Two-Year Outcomes from a Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion vs. Non-Surgical Management for Sacroiliac Joint Dysfunction

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.

Management of sacroiliac joint pain: current concepts

INTRODUCTION

Managing sacroiliac joint (SIJ) pain is challenging and unpredictable. There are no internationally accepted recommendations. In light of the lack of global consensus and guidelines and the ongoing advancements in management options, a widely accepted treatment algorithm remains absent. This systematic review updates and evaluates the existing evidence on strategies for managing SIJ pain.

METHODS

This study followed the guidelines defined in the 2020 PRISMA statement. All clinical studies concerning the clinical management of SIJ pain were considered. Web of Science, PubMed, and Embase were accessed in January 2025 without additional filters or temporal constraints. The risk of bias evaluation and statistical analysis followed the guidelines described in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Fifteen randomised controlled trials, 13 clinical trials, and 10 retrospective studies were included. Data from 2666 patients (1429 women) were retrieved. The mean length of follow-up was 14.7 ± 15.2 months. The mean age was 54.0 ± 5.8 years, and the mean BMI was 28.5 ± 2.5 kg/m2. Non-surgical options primarily focus on physical therapy to relieve discomfort. Different medications aim to decrease inflammation and pain at the SIJ. Fluoroscopically guided SIJ injections allow for directly administering steroids or mesenchymal stem cells into the joint. Radiofrequency denervation is frequently used to address SIJ pain, while surgical fusion is usually reserved for cases where conservative treatment is ineffective.

CONCLUSION

Managing SIJ pain is challenging due to limited and inconsistent evidence. Treatment progresses from conservative options, physiotherapy, lifestyle changes, and non-steroidal anti-inflammatory drugs to more invasive approaches like injections, radiofrequency denervation, and, in severe cases, surgical management. Research limitations include small sample sizes, short follow-ups, and inconsistent methodologies. Future high-quality studies are needed to establish clear diagnostic and treatment guidelines, compare techniques, and explore new therapies like regenerative medicine.

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

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 non-spine surgeon supervision.

STUDY DESIGN/SETTING

A prospective multicenter randomized controlled trial conducted across multiple ambulatory surgery centers between 2020 and 2022.

PATIENT SAMPLE

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

276 patients were in this study and were randomly assigned to Group 1 or Group 2. 66 patients (Group 1; spine surgeon supervised). 67 patients, clinical specialist supervised, plus 143 assigned to sales representatives/independent distributors supervised (Group 2; non-spine 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 twelve 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.

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

STUDY DESIGN

Prospective, multicenter, single-arm study with five-year follow up.

OBJECTIVE

To report long-term (five years) safety, effectiveness, and radiographic outcomes after sacroiliac (SI) joint fusion (SIJF) with 3D-printed triangular titanium implants (TTI) and compare them with solid titanium plasma spray coated implants.

SUMMARY OF BACKGROUND DATA

A large literature base supports minimally invasive SIJF with TTI for chronic SIJ dysfunction.

MATERIALS AND METHODS

SIJF with TTI was performed in 51 subjects and scheduled follow-up occurred at 3, 6, 12, 24, and 60 months. Postoperative visits included quality of life questionnaires and functional tests. A high-resolution CT scan was performed at either 6 or 12 months, and again at 60 months. All CT scans were interpreted by an independent musculoskeletal radiologist.

RESULTS

Five-year follow-up was available in 36 of 51 subjects (71%). At five years, improvements in SI joint pain [58.1 points (0-100 scale)], SIJ-related disability [Oswestry disability index (ODI), 25.4 points) and quality of life (EuroQOL 5D: 0.24 points and EuroQOL visual analog scale: 13.4 points) were sustained and showed no signs of diminution. The percentage of patients using opioids for SIJ pain decreased markedly from baseline (57%) to five years (17%). Physical function tests showed persistent improvements from baseline. There was no evidence of device breakage, migration or subsidence and few late adverse events occurred attributable to the device. Independent analysis of CT scans showed bone opposed to implants in all cases, and evidence of bone bridging in 90% of cases, and no evidence of radiolucency or other adverse bone reactions.

CONCLUSIONS

Prospective five-year follow-up showed that SIJ fusion 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 revision surgery. Radiographic evidence showed implant integration and joint fusion.

LEVEL OF EVIDENCE

Level II.

Triangular pelvic fixation in the management of adult spinal deformities: technical note and preliminary results

INTRODUCTION AND HYPOTHESIS

Optimal choice of the lower instrumented vertebra in the management of adult spinal deformity that include lumbosacral junction is still unclear. It is therefore possible to stop fixation in S1 but also lower (S2AI or iliac screws) in order to reduce the risk of implants pullout. In such situations, mechanical solicitations can lead to secondary degradation of sacro-iliac joints.

TECHNIQUE AND RESULTS

Based on triangular pelvic fixation described for pelvic trauma, a posterior only fixation that combine S1 screws, iliac screws and sacro-iliac implants can be performed.

DISCUSSION

We are describing here the operative technique of this « bedrock » fixation under fluoroscopic guidance and its preliminary results about 15 patients.

LEVEL OF EVIDENCE

IV.

Efficacy and Safety of Posterior Minimally Invasive Sacroiliac Joint Fusion: A Narrative Review of Recent Evidence

PURPOSE OF REVIEW

Chronic low back pain is one of the top three causes of diminished quality of life in well-developed countries. There are many etiologies of lower back pain, and sometimes, the pain is of true spinal pathology. However, this is not always the case, and sacroiliac joint (SIJ) pain has been described as an etiology in 15-30% or more of patients who are experiencing low back pain. Overlooking SIJ dysfunction as the cause of low back pain has considerable consequences on the patient's quality of life and healthcare-associated costs. SIJ dysfunction has been gaining recognition through well-described algorithms and reports on how to diagnose and differentiate types of low back pain.

RECENT FINDINGS

When conservative management fails in patients with SIJ dysfunction, fusion of the SIJ is a possibility. SIJ fusion was introduced as an open procedure but was often seen as a "last resort" related to the high complication rates and intensity of the procedure consistent with long operative time, high blood loss, and extended hospital stays. Minimally invasive surgical techniques for SIJ fusion were developed and have produced quality relief for some patients. Most minimally invasive SIJ fusion procedures are performed through a lateral approach. However, newer studies have shown evidence of a posterior or posterior oblique approach that may be more desirable for patients. The posterior approach to SIJ fusion has demonstrated a shorter operative time, smaller incision, and quicker return to activities of daily living. This narrative review aims to highlight up to date evidence on the efficacy and safety posterior minimally invasive SIJ fusion.

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.

Nationwide Analysis of Sacroiliac Joint Fusion Trends: Regional Variations in Utilization and Population Characteristics

STUDY DESIGN/SETTING

Retrospective cohort analysis.

OBJECTIVES

This study evaluates utilization and demographic trends for sacroiliac joint (SIJ) fusions across the United States (US).

METHODS

Patients who underwent SIJ fusion from 2010-2021 were identified within the PearlDiver national database using International Classification of Disease (ICD-9, ICD-10) and Current Procedural Terminology (CPT) codes. Indications for trauma, malignancy, or infection were excluded. Demographic, clinical, and procedure characteristics were recorded along with annual utilization rates. Annual percent change (APC) was calculated to identify increasing or decreasing utilization from prior years. Negative binomial regression was performed to project subsequent utilization for 2022-2028. Chi-squared analysis followed by post-hoc comparisons were used to compare differences in diagnostic indications and clinical features associated with SIJ fusion across regions. Bonferroni adjustments were applied to P-values for pairwise analyses.

RESULTS

Overall, 18 032 patients (69.8% female, mean age = 51.0 + 13.4 years) underwent SIJ fusion between 2010 and 2021. Annual utilization increased by 33.5% on average. The South comprised the largest proportion of cases (48.9%). Projections for 2022-2028 predict continued growth in procedures, with an overall increase of 1100% from 1350 cases in 2021 to 16 195 by end of 2028. Spondyloarthropathy-induced sacroilitis was the most prevalent diagnostic indication nationwide (51%). Of patients undergoing SIJ fusion, 18% had a prior lumbar fusion, and only 45% received a preoperative diagnostic SIJ injection.

CONCLUSION

As SIJ fusion is increasingly utilized to treat refractory SIJ-based pain, establishing evidence-based guidelines, improving diagnostic strategies, and defining indications are imperative to support growing applications within clinical practice.

Minimally invasive lateral, posterior, and posterolateral sacroiliac joint fusion for low back pain: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the therapeutic effects of minimally invasive lateral, posterior, and posterolateral sacroiliac joint fusion for low back pain through a meta-analysis.

METHODS

The PubMed, Web of Science, Embase, Cochrane Library, and ClinicalTrials.gov databases were comprehensively searched for studies up to 31 August 2024. Relevant studies using lateral, posterior, and posterolateral approaches were identified. Pooled outcomes and publication bias were assessed. The study was registered with PROSPERO (registration No. CRD42023451047).

RESULTS

A total of 48 studies were included: 32 focused on the lateral approach, 10 on the posterior approach, four on the posterolateral approach, and two compared the lateral and posterolateral approaches. The pooled effect analysis showed statistically significant improvements in the visual analog scale (VAS) scores for all three approaches at 6 and 12 months postoperatively. Although no between-approach comparisons were conducted, the pooled improvements in VAS scores at 6 and 12 months postoperatively were numerically similar across all three approaches, as were the pooled fusion rates. The pooled complication rate for the lateral approach was 9.2%, numerically higher than 1% for the posterior approach. The pooled revision rate for the lateral approach was 2.4%, also numerically higher than 0.6% for the posterior approach.

CONCLUSIONS

Although pain relief and fusion rates were similar across all approaches, the lateral approach might be associated with a higher risk of total complications and revision surgery.

Safety and performance of a novel synthetic biomimetic scaffold for iliac crest defect reconstruction during surgical treatment of pelvic girdle pain: a first-in-human trial

INTRODUCTION

Surgical treatment of pelvic girdle pain (PGP) involves arthrodesis of sacroiliac (SI) and pubic symphysis joints. Fusion of pubic symphysis involves the implantation of an autologous iliac crest tricortical graft harvested from the iliac crest. The objective was to assess the safety of a novel synthetic graft substitute (b.Bone) for iliac crest reconstruction and to evaluate the results of PGP surgical treatment.

SOURCES OF DATA

Consecutive participants undergoing pelvic fusion and requiring iliac crest reconstruction were enrolled and followed-up for 12 months in a prospective first-in-human clinical investigation. Adverse events were documented, and health-related quality of life was evaluated using EuroQol-5D-5L questionnaire. Iliac crest defect healing was evaluated by the Modified Lane and Sandhu radiological scoring system. In addition, relevant published peer-reviewed scientific articles identified from PubMed.

AREAS OF AGREEMENT

The EQ-5D-5L scores improved steadily reaching the highest point at 365 days. By 365 days complete healing of the bone defect was observed.

AREAS OF CONTROVERSY

The management of PGP remains challenging with mixed results reported in the literature.

GROWING POINTS

While there is lack of consensus on how to manage PGP, the present study shows improved outcomes at one year following surgery. The synthetic b.Bone scaffold is a safe option with good healing outcomes for iliac crest defect reconstruction.

AREAS TIMELY FOR DEVELOPING RESEARCH

Although b.Bone synthetic scaffold found to be safe, further studies reporting on surgical treatment of PGP are required to confirm the findings in comparative trials.

A retrospective cohort review of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

PURPOSE

The demand for SIJ fusion among obese patients has grown substantially. However, the clinical relevance of obesity in the context of SI joint fusion has not been well investigated specifically, whether there is a BMI cutoff above which the benefit-risk ratio is low.

METHODS

Adult patients ≥ 21 years of age who underwent minimally invasive SIJ fusion between 2020 and 2023. Participants were classified using the National Institutes for Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects completed the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) at baseline and 12 months. One-way analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

Overall, mean VAS improved at 12 months by 2.5 points (p < .006). Over the 12-month follow-up period, BMI category did not impact mean improvement in VAS (ANOVA p = .08). Mean ODI at 12 months improved by 23.2 points (p < .001). BMI category did impact mean improvement in ODI (ANOVA p = .03).

CONCLUSION

This study demonstrates similar benefits across all BMI categories. This data suggests that obese patients do benefit from minimally invasive SIJ fusion, specifically the 35-40 BMI cohort of patients, and should not be denied this procedure based on arbitrary healthcare organizations BMI criteria.

Clinical outcomes for minimally invasive sacroiliac joint fusion with allograft using a posterior approach

BACKGROUND

Sacroiliac joint (SIJ) dysfunction can occur as a result of injury, degeneration, or inflammation. This dysfunction presents symptoms of pain at various locations, including the low back, hips, buttocks, and legs. The diagnosis of SIJ dysfunction is challenging and cannot be achieved solely with imaging studies such as X-rays, MRI, or CT. The current gold standard diagnostic modality is intra-articular SIJ blocks using two differing local anesthetics. Current treatments for SIJ dysfunction may be beneficial for short-term relief but lack long-term efficacy. The purpose of our study was to examine the outcomes of patients who underwent minimally invasive, posterior SIJ fusion using allograft at a single center.

METHODS

This was a retrospective study which received exemption from the WCG IRB. Data regarding preoperative and postoperative pain levels, surgical time, complications, and medication usage were obtained retrospectively from patient electronic medical records and prescription drug monitoring program reports. No mapping was completed prior to the procedure. Pain was assessed with the 11-point (0-10) Visual Analogue Scale (VAS) and medication usage was assessed using Morphine Milligram Equivalents (MME). Patients were included if they had been diagnosed with SIJ dysfunction using two intra-articular diagnostic blocks that resulted in at least an 80% decrease in pain and had failed conservative management. Patients with sacral insufficiency fractures were excluded.

RESULTS

VAS scores reduced from 8.26 (SD = 1.09) at baseline to 2.59 (SD = 2.57), 2.55 (SD = 2.56), 2.71 (SD = 2.88), and 2.71 (SD = 2.88) at 3, 6, 9, and 12 months, respectively. MME reduced from 78.21 mg (SD = 51.33) to 58.95 mg (SD = 48.64), 57.61 mg (SD = 47.92), 61.71 mg (SD = 45.64), and 66.29 mg (SD = 51.65) at 3, 6, 9, and 12 months, respectively. All reductions in VAS scores and MME were statistically significant. No adverse events occurred, and the average operating room time was 40.16 min (SD = 6.27).

CONCLUSION

Minimally invasive, posterior SIJ fusion using allograft is a safe and efficacious method for managing SIJ dysfunction.

Sacroiliac Joint: Function, Pathology, Treatment, and Contribution to Outcomes in Spine and Hip Surgery

➢ Low back pain has a lifetime incidence of up to 84% and represents the leading cause of disability in the United States; 10% to 38% of cases can be attributed to sacroiliac joint (SIJ) dysfunction as an important pain generator.➢ Physical examination of the SIJ, including >1 provocation test (due to their moderate sensitivity and specificity) and examination of adjacent joints (hip and lumbar spine) should be routinely performed in all patients presenting with low back, gluteal, and posterior hip pain.➢ Radiographic investigations including radiographs, computed tomography, and magnetic resonance imaging with protocols optimized for the visualization of the SIJs may facilitate the diagnosis of common pathologies.➢ Intra-articular injections with anesthetic can be helpful in localizing the source of low back pain. Over-the-counter analgesics, physiotherapy, intra-articular injections, radiofrequency ablation, and surgery are all management options and should be approached from the least invasive to the most invasive to minimize the risks of complications.➢ Lumbar fusion surgery predisposes patients to more rapid SIJ degeneration and can also result in more rapid degenerative changes in the hip joints, especially with SIJ fusion.➢ Hip surgery, including hip arthroplasty and preservation surgery, is not a risk factor for SIJ degeneration, although reduced outcomes following hip surgery can be seen in patients with degenerative SIJ changes.

Triangular titanium implants for sacroiliac joint fusion

BACKGROUND

The sacroiliac joint (SIJ) is a common source of chronic low back pain. Published cohorts have reported favorable outcomes after SIJ fusion. We report the 12-month follow-up from SIJ fusion of the so far largest single-center and single-surgeon group.

METHODS

Over 15,000 outpatients were evaluated for chronic low back and leg pain, of whom 3,477 underwent SIJ blocks. 541 patients were stringently selected to undergo SIJ fusion with triangular titanium implants (TTI). 483 patients had a follow-up of 12 months. Patients were seen every 3 months and completed visual analog scale (VAS) and Oswestry Disability Index (ODI) ratings.

RESULTS

Mean age of all patients was 61 years, and the majority (65%) were women. 44% had undergone prior lumbar fusion and 10% had a spinal cord stimulator (SCS) in place at the time of SIJ surgery. 26% underwent non-simultaneous bilateral SI joint fusion. At 12 months, the proportion of patients with clinically important improvements in pain (≥ 2 points) was very high (100%). The proportion with substantial improvement (≥ 4 points) was 98%. Similarly, improvement in ODI was high, with nearly 99% having an improvement of ≥ 15 points by month 12. The proportions of patients with VAS ≤ 2 or ODI ≤ 15 was also high (92.8% and 48.9%).

CONCLUSIONS

In our clinical practice, SIJ fusion with TTI produces significant improvement in pain and disability. The most important factor for achieving these clinical results may be the very stringent multistep selection of patients for surgery, which is described in detail, as well as the highly standardized and streamlined surgical procedure and the particular postoperative management.

Sacroiliac joint pain: what treatment and when

INTRODUCTION

Spinal and non-spinal pathologies can cause low back pain. Non-spinal sources of low back pain include the sacroiliac joint (SIJ) and the hip. SIJ pain can be treated either conservatively or surgically. Current strategies for managing sacroiliac joint pain are debated, and limited evidence exists.

AREAS COVERED

The present expert opinion updates current evidence on conservative and surgical modalities for SIJ pain.

EXPERT OPINION

Surgical management for SIJ pain is effective. However, it exposes patients to surgery and, therefore, related complications. Conservative management may be implemented in patients with moderate SIJ pain, with less than six months of symptoms, or not eligible for surgery. Several noninvasive modalities are available, mostly centered on intra-articular injections. Corticosteroids, platelet-rich plasma, and stem cells have only midterm lasting effects, at most for nine months. Radiofrequency ablation is another methodology for pain relief. Both continuous and pulsatile radiofrequency ablation are associated with good outcomes. SIJ fusion can be performed using different techniques; however, a clear recommendation on the most appropriate modality for the management of SIJ pain is still debated.

The Sacroiliac Joint Fusion Patient Population and Its Prevalence of Total Hip Arthroplasty

INTRODUCTION

The prevalence of sacroiliac joint (SIJ) pathology generating lower back pain is increasing, often requiring SI joint fusion in refractory cases. Similarly, total hip arthroplasty (THA) is an increasing procedure in the older growing population. Prior SIJ fusion in patients undergoing THA has increased hip dislocation. This study aims to determine the prevalence of preexisting THA in SIJ fusion patients at our institution.

METHODS

After institutional review board approval, we completed a retrospective review of consecutive SIJ fusion cases performed by fellowship-trained orthopaedic spine surgeons between October 2019 and June 2022. The senior surgeon reviewed pelvis radiographs to determine whether a THA was present. Patient demographics, surgical history, SIJ fusion date, and laterality information from study participants' medical records were collected and analyzed.

RESULTS

We screened 157 consecutive cases and excluded 45 not meeting the inclusion criteria. One hundred twelve radiographs were reviewed, with seven additional patients excluded. The final analysis consisted of 105 patients (33M:72F). The mean age was 50.4 ± 13.8 years, and the mean body mass index was 29.1 ± 6.1 kg/m 2 . SIJ fusion laterality included 51 right (48.6%), 44 left (41.9%), and 10 bilateral (9.5%). One patient (0.95%) had a preexisting right THA, and two patients (1.9%) underwent ipsilateral THA after SIJ fusion.

CONCLUSIONS

This study demonstrated a low prevalence (0.95%) of preexisting THA in SIJ fusion patients at our institution, similar to the THA prevalence of the total US population. Additional research is needed to determine the outcomes of patients with preexisting THA undergoing SIJ fusion.

Sacroiliac dysfunction and minimally invasive sacroiliac joint fusion

The sacroiliac joint (SIJ) is the largest diarthrodial joint in the human body and accounts for approximately 20% of all low back pain, which is commonly seen in patients with lumbosacral fusions. Despite this, SIJ dysfunction often poses a challenging diagnosis depending on clinical evaluation, imaging, and image-guided joint injection. SIJ fusion is an effective and safe method of treatment, with minimally invasive approaches fitting well within the armamentarium of interventional radiologists treating chronic pain and other musculoskeletal conditions. Contemporary technical approaches and clinical considerations are discussed.

Catamaran SI Joint Fusion System(R) MAINSAILTM Study: a prospective, single-arm, multi-center, post-market study of six-month clinical outcomes and twelve-month radiographic findings

BACKGROUND

Minimally invasive surgical techniques for sacroiliac joint (SIJ) fixation have the potential to reduce risk and improve patient outcomes, but evidence remains limited. This interim analysis presents initial findings from an ongoing prospective study evaluating the safety and efficacy of the Catamaran System.

METHODS

The primary endpoint of success at 6 months was defined as a ≥20 mm improvement in SIJ pain (Visual Analog Scale, VAS), no neurologic worsening, absence of device-related serious adverse events (SAEs), and no surgical reintervention. Secondary endpoints included 6 month evaluation of the Oswestry Disability Index (ODI), patient satisfaction, and 12 month radiographic CT fusion, performed by an indpendent radiologist.

RESULTS

Thirty-three consecutive patients (mean age: 58.9 years; %-females: 76%; Body Mass Index: 30.5) were treated across six U.S. clinical sites. At the primary endpoint of 6 months, 80% of patients met the criteria for success, with no device-related SAEs and no surgical reintervention reported. VASSIJ-Pain significantly decreased from preoperative levels (mean: 80.9 mm) to 6 months postoperatively (31.1 mm; p < 0.001). Mean ODI scores also showed a significant improvement from preoperative values (51.9%) to 6 months postoperatively (29.6%, p < 0.01). Patients reported high satisfaction rates throughout all follow-ups, with 93.3% of patients being satisfied at 6 months.

CONCLUSION

In patients diagnosed with chronic SIJ pain, minimally invasive inferior-posterior delivery of the Catamaran implant was safe and effective in relieving pain and reducing disability.

Randomized Trial of Augmented Pelvic Fixation in Patients Undergoing Thoracolumbar Fusion for Adult Spine Deformity: Initial Results from a Multicenter Randomized Trial

BACKGROUND

The optimal configuration for spinopelvic fixation during multilevel spine fusion surgery for adult spine deformity remains unclear. Postoperative sacroiliac (SI) joint pain, S2AI screw loosening and implant breakage could be related to continued motion of the SI joint with use of only a single point of fixation across the SI joint.

METHODS

Prospective, international, multicenter randomized controlled trial of 222 patients with adult spine deformity scheduled for multilevel (4 or more levels) spine fusion surgery with pelvic fixation. Subjects were randomized to sacroalar (S2) iliac (S2AI) screws alone for pelvic fixation or S2AI + triangular titanium implants placed cephalad to S2AI screws. Quad rod techniques were not allowed or used. Baseline spinal deformity measures were read by an independent radiologist. Site-reported perioperative adverse events were reviewed by a clinical events committee. Quality of life questionnaires and other clinical outcomes are in process with planned 2-year follow-up.

RESULTS

One hundred thirteen participants were assigned to S2AI and 109 to S2AI + titanium triangular implants (TTI). 35/222 (16%) of all subjects had a history of SI joint pain or were diagnosed with SI joint pain during preoperative workup. Three-month follow-up was available in all but 4 subjects. TTI placement was successful in 106 of 109 (98%) subjects assigned to TTI. In 2 cases, TTI could not be placed due to anatomical considerations. Three TTI ventral iliac breaches were observed, all of which were managed non-surgically. One TTI subject had a transverse sacral fracture and 1 TTI subject had malposition of the implant requiring removal.

CONCLUSIONS

SI joint pain is common in patients with adult spinal deformity who are candidates for multilevel spine fusion surgery. Concurrent placement of TTI parallel to S2AI screws during multilevel spine fusion surgery is feasible and safe. Further follow-up will help to determine the clinical value of this approach to augment pelvic fixation.

Patient-reported outcomes after minimally invasive sacro-iliac joint surgery: a cohort study based on the Swedish Spine Registry

BACKGROUND AND PURPOSE

There is conflicting evidence regarding treatment outcomes after minimally invasive sacroiliac joint fusion for long-lasting severe sacroiliac joint pain. The primary aim of our cohort study was to investigate change in patient-reported outcome measures (PROMs) after minimally invasive sacroiliac joint surgery in daily practice in the Swedish Spine Registry. Secondary aims were to explore the proportion of patients reaching a patient acceptable symptom score (PASS) and the minimal clinically important difference (MCID) for pain scores, physical function, and health-related quality of life outcomes; furthermore, to evaluate self-reported satisfaction, walking distance, and changes in proportions of patients on full sick leave/disability leave and report complications and reoperations.

METHODS

Data from the Swedish Spine Registry was collected for patients with first-time sacroiliac joint fusion, aged 21 to 70 years, with PROMs available preoperatively, at 1 or 2 years after last surgery. PROMs included Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for low back pain (LBP) and leg pain, and EQ-VAS, in addition to demographic variables. We calculated mean change from pre- to postoperative and the proportion of patients achieving MCID and PASS.

RESULTS

68 patients had available pre- and postoperative data, with a mean age of 45 years (range 25-70) and 59 (87%) were female. At follow-up the mean reduction was 2.3 NRS points (95% confidence interval [CI] 1.6-2.9; P < 0.001) for LBP and 14.8 points (CI 10.6-18.9; P < 0.001) for ODI. EQ-VAS improved by 22 points (CI 15.4-30.3, P < 0.001) at follow-up. Approximately half of the patients achieved MCID and PASS for pain (MCID NRS LBP: 38/65 [59%] and PASS NRS LBP: 32/66 [49%]) and physical function (MCID ODI: 27/67 [40%] and PASS ODI: 24/67 [36%]). The odds for increasing the patient's walking distance to over 1 km at follow-up were 3.5 (CI 1.8-7.0; P < 0.0001), and of getting off full sick leave or full disability leave was 0.57 (CI 0.4-0.8; P = 0.001). In the first 3 months after surgery 3 complications were reported, and in the follow-up period 2 reoperations.

CONCLUSION

We found moderate treatment outcomes after minimally invasive sacroiliac joint fusion when applied in daily practice with moderate pain relief and small improvements in physical function.

Navigated Simultaneous Lateral Minimally Invasive Tubular and Posterior Mini-Open Access for Removal and Revision of Triangular Sacroiliac Joint Implants: A Technical Note

BACKGROUND

Sacroiliac joint (SIJ) fusion, to treat back pain caused by SIJ dysfunction, can employ open or minimally invasive surgery (MIS) techniques and either cylindrical (screw-shaped) or triangular (wedge-shaped) implants. Fusion nonunion sometimes explains recurrent SIJ pain following fusion and occasionally requires hardware revision. MIS revision minimizes patient pain, infection, and disability, but due to the triangular implant size and form factor, implant removal can present challenges for MIS access during the explantation and achieving good bony purchase for reinstrumentation. Here, we report a prone single-position lateral MIS/posterior mini-open procedure for triangular-implant SIJ fusion revision.

METHODS

The patient is a 72-year-old female who underwent right SIJ fusion for lower back and leg pain sustained after a fall 2 years prior but experienced recurrent pain over the subsequent 2 years, with imaging findings of right SIJ peri-hardware lucencies and diagnostic injections confirming persistent right-sided sacroiliitis.

RESULTS

The patient underwent hardware removal using the lateral MIS incision with table-mounted tubular access and image-guided navigation to maintain exposure, plus simultaneous reinstrumentation using a navigated S2-alar-iliac screw and iliac bolt construct with connecting rod through the posterior mini-open incision made for the navigation reference frame spinous process clamp.

CONCLUSIONS

The use of navigation and MIS access can significantly decrease the complexity of lateral hardware removal, and mini-open navigated screw-and-rod constructs offer reinstrumentation options accessible to surgeons unfamiliar with specialized posterior SIJ systems.

Effects of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

BACKGROUND CONTEXT

Obesity is increasing. Previous studies have demonstrated an association between obesity and adverse events after lumbar fusion. There is limited evidence on the effect of obesity on minimally invasive SI joint fusion (SIJF) outcomes.

PURPOSE

The purpose of this study was to investigate the impact of obesity on patient-reported outcomes in patients undergoing SIJF surgery using triangular titanium implants (TTI).

STUDY DESIGN

Retrospective cohort study based on four prospective clinical trials (INSITE [NCT01681004], SIFI [NCT01640353], iMIA [NCT01741025], and SALLY [NCT03122899]).

PATIENT SAMPLE

Adult patients ≥18 years of age who underwent minimally invasive surgery (MIS) sacroiliac joint (SIJ) fusion between 2012 and 2021.

OUTCOME MEASURES

Visual analog scale (VAS Pain), Oswestry Disability Index (ODI).

METHODS

Participants were classified using the National Institutes of Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects underwent either minimally invasive SIJ fusion with TTI or nonsurgical management (INSITE and iMIA studies only). All subjects completed SIJ pain scale scores (measured with a 100-point VAS) and disability scores (measured with ODI) at baseline and at scheduled visits to 24 months. Repeated measures analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

In the SIJF group, mean SIJ pain improved at 24 months by 53.3 points (p<.0001). Over the 24-month follow-up period, BMI category did not impact mean improvement in SIJ pain scale score (repeated measures analysis of variance (ANOVA) p=.44). In the SIJF group, mean ODI at 24 months improved by 25.8 points (p<.0001). BMI category did not impact mean improvement in ODI (ANOVA p=.60). In the nonsurgical management (NSM) group, mean improvements in SIJ pain scale and ODI were clinically small (8.7 and 5.2 points, respectively) and not affected by BMI category (ANOVA p=.49 and .40).

CONCLUSION

This study demonstrates similar benefits and risks of minimally invasive SIJ fusion with TTI across all BMI categories. This analysis suggests that obese patients benefit from minimally invasive SIJ fusion and should not be denied this procedure based solely on elevated BMI.

Interventional treatments for low back pain due to sacroiliac joint dysfunction: a systematic review of the literature

PURPOSE

This systematic review aimed to report the current evidence in the literature about the efficacy of interventional treatments in the management of low back pain (LBP) due to sacroiliac joint dysfunction.

METHODS

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Medline, EMBASE, Scopus, CINAHL, Cochrane Library, and CENTRAL bibliographic databases were searched. The search was performed from October to December 2021, and articles from the inception of the database to December 2021 were searched.

RESULTS

Fourteen studies were included for qualitative synthesis. Five studies used the traditional radiofrequency approach (tRF), five studies used cooled radiofrequency approach (cRF), one study used botulinum toxin (BT), two studies used steroid injection, triamcinolone (TA) and local anesthetics injections, and one study used pulsed radiofrequency (PRF) denervation. Two studies used sham as a comparator.

CONCLUSIONS

Cooled radiofrequency seems to be the most effective treatment in improving pain and functionality, while intra-articular injections are helpful only as diagnostic tools. However, due to the lack of high-quality studies, it was not possible to draw significant conclusions.

Intraoperative fat embolism syndrome associated with implantation of titanium sacroiliac joint fusion implants: a report of two cases

Background

For patients undergoing long-construct fusion surgeries, simultaneous sacroiliac joint (SIJ) fusion is a growing trend in spine surgery. Some options for posterior SIJ fusion include 3D-printed triangular titanium implants or self-harvesting SIJ screws. Both implants require fixation within the sacrum and ileum. Fat embolism syndrome is a rare but known complication of lumbar pedicle instrumentation but has never been reported in association with SIJ fusion, regardless of implant type. We report the first two known cases of fat embolism associated with placement of SIJ fusion devices during long construct posterior spine fusion.

Case Description

Case 1-a 50-year-old female with multiple previous spine surgeries complicated by osteomyelitis/diskitis that was successfully eradicated, underwent T10-pelvis posterior spinal fusion (PSF), L4 pedicle-subtracting-osteotomy, and bilateral SIJ fusion. During implantation of each SIJ fusion device, the patient's hemodynamic status deteriorated necessitating vasopressor support, intravenous fluid bolus, and hyperventilation, but quickly resolved. The case was completed without further issue, and she had an uneventful post-operative course. Case 2-a 71-year-old female with a past medical history of ankylosing spondylitis, previous L2-L5 PSF, rheumatoid arthritis on chronic steroids, underwent a T9-pelvis PSF, bilateral SIJ fusion, L4 pedicle subtraction osteotomy, T10-L1 Smith Peterson osteotomies. After implantation of the second SIJ fusion device, she became hypotensive and tachycardic, pulses were absent, and cardiopulmonary resuscitation was initiated. Pulses returned quickly, the index surgery was terminated, and she was transferred to the intensive care unit (ICU). In the ICU she was quickly weaned off the ventilator on post-operative day 1. On post-operative day 4, the patient returned to the operating room for completion of the surgery and had an extended, but uneventful, recovery afterwards.

Conclusions

We report on the first two known cases of fat embolism syndrome occurring immediately after implantation of SIJ fusion devices. Spine surgeons should be aware of this rare, but potentially fatal, complication. Collaboration with the anesthesia team and optimization of the patient's hemodynamic status prior to implantation may help prevent catastrophic complications.

Patient-Reported Outcomes and Computed Tomography Review After Minimally Invasive Fusion of the Sacroiliac Joint With Aggressive Joint Decortication and Joint Compression

The sacroiliac joint (SIJ) is a common, underrecognized source of low back pain. We evaluated outcomes in patients undergoing sacroiliac joint fusion (SIJF) using a novel, minimally invasive SIJF system emphasizing compressive forces across an aggressively debrided SIJ. We retrospectively reviewed data from a continuous set of patients presenting to a large, tertiary care hospital from September 2017 to August 2019. All patients received the novel SIJF device. Outcomes were assessed at 8 weeks, 6 months, and 12 months using the Oswestry Disability Index (ODI) score, Numerical Rating Scale (NRS) score, Single Assessment Numerical Evaluation (SANE) score, and Patient-Reported Outcomes Measurement Information System (PROMIS) measures, plus radiographic evaluation of fusion status. Data from 75 patients were analyzed. At 8 weeks, 6 months, and 12 months, the ODI score improved by 10.5 points (P=.002), 17.4 points (P<.0001), and 23.6 points (P<.0001), respectively, while the NRS score improved by 4.6 points (P<.0001), 4.4 points (P<.0001), and 4.6 points (P<.0001), respectively. SANE scores indicated high levels of patient satisfaction (81.0%, 92.18%, and 89.2%, respectively). PROMIS physical function scores improved by 2.65 points, 3.30 points, and 3.63 points, respectively, while PROMIS mental health scores showed changes of -1.93 points, 1.57 points, and -0.47 points, respectively. A review of computed tomography scans demonstrated grade 3 fusion (complete) in 81% of cases at a mean of 371 days postoperatively. There was one revision case for a malpositioned implant. The use of a novel SIJF device emphasizing compressive forces provided early, durable improvements in patient-reported outcomes and extremely high patient satisfaction. [Orthopedics. 2024;47(2):101-107.].

Return to Duty in Military Service Members Following Minimally Invasive Sacroiliac Joint Fusion

INTRODUCTION

As the utilization of minimally invasive sacroiliac joint fusion (SIJF) continues to expand, a better understanding of postoperative outcomes is needed, particularly in young and active individuals. The purpose of this study is to assess the outcomes of this procedure in an active duty military population by examining return-to-duty (RTD) rates.

MATERIALS AND METHODS

A retrospective review of the electronic medical record from a tertiary military medical center was performed for active duty service members undergoing SIJF from January 2013 to January 2019. The primary outcome measured was RTD at 6 months, with active duty status at 1 year, last follow-up, and revision surgery as secondary outcomes. Demographic and surgical variables recorded included patient age, gender, military rank, utilization of navigation, and implant type.

RESULTS

Sixteen service members met the inclusion criteria, with a mean age of 40.5 ± 6.7 years. The mean follow-up after surgery was 24 ± 15 months. Patients received either cylindrical (n = 6) or triangular (n = 10) implants placed with (n = 6) or without (n = 10) navigation. Within 6 months of surgery, 56% of patients were able to RTD. Patients undergoing navigation-assisted procedures were significantly more likely to RTD at 6 months (100% vs. 30%, P = .011) compared to those undergoing surgery performed with orthogonal fluoroscopic imaging. Compared to those with cylindrical implants, patients with triangular implants were also more likely to RTD at 6 months (80% vs. 17%, P = .035).

CONCLUSIONS

Following SIJF, a small majority of service members were able to return to full active duty status by 6 months. Further studies are needed to assess the potential benefits of navigation and implant selection, as our retrospective review noted differences in outcomes based on these variables.

Treatment of an Impending Pathologic Sacral Fracture with a Novel Iliosacral Fusion Construct: A Case Report

CASE

A 49-year-old woman presented with left leg radiculopathy and posterior pelvic pain. Subsequent evaluation demonstrated metastatic multiple myeloma with an impending left S1 sacral fracture. Immediate posterior pelvic ring stabilization was recommended to prevent fracture and disruption of her oncologic recovery. This was performed percutaneously with computer-assisted navigation using a novel cannulated screw design.

CONCLUSION

The patient was treated with prophylactic percutaneous posterior pelvic ring fixation with a novel cannulated screw design that provided a durable construct for immediate weight-bearing. The fixation prevented a pathologic fracture and allowed immediate return to activity.

Minimally invasive sacroiliac joint fusion using triangular titanium implants versus nonsurgical management for sacroiliac joint dysfunction: a systematic review and meta-analysis

BACKGROUND

Minimally invasive sacroiliac joint (MISIJ) fusion is a surgical option to relieve SIJ pain. The aim of this systematic review and meta-analysis was to compare MISIJ fusion with triangular titanium implants (TTI) to nonoperative management of SIJ dysfunction.

METHODS

We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. We included prospective clinical trials that compared MISIJ fusion to nonoperative management in individuals with chronic low back pain attributed to SIJ dysfunction. We evaluated pain on visual analogue scale, Oswestry Disability Index (ODI) score, health-related quality of life (HRQoL) using the 36-Item Short Form Health Survey (SF-36) physical component (PCS) and mental component summary (MCS) scores, patient satisfaction, and adverse events.

RESULTS

A total of 8 articles representing 3 trials that enrolled 423 participants were deemed eligible. There was a significant reduction in pain score with MISIJ fusion compared with nonoperative management (standardized mean difference [SMD] -1.71, 95% confidence interval [CI] -2.03 to -1.39). Similarly, ODI scores (SMD -1.03, 95% CI -1.24 to -0.81), SF-36 PCS scores (SMD 1.01, 95% CI 0.83 to 1.19), SF-36 MCS scores (SMD 0.72, 95% CI 0.54 to 0.9), and patient satisfaction (odds ratio 6.87, 95% CI 3.73 to 12.64) were significantly improved with MISIJ fusion. No significant difference was found between the 2 groups with respect to adverse events (SMD -0.03, 95% CI -0.28 to 0.23).

CONCLUSION

Our analysis showed that MISIJ fusion with TTI shows a clinically important and statistically significant improvement in pain, disability score, HRQoL, and patient satisfaction with a similar adverse event profile to nonoperative management in patients with chronic low back pain attributed to SIJ dysfunction.

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

Contemporary Trends in Minimally Invasive Sacroiliac Joint Fusion Utilization in the Medicare Population by Specialty

BACKGROUND AND OBJECTIVES

Sacroiliac (SI) joint dysfunction constitutes a leading cause of pain and disability. Although surgical arthrodesis is traditionally performed under open approaches, the past decade has seen a rise in minimally invasive surgical (MIS) techniques and new federally approved devices for MIS approaches. In addition to neurosurgeons and orthopedic surgeons, proceduralists from nonsurgical specialties are performing MIS procedures for SI pathology. Here, we analyze trends in SI joint fusions performed by different provider groups, along with trends in the charges billed and reimbursement provided by Medicare.

METHODS

We review yearly Physician/Supplier Procedure Summary data from 2015 to 2020 from the Centers for Medicare and Medicaid Services for all SI joint fusions. Patients were stratified as undergoing MIS or open procedures. Utilization was adjusted per million Medicare beneficiaries and weighted averages for charges and reimbursements were calculated, controlling for inflation. Reimbursement-to-charge (RCR) ratios were calculated, reflecting the proportion of provider billed amounts reimbursed by Medicare.

RESULTS

A total of 12 978 SI joint fusion procedures were performed, with the majority (76.5%) being MIS procedures. Most MIS procedures were performed by nonsurgical specialists (52.1%) while most open fusions were performed by spine surgeons (71%). Rapid growth in MIS procedures was noted for all specialty categories, along with an increased number of procedures offered in the outpatient setting and ambulatory surgical centers. The overall RCR increased over time and was ultimately similar between spine surgeons (RCR = 0.26) and nonsurgeon specialists (RCR = 0.27) performing MIS procedures.

CONCLUSION

Substantial growth in MIS procedures for SI pathology has occurred in recent years in the Medicare population. This growth can largely be attributed to adoption by nonsurgical specialists, whose reimbursement and RCR increased for MIS procedures. Future studies are warranted to better understand the impact of these trends on patient outcomes and costs.

Initial Validation of a Sacroiliac Joint-Specific Disability Questionnaire

Low back pain is a multidimensional disorder that can originate from a variety of pain generators, including the sacroiliac (SI) joint. Although the Oswestry Disability Index (ODI) is often used in SI joint treatment studies, the effects of the SI joint on functional disability are likely different from those of other low back pain generators. Thus, we developed the Denver SI Joint Questionnaire (DSIJQ) and performed validation testing in patients (n=24) with SI joint-specific pain at baseline, +2 weeks, and +6 months. Psychometric analyses included test-retest reliability, internal consistency, content validity, convergent criterion validity, divergent criterion validity, and responsiveness. The DSIJQ showed good test-retest reliability (intraclass correlation coefficient=0.87), internal consistency (Cronbach's alpha=0.842), content validity (<30% floor/ceiling effects), convergent criterion validity (r=0.89; P<.001), and divergent criterion validity (r=-0.33; P=.12). The DSIJQ was correlated with performance on two physical function tests: Timed Upand-Go (r=0.53; P=.008) and 5 Minute Walk (r=-0.52; P=.009). The DSIJQ showed better responsiveness than the ODI (standardized response mean and effect size, 1.14 and 1.45 for DSIJQ and 0.75 and 0.81 for ODI). Overall, the DSIJQ performed well on all psychometrics. Importantly, we validated the DSIJQ with patients' ability to complete two tests of physical functioning. Moreover, the DSIJQ was more sensitive to changes in SI joint disability than the ODI. These psychometrics suggest the DSIJQ is appropriate for evaluating SI joint disability and detecting changes in disability after targeted SI joint treatment. [Orthopedics. 2023;46(6):345-351.].

Biomechanics of sacroiliac joint fixation using lag screws: a cadaveric study

BACKGROUND

Iliosacral screw placement is ubiquitous and now part of the surgeon's pelvic trauma armamentarium. More recent evidence supports sacroiliac arthrodesis for treating sacroiliac joint (SIJ) dysfunction in select patients. Regardless of the surgical indication, there are currently no studies examining lag screw compression biomechanics across the SIJ. The objective of this biomechanical investigation was to quantify iliosacral implant compressive loads and to examine the insertion torque and compressive load profile over time.

METHODS

Eight human cadaveric pelvic specimens underwent SIJ fixation at S1 and S2 using 11.5 and 10.0 mm iFuse-TORQ Lag implants, respectively, and standard 7.3 mm trauma lag screws. Load decay analysis was performed, and insertion and removal torques were measured.

RESULTS

For both implants at S1 and S2 levels, the load relaxed 50% in approximately 67 min. Compressive load decay was approximately 70% on average occurring approximately 15 h post-insertion. Average insertion torque for the 11.5 mm TORQ implant at S1 was significantly greater than the trauma lag screw. Similarly, at S2, insertion torque of the 10.0 mm TORQ implant was greater than the trauma lag screw. At S1, removal torque for the 11.5 mm TORQ implant was higher than the trauma lag screw; there was no significant difference in the removal torque at S2.

CONCLUSIONS

In this study, we found that a novel posterior pelvic implant with a larger diameter, roughened surface, and dual pitch threads achieved improved insertion and removal torques compared to a standard screw. Load relaxation characteristics were similar between all implants.

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.

Posterior oblique technique for sacroiliac joint fusion leads to greater pain relief and similar improvement in function compared to the lateral technique: A retrospective, comparative study

BACKGROUND

Management of chronic sacroiliac joint (SIJ) pain among patients who do not respond to nonsurgical treatment is increasingly turning toward minimally invasive SIJ fusion. There are different techniques available to perform this procedure, with the lateral technique being more commonly studied than the posterior oblique technique. This study examined the effects of these techniques on pain relief and functional improvement, both preoperatively and at a 12-month follow-up.

METHODS

This retrospective cohort study analyzed data from 45 patients who underwent SIJ fusion. Included patients were ≥50 years old, nonresponsive to conservative treatment. Subjects were divided into 2 cohorts based on the SIJ fusion technique. Primary outcomes were pain relief, measured by Visual Analog Scale (VAS), and functional improvement, determined by the Oswestry Disability Index (ODI); both were recorded and assessed at baseline, postoperative, and the change from pre- to postoperative. Additionally, data regarding patient demographics, previous lumbar fusion, operative time, and duration of hospital stay were collected and analyzed.

RESULTS

Baseline demographic and clinical variables exhibited no significant differences in distribution between groups. The posterior oblique cohort demonstrated a substantial reduction in operative time (over 50%) and duration of hospital stay compared to lateral cohort. Pain relief (postoperative VAS: lateral 3.5±1.7 vs. posterior oblique 2.4±1.5 [p=.02]) and functional improvement (postoperative ODI: lateral 29.6±7.3 vs. posterior oblique 21±5.7 [p≤.001]) were significantly better in the posterior oblique group. Pre- to postoperative improvement analysis indicated greater reduction in pain (VAS: lateral -4.4±1.9 vs. posterior oblique -6.1±1.5 [p=.002]) in the posterior oblique group.

CONCLUSIONS

Compared to the lateral technique group, patients undergoing minimally invasive SIJ fusion through the posterior oblique technique experienced greater pain relief and demonstrated a trend toward better functional improvement, with shorter operative times and duration of hospital stay. The posterior oblique technique may be more efficient and beneficial to manage patients suffering from chronic SIJ pain through joint fusion.

Comparative Efficacy of Clinical Interventions for Sacroiliac Joint Pain: Systematic Review and Network Meta-analysis With Preliminary Design of Treatment Algorithm

OBJECTIVE

We aimed to identify the most effective clinical treatment method for sacroiliac joint (SIJ)-related pain based on the systematic review and network meta-analysis (NMA) to evaluate the comparative efficacy of clinical interventions for sacroiliac joint pain by pooling the randomized controlled trials (RCTs).

METHODS

Our team conducted a systematic review and NMA of RCTs to determine the most effective clinical treatment for SIJ-related pain. We searched the PubMed (MEDLINE), Web of Science, Cochrane Library, and Scopus databases for RCTs until February 2023. The PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines were followed. Pairwise and network meta-analyses were conducted using a random effects model.

RESULTS

Based on the search strategy and inclusion criteria, our systematic review and NMA included 9 randomized studies with 652 participants. Research has mainly focused on various radiofrequency sources, but their number is still low. In the network analysis, according to the NMA and mean ranking probabilities for the improvement of pain intensity (PI) and quality of life (QoL), sacroiliac joint fusion and cooled radiofrequency were associated with high treatment rank for improving PI and QoL in patients with sacroiliac joint pain.

CONCLUSION

This NMA suggest that SIJ fusion and cooled radiofrequency could be potential options for improving the QoL and relieving pain in patients with SIJ-related pain. Comparison studies of outcomes between these 2 procedures with solid methodology and a low risk of bias would be very beneficial to identify the optimal treatment option for this challenging disease.

Medicare Reimbursement Rates and Utilization Trends in Sacroiliac Joint Fusion

INTRODUCTION

Sacroiliac joint (SIJ) fusion is a surgical treatment option for SIJ pathology in select patients who have failed conservative management. More recently, minimally invasive surgical (MIS) techniques have been developed. This study aimed to determine the trends in procedure volume and reimbursement rates for SIJ fusion.

METHODS

Publicly available Medicare databases were assessed using the National Summary Data Files for 2010 to 2020. Files were organized according to current procedural terminology (CPT) codes. CPT codes specific to open and MIS SI joint fusion (27279 and 27280) were identified and tracked. To track surgeon reimbursements, the CMS Medicare Physician Fee Schedule Look-Up Tool was used to extract facility prices. Descriptive statistics and linear regression were used to evaluate trends in procedure volume, utilization, and reimbursement rates. Compound annual growth rates were calculated, and discrepancies in inflation were corrected for using the Consumer Price Index.

RESULTS

A total of 33,963 SIJ fusions were conducted in the Medicare population between 2010 and 2020, with an overall increase in procedure volume of 2,350.9% from 318 cases in 2010 to 7,794 in 2020. Since the introduction of the 27279 CPT code in 2015, 8,806 cases (31.5%) have been open and 19,120 (68.5%) have been MIS. Surgeon reimbursement for open fusions increased nominally by 42.8% (inflation-adjusted increase of 20%) from $998 in 2010 to $1,425 in 2020. Meanwhile, reimbursement for MIS fusion experienced a nominal increase of 58.4% (inflation-adjusted increase of 44.9%) from $582 in 2015 to $922 in 2020.

CONCLUSION

SIJ fusion volume in the Medicare population has increased substantially in the past 10 years, with MIS SIJ fusion accounting for most of the procedures since the introduction of the 27279 CPT code in 2015. Reimbursement rates for surgeons have also increased for both open and MIS procedures, even after adjusting for inflation.

Halo Formation and Resolution at 7-Year Follow-Up After Sacroiliac Joint Fusion Revision: A Case Report

CASE

A 49-year-old woman presented with low back pain after a work-related injury. She failed 5 months of conservative management and subsequently underwent minimally invasive (MI) left sacroiliac joint (SIJ) fusion with 3 triangular titanium implants. Four months postoperatively, she developed recurrence of symptoms and radiographic halo phenomenon about the implants. The cephalad and caudal implants were replaced with threaded self-tapping implants, and the middle implant was unable to be removed. At 7-year follow-up, the halo phenomenon had resolved.

CONCLUSION

This is an unusual case of radiographic halo phenomenon formation after MI SIJ fusion and halo resolution after subsequent revision.

The "In-Parallel" Technique for Awake, Bilateral Simultaneous Minimally Invasive Transforaminal Lumbar Interbody Fusion and Multilevel Lumbar Decompression

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and MIS lumbar decompression have been successfully undertaken in the absence of general anesthesia in well-selected patients. By leveraging spinal anesthesia, surgeons may safely conduct surgeries on one- or two-level lumbar pathology. However, surgeries on more extensive pathology have not yet been described, because of concerns about the duration of efficacy of spinal anesthetic in the awake patient.

OBJECTIVE

To report the use of a novel awake technique for "in parallel," simultaneous lumbar spinal surgery on three-segment pathology.

METHODS

We describe concurrent performance of a dual microscopic, navigated MIS TLIF and MIS two-level decompression, using a combination of liposomal bupivacaine erector spinae block in conjunction with a spinal anesthetic.

RESULTS

We show that a left-sided, two-level MIS tubular microscopic decompression combined with a concurrent right-sided, transfacet MIS TLIF via a tubular microscopic approach was well tolerated in an 87-year-old patient with multilevel lumbar stenosis with a mobile spondylolisthesis.

CONCLUSION

We provide the first description of a dual-surgeon approach for minimally invasive spine surgery. This "in-parallel" technique-reliant on 2, independent spine surgeons-may aid in the performance of surgeries previously considered too extensive, given the time constraints of regional anesthesia and can be successfully applied to patients who otherwise may not be candidates for general anesthesia.

Ethnic Differences in Western and Asian Sacroiliac Joint Anatomy for Surgical Planning of Minimally Invasive Sacroiliac Joint Fusion

Pain originating in the sacroiliac joint (SIJ) is a contributor to chronic lower back pain. Studies on minimally invasive SIJ fusion for chronic pain have been performed in Western populations. Given the shorter stature of Asian populations compared with Western populations, questions can be raised regarding the suitability of the procedure in Asian patients. This study investigated the differences in 12 measurements of sacral and SIJ anatomy between two ethnic populations by analyzing computed tomography scans of 86 patients with SIJ pain. Univariate linear regression was performed to evaluate the correlations of body height with sacral and SIJ measurements. Multivariate regression analysis was used to evaluate systematic differences across populations. Most sacral and SIJ measurements were moderately correlated with body height. The anterior-posterior thickness of the sacral ala at the level of the S1 body was significantly smaller in the Asian patients compared with the Western patients. Most measurements were above standard surgical thresholds for safe transiliac placement of devices (1026 of 1032, 99.4%); all the measurements below these surgical thresholds were found in the anterior-posterior distance of the sacral ala at the S2 foramen level. Overall, safe placement of implants was allowed in 84 of 86 (97.7%) patients. Sacral and SIJ anatomy relevant to transiliac device placement is variable and correlates moderately with body height, and the cross-ethnic variations are not significant. Our findings raise a few concerns regarding sacral and SIJ anatomy variation that would prevent safe placement of fusion implants in Asian patients. However, considering the observed S2-related anatomic variation that could affect placement strategy, sacral and SIJ anatomy should still be preoperatively evaluated.

Posterior Oblique Approach for Sacroiliac Joint Fusion

Introduction Sacroiliac joint (SIJ) pain is a common source of low back pain. Though this condition can be treated with conservative measures, there is a subset of patients who fail to respond to conservative treatment. For them, surgical treatment using minimally invasive techniques could be considered. There are currently a number of SIJ fixation methods described. However, there is no case series reported on posterior oblique approach. Therefore, in this paper, the authors report their experience with the Sacrix system via the posterior oblique approach. Method In this series, 19 patients aged 44-84 years, with a median of 58 years, underwent SIJ fusion using this technique. This is a posterior oblique approach in which two screws are inserted into the ilium through the posterior part of the iliac crest and then advanced into the sacrum through the SIJ. Results The follow-up is between 7 and 30 months, with a median of 12 months. Eighteen patients had excellent pain relief. There was no complication from the procedure, and the blood loss was minimal. All eight patients who had follow-up radiographs showed solid fusion. Conclusion Posterior oblique approach for SIJ fusion is a minimally invasive procedure that proved to be effective and safe in this series. It also resulted in solid radiographic fusion, decreased pain, and improved function.

Double-center observational study of minimally invasive sacroiliac joint fusion for sacroiliac joint dysfunction: one-year results

BACKGROUND

For a substantial part of patients with chronic low back pain, the origin is located in the sacroiliac joint (SIJ). Minimally invasive sacroiliac joint fusion (MISJF) is increasingly being implemented as a treatment option in SIJ dysfunction. Despite remaining controversy, evidence continues to increase. This study evaluates the clinical results and safety of MISJF in a double-center consecutive case series in patients with SIJ dysfunction over a one-year observation period.

METHODS

SIJ complaints were diagnosed after history taking, physical examination and least a 50% reduction of SIJ pain 30-60 min following image-guided injection. Primary outcome measures were patient reported outcome measurements (PROMs), consisting of Visual Analogue Scale (VAS) pain score and EuroQol 5-dimensions 3-levels (EQ-5D-3L). Patients' perspectives on the effects of surgery were collected through questionnaires. Secondary outcome measures were implant positioning and (serious) adverse events ((S)AE's).

RESULTS

A total of 29 patients were included. In 44.8% of patients, SIJ dysfunction was of postpartum origin. The mean VAS-pain score improved from 7.83 (± 1.71) to 4.97 (± 2.63) postoperatively (p < 0.001). EQ-5D-3L score improved from 0.266 (± 0.129) to 0.499 (± 0.260) postoperatively (p < 0.001). Opioid consumption decreased from 44.8 to 24.1% postoperatively (p = 0.026). In 13.7% of patients, an (S)AE occurred.

CONCLUSION

MISJF appears to be an effective and safe procedure in this cohort. Statistically significant and clinically relevant improvements in pain and quality of life were observed one-year postoperatively. Future studies should focus on the long-term outcomes to further evaluate the safety and effectiveness of MISJF.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain

Introduction

Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety.

Objective

The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders.

Methods

The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented.

Results

After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain.

Conclusion

The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Sacroiliac Joint Fusion: Fusion Rates and Clinical Improvement Using Minimally Invasive Approach and Intraoperative Navigation and Robotic Guidance

STUDY DESIGN

This study adopted a retrospective study design.

PURPOSE

This study was designed to describe the fusion rate and technique and patient subjective improvement after sacroiliac (SI) joint fusion using a minimally invasive surgical (MIS) approach.

OVERVIEW OF LITERATURE

The SI joint can mimic radicular or discogenic pain localized to the lower back, gluteal region, or sacral region, posing a challenge in the diagnosis and treatment. This study determines the radiological fusion rate and patient reported subjective clinical outcomes of SI joint fusion using an MIS approach, comparing the use of the Rialto SI joint fusion system (Medtronic, Minneapolis, MN, USA) with the help of the Stealth Navigation System with the use of ExcelsiusGPS Robotic Navigation Platform (Globus Medical Inc., Audubon, PA, USA) using SI-LOK screws (Globus Medical Inc.).

METHODS

In this retrospective study, 43 consecutive patients who underwent SI joint fusion between August 2017 and February 2020 were enrolled; 60 SI joints were fused. The patients' fusion was documented on computed tomography or X-rays, and Visual Analog Scale (VAS) scores were used to determine patient subjective clinical outcomes.

RESULTS

A total of 60 joints were fused, including 26 joints fused using robotic guidance and 34 joints fused using the Stealth Navigation System. Student t-test was used to compare the mean preoperative VAS score (7.52±1.3) with the mean postoperative VAS score at the 12-month follow-up (1.43±1.22) (p<0.05). The SI joint fusion rate using this technique was 61% at 6 months, 96.4% at 12 months, and 100% at 18 months.

CONCLUSIONS

The use of navigation guidance or robotic assistance enables accurate percutaneous screw placement across the SI joint. The use of bone morphogenetic protein in the screw bore hastens fusion across the joint, improving patient-perceived pain.

Minimally invasive sacroiliac fusion, a case series, and a literature review

INTRODUCTION

Non-autoimmune sacroiliac joint pain contributes to nearly a quarter of low back pain patients. Non-surgical management fails to satisfy patients. A new minimally invasive technique for sacroiliac stabilization has been introduced, defying the traditional rules of fusion. The results outside explanatory trials and in day-to-day practice have not been reported.

MATERIALS AND METHODS

This case series includes 20 patients diagnosed with chronic sacroiliac pain resistant to conservative management for at least 6 months. The diagnosis was confirmed with a positive sacroiliac injection. Patients underwent stabilization using the iFuse^® implant. Patients were followed up for a minimum of one year. The primary outcome was the functional outcomes, assessed using VAS, ODI, and SF36. Secondary procedure rates, complication rates, and radiological assessments of fusion were collected as secondary outcomes.

RESULTS

At one year, the mean VAS score improved from 81.25 ± 10.7 SD preoperatively to 52.5 ± 26.8, p-value 0.0013. The mean ODI improved from 54.8 ± 11.21 SD preoperatively to 41.315 ± 15.34, P value = 0.0079. The mean PCS and MCS of SF36 improved by 17 and 20 points, respectively. Only 55% of patients achieved the MCID for the VAS score. 35% of the cohort had secondary procedures.

DISCUSSION

Minimally invasive sacroiliac fusion resulted in an improvement in mean functional scores with a wide dispersion. Patients not achieving MCID are patients with either a malpositioned implant, an associated lumbar pathology, or an inaccurate diagnosis. Our results are underwhelming compared to similar work but are still better than conservative cohorts in comparative studies.

CONCLUSION

Minimally invasive sacroiliac fusion can be used successfully in select patients. Attention to diagnosis and surgical technique can improve the reproducibility of results.

The efficacy of primary sacroiliac joint fusion for low back pain caused by sacroiliac joint pathology: a systematic review and meta-analysis

PURPOSE

Conduct a systematic review to quantify the effect of primary sacroiliac joint fusion (SIJF) for the treatment of sacroiliac (SI) joint pathology on patient reported outcomes.

METHODS

Medline, Embase, Cochrane, PubMed, and Scopus databases were searched prior to August 18th, 2020 for all English-Language studies involving the treatment of SIJ pathology through SIJF and/or conservative management (CM). The quality of included studies was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Primary outcome measure was the Visual Analogue Scale (VAS) for low back pain. Secondary outcome measure was the Oswestry Disability Index (ODI) and the incidence of adverse reactions.

RESULTS

A total of 564 patients and six studies were included. The overall quality of evidence analyzed by this review was low (GRADE = 0). Five out of the six studies were industry funded. The VAS standardized mean difference (SMD) between SIJF and CM at three months and six months follow-up was - 1.4 [95% confidence interval - 2.3, - 0.6] and - 1.5 [95% CI - 1.8, - 1.1]. The ODI SMD between SIJF and CM scores at three months and 6 months follow-up was - 0.9 [95% CI - 1.1, - 0.7] and - 1.1 [95% CI - 1.6, - 0.5]. The odds ratio of adverse reactions due to SIJF compared to CM was 1.9 [95% CI 0.1, 42.8].

CONCLUSION

Based on the limited number of independent trials with long-term follow-up, SIJF shows potential as a surgical treatment option for SIJ pathology.

PROSPERO REGISTRATION

CRD42020206149 (25th September 2020).

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.