Influence of size and shape of the auricular surfaces on subchondral bone density distribution in the sacroiliac joint.

The sacroiliac auricular surface has a variable morphology and size. The impact of such variations on subchondral mineralization distribution has not been investigated. Sixty-nine datasets were subjected to CT-osteoabsorptiometry for the qualitative visualization of chronic loading conditions of the subchondral bone plate using color-mapped densitograms based on Hounsfield Units in CT. Auricular surface morphologies were classified into three types based on posterior angle size: Type 1: >160°, Type 2: 130-160° and Type 3: <130°. Auricular surface size was categorized based on the mean value (15.4 cm2 ) separating the group into 'small' and 'large' joint surfaces. Subchondral bone density patterns were qualitatively classified into four color patterns: two marginal patterns (M1 and M2) and two non-marginal patterns (N1 and N2) and each iliac and sacral surface was subsequently categorized. 'Marginal' meant that 60-70% of the surface was less mineralized compared with the highly dense regions and vice versa for the 'non-marginal' patterns. M1 had anterior border mineralization and M2 had mineralization scattered around the borders. N1 had mineralization spread over the whole superior region, N2 had mineralization spread over the superior and anterior regions. Auricular surface area averaged 15.4 ± 3.6 cm2 , with a tendency for males to have larger joint surfaces. Type 2 was the most common (75%) and type 3 the least common morphology (9%). M1 was the most common pattern (62% of surfaces) by sex (males 60%, females 64%) with the anterior border as the densest region in all three morphologies. Sacra have a majority of surfaces with patterns from the marginal group (98%). Ilia have mineralization concentrated at the anterior border (patterns M1 and N2 combined: 83%). Load distribution differences related to auricular surface morphology seems to have little effect on long-term stress-related bone adaptation visualized with CT-osteoabsorptiometry. Higher iliac side mineralization was observed in larger joint surfaces and age-related morphomechanical size alterations were seen in males.

Quantification of fat in the posterior sacroiliac joint region: fat volume is sex and age dependant.

Fat is appreciated as a structural component of synovial joints. It may serve a shock-absorbing function for the incongruent surfaces, vessels and ligaments, but has not been investigated in the posterior sacroiliac joint (PSIJ). Sixty-six cadaveric hemipelves were serially-sectioned and photographed. The amount of visible fat in the PSIJ was quantified using a modified version of Cavalieri's method. Total volume, fat volume and fat percentage of the PSIJ were calculated in predefined sub-regions. Fat is consistently present in the PSIJ (1.9 ± 1.3 cm3). Fat volume correlates with the PSIJ total volume (p < 0.0001; r = 0.73) and age (p = 0.024; r = 0.24), and is smaller in males (1.4 ± 0.8 cm3) than females (2.4 ± 1.5 cm3). Fat volumes in the middle and inferior sub-regions of the PSIJ show side- (p < 0.0001) and sex-differences (p = 0.013 females, middle sub-region). Age and PSIJ total volume correlate between sexes in various sub-regions (p = 0.05 females superior sub-region; males inferior sub-region). Fat percentage differs between sexes and sub-regions (p = 0.018 females, superior sub-region) but is independent of age and sides. The presence of fat within the PSIJ is a normal finding and shows sex-dependant and age-related differences. It is unclear whether fat is linked to age-related degeneration or has a shock-absorbing role in stress- and load-dissipation in the PSIJ.

A Systematic Review of the Normal Sacroiliac Joint Anatomy and Adjacent Tissues for Pain Physicians.

BACKGROUND: The sacroiliac joint (SIJ) forms a complex joint and has shown to be underappreciated in its involvement with lower back pain. Research efforts have intensified on SIJ anatomy and biomechanics because of its predisposing position to pain and dysfunction in individuals suffering from lower back discomfort. Previous work has focused on SIJ anatomy including bone and joint structure, innervation, as well as biomechanics and the treatment of SIJ pain. However, to date, no review exists describing the range of 'normal' anatomic features of the SIJ. OBJECTIVES: To describe the normal appearance of the SIJ and adjacent tissues, as opposed to 'abnormal' conditions involving SIJ morphology. It will also identify key areas that require further study because of lacking information or disagreement. STUDY DESIGN: A systematic literature review. SETTING: The research took place at the University of Otago, New Zealand. All published research on 'normal SIJ anatomy' available from MEDLINE, OVID, Scopus, Web of Science, PubMed, and Science Direct were included, available until December 2018, in English, French, and German. Subject areas included bony landmarks, joint type, bone morphology, ligamentous attachments, muscular and fascial relationships, blood supply, fatty infiltration, and morphologic variation. METHODS: Articles met the selection criteria if they contained specific information on SIJ anatomy, including bone morphology and architecture, ligaments, muscle attachments, innervation, vasculature, and the presence of fat. Biomechanics and kinematics related keywords were used as the literature often couples these with the anatomy. Keywords of individual articles were named as 'structures of interest.' RESULTS: A total of 88 primary and 101 secondary articles were identified in the time frame from 1851 to 2018. Primary articles provided quantitative data and detailed anatomic descriptions. Secondary articles did not focus specifically on the anatomy of the SIJ. Although research appeared to be in general agreement on bony landmarks, joint type, myofascial attachments, vasculature, and innervation of the SIJ, there was only part consensus on ligament attachments and cartilage structure. Information regarding bone density of the articulating surfaces of the SIJ is lacking. Despite its potential clinical significance, fatty infiltration within the joint lacks research to date. LIMITATIONS: Only the given databases were used for the initial search. Keyword combinations used for this review may not have been inclusive of all articles relevant to the SIJ. Work in languages other than the ones listed or work that is not available via the internet may be missing. CONCLUSIONS: This study provides an overview of normal SIJ structures, including all neuromusculoskeletal elements related to the joint. There is a lack of knowledge on the SIJ ligaments warranting further investigation. Furthermore, there are discrepancies in relation to the nomenclature, layers, attachment sites, and on the topographical relationships between ligamentous tissues and nerves. Subsequent studies on the quantification of fat and bone density in the SIJ have been suggested. These could be useful radiologic parameters to assess the condition of the joint clinically. This review may provide insight into the clinical signs and abnormal biomechanical features of the joint for the purposes of treating SIJ pain. KEY WORDS: Bone density, bony landmarks, fat infiltration, innervation, ligaments morphology, muscles, sacroiliac joint, vasculature.

Co-expression of CD21L and IL17A defines a subset of rheumatoid synovia, characterised by large lymphoid aggregates and high inflammation.

OBJECTIVE: To determine whether the expression of IL17A and CD21L genes in inflamed rheumatoid synovia is associated with the neogenesis of ectopic lymphoid follicle-like structures (ELS), and if this aids the stratification of rheumatoid inflammation and thereby distinguishes patients with rheumatoid arthritis that might be responsive to specific targeted biologic therapies. METHODS: Expression of IL17A and CD21L genes was assessed by RT-PCR, qRT-PCR and dPCR in synovia from 54 patients with rheumatoid arthritis. A subset of synovia (n = 30) was assessed by immunohistology for the presence of CD20+ B-lymphocytes and size of CD20+ B-lymphocyte aggregates as indicated by maximum radial cell count. The molecular profiles of six IL17A+/CD21L+ and six IL17A-/CD21L- synovia were determined by complementary DNA microarray analysis. RESULTS: By RT-PCR, 26% of synovia expressed IL17A and 52% expressed CD21L. This provided the basis for distinguishing four subgroups of rheumatoid synovia: IL17A+/CD21L+ (18.5% of synovia), IL17A+/CD21L- (7.5%), IL17A-/CD21L+ (33.3%) and IL17A-/CD21L- (40.7%). While the subgroups did not predict clinical outcome measures, comparisons between the synovial subgroups revealed the IL17A+/CD21L+ subgroup had significantly larger CD20+ B-lymphocyte aggregates (P = 0.007) and a gene expression profile skewed toward B-cell- and antibody-mediated immunity. In contrast, genes associated with bone and cartilage remodelling were prominent in IL17A-/CD21L- synovia. CONCLUSIONS: Rheumatoid synovia can be subdivided on the basis of IL17A and CD21L gene expression. Ensuing molecular subgroups do not predict clinical outcome for patients but highlight high inflammation and the predominance of B-lymphocyte mediated mechanisms operating in IL17A+/CD21L+ synovia. This may provide a rationale for more refined therapeutic selection due to the distinct molecular profiles associated with IL17A+/CD21L+ and IL17A-/CD21L- rheumatoid synovia.

Unusual manifestation of Erdheim-Chester disease.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare multisystem non-Langerhans cell histiocytosis that is characterized histologically by xanthogranulomatous infiltrates and radiologically by symmetrical sclerosis of long bones. The xanthomatous process is characterized by prominent foamy histiocytes staining positive for CD68, occasionally for PS100 and negative for S100 and CD1a. Gastroenterological involvement is exceedingly rare. CASE PRESENTATION: This case report describes the case of a 69-year-old man who presented otherwise well to the gastroenterology department with unspecific abdominal symptoms, nausea, vomiting and weight loss. ECD involving the gastrointestinal tract was confirmed clinically, radiologically and histologically. CONCLUSION: Gastroenterological manifestation of ECD is rare but should be considered in the differential diagnosis in patients presenting with evidence of multi-organ disease and typical radiological features of Erdheim-Chester disease elsewhere.

Sutureless pericardial patch augmentation for impending left ventricular free wall rupture.

Left ventricular rupture may occur as a complication of acute myocardial infarction and is associated with significant morbidity and mortality. The risk associated with impending rupture of the left ventricular free wall has not been quantified but it is likely a predisposing factor to complete rupture. Few cases of impending rupture of the left ventricular free wall have been discussed in the literature; we present one such case and describe simple operative management with an autologous pericardial patch and subsequent outcome.

Lateral hip pain: findings from magnetic resonance imaging and clinical examination.

STUDY DESIGN: Prospective cross-sectional study. OBJECTIVES: To examine the radiological and physical therapy diagnoses of lateral hip pain (LHP), and determine the validity of selected clinical variables for predicting gluteal tendon pathology. BACKGROUND: LHP is frequently encountered by clinicians. Further investigation is required to establish the specific pathologies implicated in the cause of LHP, and which clinical tests are useful in the assessment of this problem. METHODS AND MEASURES: Forty patients with unilateral LHP underwent a physical therapy examination followed by magnetic resonance imaging (MRI) studies. Three radiologists analyzed the images of both hips for signs of pathology. Interobserver reliability of the image analyses, the agreement between the physical therapy and radiological diagnoses, and the validity of the clinical tests were examined. RESULTS: Gluteus medius tendon pathology, bursitis, osteoarthritis and gluteal muscle atrophy (predominantly affecting gluteus minimus) were all implicated in the imaging report of LHP. While prevalent in symptomatic hips, abnormalities were also identified in asymptomatic hips, particularly relating to the diagnosis of bursitis. The strength of agreement between radiologists was variable and little agreement existed between the physical therapy and radiological diagnoses of pathology. Nine of the 26 clinical variables examined in relation to gluteal tendon pathology had likelihood ratios above 2.0 or below 0.5, but the associated 95% confidence intervals were large. CONCLUSIONS: The diagnosis of LHP is challenging and our results highlight some problems associated with the use of MRI as a diagnostic reference standard. This factor, together with the imprecise point estimates of the likelihood ratios, means that no firm conclusions can be made regarding the diagnostic utility of the clinical tests used in the assessment of gluteal tendon pathology.

Small bowel MRI: comparison of a polyethylene glycol preparation and water as oral contrast media.

PURPOSE: To compare water and a polyethylene glycol (PEG) preparation as potential oral contrast media for magnetic resonance imaging (MRI) of the small bowel. MATERIALS AND METHODS: Twenty-two healthy volunteers underwent separate MRI examinations after drinking up to two liters of water or PEG preparation. Small bowel images were obtained every 10 minutes for at least two hours using breath-hold single shot half-Fourier imaging, including both thick section projection and thin section images. Examinations were evaluated by two radiologists in consensus, blinded to the volunteer and contrast details, for arrival at the terminal ileum, transit time, and demonstration of small bowel segments. RESULTS: The PEG preparation was significantly better than water at reaching the terminal ileum (PEG 21/22 volunteers [95.45%], water 14/22 volunteers [63.6%], P = 0.04). There was no significant difference in the mean transit time (water 51 +/- 48 minutes, PEG 37.7 +/- 22 minutes) or in the demonstration of the stomach, duodenum, and jejunum, but the PEG preparation was significantly better at demonstrating the ileum (P = 0.005) and terminal ileum (P = 0.002). CONCLUSION: A PEG preparation is significantly better than water as an oral contrast medium for demonstrating the distal small bowel during breath-hold T2-weighted MRI.