Further expanding the phenotype of anti-Ku antibody associated disease in children and adolescents.

Anti-Ku autoantibodies are associated with several autoimmune inflammatory diseases. We aimed to review our anti-Ku positive pediatric patients in this study. Four pediatric patients (all female) who had anti-Ku positivity were included (Patients 1-2-3 with idiopathic inflammatory myopathy (IIM); Patient 4 with chronic urticaria). Patient 1 (onset:10.5 years) had proximal muscle weakness, Raynaud phenomenon, sclerodactyly, hyperpigmentation, joint contracture, and tenosynovitis. The disease course was progressive despite treatment with corticosteroids, intravenous immunoglobulin (IVIG), plasma exchange, and 11 different immunosuppressive drugs. Patient 2 (onset:15 years) presented with proximal muscle weakness, fatigue, weight loss. She recovered normal muscle strength after treatment with corticosteroids, IVIG, methotrexate, cyclosporine A, mycophenolate mofetil. Patient 3 (onset:10 years) had juvenile dermatomyositis with proximal muscle weakness, Gottron's papules, and calcinosis. She also had anti-NXP2 positivity. Remission was achieved with corticosteroids, methotrexate, azathioprine, and infliximab. Muscle biopsy findings revealed a variable spectrum of necrosis, regeneration, perifascicular pattern, and inflammation. Patient 4 had only chronic urticaria (onset: 6.5 years). The striking features of this series were heterogeneity in clinical presentations including solely chronic urticaria and IIM; variable response to immunosuppressive treatments; and histopathology revealing a spectrum of necrosis, regeneration and inflammatory infiltration. Expanding the spectrum of anti-Ku positivity will allow better understanding of anti-Ku-associated phenotype clusters.

Preferential involvement of the pelvis and hips along with active sacroiliitis in chronic nonbacterial osteomyelitis: MRI of 97 patients from a single tertiary referral center.

OBJECTIVE: To present MRI distribution of active osteitis in a single tertiary referral center cohort of patients with chronic nonbacterial osteomyelitis (CNO). METHODS: Two musculoskeletal radiologists retrospectively reviewed MRI examinations of all patients with a final clinical diagnosis of CNO over 15 years. Sites of active osteitis at any time during the course of disease were divided into seven groups: (A) mandible, sternum, clavicles, or scapulas; (B) upper extremities; (C) subchondral sacrum and ilium immediately subjacent to sacroiliac joints (active osteitis denoting "active sacroiliitis" here); (D) pelvis and proximal 1/3 of femurs (excluding group C); (E) bones surrounding knees including distal 2/3 of femurs and 1/2 of proximal tibias and fibulas; (F) distal legs (including distal 1/2 of tibias and fibulas), ankles, or feet; (G) spine (excluding group C). Temporal changes of lesions in response to treatment (or other treatment-related changes such as pamidronate lines) were not within the scope of the study. RESULTS: Among 97 CNO patients (53 males [55%], 44 females; age at onset, mean ± SD, 8.5 ± 3.2 years; age at diagnosis, 10.3 ± 3.3 years), whole-body (WB) MRI was performed in 92%, mostly following an initial targeted MRI (94%). A total of 557 (346 targeted and 211 WB) MRIs were analyzed. Biopsy was obtained in 39 patients (40%), all consistent with CNO or featuring supporting findings. The most common locations for active osteitis were groups D (78%; 95% CI 69‒85%) and C (72%; 95% CI 62‒80%). CONCLUSION: Pelvis and hips were preferentially involved in this cohort of CNO patients along with a marked presence of active sacroiliitis. CLINICAL RELEVANCE STATEMENT: When suggestive findings of CNO are identified elsewhere in the body, the next targeted site of MRI should be the pelvis (entirely including sacroiliac joints) and hips, if whole-body MRI is not available or feasible. KEY POINTS: • Heavy reliance on MRI for diagnosis of CNO underscores the importance of suggestive distribution patterns. • Pelvis and hips are the most common (78%) sites of CNO involvement along with active sacroiliitis (72%). • Pelvis including sacroiliac joints and hips should be targeted on MRI when CNO is suspected.

Chondro-osseous border in baby hip ultrasonography for developmental dysplasia of the hip: an indispensable litmus paper for the accuracy of scientific publications.

PURPOSE: The aim of our study was to use the chondro-osseous border (COB) as an indispensable assessment criterion to evaluate the quality of baby hip ultrasonography (US) images in the literature pertaining to the application of Graf's technique. MATERIALS AND METHODS: Our literature review search yielded 144 articles. Of these, 41 contained images that were stated to be based on the application of Graf's technique. Two reviewers, a radiologist and an orthopaedic surgeon, both course instructors for the use of baby hip US for developmental dysplasia of the hip (DDH), independently evaluated the articles to assess the diagnostic validity of the published images on the basis of a single criterion: the identification of the COB. RESULTS: Of the 41 articles which were analyzed, 15 contained images without a COB, which corresponds to 36% (roughly, one out of three). Articles from countries where universal screening is performed (Germany, Italy, Switzerland, Mongolia) were all correct. All the articles from Turkey, a country which has made significant contribution with published material about Graf's technique over many years, and most of the articles from China (80%), where Graf's technique has become popular in recent years, contained correct images. CONCLUSION: Published literature lacks strict criteria for the publication of correct images corresponding to Graf's technique in baby hip US. This fact raises concerns about the quality of published material (and, as a corollary, the quality of clinical application of the technique) and should have ramifications on scientific journal policies regarding the publication of such manuscripts.

Sacroiliac joint involvement in osteochondromatosis: identifying its prevalence and characteristics from cross-sectional imaging

PURPOSE: Apart from a few case reports, sacroiliac joint (SIJ) involvement in osteochondromatosis has not been studied. We aimed to determine the prevalence and characteristics of such involvement using cross-sectional imaging. METHODS: In this retrospective study, three observers (one junior radiologist and two musculoskeletal radiologists) independently reviewed computed tomography (CT) or magnetic resonance imaging (MRI) of patients in our database who had osteochondromatosis (≥2 osteochondromas across the skeleton) for SIJ involvement. The final decision was reached by the consensus of the two musculoskeletal radiologists in a later joint session. RESULTS: Of the 36 patients with osteochondromatosis in our database, 22 (61%) had cross-sectional imaging covering SIJs (14 females, 8 males; age range 7-66 years; mean age 23 years; 13 MRI, 9 CT). Of these, 16 (73%) had intra-articular osteochondromas. For identifying SIJ osteochondromas on cross-sectional imaging, interobserver agreement was substantial [κ = 0.67; 95% confidence interval (CI): 0.34, 1.00] between the musculoskeletal radiologists and moderate (κ = 0.59; 95% CI: 0.23, 0.94) between the junior radiologist and the final consensus decision of the two musculoskeletal radiologists. In the cohort with cross-sectional imaging, the anatomical variations of the accessory SIJ (n = 6, 27%) and iliosacral complex (n = 2, 9%) were identified in six different patients with (n = 2) and without (n = 4) sacroiliac osteochondromas. CONCLUSION: Cross-sectional imaging shows frequent (73%) SIJ involvement in osteochondromatosis, which, although a rare disorder, nevertheless needs to be considered in the differential diagnosis of such SIJ anatomical variants as the accessory SIJ and iliosacral complex. Differentiating these variants from osteochondromas is challenging in patients with osteochondromatosis.

Imaging Osteomyelitis: An Update.

BACKGROUND: Hematogenous osteomyelitis has increased over the past quarter century in frequency, virulence, and degree of soft-tissue involvement, bringing about changes in clinical manifestations and management of the disease especially in children that should be reflected in the current imaging approach. Likewise, the global disease burden of diabetes has increased greatly in the same period, compounding the problem of ascertaining osteomyelitis in diabetic foot. METHOD: This article provides an updated overview of imaging findings in hematogenous and contiguous osteomyelitis based on the literature and our institutional experience, along with salient features of recent recommendations from expert groups on the diagnostic algorithms and reporting terminology. RESULTS AND CONCLUSION: Findings on radiography and especially magnetic resonance imaging (MRI) closely reflect pathophysiology in osteomyelitis, whereby the characteristic involvement of the metaphysis or metaphyseal-equivalents, the formation and subperiosteal extension of intramedullary pus collection, and the development of cloaca, sequestrum, and involucrum are all diagnostic clues. Non-enhancing foci within the medullary bone, the penumbra sign, intra- or extramedullary fat globules, and surrounding soft tissue inflammation or abscesses are among key MRI findings. Diabetic foot is a special condition with characteristic pathophysiologic and imaging features that suggest the likelihood of osteomyelitis and the main differential diagnostic consideration of acute on chronic neuropathic osteoarthropathy with or without osteomyelitis. KEY POINTS: · Imaging closely reflects pathophysiology in hematogenous osteomyelitis.. · Acute hematogenous osteomyelitis predominantly involves metaphyses and metaphyseal equivalent sites.. · MRI clues for hematogenous osteomyelitis include central marrow non-enhancement, intra- or extramedullary fat globules, and the "penumbra" sign.. · An increased fluid-sensitive MRI bone signal abutting a soft tissue ulcer, abscess, or sinus tract suggests a high probability of contact osteomyelitis.. CITATION FORMAT: · Aydingoz U, Imaging Osteomyelitis: An Update. Fortschr Röntgenstr 2023; 195: 297 - 308.

A Child with Refractory and Relapsing Anti-3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Myopathy: Case-Based Review.

BACKGROUND/OBJECTIVE: Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) myopathy is rare in children. Here, we present a boy with relapsing refractory anti-HMGCR myopathy along with a systematic literature review. CASE REPORT: 17-year-old boy with five years of muscle weakness, rash, high creatinine kinase (CK) levels, and muscle biopsy compatible with inflammatory myopathy was diagnosed with juvenile dermatomyositis. He was treated with corticosteroids, intravenous immunoglobulin (IVIG), and methotrexate. His muscle weakness improved with this treatment although never completely resolved. CK levels decreased from ∼15000 U/L to ∼3000 U/L. At the age of 15, muscle weakness relapsed after an upper respiratory tract infection; pulse corticosteroid treatment was administered. The re-evaluated muscle biopsy showed a necrotizing pattern and the HMGCR antibody was positive confirming anti-HMGCR myopathy when he was 16. The diagnostic delay was 50 months. Disease activity was monitored by Medical Research Council score, MRI and functional tests. Despite corticosteroids, methotrexate, IVIG, cyclosporine A, and rituximab therapies, muscle weakness improved only slightly during the first three months and remained stable afterwards.Results of the Literature Search:We identified 16 articles describing 50 children (76% female) with anti-HMGCR myopathy by reviewing the English literature up to March 1st, 2022. Proximal muscle weakness was the most common clinical symptom (70.8%). Corticosteroids (84.8%), IVIG (58.7%), and methotrexate (56.5%) were preferred in most cases. Complete remission was achieved in nine patients (28.1%). CONCLUSION: Diagnosis and management of children with anti-HMGCR myopathy are challenging. Complete remission is achieved in only one third of these patients. Imaging biomarkers may aid treatment.

Zero Echo Time Musculoskeletal MRI: Technique, Optimization, Applications, and Pitfalls.

Zero echo time (ZTE) imaging is an MRI technique that produces images similar to those obtained with radiography or CT. In ZTE MRI, the very short T2 signal from the mineralized trabecular bone matrix and especially cortical bone-both of which have a low proton density (PD)-is sampled in a unique sequence setup. Additionally, the PD weighting of the ZTE sequence results in less contrast between soft tissues. Therefore, along with gray-scale inversion from black to white and vice versa, ZTE imaging provides excellent contrast between cortical bone and soft tissues similar to that of radiography and CT. However, despite isotropic or near-isotropic three-dimensional (3D) imaging capabilities of the ZTE sequence, spatial resolution in this technique is still inferior to that of radiography and CT, and 3D volume renderings are currently time-consuming and require postprocessing software that features segmentation and manual contouring. Optimization of ZTE MRI mostly entails adjustments of bandwidth, flip angle, field of view, and image matrix. A wide range of structural abnormalities and disease or healing processes in the musculoskeletal system are well delineated with ZTE MRI, including conditions that involve bone-based morphometric analyses (which aid diagnosis, help prognostication, and guide surgery), impaction, avulsion and stress fractures, loose bodies or erosions in and around joints, soft-tissue calcifications and ossifications, and bone tumors (including treatment response). The pitfalls of ZTE imaging include mimics of foci of calcification or ossification such as intra-articular gas and susceptibility artifacts from surgical materials and hemosiderin deposition, which can be avoided in many instances by cross-referencing images obtained with other MRI sequences. Online supplemental material is available for this article. ©RSNA, 2022.

Different Attenuation Models of Diffusion-Weighted MR Imaging for the Differentiation of Benign and Malignant Musculoskeletal Tumors.

BACKGROUND: Several functional imaging techniques, including monoexponential diffusion-weighted imaging (m-DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis (DK) imaging, have been used in differentiating benign and malignant musculoskeletal tumors. Combining all three techniques in the same study population may improve differentiation. PURPOSE: To compare the diagnostic performance of m-DWI, IVIM, and DK models and their combinations in differentiating benign and malignant musculoskeletal tumors. STUDY TYPE: Prospective. POPULATION: Fifty patients with benign and malignant musculoskeletal tumors divided into nonmyxoid and nonchondroid and myxoid and/or chondroid subgroups. FIELD STRENGTH/SEQUENCE: A 1.5 T/m-DWI, IVIM, and DK single-shot spin-echo echo-planar sequences. ASSESSMENT: Minimum and volumetric values of apparent diffusion coefficient (ADC), pure molecular diffusion (Divim ), pseudodiffusion (D*), perfusion fraction (f), diffusion coefficient for kurtosis model (DK ), and Kurtosis (K) were compared between all benign and malignant tumors. Subgroup analysis was also performed for nonmyxoid and nonchondroid and myxoid and/or chondroid tumors. STATISTICAL TESTS: Independent samples t-test, Mann-Whitney U test, intraclass correlation coefficient, ROC analysis, and logistic regression analysis. A P value < 0.05 was considered statistically significant. RESULTS: ADCmin , Divim-min , D*vol , DK-min, Kvol, and Kmin values showed statistically significant differences between all benign and malignant tumors and nonmyxoid and nonchondroid tumor subgroup. Kmin showed the highest diagnostic performance in differentiating benign and malignant tumors with AUCs of 0.760 for "all tumors" and 0.825 for the nonmyxoid and nonchondroid tumor subgroup. No significant differences were detected in m-DWI-, IVIM-, and DK-derived parameters for differentiating benign and malignant myxoid and/or chondroid tumors. Only three of 63 combinations of prediction models demonstrated a higher diagnostic performance than Kmin ; however, improvements were not significantly different. DATA CONCLUSION: ADCmin , Divim-min , D*vol , DK-min , Kvol , and Kmin values can be used to differentiate benign and malignant musculoskeletal tumors. Our findings suggest that the added value of multiparametric approach in such differentiation is not significant. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Machine learning identifies factors related to early joint space narrowing in dysplastic and non-dysplastic hips.

OBJECTIVES: To utilise machine learning, unsupervised clustering and multivariate modelling in order to predict severe early joint space narrowing (JSN) from anatomical hip parameters while identifying factors related to joint space width (JSW) in dysplastic and non-dysplastic hips. METHODS: A total of 507 hip CT examinations of patients 20-55 years old were retrospectively examined, and JSW, center-edge (CE) angle, alpha angle, anterior acetabular sector angle (AASA), and neck-shaft angle (NSA) were recorded. Dysplasia and severe JSN were defined with CE angle < 25o and JSW< 2 mm, respectively. A random forest classifier was developed to predict severe JSN based on anatomical and demographical data. Multivariate linear regression and two-step unsupervised clustering were performed to identify factors linked to JSW. RESULTS: In dysplastic hips, lateral or anterior undercoverage alone was not correlated to JSN. AASA (p < 0.005) and CE angle (p < 0.032) were the only factors significantly correlated with JSN in dysplastic hips. In non-dysplastic hips, JSW was inversely correlated to CE angle, AASA, and age and positively correlated to NSA (p < 0.001). A random forest classifier predicted severe JSN (AUC 69.9%, 95%CI 47.9-91.8%). TwoStep cluster modelling identified two distinct patient clusters one with low and one with normal JSW and different anatomical characteristics. CONCLUSION: Machine learning predicted severe JSN and identified population characteristics related to normal and abnormal joint space width. Dysplasia in one plane was found to be insufficient to cause JSN, highlighting the need for hip anatomy assessment on multiple planes. KEY POINTS: • Neither anterior nor lateral acetabular dysplasia was sufficient to independently reduce joint space width in a multivariate linear regression model of dysplastic hips. • A random forest classifier was developed based on measurements and demographic parameters from 507 hip joints, achieving an area under the curve of 69.9% in the external validation set, in predicting severe joint space narrowing based on anatomical hip parameters and age. • Unsupervised TwoStep cluster analysis revealed two distinct population groups, one with low and one with normal joint space width, characterised by differences in hip morphology.

Diffusion-weighted imaging for the differentiation of Ewing sarcoma from osteosarcoma.

OBJECTIVE: The purpose of this study is to assess the ability of apparent diffusion coefficient (ADC) values in differentiating Ewing sarcoma and osteosarcoma. MATERIALS AND METHODS: This retrospective cross-sectional observational study included a total of 35 patients with a recent diagnosis of Ewing sarcoma (n = 13) and osteosarcoma (n = 22) who underwent conventional MRI and diffusion-weighted imaging (DWI). Three ADC measurements from the areas of the lowest diffusivity in ADC maps (ADCmin), and other areas with low diffusivity (ADCother), were made independently by two observers on pre-treatment MRI, and the means of these measurements were compared using independent samples t-test. Intraclass correlation coefficient was calculated for inter-observer agreement. RESULTS: There was a significant difference between the ADCmin (P < 0.001) and ADCother (P < 0.001) in Ewing sarcoma and osteosarcoma for both observers. For Ewing sarcoma and osteosarcoma, mean ADCmin was 0.566 ± 0.07 and 1.193 ± 0.33 × 10-3 mm2/s; 0.551 ± 0.08 and 1.182 ± 0.33 × 10-3 mm2/s; and mean ADCother was 0.813 ± 0.11 and 1.510 ± 0.35 × 10-3 mm2/s; 0811 ± 0.12 and 1.501 ± 0.33 × 10-3 mm2/s for observers 1 and 2, respectively. Inter-observer correlation coefficient for mean ADCmin was 0.994 and for mean ADCother was 0.995. CONCLUSION: Diffusion-weighted imaging and ADC values could be used in the differentiation of Ewing sarcoma and osteosarcoma in borderline cases.

Sclerosing epithelioid fibrosarcoma of bone: morphological, immunophenotypical, and molecular findings of 9 cases.

Primary sclerosing epithelioid fibrosarcoma (SEF) of bone is a rare and scarcely reported neoplasm. We document clinicopathological and molecular features of 9 additional cases. Five males and 4 females had a mean age of 39 years (14-71 years). Most tumors affected flat/irregular bones; only 3 cases involved a long bone. By radiology, it has characteristic radiographic features of a predominantly lytic expansile lesion with a sclerotic rim. Referring diagnoses were SEF (n = 2), low-grade osteosarcoma (n = 2), chondrosarcoma (n = 1), and chondromyxoid fibroma (n = 1). Histologically, five cases revealed classical morphology of SEF of soft tissue. Remaining cases were classified as hybrid SEF/low-grade fibromyxoid sarcoma, characterized by spindle or stellate cells, prominent stroma, and giant hyalinized areas. Various morphological deviations such as prominent vasculature (n = 3), osteoid-like material (n = 4), or parallel bone trabeculae (n = 2) were observed. Immunohistochemically, all cases showed diffuse and strong MUC4 expression. SATB2 was observed in 5/8 cases. Using FISH, EWSR1, and FUS rearrangements were detected in 4 cases and 1 case, respectively. EWSR1-CREB3L1 fusion was identified in 1 additional case by next-generation sequencing. Recurrence and metastasis were observed in 1 case and 2 cases, respectively. All but one patient were alive with disease for a mean interval of 31 months. SEF of bone is a relatively indolent sarcoma of adults, most commonly located in the flat/irregular bones. Due to overlapping histological features, it is often misdiagnosed as osteosarcoma or a chondroid tumor. Most SEF of bone exhibit EWSR1 rearrangements, but rare cases may harbor a FUS gene fusion.

International Interdisciplinary Consensus Meeting on the Evaluation of Developmental Dysplasia of the Hip.

In September 2018, an international meeting of doctors of various disciplines, with expertise in the detection and treatment of DDH, was held in Csolyospalos, Hungary. The aim was to achieve consensus on the detection and early treatment of the condition and to develop a standardized system of teaching and training for hip ultrasound. There was strong agreement that US screening is essential. Specifically the Graf technique was selected as the technique of choice. Universal US screening was strongly favored. Screening should be carried out as soon as possible, but not later than the sixth week of age. US screening is cost-effective, does not result in overtreatment, and contributes to a reduction of long-term consequences. The essential principle of treatment is timely application of a device to achieve reduction, retention and maturation, by holding the hips in flexion, and a safe degree of abduction. It was agreed that the effectiveness of any screening policy depends on the correct scanning technique. Therefore, standardization of teaching and training of the Graf technique is mandatory. A unified teaching policy and materials should be developed for this purpose. Certification, re-certification and audit were discussed. The group, which has been formalized as the International Interdisciplinary Consensus Committee On DDH Evaluation (ICODE), will continue to meet and work towards establishing international consensus on DDH, standardizing and developing teaching and training of the Graf technique for hip US, and maintaining standards for detection and management.

Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma of bone: Clinicopathologic features of 5 cases.

Pseudomyogenic hemangioendothelioma (PHE) is an uncommon mesenchymal tumor of intermediate malignant potential with characteristic clinicopathologic and genetic features. Although bone involvement accompanies nearly one-fourth of reported cases of soft tissue PHEs, primary intraosseous PHE is rare. Herein, we report five cases of primary intraosseous PHEs. Male to female ratio was 4:1, with an average age of 28 years (age range, 5-44 years). Radiologically, tumors presented as lytic lesions in the proximal femur (two), diaphysis of the tibia (one), distal radius (one) and vertebrae (one). Multifocal lesions were observed in four cases. Histopathologic examination revealed plump spindle cells and prominent nucleoli. New bone formation was noted in three cases. Immunohistochemically, all tumors were positive for CD31 and negative for CD34. Pan Cytokeratin (CK) (AE1/3) was positively expressed in all, except a single tumor, in which CK7 and Cam5.2 were expressed. INI1/SMARCB1 was completely retained in all tumors. A single patient underwent surgical resection. During follow-up, two cases showed no evidence of disease within two and five years, respectively. Differential diagnosis of a PHE of bone includes osteoblastoma, epithelioid angiosarcoma, metastatic carcinoma, metastatic rhabdomyosarcoma, and epithelioid sarcoma. Caution must be exercised as pan CK (AE1/3) might not be expressed; therefore, the use of other cytokeratins, such as Cam5.2 is recommended. Awareness of such an entity in bone is the key to the diagnosis.

Rotator cuff tear characteristics: how comparable are the pre-operative MRI findings with intra-operative measurements following debridement during arthroscopic repair?

PURPOSE: Magnetic resonance (MRI) is a valuable imaging method which can detect pre-operative rotator cuff tear characteristics accurately. However, tendon degeneration almost always necessitates a certain amount of debridement during arthroscopic repair, which alters tear size and shape. The aim of this study is to question the accuracy of the pre-operative tear size and classification in MRI and its relation to the tear size and type of the debrided tendon during arthroscopic repair. METHODS: A retrospective survey was performed to identify shoulders that underwent arthroscopic rotator cuff repair. Rotator cuff tears with an adequate history, a standard pre-operative MRI, and available surgical video records with appropriate measurements were included. Traumatic tears, calcifying tendonitis, isolated subscapularis tears, and revisions were excluded. In total, 60 shoulders' (30 males, 27 females; age 55.2 [35-73]) preoperative MRIs and intra-operative measurements were analyzed by orthopaedic surgeons and radiologists. Tear width and type were recorded. Interdisciplinary and intradisciplinary consistency of measurements and classifications were analyzed. Tear width measured on pre-operative MRI and after debridement were compared. RESULTS: Average measured tear width was 9 ± 5.3 mm on MRI. Surgeons (9.98 ± 4.6 mm) measured tears significantly wider than radiologists (7.71 ± 6.6 mm). Radiologists (ICC, 0.930; CI, 0.883-0.959) showed superior consistency on MRI than surgeons (CI, 0.502; CI, 0.105-0.726). Average tear width measured after debridement (29.3 ± 9.6 mm) was significantly higher than tear width measured on pre-operative MRI (p < 0.0001). None of the researchers assessing tear type on pre-operative MRI showed agreement with surgeons assessing intra-operative data. CONCLUSIONS: There were significant differences between the pre-operative tear characteristics on MRI and the debrided tendon characteristics during surgery, which were extensive enough to classify the tear in a different category.

Chronic recurrent multifocal osteomyelitis in children: a single center experience over five years.

Sag E, Sönmez HE, Demir S, Bilginer Y, Ergen FB, Aydingöz Ü, Özen S. Chronic recurrent multifocal osteomyelitis in children: a single center experience over five years. Turk J Pediatr 2019; 61: 386-391. Chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease characterized by sterile bone inflammation. It is an orphan disease with many unclear aspects in terms of diagnosis, treatment and follow-up. The aim of this study was to report our experience of pediatric CRMO patients. Children who were diagnosed with CRMO, and were followed-up between January 2008 and January 2017, were included in this study. There were 15 CRMO patients (8M/7F) with a median age at diagnosis of 9.0 years (range: 0.6-15.0). Bone pain was the most common presenting symptom. All of the patients had multifocal bone lesions. Vertebrae (66.7%) and femur (66.7%) were the most commonly affected bones. Eight of the patients also had sacroiliitis; however, only one of them was HLA-B27 positive. Whole-body magnetic resonance imaging (MRI) was used as a diagnostic tool in 13 patients revealing bone marrow edema (84.6%), osteitis (69.2%), and periosteal reaction (61.5%). All patients were initially treated with non-steroidal anti-inflammatory drugs (NSAIDs), however, disease-modifying anti-rheumatic drugs, anti-TNF agents or pamidronate were added to therapy due to inadequate treatment response. Clinical remission was achieved in 12 patients (1 with NSAIDs, 3 with methotrexate, 1 with pamidronate and 7 with an anti-TNF agent). During the follow-up period, relapses were observed in four patients who presented with pain and/or a newly formed bone lesion on MRI. Eventually, however, all of these patients also reached remission. CRMO is a chronic disease which may have a progressive or relapsing-remitting course. Improvement of the knowledge about this rare disease may help to enlighten the unknowns of the disease.