Deep learning-based classification of erosion, synovitis and osteitis in hand MRI of patients with inflammatory arthritis.

OBJECTIVES: To train, test and validate the performance of a convolutional neural network (CNN)-based approach for the automated assessment of bone erosions, osteitis and synovitis in hand MRI of patients with inflammatory arthritis. METHODS: Hand MRIs (coronal T1-weighted, T2-weighted fat-suppressed, T1-weighted fat-suppressed contrast-enhanced) of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients from the rheumatology department of the Erlangen University Hospital were assessed by two expert rheumatologists using the Outcome Measures in Rheumatology-validated RA MRI Scoring System and PsA MRI Scoring System scores and were used to train, validate and test CNNs to automatically score erosions, osteitis and synovitis. Scoring performance was compared with human annotations in terms of macro-area under the receiver operating characteristic curve (AUC) and balanced accuracy using fivefold cross-validation. Validation was performed on an independent dataset of MRIs from a second patient cohort. RESULTS: In total, 211 MRIs from 112 patients (14 906 region of interests (ROIs)) were included for training/internal validation using cross-validation and 220 MRIs from 75 patients (11 040 ROIs) for external validation of the networks. The networks achieved high mean (SD) macro-AUC of 92%±1% for erosions, 91%±2% for osteitis and 85%±2% for synovitis. Compared with human annotation, CNNs achieved a high mean Spearman correlation for erosions (90±2%), osteitis (78±8%) and synovitis (69±7%), which remained consistent in the validation dataset. CONCLUSIONS: We developed a CNN-based automated scoring system that allowed a rapid grading of erosions, osteitis and synovitis with good diagnostic accuracy and using less MRI sequences compared with conventional scoring. This CNN-based approach may help develop standardised cost-efficient and time-efficient assessments of hand MRIs for patients with arthritis.

Neuropathic and Nociplastic Pain Profiles are Common in Adult Chronic Nonbacterial Osteitis (CNO).

Chronic nonbacterial osteitis (CNO) is a rare musculoskeletal disease causing chronic bone pain. It is known that chronic musculoskeletal pain may involve other mechanisms than nociceptive pain only. We investigate the prevalence of neuropathic and nociplastic pain in adult CNO and their association with clinical characteristics and treatment outcomes. Survey study among the Dutch adult CNO cohort (n = 84/195 participated), including PAIN-detect for neuropathic pain, and the Central Sensitization Inventory (CSI), Fibromyalgia Rapid Screening Tool (FiRST), and ACTTION-APS Pain Taxonomy (AAPT) for nociplastic pain. Clinical characteristics and CNO-related bone pain scores were compared between patients with exclusive nociceptive pain and those with nociceptive pain plus neuropathic and/or nociplastic pain (mixed pain). 31% (95% CI 21-41) of patients classified as likely having neuropathic pain according to PAIN-detect. 53% (41-64) of patients displayed central sensitization on CSI, 61% (50-72) screened positive for fibromyalgia on FiRST and 14% (7-23) of patients fulfilled the AAPT criteria, all indicative of nociplastic pain. Mixed pain was associated with longer diagnostic delay (mean difference 2.8 years, 95% CI 0.4-5.2, p = 0.023), lower educational level (72% versus 20%, p < 0.001), and opioid use (37% versus 13%, p = 0.036). Despite comparable disease severity and extent, patients with mixed pain reported significantly higher CNO-related bone pain scores. This study demonstrates the high prevalence of mixed pain in adult CNO, in which neuropathic and nociplastic pain exist alongside nociceptive inflammatory bone pain. Disease burden in CNO may extend beyond inflammatory activity, highlighting the need for a multifaceted management approach.

Modified pustulotic arthro-osteitis diagnostic guidance 2022 - Modified Sonozaki criteria - Secondary publication.

The concept of pustulotic arthro-osteitis (PAO) was first reported by Sonozaki et al. in 1979, with diagnostic criteria (Sonozaki criteria) proposed in 1981. These criteria have served as the gold standard for PAO diagnosis for over 40 years. In recent years, there has been an increasing emphasis on maximizing the quality of life of patients with PAO. This is achieved by striving for clinical remission, structural remission, and functional remission through early diagnosis and appropriate therapeutic intervention from an early stage. This article is an English translation of a summary of the 'Modified PAO Diagnostic Guidance 2022', edited by the Japan Ministry of Health, Labour and Welfare's Research Group on improvement of medical standard and quality of life of patients with spondyloarthritis and related diseases represented by ankylosing spondylitis and the Japan Spondyloarthritis Society. This guidance is intended to be helpful to both Japanese and global communities in rheumatology and spondyloarthritis.

Postoperative mediastinitis and sternal osteitis after cardiac surgery caused by Mycoplasma hominis: A case report.

BACKGROUND: Mediastinitis and sternal osteitis are critical complications in cardiac surgery. Cases of these complications caused by Mycoplasma hominis are extremely rare. CASE PRESENTATION: We present a case of mediastinitis and sternal osteitis caused by M. hominis infection following ascending aortic replacement surgery. Whole gene sequencing analysis suggested the genitourinary tract as the most likely source of this M. hominis infection. Successful infection control was achieved through a regimen of moxifloxacin treatment. Additionally, a notable correlation was observed between serum levels of interleukin-6 and M. hominis infection. CONCLUSIONS: The significance of M. hominis as a potential cause of postoperative infection in cardiac surgery is still not fully recognized. Special attention should be paid to patients with bacteriologically negative infections, as M. hominis should not be disregarded, despite its rarity.

The clinical characteristics and prognosis of patients with SAPHO syndrome--a real-world cohort study.

OBJECTIVES: We aimed to analyze the clinical characteristics and outcomes of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. METHODS: The clinical records of 64 patients with SAPHO syndrome were collected, and the treatment and outcomes of 27 patients were followed up. The patients were divided into three groups according to the site of bone lesions: only anterior chest wall (ACW) involvement, only spinal involvement, and bone lesion involvement at both sites. The clinical characteristics and outcomes were compared. The clinical characteristics of the patients with and without peripheral joint involvement were compared. RESULTS: Among all patients, 31.25% (20/64) had only ACW involvement, 15.63% (10/64) had only spinal involvement, and 53.12% (34/64) had both ACW and spinal involvement. Peripheral joint involvement was observed in 25.00% (16/64) of the patients. Patients with only spinal involvement were older than those with only ACW involvement (p = 0.006). Patients with both ACW and spinal involvement were older than those with only ACW involvement (p = 0.002) and had a longer diagnosis delay (p = 0.015). Patients with peripheral joint involvement were younger than those without peripheral joint involvement (p = 0.028). During follow-up, 88.89% (24/27) of patients had good outcomes. Twenty-two patients were treated with non-steroidal anti-inflammatory drugs + Iguratimod (IGU), and the outcomes of 90.91% (20/22) improved. CONCLUSIONS: A relationship may exist between the sites of bone lesions and clinical characteristics of patients with SAPHO syndrome. The clinical outcomes of these patients may be good, and IGU may be effective in treating SAPHO syndrome. Key Points • This study is the first long-term follow-up on the effectiveness of iguratimod in treating patients with SAPHO. • This study revealed that patients with SAPHO and different bone lesion sites may present with different clinical characteristics.

Treatment and monitoring of SAPHO syndrome: a systematic review.

BACKGROUND AND OBJECTIVES: Synovitis acne pustulosis hyperostosis osteitis (SAPHO) is a rare heterogeneous disease of unknown aetiopathology. Externally validated and internationally agreed diagnostic criteria or outcomes and, as a result, prospective randomised controlled trials in SAPHO are absent. Consequently, there is no agreed treatment standard. This study aimed to systematically collate and discuss treatment options in SAPHO. METHODS: Following 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' guidance, a systematic literature search was conducted using PubMed, Scopus and Web of Science databases. Prospective clinical studies and retrospective case collections discussing management and outcomes in SAPHO involving five or more participants were included. Articles not published in English, studies not reporting defined outcomes, and studies solely relying on patient-reported outcomes were excluded. RESULTS: A total of 28 studies (20 observational, 8 open-label clinical studies) reporting 796 patients of predominantly European ethnicity were included. Reported therapies varied greatly, with many centres using multiple treatments in parallel. Most patients (37.1%) received non-steroidal anti-inflammatory drugs alone or in combination. Bisphosphonates (22.1%), conventional (21.7%) and biological (11.3%) disease-modifying antirheumatic drugs were the next most frequently reported treatments. Reported outcomes varied and delivered mixed results, which complicates comparisons. Bisphosphonates demonstrated the most consistent improvement of osteoarticular symptoms and were associated with transient influenza-like symptoms. Paradoxical skin reactions were reported in patients treated with TNF inhibitors, but no serious adverse events were recorded. Most treatments had limited or mixed effects on cutaneous involvement. A recent study investigating the Janus kinase inhibitor tofacitinib delivered promising results in relation to skin and nail involvement. CONCLUSIONS: No single currently available treatment option sufficiently addresses all SAPHO-associated symptoms. Variable, sometimes descriptive outcomes and the use of treatment combinations complicate conclusions and treatment recommendations. Randomised clinical trials are necessary to generate reliable evidence.

Osteomielitis crònica no bacteriana / Osteomielitis crónica no bacteriana / Chronic non-bacterial osteomyelitis

Introducció. L’osteomielitis crònica no bacteriana (OCNB)és una entitat poc freqüent en pediatria. Es tracta d’unamalaltia inflamatòria no infecciosa de l’os que sol cursaramb remissions i exacerbacions espontànies. Té una etiologia desconeguda. Sol presentar-se com un dolor ossisubagut, acompanyat o no de clínica sistèmica, i és necessari descartar altres causes, com la neoplàstica o la infecciosa. Les proves d’imatge donen suport al diagnòstic.Observació clínica. Es presenten dos casos de pacients ambdolor ossi insidiós a les extremitats inferiors de diversessetmanes d’evolució, amb alteració de la força i la mobilitat. Ambdós casos s’associen a anorèxia. L’analítica presenta elevació dels paràmetres inflamatoris, VSG (velocitatde sedimentació globular) i PCR (proteïna C reactiva). Lagammagrafia òssia i la ressonància magnètica nuclear permeten fer el diagnòstic d’OCNB. En ambdós casos es fatractament amb antiinflamatoris no esteroidals durant quatre setmanes, i es requereix l’addició de bifosfonats a causad’una resposta parcial.Comentaris. L’OCNB és una causa d’inflamació òssia en elsinfants en què un diagnòstic precoç i la instauració d’untractament efectiu permet evitar complicacions. És important tenir-la en compte en fer el diagnòstic diferencial deldolor ossi insidiós. Un coneixement millor en pot disminuirl’infradiagnòstic. (AU)

Introducción. La osteomielitis crónica no bacteriana (OCNB) esuna entidad poco frecuente en pediatría. Se trata de una enfermedad inflamatoria no infecciosa del hueso que suele cursar conremisiones y exacerbaciones espontáneas. Su etiología es desconocida. Suele presentarse como un dolor óseo subagudo, acompañado o no de clínica sistémica, y es necesario descartar otrascausas como la neoplásica o la infecciosa. Las pruebas de imagenapoyan el diagnóstico.Observación clínica. Se presentan dos casos de pacientes con doloróseo insidioso en extremidades inferiores de varias semanas de evolución con alteración de la fuerza y la movilidad. Ambos casosse asocian a anorexia. A nivel analítico presentan elevación de losparámetros inflamatorios, VSG (velocidad de sedimentación globular) y PCR (proteína C reactiva). La gammagrafía ósea y la resonancia magnética nuclear permiten realizar el diagnóstico de OCNB.En ambos casos se realiza tratamiento con antiinflamatorios noesteroideos durante cuatro semanas, requiriendo la adición de bifosfonatos debido a respuesta parcial.Comentarios. La OCNB es una causa de inflamación ósea en losniños en la que un diagnóstico precoz y la instauración de untratamiento efectivo permite evitar complicaciones. Es importantetenerla en cuenta al realizar el diagnóstico diferencial del doloróseo insidioso. Un mayor conocimiento puede disminuir su infradiagnóstico. (AU)

Introduction. Chronic non-bacterial osteomyelitis (CNBO) is a rarecondition in pediatrics. It is a non-infectious inflammatory diseaseof the bone that usually results in spontaneous remissions andexacerbations. Its etiology is unknown. It usually presents as subacute bone pain, with or without systemic signs and symptoms. Itis often necessary to rule out other causes such as neoplastic orinfectious. Imaging tests support the diagnosis.Clinical observation. We present two cases of patients with insidious bone pain in the lower extremities of several weeks of evolution with impaired strength and mobility. Both cases were associated with anorexia nervosa. Laboratory evaluation showed elevatedinflammatory parameters, erythrocyte sedimentation rate andC-reactive protein. Bone scintigraphy and nuclear magnetic resonance imaging allowed the diagnosis of CNBO. In both cases,treatment with nonsteroidal anti-inflammatory drugs was performed for 4 weeks, requiring the addition of bisphosphonates due topartial response.Comments. CNBO is a cause of bone inflammation in children inwhich early diagnosis and effective treatment can prevent complications. It is important to keep this entity in mind when makingthe differential diagnosis of insidious bone pain. Greater knowledgemay decrease its underdiagnosis. (AU)

Diagnostic and therapeutic practices in adult chronic nonbacterial osteomyelitis (CNO).

BACKGROUND: Chronic nonbacterial osteomyelitis (CNO) is a rare, and impactful auto-inflammatory bone disease occurring in children and adults. Clinical care for CNO is challenging, as the condition lacks validated classification criteria and evidence-based therapies. This study aimed to map the current diagnostic and therapeutic practices for CNO in adults, as a first step towards a standardized disease definition and future consensus treatment plans. METHODS: A primary survey was spread among global rheumatological/bone networks and 57 experts as identified from literature (May 2022), covering terminology, diagnostic tools (clinical, radiological, biochemical) and treatment steps. A secondary survey (sent to primary survey responders in August 2022) further queried key diagnostic features, treatment motivations, disease activity and treatment response monitoring. RESULTS: 36 and 23 physicians completed the primary and secondary survey respectively. Diagnosis was mainly based on individual physician assessment, in which the combination of chronic relapsing-remitting bone pain with radiologically-proven osteitis/osteomyelitis, sclerosis, hyperostosis and increased isotope uptake on bone scintigraphy were reported indicative of CNO. Physicians appeared more likely to refer to the condition as synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome in the presence of joint and skin pathology. MRI was most frequently performed, and the preferred diagnostic test for 47%. X-rays were second-most frequently used, although considered least informative of all available tools. Typical imaging features reported were hyperostosis, osteitis, osteosclerosis, bone marrow edema, while degeneration, soft tissue calcification, and ankylosis were not regarded characteristic. Inflammation markers and bone markers were generally regarded unhelpful for diagnostic and monitoring purposes and physicians infrequently performed bone biopsies. Management strategies diverged, including indications for treatment, response monitoring and declaration of remission. Step-1 treatment consisted of non-steroidal anti-inflammatory drugs/COX-2 inhibitors (83%). Common step 2-3 treatments were pamidronate, methotrexate, and TNF-a-inhibition (anti-TNFα), the latter two regarded especially convenient to co-target extra-skeletal inflammation in SAPHO syndrome. Overall pamidronate and anti-TNFα and were considered the most effective treatments. CONCLUSIONS: Following from our survey data, adult CNO is a broad and insufficiently characterized disease spectrum, including extra-osseous features. MRI is the favoured imaging diagnostic, and management strategies vary significantly. Overall, pamidronate and anti-TNFα are regarded most successful. The results lay out current practices for adult CNO, which may serve as backbone for a future consensus clinical guideline.

Utility of nailfold capillary assessment for predicting pustulotic arthro-osteitis in palmoplantar pustulosis based on a prospective cohort study.

BACKGROUND: Pustulotic arthro-osteitis (PAO) is 1 of the most serious comorbidities associated with palmoplantar pustulosis (PPP). Risk factors of PAO development are not well-known. OBJECTIVE: To evaluate the clinical significance of nailfold capillary (NFC) changes in patients with PPP. METHODS: We conducted a prospective cohort study in a population of 102 PPP patients. Correlations of NFC abnormalities, including nailfold bleeding and enlarged capillaries, with the prevalence of PAO, the incidence of new PAO, and serum levels of cytokines were analyzed. RESULTS: Detailed examination revealed that of 102 PPP patients, 52 without PAO and 50 with PAO. Both nailfold bleeding and enlarged capillaries were significantly more frequent in patients with PAO (50.0% vs 92.0%, P < .0001; 50.0% vs 94.0%, P < .0001). In addition, PPP patients without PAO were prospectively observed before they developed PAO (mean 28 months [1-52 months]). Multivariate analysis suggested that these NFC abnormalities were predictors of PAO development (hazard ratio 3.37, 95% confidence interval 1.13-10.07; 3.37, 1.13-10.07) and guselkumab prevent PAO development (0.093, 0.012-0.76). The degree of NFC abnormalities correlated with the severity of PAO and serum cytokine levels. LIMITATIONS: All participants were Japanese. CONCLUSION: NFC abnormalities could be predictors of PAO in PPP patients, and their degree indicators of disease severity.

Successful treatment of pustulotic arthro-osteitis with amoxicillin: A case report and review of the literature.

Palmoplantar pustulosis (PPP) is a chronic skin inflammatory disease characterized by sterile pustules on the palms and soles. Pustulotic arthro-osteitis (PAO) is a major comorbidity of PPP, frequently affecting the anterior chest wall. PPP and PAO are thought to be closely associated with focal infection. We report a female in her 40s who developed pustules on her palms and soles with tenderness of both sternoclavicular and left sacroiliac joints, which were not improved with non-steroidal anti-inflammatory drugs. Of note, she showed a great response to amoxicillin, resulting in the almost complete resolution of her skin lesions and arthralgia. We also reviewed previous reports to learn more about the potential therapeutic options of antibiotics for PAO.

Non-bacterial vertebral osteitis as the first manifestation of pustulotic arthro-osteitis.

Pustulotic arthro-osteitis (PAO) is an osteoarticular comorbidity of palmoplantar pustulosis, a chronic, recurrent, inflammatory skin disease presenting with erythema, scales, and pustules on the palms and soles. Palmoplantar pustulosis is one of the most common skin diseases in Japan and is accompanied by PAO in 10-30% of patients. PAO often involves anterior chest wall lesions, but vertebral involvement is uncommon. The present report describes a case of PAO in which the initial manifestation was only non-bacterial vertebral osteitis, with palmoplantar pustulosis developing 8 months after its onset. A patient with vertebral osteitis of unknown aetiology should be followed up and examined periodically for skin problems, which may provide a clue to the presence of PAO.

Comparison of hip abductor and adductor muscle performance between healthy and osteitis pubis professional footballers.

OBJECTIVE: The study aimed to compare the concentric and eccentric muscle performance of the hip abductor and adductor muscles at a high angular velocity in football players with osteitis pubis and healthy players. METHODS: A total number of 32 male football players with osteitis pubis and 20 healthy footballers were tested using an isokinetic dynamometer at a speed of 180°/s. Hip abductor and adductor peak torque/body weight, time to peak torque, acceleration, and deceleration times produced during concentric and eccentric muscle contraction modes were measured using a Biodex dynamometer. RESULTS: Football players with osteitis pubis demonstrated a significantly higher time to peak torque, acceleration, and deceleration times (p < 0.05); however, when compared to healthy athletes, there was no significant change in muscle strength. CONCLUSION: The present study showed that football players with osteitis pubis had a reduction in neuromuscular reaction. Therefore, the reaction time of these muscles is critical, and the reduction could result in magnified stresses and/or poorly distributed loads across the musculotendinous structure of the anterior pelvis, which presumably could lead to the development of osteitis pubis. Incorporate findings of the current study in clinical practice could afford critical information when evaluating the hip muscles in football players with osteitis pubis, for pre-screening, enhancing the rehabilitation programs, and guiding the decision of returning to sports after injury.

Destructive cervical spondylitis due to Cutibacterium acnes with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome: A case report.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a spectrum of heterogeneous diseases commonly recognised by skin and osteoarticular lesions. There have been reports of some surgical cases of the progressive, destructive spondylitis associated with SAPHO syndrome, wherein the destructive spondylitis was considered to have developed due to the progression of spondylitis with SAPHO syndrome as the pathogenic bacteria were not isolated. We herein report a surgical case of destructive cervical spondylitis associated with SAPHO syndrome. A 54-year-old woman with a history of palmoplantar pustulosis suffered severe neck pain for 6 months. Radiography and computeed tomography showed sclerosed and collapsed cervical vertebrae, and the patient was referred to our hospital for further evaluation and management upon suspicion of infection or spondylitis with SAPHO syndrome. For the severe neck pain and progressive destruction of cervical vertebrae, we performed posterior fusion surgery with subsequent anterior fusion. Cutibacterium acnes (C. acnes) was isolated by enrichment culture with thioglycolate broth from both the anterior and the posterior tissue samples. We diagnosed pyogenic spondylitis secondary to C. acnes infection and administered doxycycline for 6 weeks after the first surgery. The neck pain was resolved and cervical fusion was achieved one year postoperatively. C. acnes infection could elicit destructive spondylitis. An enrichment culture should be performed to isolate the pathogenic bacteria in cases of destructive spondylitis with SAPHO syndrome.

A case of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome with isolated lesions of the thoracic spine.

We report a case of isolated lesions of the thoracic spine attributed to synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. A 55-year-old woman who suffered from 6 months of back pain had vertebral osteomyelitis on magnetic resonance imaging (MRI). There were no laboratory findings suggestive of infection, malignancy, or autoimmune disease. Radiography, computed tomography (CT), and MRI of the thoracic spine showed mixed lesions of sclerosis and erosion, whereas bone scintigraphy did not show accumulation at any site except the thoracic spine. No lesions in the anterior chest wall or sacroiliac joints were apparent from CT and MRI. No lesions other than at the thoracic spine were observed. As the isolated lesions of the thoracic spine were considered not to have resulted from infection, malignancy, or autoimmune disease, the patient was referred to our department for differential diagnosis. Given that isolated sterile hyperostosis/osteitis among adults is included in the modified diagnostic criteria for SAPHO syndrome, we suspected that the mixed lesions of sclerosis and erosion of the thoracic spine in this case may reflect SAPHO syndrome with chronic non-bacterial osteitis (CNO) of the thoracic spine. Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) was initiated and led to alleviation of her back pain, although the thoracic spine lesions remained on the 6-month MRI. Based on the CNO of the thoracic spine and the rapid response to NSAIDs, the final diagnosis was SAPHO syndrome with isolated lesions of the thoracic spine.

Standardized reporting and quantification of whole-body MRI findings in children with chronic non-bacterial osteomyelitis treated with pamidronate.

OBJECTIVES: The objectives were to assess changes in radiological disease activity in children with chronic non-bacterial osteomyelitis (CNO) receiving pamidronate therapy and to test a modified radiological index for non-bacterial osteitis (mRINBO) in CNO. mRINBO was used for standardized reporting and quantification of whole-body MRI (WBMRI) findings resulting in an individual summary patient score. METHODS: WBMRI was retrospectively assessed in 18 children with CNO at baseline and after receiving pamidronate therapy for one year. Parameters of interest were: number and anatomic site of radiologically active bone lesions (RAL), size of RAL, extramedullary affection, spinal involvement and changes in mRINBO, which includes both the number and maximal size of RAL (RALmax) in addition to extramedullary and chronic changes. RESULTS: At the time of diagnosis, the mean age of the children was 9.8 (sd, 8.7-10.9) years and 11/18 were females. The number of RALs per patient decreased from median [interquartile range] 4.5 [3-8] to 3 [2-5] RALs per patient (p = 0.02) and extramedullary inflammatory changes regressed. Sixty-one percent of all RALs occurring at baseline resolved and three children became without active inflammatory lesions by WBMRI. The median size of RALs did not change when taking new lesions occurring in 7/18 children into account, but RALmax decreased significantly from 39 [29-45] mm at baseline to 28 [20-40] mm (p < 0.01) at year-one with a concomitant decrease of mRINBO from a median of 5 [4-7] to 4 [3-5] (p = 0.05). CONCLUSIONS: Pamidronate therapy resulted in a decrease of mRINBO from baseline to year one. mRINBO may be a potential scoring method to quantify changes in radiological disease activity in children with CNO. However, further studies are needed to test feasibility and validity of mRINBO.

Pro and contra: is synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) a spondyloarthritis variant?

PURPOSE OF REVIEW: The purpose of this review is to present the up-to-date evidence on the epidemiology, pathogenesis, musculoskeletal manifestations, and imaging of the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to discuss its relationship with spondyloarthritis (SpA). RECENT FINDINGS: SAPHO is a rare inflammatory disorder of bone, joints, and skin, with a worldwide distribution that predominantly affects the middle-age adults. The hallmark of the syndrome is a constellation of sterile inflammatory osteitis, hyperostosis, and synovitis involving the anterior chest wall, associated with acneiform and neutrophilic dermatoses, such as palmoplantar pustulosis and severe acne. The axial skeleton, sacroiliac, and peripheral joints can be involved in a similar fashion to SpA. The pathogenesis of the syndrome is multifactorial. The diagnosis is mainly based on the clinical and typical radiological features. The treatment approach is based on the off-label use of antibiotics, bisphosphonates, disease-modifying antirheumatic drugs, and anticytokine biologics. SUMMARY: The SAPHO syndrome shares common features with SpA-related diseases, yet also shows some unique pathogenetic and clinical features. The nosology of SAPHO remains a subject of controversy, awaiting further research into the pathogenetic and clinical aspects of this syndrome. A better understanding of these aspects will improve the diagnostics and clinical care of patients with SAPHO.

Clinical characteristics of pustulotic arthro-osteitis in Korea.

Pustulotic arthro-osteitis (PAO) has been studied primarily in Japan. However, there is a lack of research regarding its clinical features among large populations in other countries and it is often believed to be similar to psoriatic arthritis (PsA). Although the association between psoriasis (PsO) and palmoplantar pustulosis (PPP) is debatable, differences in the clinical characteristics between PsA and PAO might support the notion that PsO and PPP are distinct entities. This study aimed to investigate the clinical characteristics of PAO in Korean patients and to compare them with those of PsA. We retrospectively reviewed the medical records of patients diagnosed with PPP, PAO, and PsA. Among 266 patients with PPP, 13.2% had PAO. Unlike Japanese patients with PAO, Korean patients had a relatively lower involvement of the chest wall. PAO patients demonstrated lower age of onset, higher proportion of females, and higher severity of cutaneous eruptions compared to PPP patients without PAO, but the differences were not statistically significant. Female predominance was prominent in PAO compared to PsA. Cutaneous eruptions occurred earlier than joint symptoms in 83.5% of the patients with PsA and in 42.9% of the patients with PAO. PAO involved axial joints more frequently compared to PsA, especially the chest wall and spine. PsA mainly involved the peripheral joints, especially the metacarpophalangeal joints and distal interphalangeal joints of the hands and feet. In conclusion, PAO and PsA exhibited different demographics and locations of joint involvement, supporting the notion that PPP and PsO are separate disorders. Many PAO patients presented with joint symptoms before the appearance of skin eruptions, underlining the important role of dermatologists in recognizing PAO among PPP patients. Physicians should be aware of the characteristics of PAO while treating patients with PPP.