Which Magnetic Resonance Imaging Lesions in the Sacroiliac Joints Are Most Relevant for Diagnosing Axial Spondyloarthritis? A Prospective Study Comparing Rheumatologists' Evaluations With Radiologists' Findings.

OBJECTIVE: Pathologic sacroiliac (SI) joint changes on magnetic resonance imaging (MRI) are important for the classification of axial spondyloarthritis (SpA). In daily practice, radiologists play a major role in interpreting imaging findings. This study was undertaken to evaluate the impact of MRI SI joint findings on the identification of axial SpA by radiologists, in comparison to diagnosis by rheumatologists. METHODS: Patients age ≤45 years were prospectively included when referred for clinical suspicion of axial SpA and underwent a complete diagnostic evaluation including STIR- and T1-weighted MRI of the SI joint. Diagnosis made by an experienced rheumatologist with access to all relevant information was considered the gold standard. MRIs were evaluated by 2 experienced radiologists who were unaware of the clinical data, who indicated which MRI lesions were "critical" to the decision for or against axial SpA. RESULTS: Of the 300 patients included, 132 (44%) were diagnosed as having axial SpA. Mean age was comparable between the 2 groups, but patients with axial SpA and those with non-axial SpA differed with regard to symptom duration (58.6 ± 69.5 versus 33.9 ± 45.1 months, respectively; P = 0.003) and HLA-B27 positivity (75.6% versus 19%, respectively; P < 0.001). Rheumatologists and radiologists agreed on the diagnosis in 262 cases (87.3%), while 34 patients (11.3%) were diagnosed as having axial SpA by rheumatologists only (clinically), and 4 cases (1.3%) were judged as suggestive of axial SpA by radiologists only. Bone marrow edema (BME) and sclerosis showed the highest sensitivity, while erosions and fatty lesions showed the highest specificity, for axial SpA diagnosis. The combination of BME with erosions had the highest positive predictive value (86.5%). CONCLUSION: The MRI findings with the highest diagnostic value in patients in whom axial SpA is suspected are structural changes in the SI joint, alone or in combination with BME. Our findings indicate that while the absence of BME is usually not compatible with a diagnosis of axial SpA, the presence of BME does not necessarily confirm a diagnosis of axial SpA.

[Differential diagnosis of axial spondyloarthritis-axSpA mimics]. / Differenzialdiagnose axiale Spondyloarthritis ­ "axSpA mimics".

The classification of axial spondyloarthritis (axSpA) comprises the classical ankylosing spondylitis (AS), which is characterized by already existing structural changes in the sacroiliac joints, and the so-called non-radiographic axSpA (nr-axSpA), in which by definition such changes are not present. This distinction is based on the ASAS classification criteria for axSpA, which are however not suitable for a diagnosis. According to the current classification, spondyloarthritis (SpA) includes axSpA, which can be associated with psoriasis and/or chronic inflammatory bowel diseases (CED), such as Crohn's disease and ulcerative colitis, and peripheral SpA, which is further divided into SpA associated with psoriasis, partially synonymous with psoriatic arthritis (PsA), reactive SpA, partially synonymous with reactive arthritis (ReA) and SpA associated with CED, partially synonymous with arthritis associated with CED (e.g. Crohn's disease, ulcerative colitis) and peripheral undifferentiated SpA, which by definition is not associated with any of the above. In this article only the most important differential diagnoses are discussed, i. e. diffuse idiopathic skeletal hyperostosis (DISH), fractures and infections in the axial skeleton. In addition, the frequency of certain musculoskeletal findings in the normal population examined by magnetic resonance imaging (MRI) are also discussed.

[Imaging of the sacroiliac joints]. / Bildgebung der Sakroiliakalgelenke.

The sacroiliac joints (SIJ) are an important part of the axial skeleton and a main area to consider in the examination of back pain both clinically and on imaging. Patients with inflammatory-rheumatic symptoms as well as those with other diagnoses may present with pathological changes in the SIJ even at young ages. Although imaging of the SIJ is not the only factor in approaching the final diagnosis, it nevertheless provides a lot of important information about differential diagnoses, thereby enabling certain causes of back pain to be excluded. Overall, there are four important imaging methods that are being used to evaluate the SIJ in daily routine: conventional radiographs, computed tomography, scintigraphy and magnetic resonance imaging (MRI). In recent years, most of the scientific work on imaging of the SIJs has concentrated on a better understanding of the MRI in this context. This overview article describes the advantages and limitations of the different imaging techniques for the visualization of pathologic changes in the SIJ, also taking into account their value in helping the treating physician to make diagnostic and therapeutic decisions in daily clinical practice.

[Inflammatory spinal diseases: axial spondyloarthritis : Central importance of imaging]. / Entzündliche Wirbelsäulenerkrankungen: axiale Spondyloarthritis : Zentrale Bedeutung der Bildgebung.

The diagnosis of axial spondyloarthritis (axSpA) includes classical ankylosing spondylitis (AS) as well as earlier stages and abortive courses of the disease, in which structural alterations have not yet occurred. These are classified as non-radiographic axSpA (nr-axSpa). Inflammatory changes in the entire axial skeleton are characteristic for axSpA and can be visualized by magnetic resonance imaging (MRI), while in most patients structural alterations, such as new bone formation with syndesmophytes and ankylosis develop in the later course of the disease. These bony alterations can best be visualized by conventional radiography and by computed tomography. Certain MRI sequences are nowadays considered as the standard method for depiction of inflammatory changes in axSpA. The introduction of MRI has led to a paradigm shift for this disease because the inflammatory lesions characteristic for the disease can be visualized at an early stage using appropriate MRI sequences.

[Cuff tear arthropathy ­ long-term results of reverse total shoulder arthroplasty]. / Defektarthropathie ­ langzeitergebnisse der inversen Schultertotalendoprothesenimplantation

The results after reverse total shoulder arthroplasty for cuff tear arthropathy are superior and the complications fewer than for other etiologies, such as rheumatoid arthritis, fracture, fracture sequelae or even revision. The improvements in function and pain are excellent whereas rotation may be unaffected. Revisions and complications can be encountered in the first 3 years and the survival curve of the prosthesis is still good after 10 years with 90%. Progressive functional and radiological deterioration is observed after 9 years in approximately 30% of the patients without apparent problems with the prosthesis. Notching is progressive with incidence and size over time, without a proven correlation to the functional results but remains a major concern. Modification of the implants, the operative techniques and experience could significantly improve the results and reduce the rate of complications. Lateralization of the center of rotation and smaller inclination angles have a positive effect on the rate of notching and the range of motion, especially for the rotation. New prosthetic designs and operative techniques attempt to implement a combination of the biomechanical improvements. Reverse shoulder arthroplasty remains a challenging operation with a high rate of complications. The results depend on the etiology and the function of the remaining muscles and therefore on the experience and the skill of the surgeon to implement the appropriate biomechanical factors. Because of the concerns regarding the longevity, reverse shoulder arthroplasty should be reserved for the elderly over 70 years of age.