION

Minimally invasive SI joint fusion helped patients who developed SI joint syndrome after lumbosacral fusion to improve clinically and functionally.

LEVEL OF EVIDENCE

IV, retrospective study.

Utility of minimally invasive percutaneous arthrodesis of the sacroiliac joint for the treatment of low back pain: systematic review of the literature

BACKGROUND

The surprising increase observed in recent years in the use of minimally invasive sacroiliac joint arthrodesis techniques as a treatment for low back pain justifies an objective review of this results.

PURPOSE

carry out a systematic review of the literature to evaluate the clinical results of patients with low back pain treated with percutaneous arthrodesis of the SIJ.

STUDY DESIGN

Systematic review.

METHODS

Systematic search of the medical literature. The words used in the Search were: "Hollow screw system", "percutaneous sacroiliac joint stabilization", "sacroiliac joint", "minimally invasive", "sacroiliac pain", "sacroiliac dysfunction". With logical connectors such as "and", "not" and "or".

DATABASES

Pubmed, Scopus, Embase, Ovid, EBSCO host and google scholar. The search extended from the beginning of the databases until September 2024. The "Rayyan" program was used to collect the information and facilitate the analysis process.

INCLUSION CRITERIA

Systematic review from the literature, clinical trials, observational studies and case series. They followed PRISMA principles.

RESULTS

661 articles were found, of which 108 articles were duplicates. The criteria (Inclusion/Exclusion) were applied to the 553 articles identified based on the independent reading of the summaries by each of the authors on the Rayyan platform and 434 articles were excluded. The 119 selected articles were completely reviewed to finally obtain 102 articles included in the review. Epidemiological data were extracted into an Excel table, methodological and related to clinical results and safety of procedures made. The Prisma checklist for systematic reviews was applied in each article. The epidemiological quality of the articles was evaluated based on the checklists STROBE and CONSORT. The results regarding clinical improvement were overwhelming. However, most of the studies were sponsored by industry and with a limited population and follow-up not always prolonged.

CONCLUSIONS

Although the clinical results regarding the effectiveness of SIJ fusion are forceful for their effectiveness, we recommend considering some aspects for their analysis and especially long-term studies.

Surgical Treatment of Patients with Sacroiliac Joint Syndrome: Comparative Study of Two Implants

The treatment of patients with ISJ dysfunction is difficult due to the multifactorial causes of pain and various problems in clarification. Treatment includes physical therapy, corticosteroids, prolotherapy, radiofrequency denervation and sacroiliac joint fusion. A new option for the surgical treatment of ISG dysfunction is the Torpedo implant system. For a safe fusion, only 2 implants are needed, which are available in lengths of 30-50 mm. The new implant system has been tested in pilot studies for efficacy and biocompatibility with good results. For further documentation for the Torpedo implant system, a comparative study against the iFuse system was carried out.Two different implants were used: Group 1: Deltacor Torpedo, Group 2: iFuse implants (Si-Bone). The data generated during admission and subsequent check-ups (VAS, ODI, opioid use) were entered into an evaluation file set up for this purpose. Follow-up appointments were set at 1 month, 3, 6 and 12 months postoperatively.The data of 65 patients were evaluated comparatively. In all comparisons, only very small effect sizes were found with regard to the differences in the decrease in pain intensities, so that equivalent effectiveness of the two methods could initially be postulated from a clinical point of view. Most patients in both groups reported taking opioids to treat pain before surgery. According to the decrease in pain intensity, opioid treatment could be discontinued in some patients after the operation. After 12 months, the number of patients treated with opioids decreases to 23% in group 1 and to 17% in group 2. The success of the fusions with the two methods can also be proven by image documentation, from which the position of the implants can also be clearly recognised. In no case was there any loosening.Overall, the evaluation of this study allows the conclusion that both implant systems can be successfully used for the treatment of patients with ISJ syndrome. The present results should be confirmed in further comparative studies with the proposed evaluation methods.

Safety and Preliminary Effectiveness of Lateral Transiliac Sacroiliac Joint Fusion by Interventional Pain Physicians: A Retrospective Analysis

Introduction

Minimally invasive sacroiliac (SI) joint fusion has become the mainstay treatment for chronic refractory sacroiliac joint dysfunction. Multiple procedures are now available including transfixing procedures with implants placed in the lateral or posterolateral transiliac trajectories, and intra-articular procedures with devices and/or allograft placed via a dorsal approach. To date, the published literature on the lateral approach has been primarily by surgeons. This retrospective chart review aims to evaluate the safety and preliminary effectiveness when the procedure is performed by physicians trained in interventional pain management.

Methods

Retrospective analysis of patients who underwent lateral SI joint fusion using a lateral transiliac approach between December 2022 and September 2023 by a single physician. Data on demographics, perioperative details, complications, and postoperative outcomes were collected and analyzed. The study was reviewed by WCG IRB and received an exemption authorization.

Results

Medical charts were reviewed for the first 49 consecutive cases performed. Mean (SD, range) age was 64 (11, 34-83), BMI was 32.5 (8.4), 59% were female, 35% were smokers, and 82% were on opioids at baseline. Mean (SD) operative time was 40 (11) minutes and all procedures were performed at an ambulatory surgery center under monitored anesthesia care. No device- or procedure-related complications occurred. Mean follow up was 175 days; Mean (SD) baseline reported pain was 9 (1.5) on a 0-10 numerical rating scale. At follow up, 88% of the patients reported ≥50% pain relief. Six patients who reported 0% relief suffer from multiple pain generators and are on long term opioids.

Conclusion

Results of this single center experience support the safety of lateral SI joint fusion using a threaded implant when performed by interventional pain management physicians. However, further prospective studies with larger sample sizes and longer follow-ups are warranted to validate these findings.

Enhancing immune modulation and bone regeneration on titanium implants by alleviating the hypoxic microenvironment and releasing bioactive ions

Bone implantation inevitably causes damage to surrounding vasculature, resulting in a hypoxic microenvironment that hinders bone regeneration. Although titanium (Ti)-based devices are widely used as bone implants, their inherent bioinert surface leads to poor osteointegration. Herein, a strontium peroxide (SrO2)-decorated Ti implant, Ti_P@SrO2, was constructed through coating with poly-L-lactic acid (PLLA) to alleviate the hypoxic microenvironment and transform the bioinert surface of the implant into a bioactive surface. PLLA degradation resulted in an acidic microenvironment and the release of SrO2 nanoparticles. The acidic microenvironment then accelerated the decomposition of SrO2, resulting in the release of O2 and Sr ions. O2 released from Ti_P@SrO2 can alleviate the hypoxic microenvironment, thus enhancing cell proliferation in an O2-insufficient microenvironment. Furthermore, under hypoxic and normal microenvironments, Ti_P@SrO2 enhanced alkaline phosphatase activity and bone-related gene expression in C3H10T1/2 cells with the continuous release of Sr ions. Meanwhile, Ti_P@SrO2 suppressed M1 polarization and promoted M2 polarization of bone marrow-derived monocytes under hypoxic and normal conditions. Furthermore, in a rat implantation model, the implant enhanced new bone formation and improved osteointegration after modification with SrO2. In summary, the newly designed O2- and Sr ion-releasing Ti implants are promising for applications in bone defects.

Safety, Efficacy, and Durability of Outcomes: Results from SECURE: A Single Arm, Multicenter, Prospective, Clinical Study on a Minimally Invasive Posterior Sacroiliac Fusion Allograft Implant

Introduction

Research suggests that sacroiliac joint (SIJ) dysfunction is responsible for 15% to 30% of reported low back pain cases. Recently, there has been an increasing interest in SIJ fusion using minimally invasive surgery (MIS) due to safety. Initially, devices designed for MIS were intended for lateral approaches. A minimally invasive sacroiliac fusion implant for use with a posterior approach has been developed and is regulated for clinical use under the regulatory framework required for human cells, tissues, or cellular or tissue-based products (HCT/Ps).

Methods

A multi-center, prospective, single-arm study was launched after initial studies provided preliminary data to support safety, efficacy, and durability of this minimally invasive sacroiliac posterior fusion LinQ allograft implant (NCT04423120). Preliminary results were reported previously. Final results for the full participant cohort are presented here.

Results

One-hundred and fifty-nine (159) participants were enrolled across 16 investigational sites in the US between January 2020 and March 2022. One-hundred and twenty-two (122) participants were implanted. At the 1-month follow-up, 82 participants satisfied all criteria for the composite responder endpoint, representing 73.2% of the study cohort. These results stayed consistent across the remaining study timepoints with 66.0%, 74.4%, and 73.5% of participants classified as responders at the 3-, 6- and 12-month follow-up visits, respectively. VAS scores were significantly reduced (p < 0.0001) and ODI scores were significantly improved (p < 0.0001). All domains of the PROMIS-29 were also significantly improved (all p's <0.0001). Only one procedure-related serious AE was reported in the study.

Conclusion

These results suggest that the posterior approach LinQ Implant System is a safe and effective treatment for sacroiliac joint dysfunction at 12 months, with results that are favorable compared to outcomes reported for an FDA-cleared lateral approach.

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.

The Sacroiliac Joint: A Current State-of-the-Art Review

» The sacroiliac joint (SIJ) is a common cause of low back pain and should be included in the differential diagnosis.» Nonoperative treatment of sacroiliac pain is always the first line of therapy; however, when it is unsuccessful and becomes chronic, then recurrent nonoperative treatment becomes expensive.» Surgical treatment is cost-effective in appropriately selected patients. High-quality clinical trials have demonstrated statistically and clinically significant improvement compared with nonsurgical management in appropriately selected patients.» Spinal fusion to the sacrum increases degeneration of the SIJ and frequency of SIJ pain.

Minimally Invasive SI Joint Fusion Procedures for Chronic SI Joint Pain: Systematic Review and Meta-Analysis of Safety and Efficacy

BACKGROUND

Sacroiliac (SI) joint fusion is increasingly used to treat chronic SI joint pain. Multiple surgical approaches are now available.

METHODS

Data abstraction and random effects meta-analysis of safety and efficacy outcomes from published patient cohorts. Patient-reported outcomes (PROs) and safety measures were stratified by surgical technique: transiliac, including lateral transiliac (LTI) and posterolateral transiliac (PLTI), and posterior interpositional (PI) procedures.

RESULTS

Fifty-seven cohorts of 2851 patients were identified, including 43 cohorts (2126 patients) for LTI, 6 cohorts (228 patients) for PLTI, and 8 cohorts (497 patients) for PI procedures. Randomized trials were only available for LTI. PROs were available for pain (numeric rating scale) in 57 cohorts (2851 patients) and disability (Oswestry Disability Index [ODI]) in 37 cohorts (1978 patients).All studies with PROs showed improvement from baseline after surgery. Meta-analytic improvements in pain scores were highest for LTI (4.8 points [0-10 scale]), slightly lower for PLTI (4.2 points), and lowest for PI procedures (3.8 points, P = 0.1533). Mean improvements in ODI scores were highest for LTI (25.9 points), lowest for PLTI procedures (6.8 points), and intermediate for PI (16.3 points, P = 0.0095).For safety outcomes, acute symptomatic implant malposition was 0.43% for LTI, 0% for PLTI, and 0.2% for PI procedures. Wound infection was reported in 0.15% of LTI, 0% of PLTI, and 0% of PI procedures. Bleeding requiring surgical intervention was reported in 0.04% of LTI procedures and not reported for PLTI or PI. Breakage and migration were not reported for any device. Radiographic imaging evaluation reporting implant placement accuracy and fusion was only available for LTI.

DISCUSSION

Literature support for SI joint fusion is growing. The LTI procedure contains the largest body of available evidence and shows the largest improvements in pain and ODI. Only LTI procedures have independent radiographic evidence of fusion and implant placement. The adverse event rate for all procedures was low.

LEVEL OF EVIDENCE: 1

Salvage of failed direct lateral sacroiliac joint fixation using a new percutaneous lateral-oblique transfixation technique with two variable-threaded screws: a multicenter case report of three cases

Background

The direct lateral trans-gluteal muscle splitting transiliac approach was popularized to fixate the sacroiliac joint (SIJ) using three cannulated triangular titanium implants (TTIs) wedges. Publications support efficacy of the direct lateral approach but a paucity of literature to help surgeons revise these implants when they fail. Intuitively the implants can be removed but require an open incision and dissection through the gluteal muscles and scar tissue which can lead to muscle and neurovascular injuries. Our objective was to evaluate the clinical outcome, measured by patient-reported Visual Analog Score (VAS), of three patients who had failed direct lateral SIJ fusions each using three implants and describe a revision technique using a new percutaneous lateral-oblique transfixation technique with two variable-threaded screws while preserving the original implants.

Case Description

Two separate orthopedic spine surgeons at different hospitals performed the technique using two SacroFuse® screws for SIJ revision fusion in three patients who had clinical symptoms and radiographic findings of SIJ pseudoarthrosis after direct lateral approach. One 61 years old male patient had a previous surgery with three lateral threaded screw implants. Two females with ages 47 and 40 years old had three TTI wedges. Follow-up from 10 to 26 months. Patients discharged home the same day. Mean procedure time of 20 minutes with blood loss less than five cc. Incision size was approximately 1 inch. Each patient had a 12 mm × 60 mm and a 12 mm × 50 mm screw filled with NanoFuse Biologics synthetic bioactive glass and demineralized bone matrix. Prior implants were left in place. There was an 89% decrease in mean VAS score of 9.5 to 1.

Conclusions

This is a clinically valuable report because until now there was no reconstructive surgery to revise direct lateral implants other than removal with potential neurovascular risks. This is the first article to demonstrate a lateral-oblique transfixation technique with two variable-threaded screws for successful salvage of SIJ pseudoarthrosis after direct lateral fixation without implant removal. The Sacrix technique achieved immediate stability and long-term fusion documented on computed tomography (CT) scan as early as 6 months.

Cost-Utility Analysis of Sacroiliac Joint Fusion in High-Risk Patients Undergoing Multi-Level Lumbar Fusion to the Sacrum

Purpose

Multi-level lumbar fusion to the sacrum (MLF) can lead to increased stress and angular motion across the sacroiliac joint (SIJ), with an incidence of post-operative SIJ pain estimated at 26–32%. SIJ fusion (SIJF) can help obviate the need for revisions by reducing range of motion and screw stresses. We aimed to evaluate the cost-utility of MLF + SIJF compared to MLF alone among high-risk patients from a payer perspective, where high risk is defined as high body mass index and high pelvic incidence.

Methods

A Markov process decision-analysis model was developed to evaluate cumulative 5-year costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) of MLF + SIJF compared to MLF alone using published data; costs from Medicare claims data analyses and health state utility values (derived from EQ-5D) informed by three prospective, multicenter, clinical trials. The base case assumed a reduction in post-operative SIJ pain from 30% to 10% (relative risk reduction [RRR] of 67%). Costs and utilities were discounted 3% annually. The ICER is reported in 2020 US dollars. One-way, multi-way, and probabilistic sensitivity analyses were performed.

Results

With an assumed 30% incidence of SIJ pain after MLF alone, stabilizing with SIJF was associated with an additional 5-year cost of $2421 and a gain of 0.14 QALYs, resulting in an ICER of $17,293 per QALY gained (similar to total knee arthroplasty and more favorable than open discectomy). ICERs were most sensitive to the RRR of post-operative SIJ pain conferred by SIJF, time horizon, and probability of successful treatment with MLF alone. At a willingness-to-pay threshold of $50,000/QALY gained, MLF + SIJF has a 97.7% probability of being cost-effective in the target patient population.

Conclusion

Fusing the SIJ in high-risk patients undergoing MLF was cost-effective when the incidence of post-operative SIJ pain after MLF alone exceeds approximately 25%, providing value-based healthcare from a payer perspective.

Revision of Failed Sacroiliac Joint Posterior Interpositional Structural Allograft Stabilization with Lateral Porous Titanium Implants: A Multicenter Case Series

Background

Distraction arthrodesis (DA) and stabilization of the sacroiliac (SI) joint by placing standalone structural allograft (SA) into the joint from a posterior trajectory has recently been introduced as a surgical procedure for chronic SI joint pain refractory to non-operative care.

Methods

Retrospective case series of patients with recurrent and/or persistent pain after placement of one or more interpositional/intraarticular standalone SAs between the ilium and sacrum using a posterior procedure to treat SI joint pain/dysfunction. Patients subsequently underwent surgical revision with porous titanium fusion implants using a lateral transfixing procedure. The demographic, clinical, and radiographic features of these cases are described.

Results

Data were available for 37 patients. The average (SD) age was 57 (13) years, 62% were female, and the average BMI was 31 (5.4). On average, two SA implants were placed per joint; 46% of cases were bilateral. At follow-up, two common themes were identified: lucencies around the implants and suboptimal implant position. None of the cases showed radiographic fusion of the SI joint prior to revision. One patient had an inflammatory reaction to the SA. All patients presented for revision due to either continued (49%) or recurrence (51%) of pain. In one revision case, the SA was forced ventrally, resulting in a sacral fracture, which was treated conservatively without sequelae.

Conclusions

The popularity of standalone SA for SI joint stabilization/fusion with a posterior procedure is increasing. This case series demonstrates that clinical failures from this procedure may require surgical revision. The proposed fusion strategy (DA) for these products is unproven in the SI joint, and, therefore, properly conducted prospective randomized clinical trials with long-term clinical and radiographic follow-up are important to establish the safety and efficacy of this approach. In the meantime, the placement of lateral titanium implants appears to be an effective revision strategy.

Beyond Placement of Pedicle Screws - New Applications for Robotics in Spine Surgery: A Multi-Surgeon, Single-Institution Experience

Interest in robotic-assisted spine surgery has grown as surgeon comfort and technology has evolved to maximize benefits of time saving and precision. However, the Food and Drug Administration (FDA) has currently only approved robotics to assist in determining the ideal trajectory for pedicle screw placement after extensive research supporting its efficacy and efficiency. To be considered a durable and effective option, robotics need to expand beyond the indication of just placing pedicle screws. This article aims to illustrate a multi-surgeon, single-institution experience with unique applications of robotic technologies in spine surgery. We will explore accessing Kambin's Triangle in percutaneous transforaminal interbody fusion (percLIF), iliac fixation in metastatic cancer, and sacroiliac (SI) fusions. Each of these topics will be covered in depth with associated background information and subsequent discussion. We show that with proper understanding of its limitations, robots can help surgeons perform difficult surgeries in a safe manner.

Six Month Interim Outcomes from SECURE: A Single arm, Multicenter, Prospective, Clinical Study on a Novel Minimally Invasive Posterior Sacroiliac Fusion Device

INTRODUCTION

Sacroiliac joint disease is a prominent diagnosis across the world. A novel fixation technique employing a posterior approach, single point, bone allograft tranfixation has proven to be helpful anecdotally. The purpose of this is study is to investigate prospectively the safety and efficacy of this approach.

METHODS

A multicenter, prospective, single arm study was performed after patient identification and treatment with the novel posterior fusion, single-point transfixation system and followed for 24 months. Target enrollment is 100 patients. Interim results on the first 69 consecutive patients at 6 months is presented. Primary endpoint at 6-month analysis was Pain Intensity reduction by visual analogue scale and functional improvement by Oswestry Disability Index. Adverse events were assessed for safety analysis.

RESULTS

: 69 patients were identified for this analysis. At 6 months, a mean improvement of 34.9 was identified by a reduction in VAS and functional improvement was demonstrated by a mean reduction in ODI of 17.7. There were three adverse events, all unrelated to the device.

CONCLUSION

The posterior single point transfixation is safe and efficacious for the treatment of sacroiliac joint dysfunction with statistical improvements in pain and 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.

Novel Interventional Techniques for Chronic Pain with Minimally Invasive Arthrodesis of the Sacroiliac Joint: (INSITE, iFuse, Tricor, Rialto, and others)

Acute and chronic pain are public health issues that clinicians have been battling for years. Opioid medications have been a treatment option for both chronic and acute pain; however, they can cause unwanted complications and are a major contributor to our present opioid epidemic. The sacroiliac (SI) joint is a common cause of both acute and chronic low back pain. It affects about 15–25% of patients with axial low back pain, and up to 40% of patients with ongoing pain following lumbar fusion. Recent advances in the treatment of SI joint pain have led to the development of a wide variety of SI joint fusion devices. These fusion devices seek to stabilize the joints themselves in order that they become immobile and, in theory, can no longer be a source for pain. This is a minimally invasive procedure aimed to address chronic pain without subjecting patients to lengthy surgery or medications, including opioids with the potential for addiction and abuse. Minimally invasive SI fusion can be performed by a lateral approach (i.e., iFuse, Tricor) or posterior approach (i.e., CornerLoc, LinQ, Rialto). The posterior approach requires the patient to be in the prone position but allows for less disruption of muscles with entry. More data are necessary to determine which fusion system may be best for a particular patient. SI fusion devices are a promising way of treating chronic lower back pain related to the SI joint. This narrative review will discuss various types of SI fusion devices, and their potential use in terms of their safety and efficacy.

Prospective Trial of Sacroiliac Joint Fusion Using 3D-Printed Triangular Titanium Implants: 24-Month Follow-Up

Background

Strong evidence supports minimally invasive sacroiliac joint (SIJ) fusion using triangular titanium implants (TTI) for chronic SIJ dysfunction.

Objective

To report safety and effectiveness of SIJF using a 3D-printed TTI at 24 months.

Methods

SIJF with TTI was performed in 51 subjects. Structured follow-up occurred at 3, 6, 12 and 24 months. Both quality of life questionnaires and functional tests were performed at all study visits.

Results

84% of subjects were available for 24-month follow-up. Observed were rapid and persistent improvements in dysfunction due to pain (Oswestry Disability Index [ODI], mean 52.8 at baseline and 28.3 at 24 months, p<0.0001) and SIJ pain ratings (mean 78.5 at baseline [0–100 scale] to 21.5 at 24 months). Opioid use for SIJ pain decreased markedly from baseline. Physical function tests impaired by SIJ pain showed persistent improvements compared to baseline. There was no evidence of device breakage, migration or subsidence and few late adverse events occurred attributable to the device.

Conclusion

In this prospective study, SIJF using 3D-printed TTI resulted in immediate, marked and persistent improvements in pain and quality of life, with improved physical function, reduced opioid use and a low rate of late device-related adverse events.

Level of Evidence

Level II.

Minimally Invasive Sacroiliac Joint Fusion with Triangular Titanium Implants: Cost-Utility Analysis from NHS Perspective

OBJECTIVE

The aim was to identify the cost-effectiveness of minimally invasive sacroiliac joint fusion (MI SIJF) surgery with titanium triangular implants for patients with sacroiliac joint (SIJ) pain who have failed conservative management, compared to non-surgical management (NSM) from a National Health Service (NHS) England perspective.

METHODS

Over a time horizon of 5 years, a cohort state transition model compared the costs and outcomes of treating patients with MI SIJF to those of traditional NSM treatment pathways. The NSM arm included two treatments: grouped physical therapy and corticosteroid injections (PTSI) or radiofrequency ablation (RFA). Three different strategies were considered: (1) a stepped pathway, (2) patients split between PTSI and RFA, and (3) RFA only. The outcome measure was incremental cost-effectiveness ratio (ICER), reported in 2018 British pounds per quality-adjusted life year (QALY) gained. One-way and probabilistic sensitivity analyses were used to test the robustness of the model results.

RESULTS

Patients undergoing MI SIJF accrued total procedure-related and pain-management costs of £8358, while NSM treatment strategy 1 had total costs of £6880. The MI SIJF cohort had 2.98 QALYs compared to strategy 1 with 2.30 QALYs. This resulted in an ICER for MI SIJF versus strategy 1 of £2164/QALY gained. Strategy 2 of the NSM arm had lower costs than strategy 1 (£6564) and 2.26 QALYs, and this resulted in an ICER of £2468/QALY gained for MI SIJF. Strategy 3 of the NSM arm had lower costs than strategy 1 (£6580), and this resulted in 2.28 QALYs and an ICER of £2518/QALY gained for MI SIJF. Probabilistic sensitivity analysis shows that at a threshold of £20,000/QALY gained, MI SIJF has a probability of being cost-effective versus NSM strategies of 96%, 97%, and 91% for strategies 1, 2, and 3, respectively.

CONCLUSION

MI SIJF appears to be cost-effective over a 5-year time horizon when compared to traditional NSM pathways in an NHS context.

International Society for the Advancement of Spine Surgery Policy 2020 Update-Minimally Invasive Surgical Sacroiliac Joint Fusion (for Chronic Sacroiliac Joint Pain): Coverage Indications, Limitations, and Medical Necessity

The index 2014 International Society for the Advancement of Spine Surgery Policy Statement-Minimally Invasive Surgical Sacroiliac Joint Fusion-was generated out of necessity to provide an International Classification of Diseases, Ninth Revision (ICD-9)-based background and emphasize tools to ensure correct diagnosis. A timely ICD-10-based 2016 update provided a granular threshold selection with improved level of evidence and a more robust and relevant database (Appendix Table A1). As procedures and treatment options have evolved, this 2020 update reviews and analyzes the expanding evidence base and provides guidance relating to differences between the lateral and dorsal surgical procedures for minimally invasive surgical sacroiliac joint fusion.

Patient Reported Clinical Outcomes of Minimally Invasive Sacroiliac Joint Arthrodesis

Objective

To report patient‐reported outcomes of minimally invasive sacroiliac (SI) joint fusion as a case series.

Methods

This study was a retrospective cohort study of patients 18 years of age and older who underwent a minimally invasive SI joint fusion by a single surgeon between 1 January 2013 and 31 December 2015. Routine demographic data, characteristics, and relevant surgical and clinical data were all collected for this group. In addition, patients completed preoperative and postoperative visual analog scale (VAS) and Short Form 36 (SF‐36) questionnaires to assess outcomes. Patient selection for SI fusion was based on short‐term resolution of symptoms (80% or greater relief) with an image‐guided intra‐articular injection of local anesthetic. Routine statistical analysis was performed using the Wilcoxon signed rank test, Fisher's exact test, or χ² analysis as appropriate.

Results

This study included 19 patients comprising 24 SI fusions, with a mean follow‐up of 58 months. The average patient age was 50 years and the average surgical blood loss was 25 cc. Men comprised 79% of the cohort. The VAS score improved from 7 to 3 (P = 0.0001). SF‐36 physical function, role limitations due to physical health, and role limitations due to emotional health improved to a statistically significant extent. General health was not significantly changed. Every patient showed improvement in their SF‐36 physical function scores (mean 40 preoperatively to 55 at final follow up) and 18 of 19 showed improvement in the VAS score (mean 7 preoperatively to 3 at final follow‐up).

Conclusion

In appropriately selected patients, minimally invasive SI joint fusion results in decreased pain and improved physical functioning of patients, which is sustained for more than 4 years post‐procedure.

Minimally Invasive Sacroiliac Joint Fusion: A Lateral Approach Using Triangular Titanium Implants and Navigation

Background:

Minimally invasive sacroiliac (SI) joint fusion is indicated for low back pain from the SI joint that is due to degenerative sacroiliitis and/or sacroiliac joint disruption. This technique is safe and effective in relieving pain uncontrolled by nonoperative management^1-4. There is some controversy, but there continues to be increasing evidence of effectiveness.

Description:

This procedure is performed, with the patient under general anesthesia and in the prone position, using fluoroscopy or 3-dimensional (3D) navigation such as cone-beam computed tomographic (CT) imaging. After navigation setup, a navigated probe is used to approximate the desired location of each implant and trajectory. These positions are marked on the skin, and the skin is incised. A 3 to 5-cm lateral incision is made. The gluteal fascia is bluntly dissected to the outer table of the ilium. A guide pin is passed across the SI joint and into the center of the sacrum lateral to the neural foramina, which is confirmed with imaging. This is then drilled and broached. Triangular titanium rods are placed. Typically, 3 implants are placed, 2 in S1 and 1 in S2. Multiplanar postplacement imaging of the pelvis is obtained. The wound is irrigated and closed in layers.

Alternatives:

Nonsurgical alternatives have been reported to include pharmacological therapies, such as nonsteroidal anti-inflammatory drugs, therapeutic SI joint blocks⁵, and physical therapy, such as core stabilization, orthotics (SI belts), and radiofrequency ablation^1,2,6-8. The surgical alternative is an open anterior or posterior approach with SI joint arthrodesis. The anterior approach differs by the resection of the SI joint cartilage, the use of a plate or screws across the joint for stabilization, and the packing of bone graft to facilitate fusion⁹. These are more morbid and have a much longer recovery.

Rationale:

Conservative management for SI joint pain is inadequate for all patients. Having 3 of 5 positive physical examination maneuvers⁷, having confirmatory diagnostic block(s)¹⁰, and ruling out the hip or spine as the pain generator provide a success rate of >80%. These patients have early and sustained clinically important and significantly improved outcomes across varying measures compared with conservative treatment^1-4,11,12.

Expected Outcomes:

Patients can expect to experience decreased pain, reduced disability, increased daily function, and improved quality of life soon after the procedure is performed. These patients typically have an improvement of ≥50% in the Oswestry Disability Index score and a clinically significant decrease in visual analog pain scores¹³. The procedure appears durable through at least 5 years¹⁴. Complete pain relief is rare, but clinically important improvement is typical.

Important Tips:

Proper setup of the navigation system or fluoroscopy is needed to ensure accurate starting points.

For 3D navigation, use a reference pin in the contralateral posterior superior iliac spine.

Although navigation is used, radiographic images are made periodically to confirm proper placement of guide pins and implants. Images provide the greatest benefit when establishing navigation, after guide-pin placement when an outlet view allows for evaluation of pin depth, and after implant placement to confirm proper placement.

Blood loss is generally low, but care should be taken to avoid vascular injury. Although rare, improper placement has led to injury of the superior gluteal artery¹⁵ and iliac artery¹⁶. This can be avoided by staying in bone.

Proper placement of the implant is imperative in this procedure. There is the potential for nerve injury with improper placement of the implant: an L5 nerve injury if the implant is too ventral or an S1 or S2 nerve injury if the implant is too deep and into the foramen. Revision surgery is commonly due to nerve root impingement and/or malpositioning.

Preoperative 3D imaging is indicated when it is necessary to rule out differential diagnoses that mimic SI joint pain. This enables the surgeon to rule out intrapelvic pathology, assess sacral bone density¹⁷, and identify dysmorphic sacra or transitional vertebrae.

Prospective Trial of Sacroiliac Joint Fusion Using 3D-Printed Triangular Titanium Implants

Background

Prior trials provide strong evidence supporting minimally invasive sacroiliac joint (SIJ) fusion using triangular titanium implants (TTI) for chronic SIJ dysfunction.

Objective

To assess the safety and effectiveness of SIJF using a 3D-printed TTI.

Methods

Fifty-one subjects with carefully diagnosed SIJ dysfunction underwent SIJF with 3D TTI. Subjects completed pain, disability and quality of life questionnaires at baseline and 3, 6 and 12 months postoperatively. Functional tests were performed in the clinic at each visit. Pelvic CT scans were independently evaluated for radiolucency, bridging bone and other endpoints.

Results

Ninety percent had 12-month follow-up. Dysfunction due to pain (Oswestry Disability Index [ODI]) decreased from 52.8 at baseline to 27.9 at 12 months (p<.0001 for change, p=.004 for non-inferiority primary hypothesis). SIJ pain scores improved from 78 preoperatively to 21 at 12-month follow-up (P<.0001). Ninety-six percent experienced an improvement of 20 points or more in VAS SIJ pain by month 12. The percentage of subjects reporting minimal difficulty performing physical activities typically impaired by back/SIJ pain improved significantly for all activities. The proportion of subjects taking opioids for SIJ pain decreased from 57% to 22%. Three physical function tests improved markedly from baseline to 1 year. Positive radiographic findings were observed, including a 70% and 77% rate of bone bridging observed at 6 and 12 months, respectively. There was no evidence of device breakage, migration or subsidence.

Conclusion

In this prospective multicenter trial, SIJF with 3D-printed TTI markedly improved pain, disability and quality of life. Results are consistent with 3 prior prospective multicenter trials of a milled implant but suggest accelerated bony fusion with the newer implant. Physical function improved, and high rates of opioid cessation were observed.

Level of Evidence

Level II.