Chronic recurrent multifocal osteomyelitis: diagnosis and treatment

PTGS2 Silencing Inhibits Ferroptosis in Staphylococcus Aureus-induced Osteomyelitis By Blocking the IL-17A Signaling Pathway

OBJECTIVE

Osteomyelitis caused by Staphylococcus aureus (S. aureus) infection is an inflammatory bone disease characterized by continuous bone destruction, which is difficult to treat. This research aimed to explore the molecular mechanisms of S. aureus-induced osteomyelitis.

METHODS

Using the GSE166522 and GSE227521 datasets, hub differentially expressed genes (DEGs) were screened by bioinformatics analysis. Hub gene expression levels were validated in S. aureus-induced mouse models. An inhibitor of PTGS2, etoricoxib, was used to assess the role of PTGS2 in the osteomyelitis mouse model. PTGS2 was silenced in an LPS-induced MC3T3-E1 cell model to study its effect on cell function.

RESULTS

Six hub genes were screened, including ARG1, TIMP1, NOS2, PTGS2, SOCS3, and IL1B, highly expressed in the S. aureus-induced osteomyelitis model. Etoricoxib treatment attenuated the inflammatory infiltration of tibial tissue in mice with osteomyelitis. In vivo and in vitro, etoricoxib treatment and PTGS2 silencing reduced inflammatory factor (TNF-α, IL-1β, and IL-6) levels. PTGS2 silencing promoted LPS-induced MC3T3-E1 cell viability and inhibited apoptosis and ferroptosis. GPX4 and SLC7A11 protein levels were significantly increased after PTGS2 silencing. Mechanistically, IL-17A intervention significantly counteracted the impact of PTGS2 silencing on cell behaviors and secukinumab combined with PTGS2 silencing more effectively suppressed inflammation and ferroptosis, indicating that PTGS2 impeded the osteomyelitis progression by inhibiting the IL-17A pathway.

CONCLUSION

Silencing PTGS2 reduces ferroptosis in S. aureus-induced osteomyelitis by obstructing the IL-17A pathway, which suggests a new approach for the treatment of osteomyelitis.

Chronic Recurrent Multifocal Osteomyelitis Involving the Spine, Sternum, and Lower Extremities: A Case Report

Chronic recurrent multifocal osteomyelitis (CRMO) or chronic nonbacterial osteitis is a sterile autoinflammatory disease of bone in children that can mimic infectious osteomyelitis and osteosarcoma. Early diagnosis, treatment, and long-term follow-up of CRMO are essential. We describe a 10-year-old boy who presented with 15 days of left ankle bone more than joint pain, swelling, and limp. Plain radiographs and magnetic resonance imaging scans were nondiagnostic of osteomyelitis and tibial irrigation and biopsy were negative for infection and malignancy. Four years later, he again presented with similar pain in his right ankle. Repeat bone biopsy noted reactive bone changes and bone culture was sterile. Whole-body magnetic resonance imaging revealed multiple enhancing lesions in the long bones of bilateral lower extremities, spine, and sternum. He was diagnosed with CRMO, and treatment with celecoxib and subsequently pamidronate, infliximab, and methotrexate were initiated. After 6 months of treatment, the patient's gait and pain improved, and 2 years later, his CRMO was in clinical and radiologic remission. Of note, he developed palmoplantar pustular psoriasis, commonly seen in CRMO, that was not determined to be from tumor necrosis factor inhibition.

A Case of Chronic Recurrent Multifocal Osteomyelitis (CRMO)

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare but underdiagnosed, severe inflammatory bone disease that primarily affects children. It's typically characterized by bone pain, especially within the metaphysis of long bones, clavicles, and vertebrae, but it can present in any bone and with varied presentation, including extraosseous symptoms that may be associated with other autoimmune/inflammatory diseases. Chronic recurrent multifocal osteomyelitis is a sterile bone disease that does not typically have an infectious source. Its pathogenesis involves the dysregulation of the innate immune system via upregulation of cytokines, inflammasomes, and osteoclastic properties. Diagnostic testing is nonspecific and includes X-ray and MRI, bone biopsy, inflammatory markers, and autoimmune markers. Chronic recurrent multifocal osteomyelitis is established by the diagnosis of exclusion. First-line treatment is nonsteroidal anti-inflammatory drugs (NSAIDs); if vertebral involvement is present, a bisphosphonate is typically added. This case report emphasizes the importance of considering CRMO as a differential diagnosis of multifocal bone pain in children.

A retrospective study of the anterolateral thigh perforator flap in the treatment of chronic osteomyelitis of the leg with skin defects

Background

As a chronic inflammatory process, chronic osteomyelitis is caused by bacterial infections that lead to bone destruction. This disease is more common in patients with open fractures and those undergoing multiple surgical procedures after trauma. We aimed to provide a comprehensive overview and critical assessment of the therapeutic efficacy of the anterolateral thigh (ALT) perforator flap in the management of chronic osteomyelitis with dermatologic and soft tissue imperfections localized in the lower extremity.

Methods

A retrospective analysis involving a cohort of 16 patients who underwent ALT perforator flap reconstruction for the management of chronic osteomyelitis in the calf region that manifested with integumentary deficiencies was conducted.

Results

During the follow-up period spanning from 4 months to 2 years, all 16 patients who underwent ALT perforator flap transplantation exhibited flap viability. Among these cases, 15 patients made a full recovery from the infection and 1 patient had partial survival. Among the 15 cases, 2 patients developed vascular crisis (owing to venous thrombosis during surgical exploration). One patient had a relapse of the disease 1-year post-surgery. The success rate of this surgical method was 15/16, and the surgical complications included flap crisis, flap necrosis, delayed wound healing, and recurrence of infection.

Conclusion

The ALT perforator flap, which can cover bone and soft tissues and effectively control infections, can be applied to the treatment of chronic osteomyelitis of the lower limbs with skin defects. Overall, the muscle flap fills the dead space and medullary cavity and skin flap covers the skin defect.

Chronic recurrent multifocal osteomyelitis: Case report and review of the literature

BACKGROUNDS

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare inflammatory disease.

OBJECTIVE

This report aims to analyze the clinical characteristics of CRMO and enhance clinicians' comprehension. We present 3 atypical cases, highlighting their unique clinical features, diagnostic challenges, and effective treatment strategies.

METHODS

We retrieved 3 CRMO cases in our hospital from September 2019 to August 2022. The clinical features were analyzed retrospectively, and relevant literatures were reviewed.

RESULTS

All 3 cases initially presented with bone pain, normal leucocyte counts, negative rheumatoid factors and no signs of sclerotic or hyperostotic lesions. Case 1, a 12-year-old girl, exhibited concurrent acne on the forehead and historic necrotizing lymphadenitis, a previously unreported association with CRMO. Case 2, a 14-year-old boy, tested positive for human leukocyte antigen-B27 and displayed scoliosis along with multifocal osteomyelitis. Case 3, a 9-year-old girl, presented with scoliosis, and chest computed tomography revealed changes in the T8 vertebral body, initially suggesting Langerhans cell histiocytosis. Bone biopsy was conducted in case 1 and case 3, revealing chronic inflammation. All 3 cases affected long bones, pelvis, and vertebra, involving 8, 6 and 5 bones, respectively, identified by magnetic resonance imaging. Genetic analysis was undertaken in cases 1 and 2 but no pathogenic mutations were identified. Upon the confirmation of a CRMO diagnosis, all patients were initiated on a treatment regimen comprising nonsteroidal anti-inflammatory drugs and tumor necrosis factor-α inhibitors. In cases 1 and 2, due to the severity of their bone pain, they were also administered to disease-modifying anti-rheumatic drugs, specifically methotrexate. All 3 patients achieved remission of bone pain. To gain a more comprehensive understanding of CRMO, we conducted a thorough review of relevant literature.

CONCLUSION

CRMO is a rare autoinflammatory bone disorder with diverse clinical presentations and a lack of specific laboratory tests, which leads to potency to misdiagnosis or delayed diagnosis. By raising awareness and improving diagnostic criteria, physicians are now better equipped to identify CRMO. We contribute to share our understanding of CRMO by presenting 3 cases with untypical clinical features, highlighting the importance of recognizing this rare condition for timely and effective management.

Systemic juvenile idiopathic arthritis with chronic recurrent multifocal osteomyelitis in an adolescent: A case report

Chronic recurrent multifocal osteomyelitis is a rare auto-inflammatory disease in children, with only a few reports of its association with other inflammatory diseases, such as systemic juvenile idiopathic arthritis. A 15-year-old boy was admitted due to fever, skin rash, arthritis, and high inflammatory factors and was finally diagnosed with systemic juvenile idiopathic arthritis. After 6 months of recovery from the disease, the patient was referred due to local pain and swelling in the arms and left thigh. In radiography, bone lesions were seen in the shoulders, left humerus, and left femoral diaphysis. A whole-body bone scan showed increased absorption in these areas, which suggested a tumor or osteomyelitis. A biopsy of the bone lesion of the left humerus confirmed sterile osteomyelitis. Although the co-incidence of chronic recurrent multifocal osteomyelitis with systemic juvenile idiopathic arthritis is rare, it should be considered in differential diagnosis.

Pediatric Ribs at Chest Radiography: Normal Variants and Abnormalities

Normal variants and abnormalities of the ribs are frequently encountered on chest radiographs. Accurate identification of normal variants is crucial to avoid unnecessary investigations. A meticulous evaluation of rib abnormalities can provide valuable insights into the patient's symptoms, and even when no osseous condition is suspected, rib abnormalities may offer critical clues to underlying conditions. Rib abnormalities are associated with various conditions, including benign tumors, malignant tumors, infectious and inflammatory conditions, vascular abnormalities, metabolic disorders, nonaccidental injuries, malformation syndromes, and bone dysplasias. Abnormalities of the ribs are classified into three groups based on their radiographic patterns: focal, multifocal, and diffuse changes. Focal lesions are further subdivided into nonaggressive lesions, aggressive lesions, and infectious and inflammatory disorders. Radiologists should be aware of individual disorders of the pediatric ribs, including their imaging findings, relevant clinical information, and underlying pathogenesis. Differential diagnoses are addressed as appropriate. Since chest radiographs can suffice for diagnosis in certain cases, the authors emphasize a pattern recognition approach to radiographic interpretation. However, additional cross-sectional imaging may be necessary for focal lesions such as tumors or inflammatory conditions. Awareness of disease-specific imaging findings helps ascertain the nature of the lesion and directs appropriate management. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Imaging findings of juvenile idiopathic arthritis and autoinflammatory diseases in children

Juvenile idiopathic arthritis (JIA) is a collective term for pediatric inflammatory arthritis of unknown etiology, which presents diverse clinical and imaging findings. The pathogenesis is complex; however, most cases stem from an autoimmune mechanism. Herein we provide a short review of imaging findings of JIA. Imaging assessment begins with plain radiography demonstrating joint swelling, periarticular osteopenia, and juxtaarticular bone erosion. Bone erosion occurs later in JIA. Instead, aberrant epimetaphyseal growth often gives the first clue to the diagnosis. US and MRI can demonstrate the details of the synovium, cartilage, and subchondral bone. JIA is subdivided into oligoarthritis, polyarthritis (rheumatoid factor-negative and positive), psoriatic arthritis, enthesitis-related arthritis, and systemic JIA. Awareness of the different clinical characteristics, pathogenic background, and prognosis of each subtype facilitates a more advanced, imaging-based diagnosis. Unlike the other types, systemic JIA is an autoinflammatory disease accompanied by inflammatory cytokinemia and systemic symptoms stemming from aberrant activation of the innate immunity. Other autoinflammatory diseases, both monogenic (e.g., NOMID/CINCA) and multifactorial (e.g., CRMO), are also discussed.

Pyoderma gangrenosum following anti-TNF therapy in chronic recurrent multifocal osteomyelitis: drug reaction or cutaneous manifestation of the disease? A critical review on the topic with an emblematic case report

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory disease, clinically characterized by chronic and recurrent episodes of osteoarticular inflammation, that generally presents in children and adolescents. From a dermatological point-of-view, CMRO can be associated with skin rashes mainly including psoriasis, palmoplantar pustulosis and acne. Pyoderma gangrenosum (PG) is a rare immune-mediated inflammatory skin disease classified within the spectrum of neutrophilic dermatoses that, in some cases, has been reported as cutaneous manifestation in CMRO patients. This paper presents a 16-year female patient diagnosed with CMRO, who presented PG lesions located on the lower leg, that arose after the administration of the tumour necrosis factor (TNF)-α inhibitor adalimumab. Cases of PG have been reported in patients being treated with certain medications, including TNF-α antagonists, leading to classified them in a setting aptly termed "drug-induced PG." In this paper, we discuss the co-occurrence of PG and CRMO, in the light of recent evidence on the pathogenesis of both diseases and giving ample space to a literature review on drug induced PG. In our case, it is plausible that PG could be considered a cutaneous manifestation of CRMO, although the mechanisms underlying this intriguingly relationship remain to be fully unraveled.

A Successful Bisphosphonates Monotherapy in Spinal Form of Paediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO)—Case Report

Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious inflammatory disorder resulting from the multifocal bone and bone marrow lesions with periodic relapses and remissions and with an uncertain prognosis. Treatment options in CRMO are based on expert opinion and relatively small groups of patients. A nine-year-old female patient with no significant past medical history presented with compression fractures and multifocal bone lesions in the thoracic and lumbar spine, as shown in imaging (CT, MRI). Densitometry revealed a diffuse decrease in bone density. Based on the patient’s clinical image and above examinations, the other possible aetiologies—infectious (including tuberculosis), neoplasms, Langerhans cell histiocytosis—were ruled out, which led to eventual final diagnosis—CRMO. The patient was successfully treated with pamidronate infusion initiated in cycles over three consecutive days every 3 months. In addition to clinical improvement, there was a significant remission of inflammation and bone structure healing assessed by MRI after four treatment cycles. Intravenous bisphosphonates usage seems to be a good therapeutic option in CRMO paediatric patients with spinal localization of the lesions complicated by compressive fractures. However, more data, based on larger patient populations, are needed to provide a detailed paediatric CRMO treatment algorithm.

Research Status and Hotspots of Chronic Osteomyelitis: A Bibliometric and Visualized Analysis

OBJECTIVE

The treatment of chronic osteomyelitis (COM) is extremely challenging for physicians and patients. It is of great significance to explore the research status, development trend and future research hotspots in the field of COM to promote the development of this field. This study is aimed to explore the global research status of COM and predict its future research hotspots based on bibliometric and visualized analysis.

METHODS

Web of Science core collection database was used to search the related literature of COM from 1994 to 2020. All data were imported into Microsoft Excel 2019 for collation. Additionally, the literature quality of countries, authors, journals, and institutions is evaluated. The VOS viewer software was used for conducting co-analysis, co-citation analysis, and keyword co-occurrence analysis of literature to analyze the global status and predict the future hotspots of the COM field.

RESULTS

A total of 726 articles were retrieved in this study. The number of global publications shows a trend of wave growth, but the increase is not significant. It is expected that the number of COM articles will remain at more than 50 per year in the next decade. The COM literature published in the United States (Publications = 160, H index = 37, average citations per item = 28.63) is of the highest quality. Girschick HJ (Publications = 16, H index = 14, average citations per item = 52.25) is the most contributed scholar in the field of COM. UNIV IOWA (Publications = 15, H index = 11, average citations per item = 57.27) and UNIV WURZBURG (Publications = 18, H index = 15, average citations per item = 47.5) are influential institutions in the field of COM. The results of co-occurrence analysis show that the field of COM can be roughly divided into the following five modules: COM surgical research, COM basic research, COM diagnosis-related research, chronic recurrent multifocal osteomyelitis (CRMO)-related research, risk factors of COM. Risk factors of COM are the module with the highest concentration of hot words.

CONCLUSION

COM-related research will continue to develop further in the next decade. The diagnosis research and risk factors of COM are the most popular research modules in recent years. Some controversial or troubled issues including the efficacy of perforator flap and fascia flap covering soft tissue, searching exclusive detection methods for the diagnosis of COM and bisphosphonates and biological agents in the treatment of CRMO may lead to the development of the COM field.

Canakinumab treatment in a young girl with refractory chronic recurrent multifocal osteomyelitis associated with pyoderma gangrenosum

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a bone inflammatory disorder characterized by osteolytic, usually multiple, symmetric lesions. Diagnosis is one of exclusion, and no standardized therapies are available. Presumed deregulation of the interleukin (IL)-1β axis, as observed in 2 monogenic autoinflammatory conditions such as Majeed syndrome (LPIN2 mutations) and deficiency of IL-1 receptor antagonist (IL1RN mutations) with CRMO-like bone involvement, suggests the blockade of IL-1 as potentially useful also in this condition, even if scarce data are available.

CASE PRESENTATION

We report the case of a 13-year-old girl affected by a multidrug-resistant and pyoderma gangrenosum-complicated CRMO treated with canakinumab, a human monoclonal antibody targeting IL-1β.

CONCLUSION

In this young patient pyoderma gangrenosum and CRMO showed a rapid and satisfactory response to canakinumab, although over time a decreased efficacy in controlling bone disease was observed.

Chronic recurrent multifocal osteomyelitis. A narrative and pictorial review

Chronic recurrent and multifocal osteomyelitis (CRMO) is a nonsporadic autoinflammatory disorder. Currently, it is diagnosed based on clinical, radiologic, pathological, and longitudinal data. Numerous aspects should be highlighted due to increased knowledge in imaging and immunology. We emphasize the use of whole-body MRI, which is a non-invasive diagnostic strategy. A literature review was carried out on longitudinal studies. Commonly, the mean age at diagnosis is 11 years, ranging between 3 and 17. The most common sites are the long bone metaphysis, particularly femoral and tibial metaphysis. In addition, the pelvis, spine, clavicle, and mandible may be involved. In long bones, the radiologic appearance can show typical structure, mixed lytic and sclerotic, sclerotic or lytic. It is frequently metaphyseal or juxta-physeal, with hyperostosis or periosteal thickening. The involvement of the vertebral skeleton is often multifocal. Therefore, whole-body MRI is essential in identifying subclinical lesions. CRMO is a polymorphic disorder in which whole-body MRI is beneficial to demonstrate subclinical edema. Vertebral collapse requires long-term monitoring.

Chronic nonbacterial osteomyelitis in children: a multicentre Belgian cohort of 30 children

BACKGROUND

To evaluate clinical characteristics, imaging findings, therapeutic approach and outcome of paediatric patients with Chronic Non-Bacterial Osteomyelitis (CNO).

METHODS

Retrospective review of 30 children diagnosed with CNO at two tertiary care centres in Belgium. Imaging data were evaluated by blinded paediatric radiologists.

RESULTS

Mean age at onset was 10.3 years and mean age at diagnosis was 11.7 years. Bone pain was the leading symptom (29/30 patients). Out of 180 symptomatic lesions, 131 were confirmed on MRI as hyperintense geographic lesions on STIR images at the metaphysis and epiphysis adjacent to growth plates of tubular bones. The most common sites of involvement were the lower limbs, spine, sternoclavicular joint and humerus. For nearly half of the patients (14/30) monotherapy with NSAIDs was sufficient to obtain remission. The remaining 16 patients received second-line therapy: bisphosphonates (n = 15/30), disease-modifying antirheumatic drugs (n = 7/30), etanercept (n = 4/30) and tocilizumab (n = 1/30). Remission was reached after a mean time of 37.6 months in 26/30 patients. The prognosis was worse for patients with spinal involvement, resulting in more long-term sequelae.

CONCLUSIONS

We present a multicentre paediatric cohort of 30 CNO patients. A typical pattern of bone involvement could be found on MRI. NSAIDs were administered as first-line treatment. Second-line strategies included bisphosphonates, corticosteroids, methotrexate, etanercept and tocilizumab.

TRIAL REGISTRATION

Retrospectively registered. Registratienummer EC KUL: MP018023.

Whole-body magnetic resonance imaging findings and patterns of chronic nonbacterial osteomyelitis in a series of Greek pediatric patients

Background:

Chronic nonbacterial osteomyelitis (CNO) is a pediatric autoinflammatory disorder presenting with sterile inflammatory bone lesions. Whole-body MRI (WBMRI) has most recently emerged for disease assessment, but data are limited.

Purpose:

The purpose is to evaluate the imaging findings and patterns of CNO on WBMRI in a series of Greek pediatric patients.

Material and Methods:

Whole-body magnetic resonance imaging studies of all children with documented CNO, performed in a single tertiary center, were retrospectively reviewed. WBMRI included coronal T1 and short-tau inversion recovery (STIR), whole spine sagittal STIR, and ankle/foot sagittal STIR images. High signal intensity lesions on STIR images corresponding to bone marrow edema were recorded. The SPSS v.20 statistical package was used for descriptive statistics.

Results:

Twenty children were included (mean age: 12, range: 6–16 years) with 1–31 lesions (mean: 11.8) on WBMRI. Two children had unifocal disease localized at the clavicle, three paucifocal (1–4 lesions), and 15 multifocal bone involvement. All but two children presented with ankle pain and exhibited lesions at the bones of the ankle joint (90%) followed by the knee (50%) and pelvis (10%). The tibia was the most frequently affected bone (70%) followed by calcaneus (60%), fibula (50%), femur (45%), talus, and metatarsals (45%). No lesions in the cervical, thoracic, lumbar spine, and mandible were documented. Only small sacral lesions were seen in 25% of patients with the extensive peripheral disease. Bilateral metaphyseal and epiphyseal involvement with transphyseal extension were common, but the periosteal reaction and well-defined lesion margins were rare.

Conclusion:

Frequent involvement of the foot and ankle and paucity of substantial spinal involvement were seen in Greek pediatric patients with CNO.

Chronic Osteomyelitis With Proliferative Periostitis of the Mandible in a Child: Report of a Case Managed by Immunosuppressive Treatment

BACKGROUND

Osteomyelitis with proliferative periostitis is a relatively uncommon inflammatory condition of the jaws, mainly characterized by periosteal formation of reactive bone. It primarily affects children and adolescences, also referred to as Garre's osteomyelitis, more frequently involving the molar region of the mandible. Cases lacking an obvious source of infection may have an immunologically mediated etiopathogenesis, falling under the spectrum of primary chronic osteomyelitis or chronic recurrent multifocal osteomyelitis (CRMO).

CASE REPORT

Herein, we present a case of chronic osteomyelitis in a 6.5-year-old girl, who suffered from recurrent painful episodes of swelling of the mandible for the last 2 years, previously requiring hospitalization and administration of intravenous (IV) antibiotics and NSAIDs with limited responsiveness. The biopsy showed features consistent with osteomyelitis with proliferative periostitis. The patient was initially managed with an IV combination antibiotic regimen with only partial improvement. The possibility of an autoimmune mechanism in the context of primary chronic osteomyelitis or CRMO was considered, and immunosuppressive therapy (TNF inhibitor etanercept along with corticosteroids and methotrexate) was administered, resulting in clinical resolution.

CONCLUSIONS

Osteomyelitis and its childhood variants are relatively rare and their management presents several challenges. Although typically treated with administration of antibiotics, possibly along with surgical intervention, other treatment modalities may be necessary for resilient and persistent cases. In a subset of cases, especially in the absence of local infectious factors, immunologically mediated mechanisms may play an important role and appropriate immunosuppressive therapy may be effective.