Pediatric-Specific Lesions in Unstable Pelvic Ring Fractures of Skeletally Immature Children: Impact on Diagnosis and Management Decisions.

Surgical fixation of pediatric pelvic ring injuries is gaining popularity to avoid the poor long-term outcomes of pelvic asymmetry. The surgical techniques and fixation choices depend on the individual injuries affecting the anterior and posterior pelvic ring areas. The immature bony pelvis of young children has anatomic differences including soft bones, elastic ligaments, and the presence of growth centers. Understanding the unique pediatric lesions with unstable pelvic fractures is essential for treatment decisions. Anterior lesions include pubic symphysis disruption through the pubic apophysis, single ramus fractures, pubic rami fractures through the triradiate cartilage, and/or the ischiopubic synchondrosis; ischiopubic ramus infolding injury; or the unstable superior and inferior quadrant lesions. Posterior pelvic lesions include iliac wing infolding and sacroiliac joint dislocation or transiliac (crescent) fracture/dislocations through the iliac apophysis growth plate. Pubic symphysis and sacroiliac disruptions are physeal injuries in children, and they have excellent healing potential. External fixation is an ideal choice for anterior ring fixation including bony and pubic symphysis injuries. Posterior lesions are mostly sacroiliac joint disruptions with iliac apophysis separation that can serve as a landmark for vertical displacement correction. Posterior lesions can be treated by percutaneous iliosacral screw fixation or open reduction techniques.

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

BACKGROUND AND PURPOSE: There is conflicting evidence regarding treatment outcomes after minimally invasive sacroiliac joint fusion for long-lasting severe sacroiliac joint pain. The primary aim of our cohort study was to investigate change in patient-reported outcome measures (PROMs) after minimally invasive sacroiliac joint surgery in daily practice in the Swedish Spine Registry. Secondary aims were to explore the proportion of patients reaching a patient acceptable symptom score (PASS) and the minimal clinically important difference (MCID) for pain scores, physical function, and health-related quality of life outcomes; furthermore, to evaluate self-reported satisfaction, walking distance, and changes in proportions of patients on full sick leave/disability leave and report complications and reoperations. METHODS: Data from the Swedish Spine Registry was collected for patients with first-time sacroiliac joint fusion, aged 21 to 70 years, with PROMs available preoperatively, at 1 or 2 years after last surgery. PROMs included Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for low back pain (LBP) and leg pain, and EQ-VAS, in addition to demographic variables. We calculated mean change from pre- to postoperative and the proportion of patients achieving MCID and PASS. RESULTS: 68 patients had available pre- and postoperative data, with a mean age of 45 years (range 25-70) and 59 (87%) were female. At follow-up the mean reduction was 2.3 NRS points (95% confidence interval [CI] 1.6-2.9; P < 0.001) for LBP and 14.8 points (CI 10.6-18.9; P < 0.001) for ODI. EQ-VAS improved by 22 points (CI 15.4-30.3, P < 0.001) at follow-up. Approximately half of the patients achieved MCID and PASS for pain (MCID NRS LBP: 38/65 [59%] and PASS NRS LBP: 32/66 [49%]) and physical function (MCID ODI: 27/67 [40%] and PASS ODI: 24/67 [36%]). The odds for increasing the patient's walking distance to over 1 km at follow-up were 3.5 (CI 1.8-7.0; P < 0.0001), and of getting off full sick leave or full disability leave was 0.57 (CI 0.4-0.8; P = 0.001). In the first 3 months after surgery 3 complications were reported, and in the follow-up period 2 reoperations. CONCLUSION: We found moderate treatment outcomes after minimally invasive sacroiliac joint fusion when applied in daily practice with moderate pain relief and small improvements in physical function.

Biomechanical Predictors of Sacroiliac Joint Uptake on Single-Photon Emission Computed Tomography/Computed Tomography.

OBJECTIVE: Single-photon emission computed tomography/computed tomography (SPECT/CT) is an emerging imaging modality that identifies sites of heightened bone metabolism in response to increased stresses. The relationship between sacroiliac (SI) joint radiotracer uptake and anatomic biomechanical parameters is poorly understood. METHODS: Adult patients with SPECT/CT scans performed at our institution between 2021 and 2023 for the workup of low back pain were included. Patient charts were reviewed for demographic factors including age, gender, and prior thoracolumbar fusion history. Biomechanical spinopelvic parameters were measured from standing scoliosis radiographs. SPECT/CT scans were reviewed for uptake at the SI joint. Patients were stratified into 2 cohorts; patients with SI uptake greater than iliac crest uptake were designated "hot," whereas those with less or equal uptake were labeled "cold." RESULTS: One-hundred and sixty patients met inclusion criteria. Patients were slightly more male (55%) with average age 55 ± 14.9 years. Sixty-eight patients (43%) had evidence of increased SI activity. Interrater reliability showed substantial agreement (kappa = 0.62). The hot cohort demonstrated greater pelvic incidence (54.8 ± 14.0 degrees vs. 51.0 ± 11.0 degrees, P = 0.031) and pelvic tilt (20.8 ± 9.5 degrees vs. 18.4 ± 8.6 degrees, P =0.047) compared with the cold cohort. Patients were otherwise similar between cohorts (P > 0.05). CONCLUSIONS: Increased pelvic incidence and pelvic tilt angles are associated with SPECT/CT uptake at the SI joint, which may reflect altered biomechanics at the spinopelvic junction. SPECT/CT may be a valuable tool to assess SI degeneration. Future studies are warranted to better characterize the clinical applications of these findings.

MRI predictors of infectious etiology in patients with unilateral sacroiliitis.

BACKGROUND: Unilateral presentation of sacroiliitis is a diagnostic dilemma, especially between infection and inflammatory sacroiliitis associated with spondyloarthritis, requiring an early and accurate diagnosis. OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) in differentiating infective versus inflammatory etiology in unilateral sacroiliitis. MATERIALS AND METHODS: Retrospective review of the MRI of 90 patients with unilateral sacroiliitis, having an established final diagnosis. MR images were evaluated for various bone and soft tissue changes using predefined criteria and analyzed using univariate and multivariate regression analysis. RESULTS: Among the 90 patients, infective etiology was diagnosed in 66 (73.3%) and inflammatory etiology in 24 (26.7%). Large erosions, both iliac and sacral-sided edema, joint space involvement with effusion or synovitis, soft tissue edema, elevated ESR/CRP, and absence of capsulitis and enthesitis were associated with infection (p < .001). The independently differentiating variables favoring infection on multivariate analysis were-both iliac and sacral-sided edema (OR 4.79, 95% CI: 0.96-23.81, p = .05), large erosions (OR 17.96, 95% CI: 2.66-121.02, p = .003), and joint space involvement (OR 9.9, 95% CI: 1.36-72.06, p = .02). Exclusive features of infection were osteomyelitis, sequestra, abscesses, sinus tracts, large erosions, and multifocality. All infective cases had soft tissue edema, joint space involvement, elevated ESR, and no capsulitis. CONCLUSION: MRI evaluation for the presence and pattern of bone and joint space involvement, soft tissue involvement, and careful attention to certain exclusive features will aid in differentiating infectious sacroiliitis from inflammatory sacroiliitis.

Reporting Sacroiliac Joint Imaging Performed for Known or Suspected Axial Spondyloarthritis: Assessment of SpondyloArthritis International Society Recommendations.

Whereas previous projects attempted to standardize imaging in patients with axial spondyloarthritis (axSpA), few studies have been published about the need for specific details regarding the image acquisition and lesions that may be less familiar to general radiologists. This work reports consensus recommendations developed by the Assessment of SpondyloArthritis International Society (ASAS) that aim to standardize the imaging reports in patients suspected of having or with known axSpA. A task force consisting of radiologists and rheumatologists from ASAS and one patient representative formulated two surveys that were completed by ASAS members. The results of these surveys led to the development of 10 recommendations that were endorsed by 73% (43 of 59) of ASAS members. The recommendations are targeted to the radiologist and include best practices for the inclusion of clinical information, technical details, image quality, and imaging findings in radiology reports. These recommendations also emphasize that imaging findings that indicate differential diagnoses and referral suggestions should be included in the concluding section of the radiology report. With these recommendations, ASAS aims to improve the diagnostic process and care for patients suspected of having or with known axSpA.

Inflammatory activity evaluation in patients with axial spondyloarthritis using MRI relaxometry and mucosal-associated invariant T cells.

Background: Currently, there is a lack of an objective quantitative measure to comprehensively evaluate the inflammatory activity of axSpA, which poses certain challenges in accurately assessing the disease activity. Objective: To explore the value of combined-parameter models of sacroiliac joints (SIJs) MRI relaxometry and peripheral blood Mucosal-associated invariant T (MAIT) cells in evaluating the inflammatory activity of axial spondyloarthritis (axSpA). Methods: This retrospective clinical study included 88 axSpA patients (median age 31.0 (22.0, 41.8) years, 21.6% females) and 20 controls (median age 28.0 (20.5, 49.5) years, 40.0% females). The axSpA group was classified into active subgroup (n=50) and inactive subgroup (n=38) based on ASDAS-CRP. All participants underwent SIJs MRI examination including T1 and T2* mapping, and peripheral blood flow cytometry analysis of MAIT cells (defined as CD3+Vα7.2+CD161+) and their activation markers (CD69). The T1 and T2* values, as were the percentages of MAIT cells and CD69+MAIT cells were compared between different groups. Combined-parameter models were established using logistic regression, and ROC curves were employed to evaluate the diagnostic efficacy. Results: The T1 values of SIJs and %CD69+MAIT cells in the axSpA group and its subgroup were higher than the control group (p<0.05), while %MAIT cells were lower than the control group (p<0.05). The T1 values and %CD69+MAIT cells correlated positively, while %MAIT cells correlated negatively, with the ASDAS-CRP (r=0.555, 0.524, -0.357, p<0.001). Between the control and axSpA groups, and between the inactive and active subgroups, the combined-parameter model T1 mapping+%CD69+MAIT cells has the best efficacy (AUC=0.959, 0.879, sensibility=88.6, 70%, specificity=95.0, 94.7%, respectively). Conclusion: The combined-parameter model T1 mapping+%CD69+MAIT cells allows a more accurate evaluation of the level of inflammatory activity.

Effective diagnosis of sacroiliitis in children: evaluating magnetic resonance imaging with the Canadian scoring system.

OBJECTIVES: To reveal the differences by comparing the magnetic resonance imaging (MRI) findings of patients with clinically symptomatic sacroiliitis with those undergoing sacroiliac imaging for other reasons using the Canadian Spondyloarthritis Research Consortium-Sacroiliac Inflammatory Scoring System (SPARCC-SIS). METHODS: In this retrospective single-center study, sacroiliac MRIs performed between 2017 and 2023 were evaluated from the database. The SPARCC-SIS scoring system is used to evaluate and grade the inflammation of the sacroiliac joints. Mild inflammation is indicated by a score below 24, moderate by a score of 24-48, and severe by a score above 49. Additionally, structural defects of the sacroiliac joint, such as erosion, sclerosis, and ankylosis, were observed. After MRI evaluation, clinically symptomatic (group 1) and non-symptomatic (group 2) patients were divided into two groups. The clinical and laboratory findings of the patients and MRI findings were compared. The patient's age, gender, clinical information from hospital records, acute phase reactants (APRs), and the presence of the Human Leukocyte Antigen (HLA-B27) gene (if applicable) were thoroughly recorded. RESULTS: One hundred thirty-six children who performed sacroiliac MRI for any indication were included in the study. The APRs positivity, presence of HLA-B27, and SPARCC scoring system were significantly higher in 24 patients with clinical sacroiliitis (group 1) than in 112 patients without sacroiliitis (group 2). In our study, the most common MRI findings in children were bone marrow edema, capsulitis, synovitis, and erosion, while chronic structural changes such as sclerosis and ankylosing were rare. CONCLUSION: In this study, the SPARCC scoring method, which shows the severity of sacroiliac joint inflammation, correlates with the clinical diagnosis of sacroiliitis. In cases with suspected sacroiliitis, except for extraordinary reasons, it can be evaluated with MRI without contrast material and can be graded to guide the clinician in treatment and approach.

[Intraoperative slide rail CT assistance in percutaneous sacroiliac joint screws for the treatment of pelvic posterior ring injury].

OBJECTIVE: To compare the clinical efficacy of intraoperative slide rail CT combined with C-arm X-ray assistance and just C-arm for percutaneous screw in the treatment of pelvic posterior ring injury. METHODS: A retrospective analysis was performed on the patient data of 76 patients with posterior pelvic ring injury admitted to the Department of Orthopedic Trauma from December 2018 to February 2022. Among them, 39 patients in the CT group were treated with C-arm combined with slide rail CT-assisted inline fixation including 23 males and 16 females with an average age of (44.98±7.33) years old;and the other 37 patients in the C-arm group were treated with intraline fixation treatment under only C-arm fluoroscopy including 24 males and 13 females with an average age of (44.37±10.82) years old. Among them, 42 patients with anterior ring fractures were treated with percutaneous inferior iliac spines with internal fixation (INFIX) or suprapubic support screws to fix the anterior pelvic ring. Postoperative follow-up time, operation time, complications of the two groups were compared. Results of Matta reduction criteria, Majed efficacy evaluation, the CT grading and the rate of secondary surgical revision were compared. RESULTS: The nailing time of (32.63±7.33) min in CT group was shorter than that of (52.95±10.64) min in C-arm group (t=-9.739, P<0.05). The follow-up time between CT group (11.97±1.86) months and C-arm group (12.03±1.71) months were not statistically significant(P>0.05). The postoperative complication rates between two groups were not statistically significant (χ2=0.159, P>0.05). Results of Matta reduction criteria (Z=2.79, P<0.05), Majeed efficacy evaluation(Z=2.79, P<0.05), CT grading (Z=2.83, P<0.05) in CT group were better than those in C-arm group(P<0.05); the secondary surgical revision rate in the CT group was significantly lower than that in the C-arm group (χ2=5.641, P<0.05). CONCLUSION: Compared with traditional C-arm fluoroscopy, intraoperative slide rail CT combined with C-arm assisted percutaneous sacroiliac joint screw placement surgery has the characteristics of short operation time, high accuracy and safety, and significant decrease in postoperative secondary revision rate, and is one of the effective methods for re-establishing the stability of the posterior ring of pelvic fracture.

Prevalence of sacroiliac joint fusion in females and males depending on parity status.

OBJECTIVES: Previous research shows that sacroiliac (SI) joint fusion is age and sex dependent. Older individuals-specifically starting in the fifth or sixth decade of life-are more likely to develop SI fusion. Females have a lower frequency of SI joint fusion than males, perhaps due to pregnancy or parturition. This study examines the relationship between SI joint fusion with both sex and parity status in females. The issue is whether the prevalence of SI fusion in nulliparous females is more similar to that of males or parous females. MATERIALS AND METHODS: The sample consists of 46 nulliparous females, 119 parous females, and 158 males from the William M. Bass Donated Skeletal Collection. Ages of the individuals ranged from 50 to 89 years. Sex, age, and parity status were self-reported. RESULTS: The frequency of SI joint fusion is significantly different among males (13.29%), nulliparous females (6.52%), and parous females (0.84%). Pairwise comparison of the three groups for SI joint fusion shows that parous females and males are significantly different, but nulliparous females are nonsignificantly different from parous females and males. DISCUSSION: Parity status does not appear to be a factor in the sexually dimorphic nature of SI joint fusion in this sample. Rather, biomechanical and hormonal factors may have a greater contribution to higher rates of SI joint fusion in males than females.

Does sacroiliitis is a mandatory criterion for enthesitis-related arthritis diagnosis? / ¿La sacroilitis es un criterio obligatorio para el diagnóstico de artritis relacionada con entesitis?

Introduction and objectives: Magnetic resonance imaging (MRI) sensitivity and specificity seem to be less studied in enthesitis-related arthritis (ERA). We aimed to determine the ability of sacroiliac MRI to diagnose ERA patients. Materials and methods: We conducted a retrospective study including 44 patients with juvenile idiopathic arthritis (JIA). Each patient had a sacroiliac joint MRI. We divided patients into two groups: G1 patients with ERA and G2 patients with non-ERA subtype. Results: ERA was noted in 61% of the cases. Sacroiliac joints were painful in 15 patients (34%). MRI was normal in 25 patients (57%) (G1:11 versus G2:14) and showed bone marrow edema in the sacroiliac joints in 19 patients (34%) (G1=16 versus G2=3, p=0.005). Sacroiliac joints MRI's sensitivity and specificity in the ERA diagnosis were 61.54% and 82.35%, respectively. Positive and negative predictive values were 84.21% and 58.33%, respectively. Furthermore, sacroiliac joint pain in the clinical examination was able to predict sacroiliac bone edema in MRI with an odds ratio of 6.8 (95% CI 1.68–28.09; p=0.006). Conclusion: Our study showed that sacroiliac joint MRI has good specificity and positive predictive value in the diagnosis of ERA patients among JIA patients. This underlines the usefulness of sacroiliac joint MRI in the early diagnosis of ERA patients.(AU)

Introducción y objetivos: La sensibilidad y especificidad de la resonancia magnética parecen estar menos estudiadas en la artritis relacionada con entesitis (ERA). Nuestro objetivo era determinar la capacidad de la resonancia magnética de la articulación sacroilíaca para diagnosticar pacientes con ERA. Materiales y métodos: Realizamos un estudio retrospectivo que incluyó a 44 pacientes con artritis idiopática juvenil (AIJ). A cada paciente se le realizó una resonancia magnética de la articulación sacroilíaca. Dividimos a los pacientes en dos grupos: G1: pacientes con ERA y G2: pacientes con subtipo no ERA. Resultados: Se observó ERA en 61% de los casos. Las articulaciones sacroilíacas resultaron dolorosas en 15 pacientes (34%). La resonancia magnética fue normal en 25 pacientes (57%) (G1:11 vs. G2:14) y mostró edema de médula ósea en las articulaciones sacroilíacas en 19 pacientes (34%) (G1=16 vs. G2=3, p=0,005). La sensibilidad y especificidad de la resonancia magnética de articulaciones sacroilíacas en el diagnóstico de ERA fueron de 61,54 y 82,35%, respectivamente. Los valores predictivos positivos y negativos fueron 84,21 y 58,33%, respectivamente. Además, el dolor en la articulación sacroilíaca en el examen clínico fue capaz de predecir el edema del hueso sacroilíaco en la resonancia magnética con un odds ratio de 6,8 (IC 95%: 1,68 a 28,09; p=0,006). Conclusión: Nuestro estudio demostró que la resonancia magnética de la articulación sacroilíaca tiene buena especificidad y valor predictivo positivo en el diagnóstico de pacientes con ERA entre pacientes con AIJ. Esto subraya la utilidad de la resonancia magnética de la articulación sacroilíaca en el diagnóstico temprano de pacientes con ERA.(AU)

Critical distance of the sacroiliac joint for open reduction using screw fixation for traumatic sacroiliac joint diastasis: a retrospective study.

BACKGROUND: Osteosynthesis for sacroiliac joint (SIJ) diastasis using an iliosacral screw (ISS) and a trans-iliac-trans-sacral screw (TITSS) can be performed using a closed or an open method. However, no clear indication for open reduction has been established. METHODS: Data on patients with unilateral traumatic SIJ diastasis who underwent ISS and TITSS fixation were retrospectively collected and separated into groups according to the reduction method: closed reduction group (C group) and open reduction group (O group). Demographic data and perioperative image assessments were compared between the groups. The critical distance of the SIJ was identified to elucidate the indication for open reduction of the diastatic SIJ. RESULTS: Fifty-six patients met the inclusion criteria over a 3-year period. There was no significant difference in the reduction quality of pelvic ring injuries between the groups, according to Matta's and Lefaivre's criteria. The improvement in the SIJ distance was significantly greater in the O group than in the C group in the axial plane on multiplanar computed tomography (p = 0.021). This model predicted that a difference of > 3.71 mm between the injured and healthy SIJ was a recommended indication for open reduction, with an area under the curve of 0.791 (95% confidence interval 0.627-0.955, p = 0.004). CONCLUSIONS: Open reduction for SIJ diastasis might achieve better reduction quality than does closed reduction in the axial plane in selected cases. When the difference between the injured and healthy SIJ was wider than 3.71 mm, open reduction was recommended for satisfactory radiological outcomes.

Extra-articular screw placement strategy in Stoppa approach based on three-dimensional reconstruction model.

The study aimed to explore an extra-articular screw placement strategy in Stoppa approach. Radiographic data of patients who underwent pelvic computed tomography from January 2016 to June 2017 were imported into Materiaise's interactive medical image control system software for three-dimensional reconstruction. Superior and lower margins of acetabulum and ipsilateral pelvic brim could be observed simultaneously through inlet-obturator view. A horizontal line from superior acetabular margin intersected pelvic brim at point "A" and another vertical line from lower margin intersected pelvic brim at point "B" were drawn, respectively. Lengths form sacroiliac joint to "A" (a), "A" to "B" (b), and "B" to pubic symphysis (c) were measured. Patients were divided into four groups depending on gender and side difference of measured hemi-pelvis: male left, male right, female left, and female right. Lengths of adjacent holes (d) and spanning different holes (e) of different plates were also measured. Mean lengths of a, b, c in four groups were 40.94 ± 1.85 mm, 40.09 ± 1.93 mm, 41.78 ± 3.62 mm, and 39.77 ± 2.23 mm (P = 0.078); 40.65 ± 1.58 mm, 41.48 ± 1.64 mm, 40.40 ± 1.96 mm, and 40.66 ± 1.70 mm (P = 0.265); 57.03 ± 3.41 mm, 57.51 ± 3.71 mm, 57.84 ± 4.40 mm, and 59.84 ± 4.35 mm (P = 0.165), respectively. Mean d length of different plates was 12.23 mm. Average lengths spanning 1, 2, 3 and 4 holes were 19.33 mm, 31.58 mm, 43.80 mm, and 55.93 mm. Our data showed that zones a and c could be safely inserted three and four screws. Penetration into hip joint could be avoided when vacant 3-hole drilling was conducted in zone b. Fracture line in zone b could serve as a landmark for screw placement.

Anterior peri-sacroiliac joint osteotomy in the treatment of malunion and nonunion of complex pelvic ring fracture: techniques and preliminary results.

PURPOSE: To introduce anterior peri-sacroiliac joint osteotomy (APSJO) through the lateral-rectus approach (LRA) for treating pelvic fracture malunion and nonunion, and to evaluate the safety, feasibility, and potential effectiveness. METHODS: Data of 15 patients with pelvic fracture malunion and nonunion who underwent treatment by APSJO were selected and analyzed. The reduction quality was assessed using the Mears and Velyvis criteria, while the pre-operative and post-operative function was revealed by the Majeed scoring system. The British Medical Research Council (BMRC) grading system was recruited for the evaluation of lumbosacral plexus function. RESULTS: The average operative duration was 264.00 ± 86.75 min, while the intra-operative blood loss was 2000 (600, 3000) mL. Anatomical reduction was complete in three cases, satisfactory in ten cases, and unsatisfactory in two cases. Among the seven patients with lumbosacral plexus injury, the pre-operative Majeed grades were good in two cases, fair in two cases, and poor in three cases, while the post-operative Majeed grades were excellent in three cases, good in three cases, and fair in one case. Muscle strength recovered to M5 in two cases, M4 in three cases, and showed no recovery in two cases. The pre-operative Majeed grades were good in five cases, fair in two cases, and poor in one case of the series without lumbosacral plexus injury, while the post-operative Majeed grades were excellent in seven cases and good in one case. CONCLUSION: APSJO through LRA may be a feasible strategy for treating pelvic fracture malunion and nonunion with promising application.

Sacroiliitis in inflammatory bowel disease on abdominal computed tomography: prevalence, misses, and associated factors.

OBJECTIVE: To evaluate the prevalence and rate of a missed diagnosis of sacroiliitis on abdominal computed tomography (CT) in patients with inflammatory bowel disease (IBD). Factors associated with sacroiliitis were also assessed. METHOD: This retrospective study included 210 patients with IBD (mean age 31.1 years) who underwent abdominal CT. Based on a validated abdominal CT scoring tool, bilateral sacroiliac (SI) joints on abdominal CT in the whole study population were retrospectively reviewed. Subsequently, patients were classified into the 'patients with sacroiliitis' group and the 'patients without sacroiliitis' group. Univariate and multivariate regression analyses were used to clarify the factors associated with sacroiliitis. RESULTS: Sacroiliitis was identified in 26 out of 210 patients (12.4%). However, sacroiliitis was recognized on the primary reading in only five of these 26 patients (19.2%) and was missed on the initial report in the remaining 21 patients (80.8%). Among the 21 patients, 20 (95.2%) were finally diagnosed with axial spondyloarthritis (axSpA). There was a higher prevalence of female sex (p = 0.04), upper gastrointestinal involvement (p = 0.04), and back pain (p < 0.01) in patients with sacroiliitis than in those without sacroiliitis. However, on multivariate analysis, back pain was the only factor associated with sacroiliitis (p = 0.01). CONCLUSION: Physicians should carefully evaluate SI joints on abdominal CT in patients with IBD to enable early detection of sacroiliitis, potentially leading to an early diagnosis of axSpA. In addition, if patients with IBD present with back pain, the possibility of sacroiliitis should be considered.

How to inject sacroiliac joints with ultrasound guidance: a pictorial essay.

Active sacroiliitis and sacroiliac joint dysfunction represent a common cause of low back pain in the population and are cause of patients' quality of life reduction and disability worldwide. The use of musculoskeletal ultrasound allows to easily identify the sacroiliac joints and to study every pathological condition affecting its most dorsal part; moreover, musculoskeletal ultrasound allows to guide highly effective injective procedures aimed at improving patients' symptoms and enhance their well-being. This paper aims to briefly explain for the musculoskeletal sonographer the anatomy and biomechanics of the sacroiliac joints, the correct ultrasound scanning method for their visualization and the most appropriate ultrasound guided injection technique to help dealing with the diagnostic and management of sacroiliac joint pain in the everyday scenario.

Diagnostic accuracy in axial spondyloarthritis: a systematic evaluation of the role of clinical information in the interpretation of sacroiliac joint imaging.

OBJECTIVES: Radiography and MRI of the sacroiliac joints (SIJ) are relevant for the diagnosis and classification of patients with axial spondyloarthritis (axSpA). This study aimed to evaluate the impact of clinical information (CI) on the accuracy of imaging interpretation. METHODS: Out of 109 patients referred because of suspicion of axSpA with complete imaging sets (radiographs and MRI of SIJ), 61 were diagnosed with axSpA (56%). Images were independently evaluated by three radiologists in four consecutive reading campaigns: radiographs and radiographs+MRI without and with CI including demographic data, SpA features, physical activity and pregnancy. Radiographs were scored according to the modified New York criteria, and MRIs for inflammatory and structural changes compatible with axSpA (yes/no). The clinical diagnosis was taken as reference standard. The compatibility of imaging findings with a diagnosis of axSpA (precision) before and after the provision of CI and radiologists' confidence with their findings (0-10) were evaluated. RESULTS: The precision of radiographs evaluation without versus with CI increased from 70% to 78% (p=0.008), and for radiographs+MRI from 81% to 82% (p=1.0), respectively. For CR alone, the sensitivity and specificity of radiologic findings were 51% and 94% without and 60% and 100% with CI, while, for radiographs+MRI, they were 74% and 90% vs 71% and 98%, respectively. The diagnostic confidence of radiologists increased from 5.2±1.9 to 6.0±1.7 with CI for radiographs, and from 6.7±1.6 to 7.2±1.6 for radiographs+MRI, respectively. CONCLUSION: The precision, specificity and diagnostic confidence of radiologic evaluation increased when CI was provided.

Does sacroiliitis is a mandatory criterion for enthesitis-related arthritis diagnosis?

INTRODUCTION AND OBJECTIVES: Magnetic resonance imaging (MRI) sensitivity and specificity seem to be less studied in enthesitis-related arthritis (ERA). We aimed to determine the ability of sacroiliac MRI to diagnose ERA patients. MATERIALS AND METHODS: We conducted a retrospective study including 44 patients with juvenile idiopathic arthritis (JIA). Each patient had a sacroiliac joint MRI. We divided patients into two groups: G1 patients with ERA and G2 patients with non-ERA subtype. RESULTS: ERA was noted in 61% of the cases. Sacroiliac joints were painful in 15 patients (34%). MRI was normal in 25 patients (57%) (G1:11 versus G2:14) and showed bone marrow edema in the sacroiliac joints in 19 patients (34%) (G1=16 versus G2=3, p=0.005). Sacroiliac joints MRI's sensitivity and specificity in the ERA diagnosis were 61.54% and 82.35%, respectively. Positive and negative predictive values were 84.21% and 58.33%, respectively. Furthermore, sacroiliac joint pain in the clinical examination was able to predict sacroiliac bone edema in MRI with an odds ratio of 6.8 (95% CI 1.68-28.09; p=0.006). CONCLUSION: Our study showed that sacroiliac joint MRI has good specificity and positive predictive value in the diagnosis of ERA patients among JIA patients. This underlines the usefulness of sacroiliac joint MRI in the early diagnosis of ERA patients.

[Diagnosis and classification of axial spondyloarthritis (axSpA) - the current status]. / Diagnostik und Klassifikation der axialen Spondyloarthritis (axSpA) ­ der aktuelle Stand.

Axial spondyloarthritis (axSpA) is an inflammatory rheumatic disease typically characterized by inflammatory back pain (IBP). The term axSpA has largely replaced the long-used term ankylosing spondylitis (AS). IBP is caused by inflammation in the axial skeleton, with the sacroiliac joints (SIJ) being particularly frequently affected initially. The spine is usually added in later stages, which is then increasingly characterized structurally by the formation of new bone. The overall concept of spondyloarthritis includes other disease manifestations such as uveitis, psoriasis and colitis and comorbidities such as cardiovascular disease and osteoporosis.The ASAS classification criteria for axSpA, in place since 2009, have replaced the 1984 modified New York criteria. In the former, in addition to conventional X-rays, changes in the SIJ detected by magnetic resonance imaging (MRI) and also the detection of HLA B27 have, for the first time, played a role. It is important to note that these are not diagnostic criteria, as they do not exist. This paper outlines 10 points that should be considered when making a diagnosis.

Axial Spondyloarthritis: Does Magnetic Resonance Imaging Classification Improve Report Interpretation.

OBJECTIVE: The interpretation of magnetic resonance imaging (MRI) reports is crucial for the diagnosis of axial spondyloarthritis, but the subjective nature of narrative reports can lead to varying interpretations. This study presents a validation of a novel MRI reporting system for the sacroiliac joint in clinical practice. METHODS: A historical review was conducted on 130 consecutive patients referred by 2 rheumatologists for initial MRI assessment of possible axial spondyloarthritis. The original MRI reports were interpreted by the rheumatologists and the radiologist who originally read the images and then categorized according to the novel system. Two musculoskeletal radiologists then reinterpreted the original MRI scans using the new system, and the resulting reports were interpreted and categorized by the same rheumatologists. The quality of the new framework was assessed by comparing the interpretations of both reports. RESULTS: Ninety-two patients met the study criteria. The rheumatologists disagreed on the categorization of the original MRI reports in 12% of cases. The rheumatologists and original radiologists disagreed on the categorization of the initial report in 23.4% of cases. In contrast, there was 100% agreement between the rheumatologists and radiologists on the categorization of the new MRI report. CONCLUSION: The new MRI categorization system significantly improved the agreement between the clinician and radiologist in report interpretation. The system provided a standard vocabulary for reporting, reduced variability in report interpretation, and may therefore improve clinical decision-making.

Prediction of the activity of early ankylosing spondylitis using radiomics texture analysis on short tau inversion recovery (STIR).

OBJECTIVES: The study aimed to explore the value of texture analysis of radiomics based on the short tau inversion recovery (STIR) sequence to evaluate the activity of bone marrow oedema of sacroiliac joints in early AS. METHODS: 43 patients with early AS whose data were randomly divided into the training cohort (n=116) and verification cohort (n=56) according to the ratio of 7:3. The optimal feature subsets were obtained by Mann-Whitney U-test, the minimum-Redundancy Maximum-Relevancy (mRMR), and then least absolute shrinkage and selection operator (LASSO) using these texture feature parameters, which were used to construct the final prediction model and obtained the Radscore. The ROC curve was performed to evaluate the performance of the model. The Spearman correlation test was used to analyse the correlation of various indicators. RESULTS: In the training cohort, to differentiate early AS sacroiliac joint bone marrow oedema between the active and stable groups, the AUCs of the Radscore, SPARCC and ADC were 0.81, 0.91, 0.78, respectively. In the validation cohort, the AUCs were 0.87, 0.89, 0.85. In the two cohorts, there were no significant differences in AUCs between values of the Radscore and SPARCC, ADC (p>0.05). There was a significant difference in AUC between SPARCC and ADC in the training cohort (p<0.05), with no statistical significance in the validation cohort (p>0.05). The correlations were all low between the Radscore values and the values of ESR, CRP, tI, ASDAS-ESR and ASDAS-CRP (p<0.05). CONCLUSIONS: Radiomics analysis based on STIR texture analysis has a good prediction for the evaluation of bone marrow oedema activity of sacroiliac joints in AS. It can be a new non-invasive and objective evaluation method for AS activity.