The sacroiliac joint (SIJ) is a frequently underestimated cause of lower back (LBP). A simple clinical test of sufficient validity would be desirable. The aim of this study was to evaluate the diagnostic value of a new PSIS distraction test for the clinical detection of SIJ arthropathy and to compare it to several commonly used clinical tests.
Consecutive patients, where a SIJ pathology had been confirmed by an SIJ infiltration were enrolled (case group, 61 SIJs in 46 patients). Before infiltration, patients were tested for pain with PSIS distraction by a punctual force on the PSIS in medial-to-lateral direction (PSIS distraction test), pain with pelvic compression, pelvic distraction, Gaenslen test, Thigh Thrust, and Faber (or Patrick’s) test. In addition, these clinical tests were applied to both SIJs of a population of individuals without history of LBP (control group, 64 SIJs in 32 patients).
Within the investigated cohort, the PSIS distraction test showed a sensitivity of 100% and a specificity of 89% for SIJ pathology. The accuracy of the test was 94%, the positive predictive value (PPV) was 90% and the negative predictive value (NPV) was 100%. Pelvic compression, pelvic distraction, Gaenslen test, Thigh Thrust, and Faber test were associated with a good specificity (> 90%) but a poor sensitivity (< 35%).
Within our population of patients with confirmed SIJ arthropathy the PSIS distraction test was found to be of high sensitivity, specificity and accuracy. In contrast, common clinical tests showed a poor sensitivity. The PSIS distraction test seems to be an easy-to-perform and clinically valuable test for SIJ arthropathy.
Sacroiliac joint pain; Provocation test; Joint infiltration; Diagnostic value
Sacroiliac joint (SIJ) pain refers to the pain arising from the SIJ joint structures. SIJ dysfunction generally refers to aberrant position or movement of SIJ structures that may or may not result in pain. This paper aims to clarify the difference between these clinical concepts and present current available evidence regarding diagnosis and treatment of SIJ disorders. Tests for SIJ dysfunction generally have poor inter-examiner reliability. A reference standard for SIJ dysfunction is not readily available, so validity of the tests for this disorder is unknown. Tests that stress the SIJ in order to provoke familiar pain have acceptable inter-examiner reliability and have clinically useful validity against an acceptable reference standard. It is unknown if provocation tests can reliably identify extra-articular SIJ sources of pain. Three or more positive pain provocation SIJ tests have sensitivity and specificity of 91% and 78%, respectively. Specificity of three or more positive tests increases to 87% in patients whose symptoms cannot be made to move towards the spinal midline, i.e., centralize. In chronic back pain populations, patients who have three or more positive provocation SIJ tests and whose symptoms cannot be made to centralize have a probability of having SIJ pain of 77%, and in pregnant populations with back pain, a probability of 89%. This combination of test findings could be used in research to evaluate the efficacy of specific treatments for SIJ pain. Treatments most likely to be effective are specific lumbopelvic stabilization training and injections of corticosteroid into the intra-articular space.
Corticosteroid Injection; Diagnostic Accuracy; Intra-Articular Injection; Lumbopelvic Stabilization Training; Pregnancy-Related Pelvic Girdle Pain; Sacroiliac Joint Dysfunction; Sacroiliac Joint Pain
Sacroiliac joint (SIJ) dysfunction is an underdiagnosed condition. Several published cohorts have reported favorable mid-term outcomes after SIJ fusion using titanium implants placed across the SIJ. Herein we report long-term (24-month) results from a prospective multicenter clinical trial.
One hundred and seventy-two subjects at 26 US sites with SI joint dysfunction were enrolled and underwent minimally invasive SI joint fusion with triangular titanium implants. Subjects underwent structured assessments preoperatively and at 1, 3, 6, 12, 18 and 24 months postoperatively, including SIJ pain ratings (0-100 visual analog scale), Oswestry Disability Index (ODI), Short Form-36 (SF-36), EuroQOL-5D (EQ-5D), and patient satisfaction. Adverse events were collected throughout follow-up. All participating patients underwent a high-resolution pelvic CT scan at 1 year.
Mean subject age was 50.9 years and 69.8% were women. SIJ pain was present for an average of 5.1 years prior to surgical treatment. SIJ pain decreased from 79.8 at baseline to 30.4 at 12 months and remained low at 26.0 at 24 months (p<.0001 for change from baseline). ODI decreased from 55.2 at baseline to 31.5 at 12 months and remained low at 30.9 at 24 months (p<.0001 for change from baseline). Quality of life (SF-36 and EQ-5D) improvements seen at 12 months were sustained at 24 months. The proportion of subjects taking opioids for SIJ or low back pain decreased from 76.2% at baseline to 55.0% at 24 months (p <.0001). To date, 8 subjects (4.7%) have undergone one or more revision SIJ surgeries. 7 device-related adverse events occurred. CT scan at one year showed a high rate (97%) of bone adherence to at least 2 implants on both the iliac and sacral sides with modest rates of bone growth across the SIJ.
In this study of patients with SIJ dysfunction, minimally invasive SI joint fusion using triangular titanium implants showed marked improvements in pain, disability and quality of life at 2 years. Imaging showed that bone apposition to implants was common but radiographic evidence of intraarticular fusion within the joint may take more than 1 year in many patients.
This prospective multicenter clinical trial was approved by local or regional IRBs at each center prior to first patient enrollment. Informed consent with IRB-approved study-specific consent forms was obtained from all patients prior to participation.
sacroiliac joint dysfunction; sacroiliac joint fusion; degenerative sacroiliitis; sacroiliac joint disruptions; multicenter clinical trial
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.
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.
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.
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.
Knowledge provided by this biomechanical study enables improvement of SIJ fixation through optimal implant trajectory.
sacroiliac joint; finite element analysis; biomechanics; arthrodesis
The degree of pain relief required to diagnose sacroiliac joint (SIJ) dysfunction following a diagnostic SIJ block (SIJB) is not known. No gold standard exists. Response to definitive (i.e., accepted as effective) treatment might be a reference standard.
Subgroup analysis of 320 subjects enrolled in two prospective multicenter trials evaluating SIJ fusion (SIJF) in patients with SIJ dysfunction diagnosed by history, physical exam and standardized diagnostic SIJB. A 50% reduction in pain at 30 or 60 minutes following SIJB was considered confirmatory. The absolute and percentage improvements in Visual Analog Scale (VAS) SIJ pain and Oswestry Disability Index (ODI) scores at 6 and 12 months after SIJF were correlated with the average acute improvement in SIJ pain with SIJB.
The average pain reduction during the first hour after SIJB was 79.3%. Six months after SIJF, the overall mean VAS SIJ pain reduction was 50.9 points (0-100 scale) and the mean ODI reduction was 24.6 points. Reductions at 12 months after SIJF were similar. Examined in multiple ways, improvements in SIJ pain and ODI at 6 and 12 months did not correlate with SIJB findings.
The degree of pain improvement during SIJB did not predict improvements in pain or ODI scores after SIJF. A 50% SIJB threshold resulted in excellent post-SIJF responses. Using overly stringent selection criteria (i.e. 75%) to qualify patients for SIJF has no basis in evidence and would withhold a beneficial procedure from a substantial number of patients with SIJ dysfunction.
Level of Evidence
The degree of pain improvement during an SIJ block does not predict the degree of pain improvement after SIJ fusion.
sacroiliac joint dysfunction; sacroiliac joint fusion; diagnostic sacroiliac joint block; risk factors
Sacroiliac joint (SIJ) fusion (SIJF), first performed 95 years ago, has become an increasingly accepted surgical option for chronic SIJ dysfunction. Few studies have reported intermediate- or long-term outcomes after SIJF.
The objective of this study is to determine patient-based outcomes after SIJF for chronic SIJ dysfunction due to degenerative sacroiliitis or SIJ disruption at ≥3 years of follow-up.
Consecutive patients who underwent SIJF prior to December 2012 were contacted over phone or through email. Participants completed questionnaires in clinic, over phone or by email, regarding SIJ pain, activities related to SIJ dysfunction, and the Oswestry Disability Index. Charts were reviewed to extract baseline parameters and the clinical course of follow-up.
One hundred seven patients were eligible and participated in this study. Mean (standard deviation) preoperative SIJ pain score was 7.5 (1.7). At mean follow-up of 3.7 years, the mean SIJ pain score was 2.6 (representing a 4.8-point improvement from baseline, P<0.0001) and the mean Oswestry Disability Index was 28.2. The ability to perform activities commonly impaired by SIJ dysfunction showed positive improvements in most patients. SIJ revision surgery was uncommon (five patients, 4.7%). Fourteen patients (13.1%) underwent contralateral SIJF during follow-up, 25.2% of patients had additional non-SIJ-related lumbar spine or hip surgeries during follow-up.
In intermediate- to long-term follow-up, minimally invasive transiliac SIJF was associated with improved pain, low disability scores, and improved ability to perform activities of daily living.
sacroiliac joint fusion; chronic low back pain; multicenter study
Supplemental Digital Content is Available in the Text.
Sacroiliac joint (SIJ) dysfunction is a prevalent cause of chronic, unremitting lower back pain.
To concurrently compare outcomes after surgical and nonsurgical treatment for chronic SIJ dysfunction.
A total of 148 subjects with SIJ dysfunction were randomly assigned to minimally invasive SIJ fusion with triangular titanium implants (n = 102) or nonsurgical management (n = 46). Pain, disability, and quality-of-life scores were collected at baseline and at 1, 3, 6, and 12 months. Success rates were compared using Bayesian methods. Crossover from nonsurgical to surgical care was allowed after the 6-month study visit was complete.
Six-month success rates were higher in the surgical group (81.4% vs 26.1%; posterior probability of superiority > 0.9999). Clinically important (≥ 15 point) Oswestry Disability Index improvement at 6 months occurred in 73.3% of the SIJ fusion group vs 13.6% of the nonsurgical management group (P < .001). At 12 months, improvements in SIJ pain and Oswestry Disability Index were sustained in the surgical group. Subjects who crossed over had improvements in pain, disability, and quality of life similar to those in the original surgical group. Adverse events were slightly more common in the surgical group (1.3 vs 1.1 events per subject; P = .31).
This Level 1 study showed that minimally invasive SIJ fusion using triangular titanium implants was more effective than nonsurgical management at 1 year in relieving pain, improving function, and improving quality of life in patients with SIJ dysfunction caused by degenerative sacroiliitis or SIJ disruptions. Pain, disability, and quality of life also improved after crossover from nonsurgical to surgical treatment.
INSITE, Investigation of Sacroiliac Fusion Treatment
MCS, mental component summary
NSM, nonsurgical management
ODI, Oswestry Disability Index
PCS, physical component summary
RFA, radiofrequency ablation
SF-36, Short Form-36
SIJ, sacroiliac joint
TTO, time trade-off
VAS, visual analog scale
Sacroiliac joint dysfunction; Chronic lower back pain; Randomized controlled trial; Minimally invasive surgery
Sacroiliac joint (SIJ) dysfunction is an important and underappreciated cause of chronic low back pain.
To prospectively and concurrently compare outcomes after surgical and non-surgical treatment for chronic SIJ dysfunction.
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.
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.
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.
sacroiliac joint dysfunction; sacroiliac joint fusion; minimally invasive surgery; randomized clinical trial
Effective stabilization of the sacroiliac joints (SIJ) is essential, since spinal loading is transferred via the SIJ to the coxal bones, and further to the legs. We performed a biomechanical analysis of SIJ stability in terms of reduced SIJ shear force in standing posture using a validated static 3-D simulation model. This model contained 100 muscle elements, 8 ligaments, and 8 joints in trunk, pelvis, and upper legs. Initially, the model was set up to minimize the maximum muscle stress. In this situation, the trunk load was mainly balanced between the coxal bones by vertical SIJ shear force. An imposed reduction of the vertical SIJ shear by 20% resulted in 70% increase of SIJ compression force due to activation of hip flexors and counteracting hip extensors. Another 20% reduction of the vertical SIJ shear force resulted in further increase of SIJ compression force by 400%, due to activation of the transversely oriented M. transversus abdominis and pelvic floor muscles. The M. transversus abdominis crosses the SIJ and clamps the sacrum between the coxal bones. Moreover, the pelvic floor muscles oppose lateral movement of the coxal bones, which stabilizes the position of the sacrum between the coxal bones (the pelvic arc). Our results suggest that training of the M. transversus abdominis and the pelvic floor muscles could help to relieve SI-joint related pelvic pain.
Static forces; Sacroiliac joints; Pelvis; Pelvic floor muscles; Human posture
The aim of this study was to investigate subgroups of magnetic resonance imaging (MRI) findings for the spine and sacroiliac joints (SIJs) using latent class analysis (LCA), and to investigate whether these subgroups differ in their demographic and clinical characteristics.
The sample included 1037 patients aged 18–40 years with persistent low back pain (LBP). LCA was applied to MRI findings of the spine and SIJs. The resulting subgroups were tested for differences in self-reported demographic and clinical characteristics.
A five-class model was identified: Subgroup 1, ‘No or few findings’ (n = 116); Subgroup 2, ‘Mild spinal degeneration’ (n = 540); Subgroup 3, ‘Moderate to severe spinal degeneration’ (n = 229); Subgroup 4, ‘Moderate to severe spinal degeneration with mild SIJ findings’ (n = 68); and Subgroup 5, ‘Mild spinal degeneration with moderate to severe SIJ findings’ (n = 84). The two SIJ subgroups (Subgroups 4 and 5) had a higher median activity limitation score (Roland Morris Disability Questionnaire calculated as a proportional score: 65 (IQR 48–78)/65 (48–78)) compared with Subgroups 1–3 (48 (35–74)/57 (39–74)/57 (39–74)), a higher prevalence of women (68 % (95 % CI 56–79)/68 % (58–78)) compared with Subgroups 2 and 3 (51 % (47–55)/40 % (33–46)), a higher prevalence of being overweight (67 % (95 % CI 55–79)/53 % (41–65)) compared with Subgroup 1 (36 % (26–46)) and a higher prevalence of previous LBP episodes (yes/no: 81 % (95 % CI 71–91)/79 % (70–89)) compared with Subgroup 1 (58 % (48–67)). Subgroup 5 was younger than Subgroup 4 (median age 29 years (IQR 25–33) versus 34 years (30–37)) and had a higher prevalence of HLA-B27 (40 % (95 % CI 29–50)) compared with the other subgroups (Subgroups 1–4: 12 % (6–18)/7 % (5–10)/6 % (3–9)/12 % (4–20)). Across the subgroups with predominantly spinal findings (Subgroups 1–3), median age, prevalence of men, being overweight and previous LBP episodes were statistically significantly lower in Subgroup 1, higher in Subgroup 2 and highest in Subgroup 3.
Five distinct subgroups of MRI findings in the spine and SIJs were identified. The results indicate that SIJ MRI findings not only can be seen as a part of the spondyloarthritis disease entity, but also are associated with age, gender and being overweight. Furthermore, the results indicate that LBP patients with SIJ MRI findings are more disabled compared with patients without SIJ MRI findings, and that moderate to severe spinal degeneration and/or SIJ MRI findings may be associated with recurrent pain.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-016-1131-x) contains supplementary material, which is available to authorized users.
Cluster analysis; Low back pain; Magnetic resonance imaging; Sacroiliac joints; Spondyloarthritis; Spine
Sacroiliac joint (SIJ) disorders are common in patients with chronic lower back pain. Minimally invasive surgical options have been shown to be effective for the treatment of chronic SIJ dysfunction.
To determine the cost-effectiveness of minimally invasive SIJ fusion.
Data from two prospective, multicenter, clinical trials were used to inform a Markov process cost-utility model to evaluate cumulative 5-year health quality and costs after minimally invasive SIJ fusion using triangular titanium implants or non-surgical treatment. The analysis was performed from a third-party perspective. The model specifically incorporated variation in resource utilization observed in the randomized trial. Multiple one-way and probabilistic sensitivity analyses were performed.
SIJ fusion was associated with a gain of approximately 0.74 quality-adjusted life years (QALYs) at a cost of US$13,313 per QALY gained. In multiple one-way sensitivity analyses all scenarios resulted in an incremental cost-effectiveness ratio (ICER) <$26,000/QALY. Probabilistic analyses showed a high degree of certainty that the maximum ICER for SIJ fusion was less than commonly selected thresholds for acceptability (mean ICER =$13,687, 95% confidence interval $5,162–$28,085). SIJ fusion provided potential cost savings per QALY gained compared to non-surgical treatment after a treatment horizon of greater than 13 years.
Compared to traditional non-surgical treatments, SIJ fusion is a cost-effective, and, in the long term, cost-saving strategy for the treatment of SIJ dysfunction due to degenerative sacroiliitis or SIJ disruption.
cost-effectiveness analysis; degenerative sacroiliitis; minimally invasive surgery; sacroiliac joint arthrodesis; sacroiliac joint disruptions; sacroiliac joint dysfunction; spine surgery
A model of sacroiliac joint (SIJ) function postulates that SIJ shear is prevented by friction, dynamically influenced by muscle force and ligament tension. Thus, SIJ stability can be accommodated to specific loading situations. The purpose of this study was to examine, in vivo, whether muscles contribute to force closure of the SIJ. SIJ stiffness was measured using a verified method combining color Doppler imaging with induced oscillation of the ilium relative to the sacrum in six healthy women. SIJ stiffness was measured both in a relaxed situation and during isometric voluntary contractions (electromyographically recorded). The biceps femoris, gluteus maximus, erector spinae, and contralateral latissimus dorsi were included in this study. Results were statistically analyzed. The study showed that SIJ stiffness significantly increased when the individual muscles were activated. This held especially true for activation of the erector spinae, the biceps femoris and the gluteus maximus muscles. During some tests significant co-contraction of other muscles occurred. The finding that SIJ stiffness increased even with slight muscle activity supports the notion that effectiveness of load transfer from spine to legs is improved when muscle forces actively compress the SIJ, preventing shear. When joints are manually tested, the influence of muscle activation patterns must be considered, since both inter- and intra-tester reliability of the test can be affected by muscle activity. In this respect, the relation between emotional states, muscle activity and joint stiffness deserves further exploration.
Sacroiliac joint; Stabilization; Emotions; Doppler; Electromyography
Study design: Retrospective case series.
Objective: To assess fusion rates in patients with sacroiliac joint (SIJ) pain following a minimally invasive technique using fibular dowel allograft.
Methods: Thirty-seven consecutive patients (mean age: 42.5 years [range, 23–63 years]) with SIJ pain treated with 38 minimally invasive elective SIJ arthrodeses were retrospectively reviewed using chart and x-ray data. The fusion procedure consisted of minimal muscle stripping over the posterior SIJ and insertion of a cranial and caudal fibular dowel graft across the joint following placement of Steinmann pins. Fusion was deemed to be present when bone bridging trabeculae could be seen crossing the SIJ on either oblique x-rays or by computed tomographic scan. Patients were followed-up for a mean of 52 months (range, 24–62 months). Visual Analog Scale (VAS) was used to monitor clinical pain improvement.
Results: Thirty-four patients with SIJ arthrodeses (89.5%) healed and led to substantial improvement in VAS pain scores (preoperative 9.1, postoperative 3.4) (P < .001). This improvement in VAS occurred over a 6-month period and was sustained through subsequent follow-up. Nonunion occurred in four patients with SIJ (10.5%). Each SIJ nonunion was successfully treated by secondary autogenous bone grafting and compression screw fixation.
Conclusions: In patients with primary low back pain attributable to the SIJ, a minimally invasive, dual fibular dowel graft provided high rates of fusion and improved pain scores.
The objective of this study was to evaluate the reliability of recognising structural lesions on MRI (erosions, fatty lesions, ankylosis) of the sacroiliac joints (MRI-SIJ) in clinical practice compared to a central reading in patients with a possible recent axial spondyloarthritis (axSpA).
Patients aged 18–50 years, with recent (<3 years) and chronic (≥3 months) inflammatory back pain, suggestive of axSpA were included in the DEvenir des Spondyloarthrites Indifférenciées Récentes (DESIR) cohort. MRI-SIJ structural lesions were scored by non-trained local readers, and by two trained central readers. Local readers scored each SIJ as normal, doubtful or definite lesions. Central readers scored separately each type of lesion. The central reading (mean of the two central readers’ scores) was the external standard. Agreement (κ) was calculated first between local (3 definitions of a positive MRI-SIJ) and central readings (9 definitions), and then between the two central readers.
664/708 patients with complete available images were included. Agreements between local and central readings were overall ‘fair’, except when considering at least 2 or 3 fatty lesions and at least 3 erosions and/or fatty lesions where agreement was ‘moderate’. Agreement between central readers was similar. MRI-SIJ was positive for 52.6% of patients according to central reading (at least 1 structural lesion) and for 35.4% of patients according to local reading (at least unilateral ‘doubtful‘ or ‘definite’ structural lesions).
Agreement on a positive structural MRI-SIJ was fair to moderate between local and central readings, as well as between central readers. The reliability improved when fatty lesions were considered.
Trial registration number
NCTO 164 8907.
Spondyloarthritis; Magnetic Resonance Imaging; Epidemiology
To compare the clinical features of patients with sacroiliac joint (SIJ)-related sciatica-like symptoms to those with sciatica from nerve root compression and to investigate the necessity to perform radiological imaging in patients with sciatica-like symptoms derived from the SIJ.
Patients with pain radiating below the buttocks with a duration of 4 weeks to 1 year were included. After physical and radiological examinations, a diagnosis of SI joint-related pain, pain due to disk herniation, or a combination of these two causes was made.
Patients with SIJ-related leg pain (n = 77/186) were significantly more often female, had shorter statue, a shorter duration of symptoms, and had more often pain radiating to the groin and a history of a fall on the buttocks. Muscle weakness, corkscrew phenomenon, finger-floor distance ≥25 cm, lumbar scoliosis, positive Bragard or Kemp sign, and positive leg raising test were more often present when radiologic nerve root compression was present. Although these investigations may help, MRI of the spine is necessary to discriminate between the groups.
Sciatica-like symptoms derived from the SIJ can clinically mimic a radiculopathy. We suggest to perform a thorough physical examination of the spine, SI joints, and hips with additional radiological tests to exclude other causes.
Sacroiliac joint; Leg pain; Sciatica; Lumbar disk; Differential diagnosis
After lumbar or lumbosacral fusion for various spine disorders, adjacent segment disease has been reported. Most of the studies have focused on proximal segment disease. The author has reported sacroiliac joint degeneration in these patients. Based on our own experiences with an increasing number of patients with sacroiliac joint (SIJ) arthralgia after multi-level lumbar or lumbosacral fusion procedures, we evaluated a surgical procedure called distraction arthrodesis of the SIJ for patients with refractory severe pain of the SIJ.
Materials and Methods:
Nineteen (19) consecutive patients were recruited and evaluated prospectively after undergoing distraction arthrodesis of the SIJ. The inclusion criteria for the surgical procedure were degeneration of the SIJ and failed conservative treatment. Magnetic resonance imaging (MRI) scans and CT scans were performed in all cases. The clinical outcome was assessed using the Visual Analog Scale and the Oswestry Disability Index (ODI). CT scans were performed postoperatively and again at the final followup to evaluate assess fusion. The data was analyzed using the SPSS software (version 10.0; SPSS, Chicago, IL) and statistical analysis was performed. The P values were based on the Student t-test.
The mean followup was 13.2 months. All patients had an instrumented lumbar or lumbosacral fusion. The overall fusion rate of SIJ was 78.9% (15/19 joints). All patients demonstrated significant improvement in VAS and ODI scores compared to preoperative values. The mean VAS score was 8.5 before surgery and was 6 at final followup, demonstrating 30% improvement. The mean ODI scores were 64.1 before surgery and 56.97 at the final followup, demonstrating 12% improvement.
Refractory sacroiliac pain as a result of multi-level fusion surgery can be successfully treated with minimally invasive arthrodesis. It offers a safe and effective treatment for severe SIJ pain. Careful patient selection is important.
Arthrodesis; distraction; interference; recesses; sacroiliac joint
The sacroiliac joint (SIJ) is an important and significant cause of low back pain. We sought to quantify the burden of disease attributable to the SIJ.
The authors compared EuroQol 5D (EQ-5D) and Short Form (SF)-36-based health state utility values derived from the preoperative evaluation of patients with chronic SIJ pain participating in two prospective clinical trials of minimally invasive SIJ fusion versus patients participating in a nationally representative USA cross-sectional survey (National Health Measurement Study [NHMS]). Comparative analyses controlled for age, sex, and oversampling in NHMS. A utility percentile for each SIJ subject was calculated using NHMS as a reference cohort. Finally, SIJ health state utilities were compared with utilities for common medical conditions that were published in a national utility registry.
SIJ patients (number [n]=198) had mean SF-6D and EQ-5D utility scores of 0.51 and 0.44, respectively. Values were significantly depressed (0.28 points for the SF-6D utility score and 0.43 points for EQ-5D; both P<0.0001) compared to NHMS controls. SIJ patients were in the lowest deciles for utility compared to the NHMS controls. The SIJ utility values were worse than those of many common, major medical conditions, and similar to those of other common preoperative orthopedic conditions.
Patients with SIJ pain presenting for minimally invasive surgical care have marked impairment in quality of life that is worse than in many chronic health conditions, and this is similar to other orthopedic conditions that are commonly treated surgically. SIJ utility values are in the lowest two deciles when compared to control populations.
sacroiliac joint fusion; chronic lower back pain; quality of life; utility assessment; comparative assessments
Erosions of the sacroiliac joints (SIJ) on pelvic radiographs of patients with ankylosing spondylitis (AS) are an important feature of the modified New York classification criteria. However, radiographic SIJ erosions are often difficult to identify. Recent studies have shown that erosions can be detected also on magnetic resonance imaging (MRI) of the SIJ early in the disease course before they can be seen on radiography. The goals of this study were to assess the reproducibility of erosion and related features, namely, extended erosion (EE) and backfill (BF) of excavated erosion, in the SIJ using a standardized MRI methodology.
Four readers independently assessed T1-weighted and short tau inversion recovery sequence (STIR) images of the SIJ from 30 AS patients and 30 controls (15 patients with non-specific back pain and 15 healthy volunteers) ≤45 years old. Erosions, EE, and BF were recorded according to standardized definitions. Reproducibility was assessed by percentage concordance among six possible reader pairs, kappa statistics (erosion as binary variable) and intraclass correlation coefficient (ICC) (erosion as sum score) for all readers jointly.
SIJ erosions were detected in all AS patients and six controls by ≥2 readers. The median number of SIJ quadrants affected by erosion recorded by four readers in 30 AS patients was 8.6 in the iliac and 2.1 in the sacral joint portion (P < 0.0001). For all 60 subjects and for all four readers, the kappa value for erosion was 0.72, 0.73 for EE, and 0.63 for BF. ICC for erosion was 0.79, 0.72 for EE, and 0.55 for BF, respectively. For comparison, the kappa and ICC values for bone marrow edema were 0.61 and 0.93, respectively.
Erosions can be detected on MRI to a comparable degree of reliability as bone marrow edema despite the significant heterogeneity of their appearance on MRI.
There are currently no initial guides for the diagnosis of somatic referred pain of lumbar zygapophyseal joint (LZJ) or sacroiliac joint (SIJ). We developed a classification system of LZJ and SIJ pain, the "pain distribution pattern template (PDPT)" depending on the pain distribution patterns from a pool of 200 patients whose spinal pain source was confirmed. We prospectively applied the PDPT to determine its contribution to clinical decision-making for 419 patients whose pain was presumed to arise from the LZJs (259 patients) or SIJs (160 patients). Forty-nine percent (128/259) of LZJ and 46% (74/160) of SIJ arthopathies diagnosed by PDPT were confirmed by nerve blocks. Diagnostic reliabilities were significantly higher in Type A and C patterns in LZJ and Type C in SIJ arthropathies, 64%, 80%, and 68.4%, respectively. For both LZJ and SIJ arthropathies, favorable outcome after radiofrequency (RF) neurotomies was similar to the rate of positive responses to diagnostic blocks in Type A to Type D, whereas the outcome was unpredictable in those with undetermined type (Type E). Considering the paucity of currently available diagnostic methods for LZJ and SIJ arthropathies, PDPT is useful in clinical decision-making as well as in predicting the treatment outcome.
Low Back Pain; Zygapophyseal Joint; Sacroiliac Joint; Diagnosis; Radiofrequency Neurotomy
Pain from the sacroiliac joint (SIJ) is an under-recognized cause of low back pain. The degree to which SIJ pain decreases quality of life has not been directly compared to other more familiar conditions of the lumbar spine.
Multivariate regression analysis of individual patient data from two prospective multicenter clinical trials of SIJ fusion and three prospective multicenter clinical trials of surgical treatments for degenerative lumbar spine conditions.
Controlling for baseline demographic parameters as well as a validated disability score, quality of life scores (EuroQOL 5-D and SF-36) were, in most cases, lower in the SIJ cohorts compared to the three other spine surgery cohorts.
Patients with SIJ dysfunction considering surgery have decrements in quality of life as or more severe compared to patients with degenerative spondylolisthesis, spinal stenosis, and intervertebral disc herniation.
spine surgery; disability; low back pain; sacroiliac joint pain; lumbar stenosis; intervertebral disc herniation; degenerative spondylolisthesis; sacroiliac joint fusion
Recently, the sacroiliac joint (SIJ) has gained increased attention as a source of persistent or new pain after lumbar/lumbosacral fusion. The underlying pathophysiology of SIJ pain may be increased mechanical load, iliac crest bone grafting, or a misdiagnosis of SIJ syndrome. Imaging studies show more frequent degeneration of the SIJ in patients with lumbar/lumbosacral fusion than in patients without such fusion. Using injection tests, it has been shown that SIJ pain is the cause of persistent symptoms in a considerable number of patients after fusion surgery. Recent articles reporting on surgical outcomes of SIJ fusion include a high percentage of patients who had lumbar/lumbosacral fusion or surgery before, although well-controlled clinical studies are necessary to assess the efficacy of surgical treatment. Taking these findings into consideration, the possibility that the SIJ is the source of pain should be considered in patients with failed back surgery syndrome after lumbar/lumbosacral fusion.
Sacroiliac joint pain; Lumbosacral fusion; Lumbar fusion; Pathophysiology
[Purpose] Physical therapists, osteopathic practitioners, and chiropractors often perform
manual tests to evaluate sacroiliac joint (SIJ) mobility. However, the available evidence
demonstrates an absence of reliability in these tests and in investigations with kinematic
analysis. The aim of this study was to verify the three-dimensional kinematic reliability
in SIJ movement measurements. [Subjects] This cross-sectional study analyzed 24 healthy
males, aged between 18 and 35 years. [Methods] Three-dimensional kinematic analysis was
performed for measurements of posterior superior iliac displacement and greater trochanter
(femur) displacement during hip flexion movement in an orthostatic position. The distance
variations were measured from a reference point in 3 blocks. The intra-observer
reliability was compared with the mean of three 3 blocks using the interclass correlation
coefficient (ICC) and a 99% significance level. [Results] The measurements indicated a
strong correlation among blocks: ICC = 0.94 for right side SIJ and ICC = 0.91 for left
side SIJ. The mean displacement between the reference points was 7.7 mm on the right side
and 8.5 mm on the left side. [Conclusion] Our results indicate that three-dimensional
kinematic analysis can be used for SIJ mobility analyses. New studies should be performed
for subjects with SIJ dysfunction to verify the effectiveness of this method.
Sacroiliac joint; Reliability; Three-dimensional kinematic
To establish the sensitivity and specificity of cross-sectional scintigraphy [single photon emission computed tomography (SPECT)] combined with computed X-ray tomography (CT) in the detection of sacroiliac joint (SIJ) mechanical dysfunction and evaluate reproducibility of reporting.
Patients with pelvic girdle pain either on the basis of peri-partum SIJ dysfunction or trauma were included. These patients were imaged with bone scintigraphy with hybrid imaging with SPECT/CT.
The study group comprised 100 patients (72 females, 28 males). Trauma accounted for 52 % and the remainder were patients with peri-partum pain. Average age was 43 years and average length of history was >2 years. The major finding was increased uptake in the upper SIJ and posterior soft-tissues/ligaments. Hybrid imaging had a sensitivity of 95 % and specificity of 99 %. Positive predictive value was 99 % and negative predictive value 94 %. Power of the test was 1.0. Reproducibility of the test was good with kappa values of 0.85.
Hybrid imaging with SPECT/CT reproducibly demonstrates metabolic alterations around the SIJ in patients with SIJ dysfunction, which we have termed SIJ incompetence. The condition is more common than previously recognised and frequently occurs after trauma, which has not been reported previously.
Sacroiliac joint; SPECT/CT; Sacroiliac joint incompetence; Pain provocation tests; Pain palpation tests
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.
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.
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.
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.
To investigate the use of a quantitative diffusion-weighted imaging (DWI) tool for measuring inflammation of the sacroiliac joints (SIJs) in enthesitis-related arthritis (ERA).
A retrospective study was performed with institutional review board approval. Subjects were adolescents who had undergone MRI of the SIJs since January 2010. 10 patients with a clinical diagnosis of ERA and 10 controls with a clinical diagnosis of mechanical back pain were assessed. Axial T1 weighted, short tau inversion recovery (STIR) and DWI (b-values 0, 50, 100, 300 and 600 mm2 s−1) images were acquired. Apparent diffusion coefficient (ADC) maps were generated using a monoexponential fit. On each of four slices, two to three linear regions-of-interest were placed on each joint. Normalized ADC (nADC) values were defined as joint ADC divided by a reference ADC derived from normal sacral bone. STIR images were scored using a modification of an established technique. The correlation between nADC values and STIR scores was evaluated using Spearman's rank correlation.
Mean nADC values were significantly higher in cases than in controls (p = 0.0015). There was a strong correlation between STIR scores and nADC values (R = 0.85).
ADC values are significantly increased in inflamed SIJs compared with controls. There is a good correlation between this diffusion-based method and STIR scores of inflammation.
Advances in knowledge:
We have described and provisionally validated a method for quantifying the severity of inflammation in the SIJs in ERA using ADC measurements. This method is quick, is reproducible and could potentially be automated.