Sources of sacroiliac region pain: insights gained from a study comparing standard intra-articular injection with a technique combining intra- and peri-articular injection

Non-invasive assessment of sacroiliac joint and lumbar spine positioning in different unilateral sitting postures

BACKGROUND

Sacroiliac joint (SIJ) motion has been documented using invasive and noninvasive kinematic techniques. No study has explored SIJ angular positions in functional postures using noninvasive techniques. The purpose of this study was to quantify SIJ positioning among different seated postures in a healthy population.

METHODS

Twelve female and 11 male healthy young participants participated. Left and right anterior and posterior superior iliac spines were manually digitized during standing, neutral sitting and four different seated postures. Rigid bodies recorded the kinematics of the lumbar spine. Angles calculated included transverse sacroiliac angle, innominate sagittal angle, sacral tilt, lumbar flexion-extension, lumbar lateral bend and lumbar axial twist.

FINDINGS

The observed range of angular positions was approximately 3 to 4 degrees across the SIJ-related angles. The main effect of seated posture was observed for all angles measured. The main effect of sex was observed for all angles except lumbar lateral bending. Females consistently experienced more posterior sacral tilt than males. Interaction effects between sex and posture were only observed at the right-transverse sacroiliac angle and sacral tilt. Previous sitting posture affected the subsequent neutral sitting posture for the right-transverse sacroiliac angle and lumbar spine angle.

INTERPRETATION

SIJ angular position differences among the seated postures were similar in magnitude to motions previously reported in participants undergoing prone passive hip abduction and external rotation. Sex differences, including greater sacral posterior tilt observed in females, likely reflect underlying morphological and physiological differences. Future studies should explore SIJ positioning during functional tasks in pathological populations to help elucidate the underlying causes of SIJ pain and inform treatment strategies.

Comparison between intra-articular and combined intra- and periarticular sacroiliac injection: a prospective randomized controlled clinical trial

BACKGROUND

Sacroiliac joint dysfunction is one of the most common causes of low back pain. The aim of our study was to determine whether combined injection (intra and periarticular) of sacroiliac joint provides greater pain relief than intra-articular injection.

METHODS

This is a randomized controlled trial between two groups. The first group involved thirty patients treated with combined injection (intra- and periarticular) of a mixture of methylprednisolone acetate 40 mg and local anesthetic into a symptomatic sacroiliac joint. The second group (30 patients) received the same mixture only intra-articular. Diagnostic block was done for all cases. All patients failed to respond to medical treatment before proceeding to the injection procedure.

RESULTS

Over 6 months of follow-up, there were statistically significant improvements in patients who received combined sacroiliac joint injection according to pain Visual Analog Scale (VAS) compared with intra-articular group. Comparing both groups, there was significant difference in the 1-month VAS (one month after the procedure) as the P value was 0.010, and in the 6-month VAS (6 months after the procedure) as the P value was 0.007. There was no significant difference in the pre-VAS (P value was 0.795) and immediate post-VAS (one week after the procedure) as the P value were 0.145. No complications were reported after the procedure.

CONCLUSIONS

Although both groups provide statistically significant pain relief, patients who received combined sacroiliac joint injection have significantly greater clinical improvement as regard to those who received only intra-articular injection.

A literature review of biomechanical studies on physiological and pathological sacroiliac joints: Articular surface structure, joint motion, dysfunction and treatments

BACKGROUND

Sacroiliac joints are affected by mechanical environments; the joints are formed under mechanical stimulation, receive impact of walking between the upper and lower parts of the bodies and can be a cause of pain due to non-physiological loads. However, there are so far very few studies that reviewed biomechanics of physiological and pathological sacroiliac joints. This review article aims to describe the current sacroiliac joint biomechanics.

METHODS

Previous original papers have been summarized based on three categories: articular surface structure, sacroiliac joint motion and sacroiliac joint dysfunction and treatments.

FINDINGS

Although the articular surface morphologies vary greatly from individual to individual, many researchers have tried to classify the joints into several types. It has been suggested that the surface morphologies may not change regardless of joint dysfunction, however, the relationship between the joint structure and pain are still unclear. The range of sacroiliac joint motion is demonstrated to be less than 1 mm and there is no difference between physiological and pathological joints. The sacroiliac joint absorbs shock within the pelvis by the joint structures of pelvic morphology, ligaments and fat tissues. The morphology and motion of the sacroiliac joints may be optimized for upright bipedal walking.

INTERPRETATION

There is no doubt that pelvic mechanical environments affect pain induction and treatment; however, no one has yet provided a concrete explanation. Future research could help develop treatments based on sacroiliac joint biomechanics to support joint function.

5. Sacroiliac joint pain

INTRODUCTION

Sacroiliac (SI) joint pain is defined as pain localized in the anatomical region of the SI joint. The reported prevalence of SI joint pain among patients with mechanical low back pain varies between 15% and 30%.

METHODS

In this narrative review, the literature on the diagnosis and treatment of SI joint pain was updated and summarized.

RESULTS

Patient's history provides clues on the source of pain. The specificity and sensitivity of provocative maneuvers are relatively high when three or more tests are positive, though recent studies have questioned the predictive value of single or even batteries of provocative tests. Medical imaging is indicated only to rule out red flags for potentially serious conditions. The diagnostic value of SI joint infiltration with local anesthetic remains controversial due to the potential for false-positive and false-negative results. Treatment of SI joint pain ideally consists of a multidisciplinary approach that includes conservative measures as first-line therapies (eg, pharmacological treatment, cognitive-behavioral therapy, manual medicine, exercise therapy and rehabilitation treatment, and if necessary, psychological support). Intra- and extra-articular corticosteroid injections have been documented to produce pain relief for over 3 months in some people. Radiofrequency ablation (RFA) of the L5 dorsal ramus and S1-3 (or 4) lateral branches has been shown to be efficacious in numerous studies, with extensive lesioning strategies (eg, cooled RFA) demonstrating the strongest evidence. The reported rate of complications for SI joint treatments is low.

CONCLUSIONS

SI joint pain should ideally be managed in a multidisciplinary and multimodal manner. When conservative treatment fails, corticosteroid injections and radiofrequency treatment can be considered.

Effect of Fluoroscopic-Guided Corticosteroid Injection in Patients With Sacroiliac Joint Dysfunction

Background Sacroiliac joint dysfunction is a major cause of axial low back pain which can masquerade as pain from lumbar disc diseases. Treatment of axial back pain arising due to sacroiliac joint dysfunction remains a challenge. This study was conducted to evaluate the long and short-term effects of intra-articular corticosteroid injection in the relief of pain and disability caused by sacroiliac joint dysfunction. Methodology A total of 83 patients with sacroiliac joint dysfunction were included in this prospective randomized control study. Patients were randomized into two groups by a computer-generated randomization table. These two groups were treated with fluoroscopy-guided corticosteroid and local anesthetic injection (group A) and distilled water and local anesthetic injection (group B). Pre and post-intervention assessment of all patients was done based on the Numeric Pain Rating Scale (NPRS) for pain and Oswestry Disability Index (ODI) for disability. The outcome measures of the study were the NPRS and ODI assessed at the initial visit one (pre-injection), two weeks post-injection (visit 2), and four weeks post-injection (visit 3). Results Demographic data were comparable in both groups. There was no significant difference in pre-injection NPRS and ODI values in both groups. The changes in NPRS and ODI values were significant from pre-injection to two weeks to four weeks. Group A patients performed better in terms of a decrease in the perception of pain and a decrease in the perception of disability compared to group B patients in the second and fourth weeks of follow-up. Conclusions Fluoroscopy-guided corticosteroid injection is an effective measure for reducing pain and disability in patients with sacroiliac joint dysfunction.

Incidence of sacroiliac joint pain after lumbosacral spine fusion: A systematic review

OBJECTIVES

To determine the incidence of sacroiliac joint (SIJ) pain after lumbosacral spinal fusion.

BACKGROUND

Persistent low back pain is a potential source of disability and poor outcomes following lumbar spine fusion. The SIJ has been described as a potential source. However, there is a paucity of data concerning its importance.

METHODS

This is a PROSPERO registered systematic review. A systematic search of the English literature was performed in Medline, Embase and Cochrane Library databases. MeSH terms such as Lumbar vertebrae, Sacrum, Spinal Fusion, Pain, Sacrum, Ligaments, Sacroiliac Joint were utilized for the search. Key words such as "sacroiliac dysfunction.mp." and "sacroiliac complex.mp." were utilized for the search. Two independent reviewers reviewed articles to determine eligibility for final review and analysis. The Newcastle-Ottawa Scale was used to appraise the quality of all nonrandomized observational studies. Inverse variance weighting with random effects was used to pool data. The GRADE approach, PRISMA workflow and checklists was performed.

RESULTS

Twelve studies were included. All studies were observational and of moderate to low quality. The pooled incidence of sacroiliac joint pain was 15.8%. The pooled incidence of SIJ pain for patients without fusion extending to the sacrum was 15.8%. The pooled incidence of SIJ pain for patients with fusion extending to the sacrum was 32.9%. There was high heterogeneity.

CONCLUSION

SIJ pain is a potential cause of persistent pain after lumbar spine surgery. The current literature of poor quality. Patients presenting with pain after lumbosacral spine fusion should be evaluated for SIJ related pain.

What You Need to Know About Sacroiliac Dysfunction

Low back pain is the leading cause of disability worldwide, and sacroiliac dysfunction is estimated to occur in 15%-30% of those with nonspecific low back pain. Nurses are in the unique position to support and provide education to patients who may be experiencing sacroiliac dysfunction or possibly apply this knowledge to themselves, as low back pain is a significant problem experienced by nurses. A patient's clinical presentation, including pain patterns and characteristics, functional limitations, common etiologies and musculoskeletal system involvement, current diagnostic tools, and realm of treatments, are discussed along with their respective efficacy. Distinction is made between specific diagnosis and treatment of joint involvement and that of sacroiliac regional pain, as well as other factors that play a role in diagnosis and treatment for the reader's consideration.

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.

Does Anesthetic Relief Correspond to Future Pain Relief?: A Prospective Trial Examining Future Pain Relief for Ultrasound-Guided Corticosteroid-Anesthetic Injections

OBJECTIVES

The aim of the study was to prospectively evaluate the association between immediate pain relief from injections of local anesthetic with corticosteroid and subsequent pain relief up to 3 mos. The secondary aim was to examine the time until subjective pain relief after these injections.

DESIGN

This was a single-center, prospective study of patients undergoing ultrasound-guided corticosteroid injections for musculoskeletal pain. Subjects completed follow-up surveys at 2 wks, 1 mo, and 3 mos postinjections. χ 2 tests and sensitivity analysis were used to examine the primary outcome, at least 50% relief from the injection. Regression modeling examined the effects of demographic and injection-related variables on outcome measures.

RESULTS

A total of 132 patients were enrolled (55% female, mean age 52 yrs). Response rates were 87.1% at 2 wks and 77.2% at 3 mos. The positive likelihood ratios from 50% initial pain relief ranged from 1.22 to 1.29 at the three time points, whereas the negative likelihood ratios ranged from 0.54 to 0.63. More than 75% of participants reported subjective pain relief by day 4 after injection.

CONCLUSIONS

The predictive value of immediate pain relief for subsequent longer-term pain relief from corticosteroid-anesthetic injections is not particularly high. Most patients will obtain pain relief within 4 days of a corticosteroid injection.

Ultrasound-guided platelet-rich-plasma injections for reducing sacroiliac joint pain: A paradigmatic case report and literature review

BACKGROUND

Sacro-iliac joint (SIJ) pain is an often-misdiagnosed cause (up to 30% cases) of atypical low back pain (LBP) that might be treated with a wide range of conservative interventions. However, Platelet-Rich-Plasma (PRP) ultrasound-guided injections at SIJ level in subjects with mitochondrial disorders have not yet been investigated.

CASE PRESENTATION

A 52-year-old Caucasian male with fluoroquinolone-related mitochondrial dysfunction referred to a Physical Medicine and Rehabilitation Outpatient, complaining of severe SIJ pain (Numeric Pain Related Scale, NPRS=8). We performed two bilateral PRP ultrasound-guided injections at the sacro-iliac level. PRP is a simple, efficient, and minimally invasive approach. After the first PRP injection, there was a considerable reduction of pain (NPRS=8 vs 5). The second PRP infiltration was performed after 2 weeks and in both cases no adverse events. At the 6-month follow-up evaluation, the patient showed good physical recovery, with the absence of pain (NPRS=0).

CONCLUSION

To the best of our knowledge, this is the first report in the literature assessing the safety and effectiveness of PRP ultrasound-guided injections for SIJ pain in a patient affected by mitochondrial disorders. Thus, this case report might have relevant clinical implications in the treatment of SIJ pain in patients affected by this rare pathological condition, albeit further observational studies are warranted to confirm these findings.

A patient-cohort study of numerical analysis on sacroiliac joint stress distribution in pre- and post-operative hip dysplasia

In acetabular dysplasia, the cartilaginous roof on the acetabular side does not fully cover the femoral head, which may lead to abnormal stress distribution in both the femoral head and pelvis. These stress changes may have implications to the adjacent sacroiliac joint (SIJ). The SIJ has a minimal range of motion and is closely coupled to the adjacent spine and pelvis. In consequence, the SIJ may react sensitively to changes in stress distribution at the acetabulum, with hypermobility-induced pain. The purpose of this study was to investigate the stress distribution of the SIJ in acetabular dysplasia, and to gain insight into the cause and mechanisms of hypermobility-induced pain at the SIJ. Finite element models of pre- and postoperative pelves of four patients with acetabular dysplasia were created and analyzed in double leg standing positions. The preoperative models were relatively inflare, the sacral nutation movement, SIJ cartilage equivalent stress, and the load on the surrounding ligaments decreased with increased posterior acetabular coverage. Acetabular morphology was shown to affect the SIJ, and improvement of the posterior acetabular coverage may help normalize load transmission of the pelvis and thus improve the stress environment of the SIJ in acetabular dysplasia.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Low back pain expert systems: Clinical resolution through probabilistic considerations and poset

OBJECTIVE

Proper diagnosis of Low Back Pain (LBP) is quite challenging in especially the developing countries like India. Though some developed countries prepared guidelines for evaluation of LBP with tests to detect psychological overlay, implementation of the recommendations becomes quite difficult in regular clinical practice, and different specialties of medicine offer different modes of management. Aiming at offering an expert-level diagnosis for the patients having LBP, this paper uses Artificial Intelligence (AI) to derive a clinically justified and highly sensitive LBP resolution technique.

MATERIALS AND METHODS

The paper considers exhaustive knowledge for different LBP disorders (classified based on different pain generators), which have been represented using lattice structures to ensure completeness, non-redundancy, and optimality in the design of knowledge base. Further the representational enhancement of the knowledge has been done through construction of a hierarchical network, called RuleNet, using the concept of partially-ordered set (poset) with respect to the subset equality (⊆) relation. With implicit incorporation of probability within the knowledge, the RuleNet is used to derive reliable resolution logic along with effective resolution of uncertainties during clinical decision making.

RESULTS

The proposed methodology has been validated with clinical records of seventy seven LBP patients accessed from the database of ESI Hospital Sealdah, India over a period of one year from 2018 to 2019. Achieving 83% sensitivity of the proposed technique, the pain experts at the hospital find the design clinically satisfactory. The inferred outcomes have also been found to be homogeneous with the actual or original diagnosis.

DISCUSSIONS

The proposed approach achieves the clinical and computational efficiency by limiting the shortcomings of the existing methodologies for AI-based LBP diagnosis. While computational efficiency (with respect to both time and space complexity) is ensured by inferring clinical decisions through optimal processing of the knowledge items using poset, the clinical acceptability has been ascertained reaching to the most-likely diagnostic outcomes through probabilistic resolution of clinical uncertainties.

CONCLUSION

The derived resolution technique, when embedded in LBP medical expert systems, would provide a fast, reliable, and affordable healthcare solution for this ailment to a wider range of general population suffering from LBP. The proposed scheme would significantly reduce the controversies and confusion in LBP treatment, and cut down the cost of unnecessary or inappropriate treatment and referral.

Relieved Low Back Pain after Total Hip Arthroplasty in Patients with Both Hip Osteoarthritis and Lumbar Degenerative Disease

Objective

To investigate the relief of low back pain after hip arthroplasty in patients with hip joint and spinal degenerative diseases, and to discuss the effects of unilateral and bilateral hip surgery on the relief of low back pain.

Methods

In this retrospective study, we followed 153 patients (69 males and 84 females, age: 43–88 years) who had undergone total hip arthroplasty (THA) via a posterolateral approach and also suffered from lumbar degenerative diseases in the period of 2009 to 2019. The inclusion criteria were: (i) patients who had been diagnosed with severe hip degenerative disease and also been diagnosed with lumbar degenerative disease; (ii) patients who had undergone THA surgery; and (iii) patients who were retrospectively recruited. The exclusion criteria were: (i) patients who had undergone lumbar fusion or internal fixation surgery; or (ii) patients who had vascular claudication, history of major trauma, diabetic polyneuropathy, lumbar and pelvic infections, tumor diseases; (iii) or patients who had undergone THA because of femoral neck fracture or ankylosing spondylitis. The improvement of hip joint function and the relief of low back pain (LBP) were studied, and the effect of unilateral and bilateral THA on the relief of LBP were discussed. Hip pain and function were evaluated by the Harris Hip Score (HHS), LBP was evaluated by Visual Analog Scale (VAS), and lumbar function was evaluated by the Japanese Orthopaedic Association (JOA) scoring system.

Results

The average follow‐up time was 44.3 months (24–108 months). All patients recovered smoothly without complications. The LBP VAS of 153 patients decreased from 4.13 ± 1.37 preoperatively to 1.90 ± 1.44 postoperatively. The average HHS increased from 45.33 ± 13.23 preoperatively to 86.44 ± 7.59 postoperatively at the latest follow‐up. According to Japanese Orthopaedic Association scoring system, the proportion of patients with good response to treatment in these 153 patients reached 93.46%. LBP VAS decreased from 4.18 ± 1.38 preoperatively to 1.95 ± 1.49 postoperatively in unilateral group and from 3.94 ± 1.32 preoperatively to 1.73 ± 1.23 postoperatively in bilateral group, respectively. There were only nine patients with persistent or aggravated LBP after operation. Among them, six patients underwent subsequent lumbar surgery (five patients had pain relieved after reoperation and one patient had not) and the other three patients chose conservative treatment for pain.

Conclusion

THA can relieve LBP while relieving hip pain and restoring hip function in patients with both hip and lumbar degenerative disease, thus possibly avoiding further spinal surgery.

Impact of flow pattern, body mass index, and age on intraprocedural fluoroscopic time and radiation dose during sacroiliac joint injections

PURPOSE

Understanding all factors that may impact radiation dose and procedural time is crucial to safe and efficient image-guided interventions, such as fluoroscopically guided sacroiliac (SI) joint injections. The purpose of this study was to evaluate the effect of flow pattern (intra- vs. periarticular), patient age, and body mass index (BMI) on radiation dose and fluoroscopy time.

METHODS

A total of 134 SI joint injections were reviewed. Injectate flow pattern, age, and BMI were analyzed in respect to fluoroscopy time (minutes), radiation dose (kerma area product (KAP); µGy m²), and estimated skin dose (mGy).

RESULTS

BMI did not affect fluoroscopy time, but increased BMI resulted in significantly higher skin and fluoroscopy doses (p < 0.001). There was no association between fluoroscopy time and flow pattern. Higher skin dose was associated with intraarticular flow (p = 0.0086), and higher KAP was associated with periarticular flow (p = 0.0128). However, the odds ratios were close to 1. There was no significant difference between fluoroscopy time or dose based on patient age.

CONCLUSION

Increased BMI had the largest impact on procedural radiation dose and skin dose. Flow pattern also showed a statistically significant association with radiation dose and skin dose, but the clinical difference was small. Proceduralists should be aware that BMI has the greatest impact on fluoroscopy dose and skin dose during SI joint injections compared to other factors.

Anatomical study of the innervation of different parts of the posterior ligamentous region of the sacroiliac joint

BACKGROUND AND OBJECTIVES

The periarticular sacroiliac joint (SIJ) technique has become an important area of focus, and the quartering of the SIJ posterior ligamentous region has been proposed as a way to refine this technique. However, detailed nerve distribution combined with the division of the SIJ posterior ligamentous region is lacking. We aimed to explore the innervation of the SIJ posteriorly based on the quartering of the SIJ posterior ligamentous region.

METHODS

Sixteen SIJs from eight embalmed cadavers were studied. Each SIJ posterior ligamentous region was equally divided into areas 0-3 from top to bottom. The origin, distribution, quantity, transverse diameter, spatial orientation, relation with bony structures, and the number of identifiable terminal nerve branches in each area were examined.

RESULTS

Areas 0-1 were innervated by the lateral branches of the dorsal rami of L4-L5 directly in all specimens. Areas 2-3 were innervated by that of both lumbar and sacral nerves via the posterior sacral network (PSN), with L5 contributing to the PSN in all specimens and L4 in 68.75%. The number of identifiable terminal nerve branches were significantly higher in areas 2-3 than in areas 0-1.

CONCLUSIONS

The inferior part of the SIJ posterior ligamentous region seems to be the main source of SIJ-related pain and is innervated by lumbar and sacral nerves via the PSN. However, the superior part directly innervated by lumbar nerves should not be neglected, and further clinical verification is needed.

Pain and functional outcomes of the sacroiliac joint after platelet-rich plasma injection: a descriptive review

The purpose of this manuscript is to highlight and review the status of literature regarding efficacy of platelet-rich plasma (PRP) in the treatment of sacroiliac joint (SIJ) dysfunction. A review of the literature on PRP interventions on the SIJ or ligaments was performed. Seven studies had improvements in their respective primary end point and demonstrated a strong safety profile without any serious adverse events. Only five articles demonstrated clinical efficacy of >50% in their primary outcome measures. There appears to be inconsistent and insufficient evidence for a conclusive recommendation for or against SIJ PRP. There is a need for adequately powered well-designed, standardized, double-blinded randomized clinical trials to determine the effectiveness of PRP in SIJ-mediated pain.

Does the presence of cranial contrast spread during a sacroiliac joint injection predict short-term outcome?

BACKGROUND

The innervation of the sacroiliac joint (SIJ) is complex, with a dual innervation originating from the lumbosacral plexus anteriorly as well as the sacral lateral branches posteriorly. Nociceptors are found in intra-articular structures as well as periarticular structures. In patients with SIJ pain, a fluoroscopy-guided SIJ injection is usually performed posteriorly into the bottom one-third of the joint with local anesthetic and corticosteroids, but this does not always reach all intra-articular structures. The correlation between a cranial contrast spread and clinical success is undetermined in patients with SIJ pain.

METHODS

In a tertiary referral pain center, electronic medical records of patients who underwent an SIJ injection were retrospectively analyzed. Only patients with at least three positive provocation maneuvers for SIJ pain were selected. Contrast images of the SIJ were classified as with or without cranial spread on fluoroscopy as a marker of intra-articular injection. Clinical success was defined as ≥50% improvement in the patient's global perceived effect after 3-4 weeks. The primary outcome was defined as the correlation between cranial contrast spread and clinical success after an SIJ injection.

RESULTS

128 patients in total were included. In 68 patients (53.1%) fluoroscopy showed cranial contrast spread. Clinical success was higher in patients with cranial spread of contrast (55 of 68, 81%) versus those without (35 of 60, 58%) (p=0.0067). In a multivariable analysis with age, gender, presence of rheumatoid arthritis, side, and number of positive provocation maneuvers, the cranial spread of contrast remained the only independent factor of clinical success (p=0.006; OR 3.2, 95% CI 1.4 to 7.7).

CONCLUSION

In patients with SIJ pain, identified by positive pain provocation maneuvers, cranial contrast spread as a marker of intra-articular injection, with subsequent injection of 3 mL of local anesthetic and methylprednisolone 40 mg, was significantly correlated with clinical success up to 4 weeks. Therefore, attempts should be made to reach this final needle position before injecting local anesthetic and corticosteroids. This result needs to be confirmed in a high-quality prospective trial.

Sacroiliac joint syndrome after lumbosacral fusion

INTRODUCTION

One-third of low back pain cases are due to the sacroiliac (SI) joint. The incidence increases after lumbosacral fusion. A positive Fortin Finger Test points to the SI joint being the origin of the pain; however, clinical examination and imaging are not specific and minimally contributory. The gold standard is a test injection of local anesthetic. More than 70% reduction in pain after this injection confirms the SI joint is the cause of the pain. The aim of this study was to evaluate the decrease in pain on a Numerical Rating Scale (NRS) after intra-articular injection into the SI joint. We hypothesised that intra-articular SI injection will significantly reduce SI pain after lumbosacral fusion.

METHODS

All patients with pain (NRS>7/10) suspected of being caused by SI joint syndrome 1 year after lumbosacral fusion with positive Fortin test were included. Patients with lumbar or hip pathologies or inflammatory disease of the SI joint were excluded. Each patient underwent a 2D-guided injection of local anesthetic into the SI joint. If this failed, a second 2D-guided injection was done; if this also failed, a third 3D-guided injection was done. Reduction of pain on the NRS by>70% in the first 2 days after the injection confirmed the diagnosis. Whether the injection was intra-articular or not, it was recorded. Ninety-four patients with a mean age of 57 years were included, of which 70% were women.

RESULTS

Of the 94 patients, 85 had less pain (90%) after one of the three injections. The mean NRS was 8.6/10 (7-10) before the injection and 1.7/10 after the injection (0-3) (p=0.0001). Of the 146 2D-guided injections, 41% were effective and 61% were intra-articular. Of the 34 3D-guided injections, 73% were effective and 100% were intra-articular.

DISCUSSION

This study found a significant decrease in SI joint-related pain after intra-articular injection into the SI joint in patients who still had pain after lumbosacral fusion. If this injection is non-contributive when CT-guided under local anesthesia, it can be repeated under general anesthesia with 3D O-arm guidance. This diagnostic strategy allowed us to confirm that pain originates in the SI joint after lumbosacral fusion in 9 of 10 patients.

CONCLUSION

If the first two CT-guided SI joint injections fail, 3D surgical navigation is an alternative means of doing the injection that helps to significantly reduce SI joint-related pain after lumbosacral fusion.

LEVEL OF EVIDENCE

IV, retrospective study.

O-arm-guided sacroiliac joint injection: New techniques with reflux test

Diagnosis of degenerative sacroiliac pain syndrome is difficult. Sacroiliac injection confirms diagnosis by relieving pain. The present study aimed to describe a sacroiliac injection technique under O-arm guidance. Fifty-four patients, with a mean age of 58 years, presenting resistant sacroiliac pain syndrome after two 2D CT-guided injections received O-arm guided sacroiliac injection. Anesthetic reflux on joint lavage validated the technique. Clinical efficacy was assessed as pain relief on a simple numeric scale (positive if>70%). Reflux was observed in 92% of cases. Pain was relieved in 81%, with mean score reduced to 3.1 from 8.5. O-arm guided sacroiliac injection was reproducible and relieved sacroiliac pain after failure of 2D-guided injection, thus confirming the clinical diagnosis.

Pain and Functional Outcomes After Sacroiliac Joint Injection with Anesthetic and Corticosteroid at Six Months, Stratified by Anesthetic Response and Physical Exam Maneuvers

OBJECTIVE

To evaluate sacroiliac joint (SIJ) injection outcomes with local anesthetic and corticosteroid.

DESIGN

Prospective cohort.

SETTING

Single academic medical center.

METHODS

Thirty-four patients referred for SIJ injection with a clinical diagnosis of SIJ pain underwent injections with 1:1 mixture of 2% lidocaine and triamcinolone 40 mg/mL. Pain provocation physical exam (PE) maneuvers were recorded immediately before and after injection. Outcome measures at two to four weeks and six months included pain numeric rating scale (NRS) and Oswestry Disability Index (ODI).

RESULTS

For the analysis of outcomes by the overall group (not stratified by PE and/or anesthetic block), a 58.8% (95% confidence interval [CI] = +/-16.5%) ≥2 NRS reduction, a 32.4% (95% CI = +/-15.7%) ≥50% NRS reduction, and a 38.2% (95% CI = +/-16.3%) ≥30% ODI reduction were observed at two to four weeks, with similar improvements at six months. Outcomes stratified based on pre-injection PE did not reveal significant differences at either time point. The stratification based on the presence of 100% postinjection anesthetic response demonstrated a significant difference at two to four weeks for ≥50% NRS improvement. The true positive/true negative group (TP/TN) stratification demonstrated a significant difference for ≥50% NRS improvement at two to four weeks, whereas six-month outcomes for TP/TN demonstrated significant differences for ≥50% NRS and ≥30% ODI improvement. An increased injection response was observed with stratification of patients more likely to have true SIJ pain (i.e., TP), with TP/TN stratification demonstrating a 75% (95% CI = +/-30.0%) ≥2 NRS improvement and a 62.5% (95% CI = +/-33.5%) improvement of ≥50% NRS and ≥30% ODI for the TP group at two to four weeks, with similar results at six months.

CONCLUSIONS

SIJ steroid injection based on referral clinical diagnosis is unlikely to demonstrate true injection efficacy, and more specific selection criteria are warranted.

Diagnosis and interventional pain management options for sacroiliac joint pain

The sacroiliac (SI) joint is among the most common sources of chronic low back pain, accounting for 15%–30% of patients presenting chronic low back pain. The complex anatomic structures, nerve innervation, and functional biomechanisms of the SI region make it challenging to diagnose and treat the SI joint as a pain source. In addition to physical therapy and medication for treating SI joint pain, multiple interventional measures including steroid injection, radiofrequency ablation, prolotherapy, and SI joint fusion have been proposed with various efficacies. This article describes the etiology, risk factors, and diagnostic methods as well as the different treatment modalities, focusing on interventional pain management options for patients suffering from SI joint pain.

Successful Thermal Neurotomy of the Painful Sacroiliac Ligament/Joint Complex—A Comparison of Two Techniques

Background

There are many physical, pharmacological, and interventional therapies aimed at alleviating sacroiliac ligament/joint complex pain, including thermal neurotomy. Sacroiliac joint (SIJ) innervation, as opposed to posterior sacroiliac ligament complex innervation, remains uncertain; thus lateral branch thermal neurotomy to alleviate sacroiliac joint pain remains controversial.

Objective

This study aimed to compare the success rates of two lateral branch neurotomy techniques, large continuous-lesion multi-electrode radiofrequency neurotomy (RFN; Simplicity, Neurotherm Inc.) and small-lesion monopolar periforaminal, to relieve pain from sacroiliac joints, as well as whether these would alter physical and psychological health.

Design

Retrospective clinical audit of prospectively gathered consecutive data.

Setting

A private community-based multidisciplinary pain clinic.

Subjects

Referred from primary care environments.

Methods

Of 96 consecutive thermal neurotomies with baseline data completed, follow-up data were found in 73 patients during the period 2011–2017. After diagnosis by dual-positive fluoroscopic intra-articular injections, 41 patients underwent 47 monopolar periforaminal neurotomies, and 32 underwent 49 large continuous-lesion multi-electrode RFNs, with &gt;12-month follow-up. The primary outcome was 50–100% relief of pain for more than six months. Results are presented as success rates. Secondary outcomes were Functional Rating Index Depression Anxiety and Stress Scale and Patient Specific Functional Scale.

Results

Follow-up data were available for 80 (83%) of the 96 procedures. Success occurred in 69% of all procedures (39% complete &gt;75% relief and 30% good 50–75% relief). Success was 57% with worst-case analysis. Success rates were 71% in the large continuous-lesion multi-electrode RFN group and 65% in the periforaminal group, with overlapping confidence intervals. Significant improvements also occurred in the secondary measures.

Conclusions

Thermal neurotomy demonstrated a 69% success rate in reduction of sacroiliac ligament/joint complex pain for more than six months equally by large continuous-lesion multi-electrode RFN and periforaminal monopolar techniques, with attendant improvement in physical and psychological function.

Pearls and pitfalls of fluoroscopic-guided foot and ankle injections: what the radiologist needs to know

OBJECTIVE

This article provides a comprehensive, joint-by-joint review of fluoroscopic-guided foot and ankle injections and emphasizes pre-procedural planning, relevant anatomy, appropriate technique, troubleshooting the difficult procedure, and the importance of communicating unexpected findings with the referring clinician. The interrogation of pain generators including variant ossicles, fractures, and post-surgical/traumatic findings is also described.

CONCLUSIONS

Even the most challenging foot and ankle injections may be successfully completed with a solid anatomical understanding and thoughtful approach.

Middle cluneal nerve entrapment mimics sacroiliac joint pain

BACKGROUND

Sacroiliac joint (SIJ)-related pain is associated with low back- and buttock pain and the SIJ score is diagnostically useful because it helps to differentiate between SIJ-related pain and pain due to other factors such as lumbar disc herniation and lumbar spinal canal stenosis. Middle cluneal nerve (MCN) entrapment (MCN-E) can produce pain involving the lower back and buttocks. Therefore, the origin of the pain must be identified. We successfully treated patients with a high SIJ score whose pain was attributable to MCN-E.

METHODS

Between August 2016 and June 2017, we treated 40 patients with non-specific low back pain. Among them, 18 (45%) presented with a positive SIJ score. Although SIJ treatment was unsuccessful in 4 of these patients, they responded to MCN-E treatment.

RESULTS

All 4 patients reported tenderness at the site of the sacrotuberous ligament (STL); 3 were positive for the one-finger test and experienced pain while sitting in a chair. The effect of SIJ block was inadequate in the 4 patients. As they reported severe pain at the trigger point in the area of the MCN, we performed MCN blockage. It resulted in pain control. However, in 1 patient, the effect of MCN block was transient and required MCN neurolysis. At the last visit, our patients' symptoms were significantly improved; their average numerical rating scale score fell from 8.3 to 1.0, their Roland-Morris Disability Questionnaire score fell from 12.8 to 0.3, and their average Japanese Orthopaedic Association score rose from 12.5 to 19.5.

CONCLUSIONS

In patients with suspected SIJ-related pain, the presence of MCN-E must be considered when the effect of SIJ block is unsatisfactory.

Fluoroscopically Guided vs Landmark-Guided Sacroiliac Joint Injections: A Randomized Controlled Study

OBJECTIVES

To determine the prevalence of intra- and extra-articular sacroiliac joint (SIJ) pain, which injection is more beneficial, and whether fluoroscopy improves outcomes.

PATIENTS AND METHODS

This patient- and evaluator-blinded comparative effectiveness study randomized 125 participants with SIJ pain from April 30, 2014, through December 12, 2017, to receive fluoroscopically guided injections into the joint capsule (group 1) or "blind" injections to the point of maximum tenderness using sham radiographs (group 2). The primary outcome was average pain on a 0 to 10 scale 1 month after injection. A positive outcome was defined as at least a 2-point decrease in average pain score coupled with positive (>3) satisfaction on a Likert scale from 1 to 5.

RESULTS

For the primary outcome, no significant differences were observed between groups (mean ± SD change from baseline, -2.3±2.4 points in group 1 vs -1.7±2.3 points in group 2; 95% CI, -0.33 to 1.36 points for adjusted difference; P=.23), nor was there a difference in the proportions of positive blocks (61% vs 62%) or 1-month categorical outcome (48% vs 40% in groups 1 and 2, respectively; P=.33). At 3 months, the mean ± SD reductions in average pain (-1.8±2.1 vs -0.9 ± 2.0 points; 95% CI, 0.11 to 1.58 points for adjusted difference; P=.02) and worst pain (-2.2±2.5 vs -1.4±2.0 points; 95% CI, 0.01 to 1.66 points for adjusted difference; P=.049) were greater in group 1 than 2, with other outcome differences falling shy of statistical significance.

CONCLUSION

Although fluoroscopically guided injections provide greater intermediate-term benefit in some patients, these differences are modest and accompanied by large cost differences.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02096653.

The association between sacroiliac joint-related pain following lumbar spine surgery and spinopelvic parameters: a prospective multicenter study

PURPOSE

To prospectively calculate the incidence of postoperative sacroiliac joint-related pain (SIJP) and investigate the association between spinopelvic parameters and postoperative SIJP after lumbar spine surgery.

METHODS

We prospectively enrolled consecutive patients who underwent lumbar spine surgery. We defined postoperative SIJP as unilateral buttock pain according to fulfillment of the following criteria within 3 months of the surgery: a sacroiliac joint (SIJ) score higher than 4/9 postoperatively; positive response to analgesic periarticular SIJ injection with fluoroscopy; no other complications related to the surgery. The patients were divided into the SIJP group and non-SIJP group. We compared the background information and analyzed the differences in spinopelvic parameters in both groups. Additionally, receiver-operating characteristic curve analyses were performed to evaluate the cutoff values of spinopelvic parameters.

RESULTS

Of the 281 patients enrolled, 265 were included and eight developed postoperative SIJP (3.0%). There were no significant differences in the background information between groups. Preoperative and postoperative radiological evaluations revealed that the pelvic incidence (PI) in the SIJP group was significantly higher than that in the non-SIJP group, and there were no significant differences in lumbar lordosis (LL), pelvic tilt, sacral slope, and PI minus LL. For preoperative PI, the area under the curve, cutoff value, sensitivity, and specificity were 0.73739, 59, 62.5%, and 81.9%, respectively.

CONCLUSIONS

The incidence of postoperative SIJP after lumbar spine surgery was 3.0%. Higher PI values were associated with a higher risk of postoperative SIJP. These slides can be retrieved under Electronic Supplementary Material.

Diagnosing Sacroiliac Joint Pain

The sacroiliac joint (SIJ) is a diarthrodial joint that has been implicated as a pain generator in approximately 10% to 25% of patients with mechanical low back or leg symptoms. Unique anatomic and physiologic characteristics of SIJ make it susceptible to mechanical stress and also create challenges in the diagnosis of SIJ pain. A variety of inciting causes for SIJ pain may exist, ranging from repetitive low-impact activities such as jogging to increased stress after multilevel spine fusion surgery to high-energy trauma such as in motor vehicle accidents. Similarly, wide variability exists in the clinical presentation of SIJ pain from localized pain or tenderness around the SIJ to radiating pain into the groin or even the entire lower extremity. No pathognomonic clinical history, physical examination finding, or imaging study exists that aids clinicians in making a reliable diagnosis. However, imaging combined with clinical provocative tests might help to identify patients for further investigation. Although provocative physical examination tests have not received reliable consensus, if three or more provocative tests are positive, pursuing a diagnostic SIJ injection is considered reasonable. Notable pain relief with intra-articular anesthetic injection under radiographic guidance has been shown to provide reliable evidence in the diagnosis of SIJ pain.

Fluoroscopic-guided sacroiliac, joint injections for treatment of chronic axial low back pain in a tertiary Hospital in Nigeria: a preliminary study

BACKGROUND

The injection of mixture of plain bupivacaine and triamcinolone acetonide into the sacroiliac joint (SIJ) to relieve chronic low back pain is uncommon in the West African sub-region. The objective of this study was to demonstrate the efficacy or otherwise of fluoroscopic-guided SI joint injection in the management of chronic axial low back pain in Nigeria.

DESIGN

This was a prospective observational interventional study.

SETTING

The study was carried out at a tertiary hospital in Nigeria.

PARTICIPANTS

Twenty-six patients with SI joint pain, based on IASP diagnostic criteria, who presented to our unit over 36 months from March 2012 to March 2015 and.

INTERVENTIONS

Fluoroscopic-guided injections of 5mls mixture of bupivacaine and triamcinolone acetonide into the sacro-iliac (SI) joints of 26 patients with SI joint pain out of 116 patients who were offered different interventions for chronic low back pain. The patients were followed up for year and pain intensity and functional status were assessed at 3-, 6- and 12 months post-intervention.

MAIN OUTCOME MEASURES

Pain relief and functional improvement were the main outcome measures.

RESULTS

The mean numeric rating score (NRS) and Oswestry Disability index (ODI) score in 14 (53.9%) patients at 12 months post-interventions were significantly lower compared with baseline values; 3.19 ± 1.10 vs 8.54 ±1.14 p=0.000 and 25.35 ± 5.40 vs 37.54 ±8.41, p=0.000 respectively.

CONCLUSION

Fluoroscopic-guided steroid injection into the SI joint resulted into reduction in pain intensity and improved physical function in the majority of patients with SI joint pain.

FUNDING

Not declared.

Validation study of a diagnostic scoring system for sacroiliac joint-related pain

Background

There are no specific radiological findings for the diagnosis of sacroiliac joint-related pain. A diagnostic scoring system had been developed in 2017. The score comprised the sum of scores of six items. The score ranged from 0 to 9 points, and the cutoff was calculated as 4.

Objective

To evaluate the validity of the diagnostic scoring system for sacroiliac joint-related pain.

Patients and methods

The sacroiliac joint-related pain group (n=31) comprised patients diagnosed with sacroiliac joint-related pain based on patient history, physical findings, and responses to analgesic periarticular injection. In addition, it was confirmed that they had no other lumbar or hip joint diseases. The non-sacroiliac joint-related pain group (n=123) comprised patients with low back pain due to a reason other than sacroiliac joint-related pain. We evaluated scores for all subjects. We analyzed the differences in each item between both groups and performed receiver-operating characteristic curve analysis to evaluate the score validity.

Results

There were no significant differences in patient characteristics between groups. There were significant differences for the following four of six items: one-finger test results (P<0.0001), pain while sitting on a chair (P=0.0141), sacroiliac joint shear test results (P<0.0001), and tenderness of the posterosuperior iliac spine (P<0.0001). The cut-off value was 5 points, the area under the curve was 0.80239, sensitivity was 77.4%, and specificity was 76.4%.

Conclusion

The score demonstrated moderate validity for diagnosing sacroiliac joint-related pain.

A Diagnostic Scoring System for Sacroiliac Joint Pain Originating from the Posterior Ligament

Objective

Sacroiliac joint (SIJ) pain originating from the posterior ligament manifests in not only the buttocks but also the groin and lower extremities and thus may be difficult to discern from pain secondary to other lumbar disorders. We aimed to develop a simple clinical diagnostic tool to help physicians distinguish between patients with SIJ pain originating from the posterior ligament and those with lumbar disc herniation (LDH) or lumbar spinal canal stenosis (LSS).

Design

Prospective case-control study.

Patients and Methods

We evaluated 62 patients with SIJ pain originating from the posterior ligament and 59 patients with LDH and LSS. Pain areas, pain increasing positions, provocation test, and tenderness points were investigated. A scoring system based on multivariate logistic regression equations using the investigated items was developed.

Results

Two pain areas (the posterosuperior iliac spine (PSIS) detected by the one-finger test and groin), pain while sitting on a chair, provocation test, and two tenderness points (PSIS and the sacrotuberous ligament) had high odds ratios (range, 25.87–1.40) and were used as factors in the scoring system. An integer score derived from the regression coefficient and clinical experience was assigned to each identified risk factor. The sum of the risk score for each patient ranged from 0–9. This scoring system had a sensitivity of 90.3% and a specificity of 86.4% for a positivity cutoff point of 4.

Conclusion

The scoring system can help distinguish between patients with SIJ pain originating from the posterior ligament and those with LDH and LSS.

Fluoroscopy-Guided Sacroiliac Intraarticular Injection via the Middle Portion of the Joint

Objective

Sacroiliac intraarticular injection is necessary to confirm sacroiliac joint (SIJ) pain and is usually performed via the caudal one-third portion of the joint. However, this is occasionally impossible for anatomical reasons, and the success rate is low in clinical settings. We describe a technique via the middle portion of the joint.

Design

Observational study.

Subjects

Enrolled were 69 consecutive patients (27 men and 42 women, with an average age of 53 years) in whom the middle portion of 100 joints was targeted.

Method

With the patient lying prone-oblique with the painful side down, a spinal needle was inserted into the middle portion of the joint. Subsequently, the fluoroscopy tube was angled at a caudal tilt of 25-30° to clearly detect the recess between the ilium and sacrum and the needle depth and direction. When the needle reached the posterior joint line, 2% lidocaine was injected after the contrast medium outlined the joint.

Results

The success rate of the injection method was 80% (80/100). Among 80 successful cases, four were previously unsuccessful when the conventional method was used. Intraarticular injection using the new technique was unsuccessful in 20 joints; in three of these cases, the conventional method proved successful, and no techniques were successful in the other 17 cases.

Conclusion

The injection technique via the middle portion of the joint can overcome some of the difficulties of the conventional injection method and can improve the chances of successful intraarticular injection.

The effect of intra-articular stimulation by pulsed radiofrequency on chronic sacroiliac joint pain refractory to intra-articular corticosteroid injection: A retrospective study

We investigated the degree of pain reduction following intra-articular (IA) pulsed radiofrequency (PRF) stimulation of the sacroiliac joint (SIJ) in patients with chronic SIJ pain that had not responded to IA corticosteroid injection. Twenty patients were recruited. Clinical outcomes after applying PRF stimulation of the SIJ were evaluated by a numeric rating scale (NRS) and a 7-point Likert scale. The NRS scores significantly changed over time. The NRS scores at 1, 2, and 3 months after PRF were significantly lower than those before PRF. However, 4 of the 20 patients (20%) reported successful pain relief (pain relief of ≥ 50%) and were satisfied with the PRF stimulation at 3 months after treatment. IA PRF stimulation of the SIJ was not successful in most patients (80% of all patients). Based on our results, we cannot recommend this procedure to patients with chronic SIJ pain that was unresponsive to IA SIJ corticosteroid injection. Further studies on the effective mode of PRF stimulation and appropriate patient group, and studies on pain conditions that are most responsive to PRF are needed in the future.

A New Sacroiliac Joint Injection Technique and Its Short-Term Effect on Chronic Sacroiliac Region Pain

OBJECTIVES

Sacroiliac joint (SIJ) injections have been used to provide short-term relief of SIJ pain. In this study, the authors investigated a new technique using a superior approach.

METHODS

Twenty four patients with chronic SI joint paint were recruited. Each patient was treated with a single SIJ intra-articular injection plus a periarticular injection of local anesthetic and corticosteroid in one procedure. Technical accuracy of the intra-articular procedure was determined by having 2 independent observers review and rate the quality of arthrograms obtained. Treatment effects were evaluated using a numerical rating scale, the Oswestry disability index (ODI) and global perceived effect (GPE).

RESULTS

Both independent observers agreed that satisfactory arthrograms were obtained in all patients. Pain scores and disability were significantly reduced at 2 weeks and 4 weeks after treatment. Nineteen patients (79%) reported satisfaction with treatment. No serious adverse effects were encountered.

CONCLUSIONS

The superior approach consistently achieves good access to the SI joint, and achieves outcomes that are compatible with those of other techniques. The superior approach constitutes an alternative to other techniques for injections into the SI joint.

Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment

Sacroiliac joint (SIJ) pain is an underappreciated source of mechanical low back pain, affecting between 15 and 30% of individuals with chronic, nonradicular pain. Predisposing factors for SIJ pain include true and apparent leg length discrepancy, older age, inflammatory arthritis, previous spine surgery, pregnancy and trauma. Compared with facet-mediated and discogenic low back pain, individuals with SIJ pain are more likely to report a specific inciting event, and experience unilateral pain below L5. Owing in part to its size and heterogeneity, the pain referral patterns of the SIJ are extremely variable. Although no single physical examination or historical feature can reliably identify a painful SIJ, studies suggest that a battery of three or more provocation tests can predict response to diagnostic blocks. Evidence supports both intra- and extra-articular causes for SIJ pain, with clinical studies demonstrating intermediate-term benefit for both intra- and extra-articular steroid injections. In those who fail to experience sustained relief from SIJ injections, radiofrequency denervation may provide significant relief lasting up to 1 year. This review covers all aspects of SIJ pain, with the treatment section being primarily focused on procedural interventions.