Percutaneous sacroiliac joint arthrodesis: a novel technique

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.

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.

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.

Minimally invasive sacroiliac joint fusion for chronic sacroiliac joint pain: a systematic review

BACKGROUND CONTEXT

Sacroiliac (SI) joint pain causes significant disability and impairment to quality of life (QOL). Minimally invasive SI joint fusion is increasingly used to relieve chronic SI joint pain among patients who do not respond to nonsurgical treatment.

PURPOSE

To systematically review the existing literature to assess the effectiveness and safety of minimally invasive SI joint fusion.

STUDY DESIGN/SETTING

Systematic review.

DATA SOURCES

PubMed, Embase, Cochrane, and a clinical trial registry from database inception to June 30, 2021.

STUDY SELECTION

Eligible studies were primary research studies published in the English language, enrolled adults with SI joint pain, and compared SI joint fusion to nonsurgical interventions or alternative minimally invasive procedures. We included randomized controlled trials (RCTs) or controlled cohort studies (CCSs) that reported effectiveness (pain, physical function, QOL, opioid use) or safety outcomes (adverse events [AEs], revision surgeries) and uncontrolled studies that reported safety outcomes.

DATA ABSTRACTION AND SYNTHESIS

Data were abstracted into structured forms; two independent reviewers assessed risk of bias using standard instruments; certainty of evidence was rated using GRADE.

RESULTS

Forty studies (2 RCTs, 3 CCSs, and 35 uncontrolled studies) were included. Minimally invasive SI joint fusion with the iFuse Implant System appeared to result in larger improvements in pain (two RCTs: mean difference in visual analog scale -40.5 mm, 95% CI, -50.1 to -30.9; -38.1 mm, p<.0001) and larger improvements in physical function (mean difference in Oswestry Disability Index -25.4 points, 95% CI, -32.5 to -18.3; -19.8 points, p<.0001) compared to conservative management at 6 months. Improvements in pain and physical function for the RCTs appeared durable at 1- and 2-year follow-up. Findings were similar in one CCS. The two RCTs also found significant improvements in QOL at 6 months and 1 year. Opioid use may be improved at 6 months and 1 to 2 years. AEs appeared higher in the fusion group at 6 months. The incidence of revision surgery varied by study; the highest was 3.8% at 2 years. Two CCSs compared the effectiveness of alternative minimally invasive fusion procedures. One CCS compared iFuse to the Rialto SI Fusion System and reported no differences in pain, function, QOL, and revision surgeries from 6 months to 1 year. One CCS compared iFuse to percutaneous screw fixation and reported significantly fewer revisions among iFuse participants (mean difference -61.0%, 95% CI, -78.4% to -43.5%). The 35 uncontrolled studies had serious limitations and reported heterogeneous safety outcomes. Two of the larger studies reported a 13.2% incidence of complications from minimally invasive SI joint fusion at 90 days using an insurance claims database and a 3.1% incidence of revision surgery over 2.5 years using a postmarket surveillance database.

CONCLUSIONS

Among patients meeting diagnostic criteria for SI joint pain and who have not responded to conservative care, minimally invasive SI joint fusion is probably more effective than conservative management for reducing pain and opioid use and improving physical function and QOL. Fusion with iFuse and Rialto appear to have similar effectiveness. AEs appear to be higher for minimally invasive SI joint fusion than conservative management through 6 months. Based on evidence from uncontrolled studies, serious AEs from minimally invasive SI joint fusion may be higher in usual practice compared to what is reported in trials. The incidence of revision surgery is likely no higher than 3.8% at 2 years. Limited evidence is available that compares different minimally invasive devices.

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

OBJECTIVE

In this study, the authors aimed to describe a new technique of sacroiliac joint (SIJ) fusion using a robotic navigation guidance system and to document clinical results with patient-reported visual analog scale (VAS) scores.

METHODS

Patients diagnosed with SIJ dysfunction were surgically treated using 2 hydroxyapatite (HA)–coated, threaded screws with the aid of the robotic navigation system. In a total of 36 patients, 51 SIJs were fused during the study period. Patients’ VAS scores were used to determine clinical improvement in pain. Postoperative imaging at routine intervals during the follow-up period was also performed for assessment of radiological fusion. In addition, complication events were recorded, including reoperations.

RESULTS

All 36 patients had successful fusion evidenced by both CT and clinical assessment at the final follow-up. Two patients underwent reoperation because of screw loosening. The mean preoperative VAS score was 7.2 ± 1.1, and the mean 12-month postoperative VAS score was 1.6 ± 1.46. This difference was statistically significant (p < 0.05) and demonstrated a substantial clinical improvement in pain.

CONCLUSIONS

Robotic navigation–assisted SIJ fusion using 2 HA-coated, threaded screws placed across the joint was an acceptable technique that demonstrated reliable clinical results with a significant improvement in patient-reported VAS pain scores.

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.

Sacroiliac joint fusion VS conservative management for chronic low back pain attributed to the sacroiliac joint: A protocol for systematic review and meta analysis

INTRODUCTION

Low back pain (LBP) is high prevalent and it is the leading cause of years lived with disability in both developed and developing countries. The sacroiliac joint (SIJ) is a common reason that caused LBP. At present, the treatment of chronic LBP attributed to SIJ is mainly conservative treatment and surgical treatment. However, there are still controversies between the 2 treating methods, and there is no recognized standard of treatment or surgical indications. Recent publications indicated that minimally invasive sacroiliac joint arthrodesis was safe and more effective improving pain, disability, and quality of life compared with conservative management in 2 years follow-up, which re-raise the focus of sacroiliac joints fusion. This paper will systematically review the available evidence, comparing the effectiveness of sacroiliac joint fusion and conservative therapy for the treatment of gait retraining for patients suffered from LBP attributed to the sacroiliac joint.

METHOD AND ANALYSIS

A systematic review and meta-analysis of relevant studies in Pubmed, Embase, SCOPUS, and Cochrane Library will be synthesized. Inclusion criteria will be studies evaluating clinical outcomes (i.e., changes to pain and/or function) comparing sacroiliac joint fusion and conservative therapy in populations sacroiliac join related LBP; studies with less than 10 participants in total will be excluded. The primary outcomes measured will be pain score, Oswestry Disability Index (ODI), and adverse events during treatment. Review Manager (Revman; Version 5.3) software will be used for data synthesis, sensitivity analysis, meta-regression, subgroup analysis, and risk of bias assessment. A funnel plot will be developed to evaluate reporting bias and Begg and Egger tests will be used to assess funnel plot symmetries. We will use the Grading of Recommendations Assessment, Development and Evaluation system to assess the quality of evidence.

ETHICS AND DISSEMINATION

Our aim is to publish this systematic review and meta-analysis in a peer-reviewed journal. Our findings will provide information comparing the efficacy and safety comparing sacroiliac joint fusion and non-surgical treatment for patients with LBP attributed to the sacroiliac joint. This review will not require ethical approval as there are no issues about participant privacy.

iFuse Implant System for Treating Chronic Sacroiliac Joint Pain: A NICE Medical Technology Guidance

Treatment and management of sacroiliac joint pain is often non-surgical, involving packages of care that can include analgesics, physiotherapy, corticosteroid injections and radiofrequency ablation. Surgical intervention is considered when patients no longer respond to conservative management. The iFuse Implant System is placed across the sacroiliac joint using minimally invasive surgery, stabilising the joint and correcting any misalignment or weakness that can cause chronic pain. The iFuse system was evaluated in 2018 by the UK National Institute for Health and Care Excellence (NICE) as part of the Medical Technologies Evaluation Programme (MTEP). Clinical evidence for iFuse suggests improved pain, Oswestry disability index (ODI) and quality of life compared to non-surgical management. The company (SI-Bone^®) submitted two cost models indicating that iFuse was cost saving compared with open surgery and non-surgical management. Clinicians advised that non-surgical management was the most appropriate comparator and Cedar (a health technology research centre) made changes to the model to test the impact of higher acquisition and procedure costs. Cedar found iFuse to be cost incurring by approximately £560 per patient at 7 years. During the consultation period, the company reduced the cost of some iFuse consumables, and Cedar extended the time horizon to test the assumption that iFuse would become cost saving over time. These changes indicated that iFuse becomes cost saving at 8 years (approximately £129 per patient), after which the cost saving continues to increase. NICE published guidance in October 2018 recommending that the case for adoption of the iFuse system in the UK National Health Service (NHS) was supported by the evidence.

Reduction of opioid intake after cooled radiofrequency denervation for sacroiliac joint pain: a retrospective evaluation up to 1 year

Background

Opioids can present intolerable adverse side-effects to patients who use these analgesics to mitigate chronic pain. In this retrospective analysis, cooled radiofrequency (CRF) denervation was evaluated to provide pain and disability relief and reduce opioid use in patients with sacroiliac joint (SIJ) derived low back pain (LBP).

Methods

Twenty-seven patients with pain from SIJ refractory to conservative treatments, and taking opioids chronically (> 3 mo), were included. Numeric rating scale (NRS) and Oswestry disability index (ODI) scores were collected at 1, 6, and 12 months post-procedure. Opioid use between baseline and each follow-up visit was compared for the entire group and for those who experienced successful (pain reduction ≥ 50% of baseline value) or unsuccessful CRF denervation.

Results

Severe initial mean pain (NRS score: 7.7 ± 1.0) and disability (ODI score: 50.1 ± 9.0), and median opioid use (morphine equivalent daily dose: 40 ± 37 mg) were significantly reduced up to 12 months post-intervention. CRF denervation was successful in 44.4% of the patients at 12 months. Regardless of procedure success, patients demonstrated similar opioid reductions and changes in opioid use at 12 months. Two patients (7.4%) experienced neuritis following CRF denervation.

Conclusions

CRF denervation of the SIJ can safely elicit pain and disability relief, and reduce opioid use, regardless of intervention success. Future studies may support CRF denervation as a dependable therapy to alleviate opioid use in patients with SIJ-derived LBP and show that opioid use measurements can be a surrogate indicator of pain.

Minimally Invasive Sacroiliac Joint Fusion: The Current Evidence

Background

Fusion of the sacroiliac (SI) joint as a treatment for low back pain remains controversial. The purpose of this manuscript is to review the current literature and clinical outcomes of SI joint fusion surgery.

Methods

We conducted a literature review and included studies with the term "sacroiliac joint fusion" that had at least 12 months of clinical follow-up, reported on minimally invasive techniques, and included patient-reported outcome measures.

Results

Two approach types (dorsal and lateral) and numerous different implant manufacturers were identified. Most studies included level 4 data, with a small number of level 2 prospective cohort studies and 2 prospective level 1 studies. Every reviewed study reported clinical benefit in terms of improved pain scores or improvement in validated disability measures. Complication rates were low.

Conclusions

Minimally invasive SI joint fusion provides clinically significant improvement in pain scores and disability in most patients, across multiple studies and implant manufacturers.

Level of Evidence

5.

Clinical Relevance

Emerging evidence in support of SI joint fusion indicates that clinicians should examine the SI joint and include SI joint pain in their differential diagnosis for low back pain patients.

The Safety Profile of Percutaneous Minimally Invasive Sacroiliac Joint Fusion

STUDY DESIGN

Literature review.

OBJECTIVES

Systematic review of the existing literature to determine the safety of minimally invasive (MI) sacroiliac (SI) joint fusion through the determination of the rate of procedural and device-related intraoperative and postoperative complications.

METHODS

All original studies with reported complication rates were included for analysis. Complications were defined as procedural if secondary to the MI surgery and device related if caused by placement of the implant. Complication rates are reported using descriptive statistics. Random-effects meta-analysis was performed for preoperative and postoperative Visual Analog Score (VAS) pain ratings and Oswestry Disability Index (ODI) scores.

RESULTS

Fourteen studies of 720 patients (499 females/221 males) with a mean follow-up of 22 months were included. Ninety-nine patients (13.75%) underwent bilateral SI joint arthrodesis resulting in a total of 819 SI joints fused. There were 91 reported procedural-related complications (11.11%) with the most common adverse event being surgical wound infection/drainage (n = 17). Twenty-five adverse events were attributed to be secondary to placement of the implant (3.05%) with nerve root impingement (n = 13) being the most common. The revision rate was 2.56%. MI SI joint fusion reduced VAS scores from 82.42 (95% confidence interval [CI] 79.34-85.51) to 29.03 (95% CI 25.05-33.01) and ODI scores from 57.44 (95% CI 54.73-60.14) to 29.42 (95% CI 20.62-38.21).

CONCLUSIONS

MI SI joint fusion is a relatively safe procedure but is not without certain risks. Further work must be done to optimize the procedure's complication profile. Possible areas of improvement include preoperative patient optimization, operative technique, and use of intraoperative real-time imaging.

Percutaneous Plate Arthrodesis

Arthrodesis is an elective surgical procedure that aims at eliminating pain and dysfunction by promoting deliberate osseous fusion of the involved joint(s). Percutaneous plating can be used to perform carpal and tarsal arthrodeses in dogs and cats. After cartilage debridement is performed, the plate is introduced through separate plate insertion incisions made remote to the arthrodesis site and advanced along an epiperiosteal tunnel, and screws are inserted through the 3 existing skin incisions. The primary advantage of this technique is a decreased risk of soft-tissue complications, including postoperative swelling, ischemia, and wound dehiscence. Preliminary clinical results have been promising.

Biomechanical analysis of motion following sacroiliac joint fusion using lateral sacroiliac screws with or without lumbosacral instrumented fusion

BACKGROUND

Sacroiliac joint hypermobility or aberrant mechanics may be a source of pain. The purpose of this study was to assess sacroiliac joint range of motion after simulated adjacent lumbosacral instrumented fusion, with or without sacroiliac joint fusion, with lateral sacroiliac screws.

METHODS

In this in vitro biomechanical study, seven cadaveric specimens were tested on a six-degrees-of-freedom machine under load control. Left posterior sacroiliac joint ligaments were severed to maximize joint range of motion. Influence of lumbosacral instrumentation on sacroiliac joint motion, with or without fixation, was studied.

FINDINGS

During flexion-extension in the setting of posterior sacroiliac joint injury and L5-S1 fixation, sacroiliac joint range of motion increased to 195% of intact. After fixation with lateral sacroiliac screws, average range of motion reduced to 144% of intact motion. Sacroiliac joint screws thus partially stabilized the joint and reduced motion. Use of 6 bilateral sacroiliac joint screws with L5-S1 screw and rod fixation in lateral bending and axial rotation yielded the greatest reduction in range of motion. Without lumbosacral fixation, baseline motion of the sacroiliac joint was reduced, and sacroiliac joint screw alone, using either 2, 3, or 6 screws, was able to restore motion at or below the level of an intact joint.

INTERPRETATION

Sacroiliac joint ligament injury with existing lumbosacral fixation doubled sacroiliac joint range of motion, but thereafter, fixation with lateral sacroiliac screws decreased range of motion of the injured sacroiliac joint. Screw configuration played a minor role, but generally, 6 sacroiliac joint screws had the greatest motion reduction.

Physiological in vitro sacroiliac joint motion: a study on three-dimensional posterior pelvic ring kinematics

The sacroiliac joint (SIJ) is a well-known source of low back and pelvic pain, of increasing interest for both conservative and surgical treatment. Alterations in the kinematics of the pelvis have been hypothesized as a major cause of SIJ-related pain. However, definitions of both the range and the extent of physiological movement are controversial, and there are no clear baseline data for pathological alterations. The present study combined a novel biomechanical setup allowing for physiological motion of the lumbosacral transition and pelvis without restricting the SIJ movement in vitro, combined with optical image correlation. Six fresh human pelvises (81 ± 10 years, three females, three males) were tested, with bodyweight-adapted loading applied to the fifth lumbar vertebra and both acetabula. Deformation at the lumbopelvises was determined computationally from three-dimensional image correlation data. Sacroiliac joint motion under the loading of 100% bodyweight primarily consisted of a z-axis rotation (0.16°) and an inferior translation of the sacrum relative to the ilium (0.32 mm). Sacroiliac joint flexion-extension rotations were minute (< 0.02°). Corresponding movements of the SIJ were found at the lumbosacral transition, with an anterior translation of L5 relative to the sacrum of -0.97 mm and an inferior translation of 0.11 mm, respectively. Moreover, a flexion of 1.82° was observed at the lumbosacral transition. Within the innominate bone and at the pubic symphysis, small complementary rotations were seen around a vertical axis, accounting for -0.10° and 0.11°, respectively. Other motions were minute and accompanied by large interindividual variation. The present study provides evidence of different SIJ motions than reported previously when exerted by physiological loading. Sacroiliac joint kinematics were in the sub-degree and sub-millimeter range, in line with previous in vivo and in vitro findings, largely limited to the sagittal rotation and an inferior translation of the sacrum relative to the ilium. This given physiological loading scenario underlines the relevance of the lumbosacral transition when considering the overall motion of the lumbopelvis, and how relatively little the other segments contribute to overall motion.

Management of Sacroiliac Joint Pain

Sacroiliac joint (SIJ)-based pain can be difficult to diagnose definitively through physical examination and conventional radiography. A fluoroscopically guided injection into the SIJ can be both diagnostic and therapeutic. The initial phase of treatment involves nonsurgical modalities such as activity modification, use of a sacroiliac (SI) belt, NSAIDs, and physical therapy. Prolotherapy and radiofrequency ablation may offer a potential benefit as therapeutic modalities, although limited data support their use as a primary treatment modality. Surgical treatment is indicated for patients with a positive response to an SI injection with >75% relief, failure of nonsurgical treatment, and continued or recurrent SIJ pain. Percutaneous SI arthrodesis may be recommended as a first-line surgical treatment because of its improved safety profile compared with open arthrodesis; however, in the case of revision surgery, nonunion, and aberrant anatomy, open arthrodesis should be performed.

A consideration for the utility of the post-operative Oswestry Disability Index for measuring outcomes after sacroiliac joint fusion

Sacroiliac joint (SIJ) dysfunction and its surgical treatment remain a controversial topic in spine surgery. Determining success after SIJ fusion may be difficult due to preexisting back pain, lumbar fusion (LF), and functional disability. We examine the utility of Oswestry Disability Index (ODI) as a measure of clinical outcomes after minimally invasive SIJ fusion. A retrospective review of 24 patients with at least 12- months follow-up. Patients were divided into two groups based on presence of previous LF. Their post-operative ODI was compared with overall satisfaction, pain reduction, and return to work status. No difference in demographics was found in patients with and without prior LF with 92% of patients reporting lower post-operative pain and 96% being satisfied. Presence of LF did not show any statistically significant differences in pain or satisfaction. However, patient with prior LF reported lower ODI than those without LF at 1-year post-operatively (P=0.015). Postoperative ODI may give a falsely pessimistic impression of outcomes in SIJ fusion patients with prior LF, and its use and limitations should be carefully considered in future studies.

Extracorporeal shock wave therapy for sacroiliac joint pain: A prospective, randomized, sham-controlled short-term trial

BACKGROUND

Sacroiliac joint (SIJ) pain can cause lower back pain and pelvic discomfort. However, there is no established standard treatment for SIJ pain. Extracorporeal shock wave therapy (ESWT) is a novel, non-invasive therapeutic modality for musculoskeletal disorders. The mechanism underlying shockwave therapy is not fully understood, but the frequency with which ESWT is applied clinically has increased over the years.

OBJECTIVE

We evaluated the efficacy of using ESWT to treating SIJ pain.

METHODS

Thirty patients with SIJ pain were assigned randomly to ESWT (n = 15) and sham control (n = 15) groups. The ESWT group received 2,000 shockwaves with energy set to the maximum level tolerable by the patient (energy density = 0.09-0.25 mJ/mm2). The probe was oriented perpendicular to the posterior SIJ line, and moved up and down along the joint line. The sham control group received 2,000 shockwaves with the probe oriented parallel to the posterior SIJ line. A 10-cm numeric rating scale (NRS) and the Oswestry Disability Index (ODI) scores were assessed before the intervention, and 1 and 4 weeks post-intervention. Participants were instructed to refrain from using any other conservative treatment, including anti-inflammatory medication and other physical modalities during the study.

RESULTS

In the ESWT group, NRS decreased significantly at post-treatment week 4 (3.64 (95% confidence interval, 2.29-4.99)) compared to baseline (6.42 (5.19-7.66); P < 0.05). ODI improved at 1 and 4 weeks compared to baseline, but not significantly. In the sham group, NRS and ODI did not differ at any post-treatment time point. There was a significant group difference in NRS at week 4 post-treatment (3.64 (2.29-4.99) in the ESWT group vs. 6.18 (5.34-7.02) in the sham control group; P < 0.05), but this was not the case for ODI.

CONCLUSIONS

ESWT represents a potential therapeutic option for decreasing SIJ pain.

Predictors of Outcome in Conservative and Minimally Invasive Surgical Management of Pain Originating From the Sacroiliac Joint: A Pooled Analysis

STUDY DESIGN

A pooled patient-level analysis of two multicenter randomized controlled trials and one multicenter single-arm prospective trial.

OBJECTIVE

The aim of this study was to identify predictors of outcome of conservative and minimally invasive surgical management of pain originating from the sacroiliac joint (SIJ).

SUMMARY OF BACKGROUND DATA

Three recently published prospective trials have shown that minimally invasive SIJ fusion (SIJF) using triangular titanium implants produces better outcomes than conservative management for patients with pain originating from the SIJ. Due to limitations in individual trial sample size, analyses of predictors of treatment outcome were not conducted.

METHODS

We pooled individual patient data from the three trials and used random effects models with multivariate regression analysis to identify predictors for treatment outcome separately for conservative and minimally invasive surgical treatment. Outcome was measured using visual analogue scale (VAS), Oswestry Disability Index (ODI), and EuroQOL-5D (EQ-5D).

RESULTS

We included 423 patients assigned to either nonsurgical management (NSM, n = 97) or SIJF (n = 326) between 2013 and 2015. The reduction in SIJ pain was 37.9 points larger [95% confidence interval (95% CI) 32.5-43.4, P < 0.0001] in the SIJF group than in the NSM group. Similarly, the improvement in ODI was 18.3 points larger (95% CI 14.3-22.4), P < 0.0001). In NSM, we found no predictors of outcome. In SIJF, a reduced improvement in outcome was predicted by smoking (P = 0.030), opioid use (P = 0.017), lower patient age (P = 0.008), and lower duration of SIJ pain (P = 0.028).

CONCLUSIONS

Our results support the view that SIJF leads to better treatment outcome than conservative management of SIJ pain and that a higher margin of improvement can be predicted in nonsmokers, nonopioid users, and patients of increased age and with longer pain duration.

LEVEL OF EVIDENCE

1.

Two-year clinical results of patients with sacroiliac joint syndrome treated by arthrodesis using a triangular implant system

BACKGROUND

Sacroiliac joint (SIJ) syndrome can cause various symptoms and may also be one reason for persistent low back pain, especially in patients with prior spinal fusions. If conservative treatments fail to improve symptoms, arthrodesis surgery can be considered. Minimally invasive approaches have emerged recently providing a good alternative to conventional methods. A novel triangular implant system (iFuse) can achieve an arthrodesis of the SIJ without the use of additional screws or bone material.

OBJECTIVE

Aim of the present study was an evaluation of short-term safety and efficacy of the implant system.

METHODS

Twenty-four patients were included in the study and treated with the iFuse system. In addition to demographic data, pain intensity (visual analogue scale) and functional impairment (Oswestry-disability index) were assessed prior to surgery and 1 month, 3 months, 6 months, 12 months and 24 months thereafter. During surgery and the follow up period all adverse events were documented and the correct implant position was controlled via plain radiographs.

RESULTS

VAS scores and ODI improved significantly directly after surgery from 84.3 ± 9.2 mm to 40.7 ± 9.2 mm and from 76.8 ± 9.2% to 40.7 ± 9.2 % (p < 0.001). The ODI improved further to 31 ± 5.4% after 24 months whereas the VAS improved until the 3 months examination and ten stayed constant between 27.7 mm and 26.5 mm to 27 ± 6.6 mm at 24 months. No adverse events, intraoperative complications, implant malpositioning or loosening could be recorded at any time.

CONCLUSIONS

The iFuse system is an effective and safe treatment for minimally invasive surgical arthrodesis of the SIJ. Pain and functional impairment can be significantly improved. However, in addition to this case series, further controlled studies are necessary, particularly in terms of a previous spinal fusion history.

Clinical outcome following anterior arthrodesis in patients with presumed sacroiliac joint pain

BACKGROUND

It has been reported that in 13-32% of patients with chronic low back pain, the pain may originate in the sacroiliac (SI) joints. When treatment of these patients with analgesics and physiotherapy has failed, a surgical solution may be discussed. Results of such surgery are often based on small series, retrospective analyses or studies using a minimal invasive technique, frequently sponsored by manufacturers.

PURPOSE

To report the clinical outcome concerning pain, function and quality of life following anterior arthrodesis in patients presumed to have SI joint pain using validated questionnaires pre- and post-operatively. An additional aim was to describe the symptoms of the patients included and the preoperative investigations performed.

MATERIAL AND METHODS

Over a 6 year period we treated 55 patients, all women, with a mean age of 45 years (range 28-65) and a mean pelvic pain duration of 9.1 years (range 2-30). The pain started in connection with minor trauma in seven patients, pregnancy in 20 and unspecified in 28. All patients had undergone long periods of treatment including physiotherapy, manipulation, needling, pelvic belt, massage and chiropractic without success, and 15 had been operated for various spinal diagnoses without improvement. The patients underwent thorough neurological investigation, plain X-ray and MRI of the spine and plain X-ray of the pelvis. They were investigated by seven clinical tests aimed at indicating pain from the SI joints. In addition, all patients underwent a percutaneous mechanical provocation test and extra-articular local anaesthetic blocks against the posterior part of the SI joints. Before surgery all patients answered the generic Short-Form-36 (SF-36) questionnaire, the disease specific Balanced Inventory for Spinal Disorders (BIS) questionnaire and rated their level of pelvic and leg pain (VAS, 0-100). At follow-up at a mean of 2 years 49 patients completed the same questionnaires (89%).

RESULTS

At follow-up 26 patients reported a lower level of pelvic pain than before surgery, 16 the same level and six a higher level. Applying Svensson's method RP_{pelvic pain}=0.3976, with 95% CI (0.2211, 0.5740) revealed a statistically significant systematic improvement in pelvic pain. At follow-up 28 patients reported a higher quality of life and 26 reported sleeping better than pre-operatively. In most patients the character of the pelvic pain was dull and aching, often accompanied by a stabbing component in connection with sudden movements. Referred pain down the leg/s even to the feet and toes was noted by half of the patients and 29 experienced frequency of micturition.

CONCLUSIONS

It is apparent that in some patients the SI joints may cause long-term pain that can be treated by arthrodesis. We speculate that continued pain despite a healed arthrodesis may be due to persistent pain from adjacent ligaments. The next step should be a prospective randomized study comparing posterior fusion and ligament resection with non-surgical treatment.

IMPLICATIONS

Anterior arthrodesis can apparently relieve pain in some patients with presumed SI joint pain. The problem is how to identify these patients within the low back pain group.

Minimally Invasive Sacroiliac Joint Fusion, Radiofrequency Denervation, and Conservative Management for Sacroiliac Joint Pain: 6-Year Comparative Case Series

BACKGROUND

Sacroiliac joint (SIJ) pain is an under-recognized condition. Substantial information supports the safety and effectiveness of SIJ fusion (SIJF). Long-term follow-up after SIJF has not been reported.

OBJECTIVE

To determine responses to conservative management (CM), SIJ denervation, and SIJF in patients with SIJ pain unresponsive to CM.

METHODS

Retrospective study with long-term (up to 6 yr) follow-up of 137 patients with SIJ pain seen in an outpatient neurosurgery clinic who received either CM (n = 63), sacroiliac denervation (n = 47), or minimally invasive SIJF (n = 27). At each routine clinic visit, patients completed pain scores and Oswestry Disability Index. Additional data were extracted from medical charts.

RESULTS

Patients treated with continued CM had no long-term improvement in pain (mean worsening of 1 point) or disability (mean Oswestry Disability Index worsened by 4-6 points), increased their use of opioids, and had poor long-term work status. SIJF patients had large improvements in SIJ pain (mean 6 points), large improvements in disability (mean 25 points), a decrease in opioid use, and good final work status. Sacroiliac denervation patients had intermediate responses (0-1 and 1-2 points, respectively).

CONCLUSION

In patients with SIJ pain unresponsive to CM, SIJF resulted in excellent long-term clinical responses, with low opioid use and better work status compared to other treatments.

Surgical Revision after Sacroiliac Joint Fixation or Fusion

BACKGROUND

Minimally invasive sacroiliac joint (SIJ) fusion has been shown to be safe and effective for the treatment of SIJ dysfunction. Multiple devices are available to perform SIJ fixation or fusion. Surgical revision rates after these procedures have not been directly compared.

METHODS

We retrospectively identified all patients in our practice who underwent SIJ fixation or fusion between 2003 and 2015. Using both chart review and focused contact with individual patients, we determined the likelihood of surgical revision. Revision rates were compared using Kaplan-Meier survival analysis.

RESULTS

Thirty-eight patients underwent SIJ fixation with screws and 274 patients underwent SIJ fusion using triangular titanium implants. Four-year cumulative revision rates were 30.8% for fixation and 5.7% for fusion.

CONCLUSIONS

In our study, SIJ fixation with screws had a much higher revision rate compared to SIJ fusion with triangular titanium implants designed for bone adherence.

Sacroiliac Joint Treatment Personalized to Individual Patient Anatomy Using 3-Dimensional Navigation

During the past 10 years, the sacroiliac (SI) joint has evolved from being barely recognized as a source of pain, to being a joint treated only nonsurgically or with great surgical morbidity, to currently being a joint treated with minimally invasive techniques that are personalized to the individual patient. The complex 3-dimensional anatomy of the SI joint and lack of parallel to traditional imaging planes requires a thorough understanding of the structures within and around the SI joint that may be at risk of injury. Thus, the SI joint is ideally suited for intraoperative 3-dimensional imaging and surgical navigation when being treated minimally invasively.

Postoperative complications in patients undergoing minimally invasive sacroiliac fusion

BACKGROUND CONTEXT

Minimally invasive sacroiliac (SI) joint fusion has become increasingly relevant in recent years as a treatment for SI joint pathology. Previous studies have found minimally invasive SI fusion to be an effective and safe treatment option for chronic SI joint pain. However, these studies have been primarily single-center, case-based, or manufacturer-sponsored investigations, and as such their findings are limited to their sample populations.

PURPOSE

The aim of this study was to investigate the safety of minimally invasive SI fusion using a large nationwide sample group to more accurately identify complication rates of this increasingly popular procedure.

STUDY DESIGN/SETTING

This is a retrospective database study.

PATIENT SAMPLE

The sample includes patients within the orthopedic subset of Humana database who underwent minimally invasive SI fusion between 2007 and 2014.

OUTCOME MEASURES

Complications and novel lumbar and nerve pathology were the outcome measures.

METHODS

Patients undergoing minimally invasive SI fusion from 2007 to 2014 were identified using the Pearl Diver patient record database (Pearl Diver Technologies, West Conshohocken, PA, USA) from the nationwide private insurance provider Humana Inc. This approach provided access to records of over 18 million patients in every major geographic region of the country. Using the ICD-9 diagnosis codes (International Classification of Diseases 9th edition), data from patient records were analyzed to reveal incidence of postoperative infection, pain, osteomyelitis, joint derangement, urinary tract infection, and novel lumbar and nervous system pathology.

RESULTS

Four hundred sixty-nine patients (305 female; 164 male) within the Humana insurance database received minimally invasive SI fusion between 2007 and 2014. Data from these patients showed a substantial increase in the use of the procedure over this 7-year period. Among these patients, an overall complication rate of 13.2% (n=62) was seen at 90 days postoperatively and 16.4% (n=77) at 6 months. The number of patients receiving a first time diagnosis of lumbar pathology following minimally invasive SI fusion in the sample population was also analyzed. The incidence of novel lumbar pathology in this population was 3.6% (n=17) at 90 days postoperatively and 5.3% (n=25) at 6 months. Men experienced diagnoses of novel lumbar pathology at higher rates than women within both 90 days (men=6.7%; women≤3.3%) and 6 months (men=9.1%; women≤3.3%) of the procedure (p<.01).

CONCLUSIONS

The results of this study show that minimally invasive SI joint fusion could possibly carry higher risks of complications than previously stated. These findings are useful for physicians and patients when considering treatment for chronic SI joint pain.

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

BACKGROUND

Sacroiliac joint (SIJ) dysfunction is an important and underappreciated cause of chronic low back pain.

OBJECTIVE

To prospectively and concurrently compare outcomes after surgical and non-surgical treatment for chronic SIJ dysfunction.

METHODS

One hundred and forty-eight subjects with SIJ dysfunction were randomly assigned to minimally invasive SIJ fusion with triangular titanium implants (SIJF, n = 102) or non-surgical management (NSM, n = 46). SIJ pain (measured with a 100-point visual analog scale, VAS), disability (measured with Oswestry Disability Index, ODI) and quality of life scores were collected at baseline and at scheduled visits to 24 months. Crossover from non-surgical to surgical care was allowed after the 6-month study visit was complete. Improvements in continuous measures were compared using repeated measures analysis of variance. The proportions of subjects with clinical improvement (SIJ pain improvement ≥20 points, ODI ≥15 points) and substantial clinical benefit (SIJ pain improvement ≥25 points or SIJ pain rating ≤35, ODI ≥18.8 points) were compared.

RESULTS

In the SIJF group, mean SIJ pain improved rapidly and was sustained (mean improvement of 55.4 points) at month 24. The 6-month mean change in the NSM group (12.2 points) was substantially smaller than that in the SIJF group (by 38.3 points, p<.0001 for superiority). By month 24, 83.1% and 82.0% received either clinical improvement or substantial clinical benefit in VAS SIJ pain score. Similarly, 68.2% and 65.9% had received clinical improvement or substantial clinical benefit in ODI score at month 24. In the NSM group, these proportions were <10% with non-surgical treatment only. Parallel changes were seen for EQ-5D and SF-36, with larger changes in the surgery group at 6 months compared to NSM. The rate of adverse events related to SIJF was low and only 3 subjects assigned to SIJF underwent revision surgery within the 24-month follow-up period.

CONCLUSIONS

In this Level 1 multicenter prospective randomized controlled trial, minimally invasive SIJF with triangular titanium implants provided larger improvements in pain, disability and quality of life compared to NSM. Improvements after SIJF persisted to 24 months. This study was approved by a local or central IRB before any subjects were enrolled. All patients provided study-specific informed consent prior to participation.

ISASS Policy 2016 Update - Minimally Invasive Sacroiliac Joint Fusion

The index 2014 ISASS Policy Statement - Minimally Invasive Sacroiliac Joint Fusion was generated out of necessity to provide an ICD9-based background and emphasize tools to ensure correct diagnosis. A timely ICD10-based 2016 Update provides a granular threshold selection with improved level of evidence and a more robust, relevant database.

Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: A Prospective Study

Study Design Prospective multicenter single-arm interventional clinical trial. Objective To determine the degree of improvement in sacroiliac (SI) joint pain, disability related to SI joint pain, and quality of life in patients with SI joint dysfunction who undergo minimally invasive SI joint fusion using triangular-shaped titanium implants. Methods Subjects (n = 172) underwent minimally invasive SI joint fusion between August 2012 and January 2014 and completed structured assessments preoperatively and at 1, 3, 6, and 12 months postoperatively, including a 100-mm SI joint and back pain visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form-36 (SF-36), and EuroQOL-5D. Patient satisfaction with surgery was assessed at 6 and 12 months. Results Mean SI joint pain improved from 79.8 at baseline to 30.0 and 30.4 at 6 and 12 months, respectively (mean improvements of 49.9 and 49.1 points, p < 0.0001 each). Mean ODI improved from 55.2 at baseline to 32.5 and 31.4 at 6 and 12 months (improvements of 22.7 and 23.9 points, p < 0.0001 each). SF-36 physical component summary improved from 31.7 at baseline to 40.2 and 40.3 at 6 and 12 months (p < 0.0001). At 6 and 12 months, 93 and 87% of subjects, respectively, were somewhat or very satisfied and 92 and 91%, respectively, would have the procedure again. Conclusions Minimally invasive SI joint fusion resulted in improvement of pain, disability, and quality of life in patients with SI joint dysfunction due to degenerative sacroiliitis and SI joint disruption.

Finite Element Analysis of Sacroiliac Joint Fixation under Compression Loads

BACKGROUND

Sacroiliac joint (SIJ) is a known chronic pain-generator. The last resort of treatment is the arthrodesis. Different implants allow fixation of the joint, but to date there is no tool to analyze their influence on the SIJ biomechanics under physiological loads. The objective was to develop a computational model to biomechanically analyze different parameters of the stable SIJ fixation instrumentation.

METHODS

A comprehensive finite element model (FEM) of the pelvis was built with detailed SIJ representation. Bone and sacroiliac joint ligament material properties were calibrated against experimentally acquired load-displacement data of the SIJ. Model evaluation was performed with experimental load-displacement measurements of instrumented cadaveric SIJ. Then six fixation scenarios with one or two implants on one side with two different trajectories (proximal, distal) were simulated and assessed with the FEM under vertical compression loads.

RESULTS

The simulated S1 endplate displacement reduction achieved with the fixation devices was within 3% of the experimentally measured data. Under compression loads, the uninstrumented sacrum exhibited mainly a rotation motion (nutation) of 1.38° and 2.80° respectively at 600 N and 1000 N, with a combined relative translation (0.3 mm). The instrumentation with one screw reduced the local displacement within the SIJ by up to 62.5% for the proximal trajectory vs. 15.6% for the distal trajectory. Adding a second implant had no significant additional effect.

CONCLUSION

A comprehensive finite element model was developed to assess the biomechanics of SIJ fixation. SIJ devices enable to reduce the motion, mainly rotational, between the sacrum and ilium. Positioning the implant farther from the SIJ instantaneous rotation center was an important factor to reduce the intra-articular displacement.

CLINICAL RELEVANCE

Knowledge provided by this biomechanical study enables improvement of SIJ fixation through optimal implant trajectory.

Sacroiliac Joint Pain and Its Treatment

The sacroiliac joint (SIJ) as a source of symptoms has been controversial; however, as knowledge about the joint increased, its role as a pain generator in patients complaining of symptoms that are often attributed to spinal pathology has become better appreciated. The literature reports that the SIJ is the pain origin in as many as 30% of patients presenting with low back pain. Clinically, the SIJ can be challenging to evaluate; however, assessing pain location, patient posture/movement, and provocative manual testing are useful in making the presumptive diagnosis of SIJ disruption. The most definitive evaluation is image-guided injection of anesthetic solutions into the joint which is diagnostic if there is at least 75% symptom relief acutely. Treatment begins with nonoperative intervention including physical therapy and/or chiropractic care. If these fail, the next option is generally radiofrequency denervation (rhizotomy) of the joint. If this does not provide adequate relief, surgical intervention, in the form of minimally invasive SIJ fusion may be considered. The literature increasingly supports favorable results of SIJ fusion in appropriately selected patients. The purpose of this review is to provide an overview of the current literature on the SIJ, with focus on its surgical treatment.

Pelvic Belt Effects on Health Outcomes and Functional Parameters of Patients with Sacroiliac Joint Pain

Introduction

The sacroiliac joint (SIJ) is a common source of low back pain. However, clinical and functional signs and symptoms correlating with SIJ pain are widely unknown. Pelvic belts are routinely applied to treat SIJ pain but without sound evidence of their pain-relieving effects. This case-control study compares clinical and functional data of SIJ patients and healthy control subjects and evaluates belt effects on SIJ pain.

Methods

17 SIJ patients and 17 healthy controls were included in this prospective study. The short-form 36 survey and the numerical rating scale were used to characterize health-related quality of life in patients in a six-week follow-up and the pain-reducing effects of pelvic belts. Electromyography data were obtained from the gluteus maximus, biceps femoris, rectus femoris and medial vastus. Alterations of muscle activity, variability and gait patterns were compared in patients and controls along with the belts’ effects in a dynamic setting when walking.

Results

Significant improvements were observed in the short-form 36 survey of the SIJ patients, especially in the physical health subscores. Minor declines were also observed in the numerical rating scale on pain. Belt-related changes of muscle activity and variability were similar in patients and controls with one exception: the rectus femoris activity decreased significantly in patients with belt application when walking. Further belt effects include improved cadence and gait velocity in patients and controls.

Conclusions

Pelvic belts improve health-related quality of life and are potentially attributed to decreased SIJ-related pain. Belt effects include decreased rectus femoris activity in patients and improved postural steadiness during locomotion. Pelvic belts may therefore be considered as a cost-effective and low-risk treatment of SIJ pain.

Trial Registration

ClinicalTrials.gov NCT02027038

A systematic review of minimally invasive sacroiliac joint fusion utilizing a lateral transarticular technique

BACKGROUND

A number of studies have been published regarding minimally invasive surgical (MIS) fusion of the sacroiliac (SI) joint using a lateral transarticular approach. Herein we report a systematic review and meta-analysis to summarize operative measures and clinical outcomes reported in published studies of MIS SI joint fusion.

METHODS

The systematic review was done according to PRISMA standards. PubMed and EMBASE were searched using the terms sacroiliac joint AND fusion. Original peer-reviewed articles in the English language that reported clinical outcomes on at least 5 cases of MIS SI joint fusion using a lateral transarticular approach were included. Random effects meta-analysis (RMA) was performed on selected variables using the DerSimonian and Laird method, including operative measures, VAS SI joint pain ratings (0-10 scale) and Oswestry Disability Index (ODI). Mean and 95% confidence intervals (CI) were calculated and heterogeneity was assessed. Other findings were summarized qualitatively.

RESULTS

A total of 18 articles met the inclusion criteria. After accounting for overlapping cohorts, 12 unique cohorts from 4 countries were extracted for a total of 432 subjects. The RMA mean (range) was 59 minutes (27-78) for procedure time, 36.9cc (10-70) for estimated blood loss and 1.7 days (range 0-7) for length of stay (LOS). The RMA mean [95% CI] pain score dropped by 5.2 points at 6 months and 5.3 points at 12 months (baseline score of 8.1 [7.8-8.4], 12-month score of 2.7 [2.1-3.3]), and a 24-month score of 2.0(1.4-2.5). ODI decreased by 31 points at 12 months (baseline score of 56.2 [51.0-61.5], 6-month score of 30.7 [21.8-39.6], and 12-month score of 25.1 [12.3-37.9]). Some estimates showed significant variation across studies and between the types of implants used. Other reported outcomes were supportive of the positive effects of SI joint fusion.

CONCLUSION

Published studies of MIS SI joint fusion using a lateral transarticular approach confirm its minimally invasive characteristics with minimal blood loss and short operating room times, and show consistent, rapid, sustained and clinically important improvements in patient reported SI joint pain, disability and quality of life scores.

Surgical and clinical efficacy of sacroiliac joint fusion: a systematic review of the literature

OBJECT

The sacroiliac joint (SIJ) and surgical intervention for treating SIJ pain or dysfunction has been a topic of much debate in recent years. There has been a resurgence in the implication of this joint as the pain generator for many patients experiencing low-back pain, and new surgical methods are gaining popularity within both the orthopedic and neurosurgical fields. There is no universally accepted gold standard for diagnosing or surgically treating SIJ pain. The authors systematically reviewed studies on SIJ fusion in the neurosurgical and orthopedic literature to investigate whether sufficient evidence exists to support its use.

METHODS

A literature search was performed using MEDLINE, Google Scholar, and OvidSP-Wolters Kluwer Health for all articles regarding SIJ fusion published from 2000 to 2014. Original, peer-reviewed, prospective or retrospective scientific papers with at least 2 patients were included in the study. Exclusion criteria included follow-up shorter than 1-year, nonsurgical treatment, inadequate clinical data as determined by 2 independent reviewers, non-English manuscripts, and nonhuman subjects.

RESULTS

A total of 16 peer-reviewed journal articles met the inclusion criteria: 5 consecutive case series, 8 retrospective studies, and 3 prospective cohort studies. A total of 430 patients were included, of whom 131 underwent open surgery and 299 underwent minimally invasive surgery (MIS) for SIJ fusion. The mean duration of follow-up was 60 months for open surgery and 21 months for MIS. SIJ degeneration/arthrosis was the most common pathology among patients undergoing surgical intervention (present in 257 patients [59.8%]), followed by SIJ dysfunction (79 [18.4%]), postpartum instability (31 [7.2%]), posttraumatic (28 [6.5%]), idiopathic (25 [5.8%]), pathological fractures (6 [1.4%]), and HLA-B27+/rheumatoid arthritis (4 [0.9%]). Radiographically confirmed fusion rates were 20%-90% for open surgery and 13%-100% for MIS. Rates of excellent satisfaction, determined by pain reduction, function, and quality of life, ranged from 18% to 100% with a mean of 54% in open surgical cases. For MIS patients, excellent outcome, judged by patients' stated satisfaction with the surgery, ranged from 56% to 100% (mean 84%). The reoperation rate after open surgery ranged from 0% to 65% (mean 15%). Reoperation rate after MIS ranged from 0% to 17% (mean 6%). Major complication rates ranged from 5% to 20%, with 1 study that addressed safety reporting a 56% adverse event rate.

CONCLUSIONS

Surgical intervention for SIJ pain is beneficial in a subset of patients. However, with the difficulty in accurate diagnosis and evidence for the efficacy of SIJ fusion itself lacking, serious consideration of the cause of pain and alternative treatments should be given before performing the operation.

Pelvic belt effects on pelvic morphometry, muscle activity and body balance in patients with sacroiliac joint dysfunction

Introduction

The sacroiliac joint (SIJ) is frequently involved in low back and pelvic girdle pain. However, morphometrical and functional characteristics related to SIJ pain are poorly defined. Pelvic belts represent one treatment option, but evidence still lacks as to their pain-reducing effects and the mechanisms involved. Addressing these two issues, this case-controlled study compares morphometric, functional and clinical data in SIJ patients and healthy controls and evaluates the effects of short-term pelvic belt application.

Methods

Morphometric and functional data pertaining to pelvic belt effects were compared in 17 SIJ patients and 17 controls. Lumbar spine and pelvis morphometries were obtained from 3T magnetic resonance imaging. Functional electromyography data of pelvis and leg muscles and center of pressure excursions were measured in one-leg stance. The numerical rating scale was used to evaluate immediate pain-reducing effects.

Results

Pelvic morphometry was largely unaltered in SIJ patients and also by pelvic belt application. The angle of lumbar lateral flexion was significantly larger in SIJ patients without belt application. Muscle activity and center of pressure were unaffected by SIJ pain or by belt application in one-leg stance. Nine of 17 patients reported decreased pain intensities under moderate belt application, four reported no change and four reported increased pain intensity. For the entire population investigated here, this qualitative description was not confirmed on a statistical significant level.

Discussion

Minute changes were observed in the alignment of the lumbar spine in the frontal plane in SIJ patients. The potential pain-decreasing effects of pelvic belts could not be attributed to altered muscle activity, pelvic morphometry or body balance in a static short-term application. Long-term belt effects will therefore be of prospective interest.

Pyogenic sacroiliitis: diagnosis, management and clinical outcome

OBJECTIVE

The purpose of the present study was to evaluate the role of diagnostic tools and management options for patients with pyogenic sacroiliitis, including potential complications.

MATERIALS AND METHODS

This retrospective study included 16 patients with pyogenic sacroiliitis who were admitted to a single orthopaedic centre between 2007 and 2012. The following data were collected: demographics, history, radiography, magnetic resonance images (MRI), biological data, type of pathogenic agent, abscess formation, type of management, and clinical outcome.

RESULTS

Our study demonstrated that only one-fifth of the patients with lumbogluteal or hip pain had established diagnoses of suspected pyogenic sacroiliitis upon admission. MRIs confirmed this diagnosis in all cases. MRI examinations revealed joint fluid in the sacroiliac joint and significant oedema of the adjacent bone and soft tissues. In 12 of the 16 cases, erosions of the subchondral bone were encountered. Contrast-enhanced MRI revealed that 9 patients had abscesses. All patients received antibiotic therapy. Antibiotic treatment was only successful in 9 cases. The other 7 patients underwent computed tomography (CT)-guided abscess drainage. Drainage was sufficient for 4 patients, but 3 patients required open surgery. One patient required sacroiliac arthrodesis. The clinical outcomes included minimal disability (n = 10), moderate disability (n = 5), and full disability (n = 1) of the spine.

CONCLUSIONS

Contrast-enhanced MRI is mandatory for a reliable diagnosis. Abscess formation was observed in approximately half of the MRI-diagnosed sacroiliitis cases and required minimally invasive drainage under CT guidance or frequently open surgery.

Comparative effectiveness of open versus minimally invasive sacroiliac joint fusion

Background

The mainstay of sacroiliac joint disruption/degenerative sacroiliitis therapy has been nonoperative management. This nonoperative management often includes a regimen of physical therapy, chiropractic treatment, therapeutic injections, and possibly radiofrequency ablation at the discretion of the treating physician. When these clinical treatments fail, sacroiliac joint fusion has been recommended as the standard treatment. Open and minimally invasive (MIS) surgical techniques are typical procedures. This study aims to compare the perioperative measures and Oswestry Disability Index (ODI) outcomes associated with each of these techniques.

Methods

A comparative retrospective chart review of patients with sacroiliac joint fusion and a minimum of 1 year of follow-up was performed. Perioperative measures and ODI scores were compared using the Fisher’s exact test and two nonparametric tests, ie, the Mann–Whitney U test and the Wilcoxon signed-rank test. The results are presented as percent or median with range, as appropriate.

Results

Forty-nine patients from two institutions underwent sacroiliac joint fusion between 2006 and 2012. Ten patients were excluded because of incomplete data, leaving 39 evaluable patients, of whom 22 underwent open and 17 underwent MIS sacroiliac joint fusion. The MIS group was significantly older (median age 66 [39–82] years) than the open group (median age 51 [34–74] years). Surgical time and hospital stay were significantly shorter in the MIS group than in the open group. Preoperative ODI was significantly greater in the open group (median 64 [44–78]) than in the MIS group (median 53 [14–84]). Postoperative improvement in ODI was statistically significant within and between groups, with MIS resulting in greater improvement.

Conclusion

The open and MIS sacroiliac joint fusion techniques resulted in statistically and clinically significant improvement for patients with degenerative sacroiliitis refractory to nonoperative management. However, the number of patients reaching the minimal clinically important difference and those showing overall improvement were greater in the MIS group.

Minimally invasive versus open sacroiliac joint fusion: are they similarly safe and effective?

BACKGROUND

The sacroiliac joint has been implicated as a source of chronic low back pain in 15% to 30% of patients. When nonsurgical approaches fail, sacroiliac joint fusion may be recommended. Advances in intraoperative image guidance have assisted minimally invasive surgical (MIS) techniques using ingrowth-coated fusion rods; however, how these techniques perform relative to open anterior fusion of the sacroiliac joint using plates and screws is not known.

QUESTIONS/PURPOSES

We compared estimated blood loss (EBL), surgical time, length of hospital stay (LOS), and Oswestry Disability Index (ODI) between patients undergoing MIS and open sacroiliac joint fusion.

METHODS

We retrospectively studied 63 patients (open: 36; MIS: 27) who underwent sacroiliac joint fusion with minimum 1-year followup at our institution from 2006 to 2011. Of those, 10 in the open group had incomplete records. All patients had sacroiliac joint dysfunction confirmed by image-guided intraarticular anesthetic sacroiliac joint injection and had failed nonoperative treatment. Patients were matched via propensity score, adjusting for age, sex, BMI, history of spine fusion, and preoperative ODI scores, leaving 22 in each group. Nine patients were not matched. We reviewed patient medical records to obtain EBL, length of surgery, LOS, and pre- and postoperative ODI scores. Mean followup was 13 months (range, 11-33 months) in the open group and 15 months (range, 12-26 months) in the MIS group.

RESULTS

Patients in the open group had a higher mean EBL (681 mL versus 41 mL, p < 0.001). Mean surgical time and LOS were shorter in the MIS group than in the open group (68 minutes versus 128 minutes and 3.3 days versus 2 days, p < 0.001 for both). With the numbers available, mean postoperative ODI scores were not different between groups (47% versus 54%, p = 0.272).

CONCLUSIONS

EBL, surgery time, and LOS favored the MIS sacroiliac fusion group. With the numbers available, ODI scores were similar between groups, though the study size was relatively small and it is possible that the study was underpowered on this end point. Because the implants used for these procedures make assessment of fusion challenging with available imaging techniques, we do not know how many patients' sacroiliac joints successfully fused, so longer followup and critical evaluation of outcomes scores over time are called for.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Comparison of the costs of nonoperative care to minimally invasive surgery for sacroiliac joint disruption and degenerative sacroiliitis in a United States commercial payer population: potential economic implications of a new minimally invasive technology

Introduction

Low back pain is common and treatment costly with substantial lost productivity and lost wages in the working-age population. Chronic low back pain originating in the sacroiliac (SI) joint (15%–30% of cases) is commonly treated with nonoperative care, but new minimally invasive surgery (MIS) options are also effective in treating SI joint disruption. We assessed whether the higher initial MIS SI joint fusion procedure costs were offset by decreased nonoperative care costs from a US commercial payer perspective.

Methods

An economic model compared the costs of treating SI joint disruption with either MIS SI joint fusion or continued nonoperative care. Nonoperative care costs (diagnostic testing, treatment, follow-up, and retail pharmacy pain medication) were from a retrospective study of Truven Health MarketScan^® data. MIS fusion costs were based on the Premier’s Perspective™ Comparative Database and professional fees on 2012 Medicare payment for Current Procedural Terminology code 27280.

Results

The cumulative 3-year (base-case analysis) and 5-year (sensitivity analysis) differentials in commercial insurance payments (cost of nonoperative care minus cost of MIS) were $14,545 and $6,137 per patient, respectively (2012 US dollars). Cost neutrality was achieved at 6 years; MIS costs accrued largely in year 1 whereas nonoperative care costs accrued over time with 92% of up front MIS procedure costs offset by year 5. For patients with lumbar spinal fusion, cost neutrality was achieved in year 1.

Conclusion

Cost offsets from new interventions for chronic conditions such as MIS SI joint fusion accrue over time. Higher initial procedure costs for MIS were largely offset by decreased nonoperative care costs over a 5-year time horizon. Optimizing effective resource use in both nonoperative and operative patients will facilitate cost-effective health care delivery. The impact of SI joint disruption on direct and indirect costs to commercial insurers, health plan beneficiaries, and employers warrants further consideration.

Evaluation of a minimally invasive procedure for sacroiliac joint fusion - an in vitro biomechanical analysis of initial and cycled properties

INTRODUCTION

Sacroiliac (SI) joint pain has become a recognized factor in low back pain. The purpose of this study was to investigate the effect of a minimally invasive surgical SI joint fusion procedure on the in vitro biomechanics of the SI joint before and after cyclic loading.

METHODS

SEVEN CADAVERIC SPECIMENS WERE TESTED UNDER THE FOLLOWING CONDITIONS: intact, posterior ligaments (PL) and pubic symphysis (PS) cut, treated (three implants placed), and after 5,000 cycles of flexion-extension. The range of motion (ROM) in flexion-extension, lateral bending, and axial rotation was determined with an applied 7.5 N · m moment using an optoelectronic system. Results for each ROM were compared using a repeated measures analysis of variance (ANOVA) with a Holm-Šidák post-hoc test.

RESULTS

Placement of three fusion devices decreased the flexion-extension ROM. Lateral bending and axial rotation were not significantly altered. All PL/PS cut and post-cyclic ROMs were larger than in the intact condition. The 5,000 cycles of flexion-extension did not lead to a significant increase in any ROMs.

DISCUSSION

In the current model, placement of three 7.0 mm iFuse Implants significantly decreased the flexion-extension ROM. Joint ROM was not increased by 5,000 flexion-extension cycles.

Pelvic joint fusion in patients with severe pelvic girdle pain - a prospective single-subject research design study

BACKGROUND

The fusion of the pelvic joints in patients with severe pelvic girdle pain (PGP) is a controversial and insufficiently studied procedure. The aims of this study were to evaluate physical function and pain after sacroiliac joint (SIJ) fusion.

METHODS

A single-subject research design study with repeated measurements was conducted; pre-operatively and at 3, 6 and 12 months post-operatively. The outcome measures considered were the Oswestry disability index (ODI), visual analogue scale (VAS), and SF-36. Eight patients with severe PGP received open-accessed unilateral anterior SIJ fusion and fusion of the pubic symphysis.

RESULTS

Seven patients reported positive results from the surgery. At 1 year post-operation, significant (p < 0.001) reductions in ODI (54 to 37) and VAS (82 to 57) were reported. The physical functioning, bodily pain, and social functioning scores in the SF-36 were also improved.

CONCLUSION

Positive and significant changes in disability and pain at 1 year after SIJ fusion were observed. Despite these positive results, open accessed anterior fusion of the SIJ was associated with adverse events and complications such as infection and nerve damage.

Utilization of Minimally Invasive Surgical Approach for Sacroiliac Joint Fusion in Surgeon Population of ISASS and SMISS Membership

Introduction:

The sacroiliac joint (SIJ) may be a source of chronic low back pain in 15 -22% of patients. Over the past four years MIS is an emerging standard of care for SI joint fusion. The International Society for the Advancement of Spine Surgery (ISASS) and Society for Minimally Invasive Spine Surgery (SMISS) conducted a survey of their members to examine current preferences in surgeon practice of MIS SI fusion.

Methods:

To qualify for survey participation, the surgeon had to perform at least one open or MIS SIJ fusion procedure between 2009 and 2012. All surgeons were instructed to review their records. This included the number of surgical procedures performed annually from 2009-2012, site of service where each procedure was commonly performed, and average length of stay for each approach.

Results:

Twenty four percent (121/500) of the eligible members participated in this survey. This survey revealed that the percentage of MIS procedures increased from 39% in 2009 to over 87% in 2012. The survey showed a significant increase in average number of MIS surgeries and a significant difference between open and MIS surgeries in 2012 (p<0.0001). In addition, 80% of the survey respondents indicated a lack of preference toward open approach if that was the only available option.

Conclusions:

According to performed survey, MIS SIJ fusion is preferred over open technique. Incorporation of the MIS technique into the spine surgeon's specter of skills would allow an increased number of surgical options as well as possible increase in outcome quality.

Safety and 6-month effectiveness of minimally invasive sacroiliac joint fusion: a prospective study

Background

Sacroiliac (SI) joint pain is an often overlooked cause of low back pain. SI joint arthrodesis has been reported to relieve pain and improve quality of life in patients suffering from degeneration or disruption of the SI joint who have failed non-surgical care. We report herein early results of a multicenter prospective single-arm cohort of patients with SI joint degeneration or disruption who underwent minimally invasive fusion using the iFuse Implant System®.

Methods

The safety cohort includes 94 subjects at 23 sites with chronic SI joint pain who met study eligibility criteria and underwent minimally invasive SI joint fusion with the iFuse Implant System® between August 2012 and September 2013. Subjects underwent structured assessments preoperatively, immediately postoperatively, and at 1, 3, and 6 months postoperatively, including SI joint and back pain visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form-36 (SF-36), and EuroQoL-5D (EQ-5D). Patient satisfaction with surgery was assessed at 6 months. The effectiveness cohort includes the 32 subjects who have had 6-month follow-up to date.

Results

Mean subject age was 51 years (n=94, safety cohort) and 66% of patients were women. Subjects were highly debilitated at baseline (mean VAS pain score 78, mean ODI score 54). Three implants were used in 80% of patients; two patients underwent staged bilateral implants. Twenty-three adverse events occurred within 1 month of surgery and 29 additional events occurred between 30 days and latest follow-up. Six adverse events were severe but none were device-related. Complete 6-month postoperative follow-up was available in 26 subjects. In the effectiveness cohort, mean (± standard deviation) SI joint pain improved from a baseline score of 76 (±16.2) to a 6-month score of 29.3 (±23.3, an improvement of 49 points, P<0.0001), mean ODI improved from 55.3 (±10.7) to 38.9 (±18.5, an improvement of 15.8 points, P<0.0001) and SF-36 PCS improved from 30.7 (±4.3) to 37.0 (±10.7, an improvement of 6.7 points, P=0.003). Ninety percent of subjects who were ambulatory at baseline regained full ambulation by month 6; median time to full ambulation was 30 days. Satisfaction with the procedure was high at 85%.

Conclusion

Minimally invasive SI joint fusion using the iFuse Implant System® is safe. Mid-term follow-up indicates a high rate of improvement in pain and function with high rates of patient satisfaction.

Comparison of the costs of nonoperative care to minimally invasive surgery for sacroiliac joint disruption and degenerative sacroiliitis in a United States Medicare population: potential economic implications of a new minimally-invasive technology

INTRODUCTION

The economic burden associated with the treatment of low back pain (LBP) in the United States is significant. LBP caused by sacroiliac (SI) joint disruption/degenerative sacroiliitis is most commonly treated with nonoperative care and/or open SI joint surgery. New and effective minimally invasive surgery (MIS) options may offer potential cost savings to Medicare.

METHODS

An economic model was developed to compare the costs of MIS treatment to nonoperative care for the treatment of SI joint disruption in the hospital inpatient setting in the US Medicare population. Lifetime cost savings (2012 US dollars) were estimated from the published literature and claims data. Costs included treatment, follow-up, diagnostic testing, and retail pharmacy pain medication. Costs of SI joint disruption patients managed with nonoperative care were estimated from the 2005-2010 Medicare 5% Standard Analytic Files using primary International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes 720.2, 724.6, 739.4, 846.9, or 847.3. MIS fusion hospitalization cost was based on Diagnosis Related Group (DRG) payments of $46,700 (with major complications - DRG 459) and $27,800 (without major complications - DRG 460), weighted assuming 3.8% of patients have complications. MIS fusion professional fee was determined from the 2012 Medicare payment for Current Procedural Terminology code 27280, with an 82% fusion success rate and 1.8% revision rate. Outcomes were discounted by 3.0% per annum.

RESULTS

The extrapolated lifetime cost of treating Medicare patients with MIS fusion was $48,185/patient compared to $51,543/patient for nonoperative care, resulting in a $660 million savings to Medicare (196,452 beneficiaries at $3,358 in savings/patient). Including those with ICD-9-CM code 721.3 (lumbosacral spondylosis) increased lifetime cost estimates (up to 478,764 beneficiaries at $8,692 in savings/patient).

CONCLUSION

Treating Medicare beneficiaries with MIS fusion in the hospital inpatient setting could save Medicare $660 million over patients' lifetimes.

Open versus minimally invasive sacroiliac joint fusion: a multi-center comparison of perioperative measures and clinical outcomes

Background

Sacroiliac (SI) joint pain is an under diagnosed source of low back pain due in part to lack of visible pathology on radiographs and symptoms mimicking other back-related disorders. Open SI joint fusion has been performed since the 1920s. This technique has fallen out of favor with the introduction of minimally invasive options. To date there has been no direct comparison between open and MIS SI joint fusion.

Methods

We conducted a multi-center, retrospective comparative cohort study of patients who underwent SI joint fusion using either an open surgical (OS) technique using a combination of screws and cages or a minimally invasive surgical (MIS) technique with a series of titanium plasma spray (TPS) coated triangular implants. Operative measures including surgical operating time, length of hospitalization and estimated blood loss (EBL) were collected along with demographics and medical history, surgical complications, and 12- and 24-month pain scores. Improvements in pain were compared after matching for age and gender and controlling for a history of lumbar spine fusion using repeated measures analysis of variance.

Results

Data were available for 263 patients treated by 7 surgeons; 149 patients treated with OS and 114 treated with MIS SI joint fusion. Compared to OS patients, MIS patients were on average 10 years older (mean age 57 vs. 46) and 69% of all patients were female. MIS operative measures of EBL, operating time and length of hospitalization were significantly lower than open surgery (p < 0.001). Pain relief, measured as change from baseline to 12 months in VAS pain rating, was 3.5 points lower in the MIS vs. OS group (-6.2 vs. -2.7 points, p < 0.001). When matched for age, gender and a history of prior lumbar spinal fusion, postoperative pain scores were on average 3.0 points (95% CI 2.1 – 4.0) lower in MIS vs. OS (rANOVA p < 0.001).

Conclusions

In this multi-center comparative study, patients who underwent either OS or MIS SI joint fusion showed postoperative improvements in pain score. Compared to OS patients, patients who underwent MIS SI joint fusion had significantly greater pain relief and more favorable perioperative surgical measures.

Minimally invasive sacroiliac joint fusion: one-year outcomes in 18 patients

Background

Sacroiliac joint (SI) pain is an often-overlooked cause of low back pain due, in part, to lack of specific findings on radiographs and symptoms mimicking other back-related disorders. We report our experience with minimally invasive (MIS) SI joint arthrodesis using a series of triangular, titanium plasma spray (TPS) coated implants in patients refractory to conservative care.

Methods

We report outcomes from 18 patients with 12 months of postoperative follow-up.

Demographics, complications, and clinical outcomes using visual analog scale (VAS) for pain, Oswestry Disability Index (ODI) for back function and SF-12 for quality of life were collected preoperatively and at 3, 6 and 12 months post-operatively.

Results

Mean age was 64 years and 67% of patients were female. There were no intraoperative complications and one explant at three months for malposition.

All patient-reported outcomes showed both clinically and statistically significant improvement at 12 months (p < 0.001 for each of the following): VAS improved by 6.6 points, ODI scores improved by −37.5 points. One year SF-12 physical and mental component (PCS, MCS) scores approximated population normal scores for both physical and mental functioning. Patient satisfaction with outcomes was high at 95%; 89% said would have the same surgery again.

Conclusions

MIS SI joint fusion using a series of triangular porous TPS coated titanium implants is a safe and effective procedure for patients with SI joint disorders who have failed conservative care.

Minimally invasive sacroiliac joint fusion: one-year outcomes in 40 patients

Background. SI joint pain is difficult to diagnose due to overlapping symptoms of the lumbar spine, and until recently, treatment options have been limited. The purpose of this retrospective study is to report on the safety and effectiveness of MIS SI joint arthrodesis using a series of triangular, porous plasma coated implants in patients refractory to conservative care. Methods. We report on the first 40 consecutive patients with one-year follow-up data that underwent MIS SI joint fusion with the iFuse Implant System (SI-BONE, Inc., San Jose, CA) by a single surgeon. Medical charts were reviewed for demographics, perioperative metrics, complications, pain scores, and satisfaction. Results. Mean age was 58 years (range 30–81) and 75% of patients were female. Postoperative complications were minimal and included transient trochanteric bursitis (5%), facet joint pain (20%), and new low back pain (2.5%). There were no reoperations at one year. Mean pain score improved from 8.7 (1.5 SD) at baseline to 0.9 (1.6) at 12 months, a 7.8-point improvement (P < .001). Patient satisfaction was very high. Conclusions. The results of this case series reveal that MIS SI joint fusion using the iFuse Implant System is a safe and effective treatment option in carefully selected patients.