The SAPHO syndrome revisited with an emphasis on spinal manifestations

Imaging of Spondylodiscitis: A Comprehensive Updated Review-Multimodality Imaging Findings, Differential Diagnosis, and Specific Microorganisms Detection

Spondylodiscitis is defined by infectious conditions involving the vertebral column. The incidence of the disease has constantly increased over the last decades. Imaging plays a key role in each phase of the disease. Indeed, radiological tools are fundamental in (i) the initial diagnostic recognition of spondylodiscitis, (ii) the differentiation against inflammatory, degenerative, or calcific etiologies, (iii) the disease staging, as well as (iv) to provide clues to orient towards the microorganisms involved. This latter aim can be achieved with a mini-invasive procedure (e.g., CT-guided biopsy) or can be non-invasively supposed by the analysis of the CT, positron emission tomography (PET) CT, or MRI features displayed. Hence, this comprehensive review aims to summarize all the multimodality imaging features of spondylodiscitis. This, with the goal of serving as a reference for Physicians (infectious disease specialists, spine surgeons, radiologists) involved in the care of these patients. Nonetheless, this review article may offer starting points for future research articles.

A clinico-radiological review of chronic non-bacterial osteomyelitis in paediatrics, adolescents, and adults: demystifying a forgotten differential

Chronic non-bacterial osteomyelitis (CNO), also known as non-bacterial osteitis, is a chronic autoinflammatory disease of unknown aetiology that primarily occurs in the paediatric population, although rare cases of adult-onset disease also exist. CNO has non-specific clinical and radiological presentations, and the affected population often present with bone pain of insidious onset secondary to sterile bony inflammation that can be associated with swelling, focal tenderness, and warmth at the affected sites. The pattern of bony involvement appears to be dependent on the age of onset, with adults frequently having axial skeletal lesions and children and adolescents often being affected in the appendicular skeletal sites. CNO is a diagnosis of exclusion, and imaging is heavily relied on to identify and characterise the bony lesions in addition to exclude diseases that can mimic CNO. Magnetic resonance imaging is often the reference standard with biochemical and histopathological findings being complementary. Although combining imaging methods can be used to facilitate the diagnosis, a single technique could be adequate depending on the clinical picture. Given the relatively rare incidence of CNO, limited awareness of the disease among care providers, and its similarity in clinical and radiological presentation to various bony diseases, there are often long delays in diagnosis, with adults being unfavourably affected compared to paediatrics and adolescents. This review of CNO will describe the condition, overview its clinical presentation, highlight the radiological features, and emphasise clinical pearls that can aid in diagnosis and ruling out the mimics.

Clinical and imaging features of six Han patients with SAPHO syndrome

BACKGROUND

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare autoimmune disease characterized by skin or osteoarticular damage. SAPHO syndrome is often misdiagnosed or missed diagnosis due to lack of overall understanding of the disease by clinicians.

PURPOSE

To analyze the clinical symptoms and imaging features of six Han patients with SAPHO syndrome in order to provide reference for doctors to diagnose SAPHO syndrome.

MATERIAL AND METHODS

This study retrospectively analyzed the clinical data of six Han patients with SAPHO syndrome.

RESULTS

All six Han patients with SAPHO syndrome had severe acne or pustulosis of the hands and feet, and all of them had osteoarticular damage, including five cases involving the sternoclavicular joint. Some patients showed a specific and typical "bull's head" sign on 99mTc-labeled methylene diphosphonate bone imaging. Among the six patients recruited, there was one thoracic vertebra, one cervical vertebra, one sacroiliac joint, and one peripheral joint involvement. Two patients had limited activity due to severe osteoarticular damage.

CONCLUSION

Due to the atypical clinical symptoms of SAPHO syndrome, most patients will experience a tortuous and long diagnostic process, while a correct understanding and timely intervention of SAPHO syndrome are essential to improve the prognosis of patients.

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.

Comparison of 68Ga-DOTA-FAPI-04 and 18F-FDG PET/CT in Patients With SAPHO Syndrome

PATIENTS AND METHODS

68Ga-DOTA-FAPI-04 PET/CT was performed on a cohort of 21 patients with known SAPHO syndrome. All patients underwent 68Ga-DOTA-FAPI-04 and 18F-FDG PET/CT on 2 consecutive days. The positive rates of the PET/CT scans at the sites of the osteoarticular symptom, the uptake values, and agreement with clinical osteoarticular symptom were compared.

RESULTS

A total of 38 sites of involvement were detected. 18F-FDG PET/CT revealed 28 lesions. In contrast, 68Ga-DOTA-FAPI-04 PET/CT detected not only all lesions shown on 18F-FDG PET/CT but additional 10 lesions. 68Ga-DOTA-FAPI-04 scan also demonstrated significantly higher uptake and target-to-background ratio than 18F-FDG studies in the skeletal involvements. The agreement between 68Ga-DOTA-FAPI-04-positive lesions and current osteoarticular lesions was substantial (κ = 0.79, P < 0.001), whereas 18F-FDG had low to moderate agreement with clinical symptoms (κ = 0.52, P < 0.001).

CONCLUSIONS

68Ga-DOTA-FAPI-04 has potential as a promising imaging agent for the evaluation of SAPHO syndrome.

Imaging of bone marrow pitfalls with emphasis on MRI

Normal marrow contains both hematopoietic/red and fatty/yellow marrow with a predictable pattern of conversion and skeletal distribution on MRI. Many variations in normal bone marrow signal and appearances are apparent and the reporting radiologist must differentiate these from other non-neoplastic, benign or neoplastic processes. The advent of chemical shift imaging has helped in characterising and differentiating more focal heterogeneous areas of red marrow from marrow infiltration. This review aims to cover the MRI appearances of normal marrow, its evolution with age, marrow reconversion, variations of normal marrow signal, causes of oedema-like marrow signal, and some common non-neoplastic entities, which may mimic marrow neoplasms.

Axial Skeleton Bone Marrow Changes in Inflammatory Rheumatologic Disorders

Magnetic resonance imaging (MRI) of the axial skeleton, spine, and sacroiliac (SI) joints is critical for the early detection and follow-up of inflammatory rheumatologic disorders such as axial spondyloarthritis, rheumatoid arthritis, and SAPHO/CRMO (synovitis, acne, pustulosis, hyperostosis, and osteitis/chronic recurrent multifocal osteomyelitis). To offer a valuable report to the referring physician, disease-specific knowledge is essential. Certain MRI parameters can help the radiologist provide an early diagnosis and lead to effective treatment. Awareness of these hallmarks may help avoid misdiagnosis and unnecessary biopsies. A bone marrow edema-like signal plays an important role in reports but is not disease specific. Age, sex, and history should be considered in interpreting MRI to prevent overdiagnosis of rheumatologic disease. Differential diagnoses-degenerative disk disease, infection, and crystal arthropathy-are addressed here. Whole-body MRI may be helpful in diagnosing SAPHO/CRMO.

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.

A case of SAPHO syndrome: a DISH of radiological features to be considered

Background

The acronym SAPHO stands for synovitis, acne, pustulosis, hyperostosis, and osteitis. It is a rare heterogenous disease with unknown etiology and a chronic relapsing and remitting course¹. Its skin and osteoarticular manifestations including palmoplantar pustulosis (PPP) and synovitis may be transient which further complicate the diagnosis. So, awareness about all features of the syndrome throughout the time seems mandatory for correct diagnosis and avoidance of unnecessary procedures.

Case presentation.

A case of SAPHO syndrome being reported in a middle-aged man who presented with bilateral PPP and exacerbation of back pain which developed shortly after covid-19 vaccine injection with a history of more than 20 years of inflammatory thoracic back pain and psoriasis vulgaris who initially had been worked up for metastatic bony lesions based on radiologic studies, irrespective of his skin lesions. The patient had good response to alendronate 70 mg weekly and celecoxib 200 mg BID without aggravation of existing skin lesions or new psoriatic lesions.

Conclusion

This case report aims to inform rheumatologists and radiologists about various radiologic and dermatologic manifestations of SAPHO syndrome with emphasizing on taking into consideration of past and present skin lesions in the interpretation of the radiologic signs in order to prevent irrelevant procedures or hazardous imaging and to urge rheumatology societies to set up a SAPHO registry for future randomized controlled trials. Suggestion of PPP responsiveness to NSAIDs as a new potential diagnostic tool for SAPHO diagnosis is another goal. It also aims to point out the possible coexistence of SAPHO and SpA or DISH syndrome.

Spinal disorders mimicking infection

Spinal infections are very commonly encountered by radiologists in their routine clinical practice. In case of typical MRI features, the diagnosis is relatively easy to interpret, all the more so if the clinical and laboratory findings are in agreement with the radiological findings. In many cases, the radiologist is able to make the right diagnosis, thereby avoiding a disco-vertebral biopsy, which is technically challenging and associated with a risk of negative results. However, several diseases mimic similar patterns, such as degenerative changes (Modic) and crystal-induced discopathy. Differentiation between these diagnoses relies on imaging changes in endplate contours as well as in disc signal. This review sought to illustrate the imaging pattern of spinal diseases mimicking an infection and to define characteristic MRI and CT patterns allowing to distinguish between these different disco-vertebral disorders. The contribution of advanced techniques, such as DWI and dual-energy CT (DECT) is also discussed.

Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis (SAPHO) Syndrome: Clinical and Therapeutic Aspects

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is a rare entity. It is frequently under-detected. We report the case of SAPHO syndrome in a 38-year-old woman, seen in consultation for pain and swelling of the anterior chest wall affecting the sternoclavicular and sternocostal joints predominantly on the right, and low back pain with an inflammatory appearance with peripheral damage, especially in the legs. We also found in our patient episodes of palmoplantar pustulosis. The diagnosis of SAPHO syndrome was retained in accordance with Kahn's diagnostic criteria, and the osteitis was confirmed by morphological examinations (CT scan, MRI, and bone scintigraphy). The patient was treated with non-steroidal anti-inflammatory drugs and methotrexate with good clinical improvement.

Diffusion-weighted MR imaging in chronic non-bacterial osteitis: Proof-of-concept of the apparent diffusion coefficient as an outcome measure

Background

The apparent diffusion coefficient (ADC), as determined by whole-body diffusion-weighted MRI, may be useful as an outcome measure for monitoring response to treatment in chronic non-bacterial osteitis.

Purpose

To test and demonstrate the feasibility of ADC-measurement methods for use as outcome measure in chronic non-bacterial osteitis.

Materials and Methods

Using data from a randomized pilot study, feasibility of change-score ADC between baseline and second MRI (ΔADC₁₂) and third MRI (ΔADC₁₃) as outcome measure was assessed in three settings: “whole-lesion,” “single-slice per lesion,” and “index-lesion per patient”. Bone marrow edema lesions were depicted on short tau inversion recovery sequence at baseline and copied to ADC maps at the three time-points. Correlations between the three settings were measured as were analysis of variances. Discriminant validity was assessed as inter- and intra-observer reproducibility and smallest detectable change.

Results

12 subjects were enrolled, and MRI was performed at baseline and weeks 12 and 36. Pearson correlation was high (r > 0.86; p ≤ 0.01) for ΔADC between single-slice—whole-lesion and whole-lesion—index-lesion and tended to be significant for single-slice—index-lesion settings (p = 0.06). For ΔADC₁₂ and ΔADC₁₃, Bland–Altman plots showed small differences (0.02, 0.03) and narrow 95% limits-of-agreement (−0.13–0.09, −0.07–0.05 μm²/s) between whole-lesion and single-slice ROI settings. Inter-observer reproducibility measured by intra-class correlation coefficient was poor-to-fair (range: 0.09–0.31), whereas intra-observer reproducibility was good-to-excellent (range: 0.67–0.90). Smallest detectable changes were between 0.21–0.28 μm²/s.

Conclusion

ADC change-score as outcome measure was feasible, and the single-slice per lesion ROI setting performed almost equally to whole-lesion setting resulting in reduced assessment time.

Differentiation between infectious spondylodiscitis versus inflammatory or degenerative spinal changes: How can magnetic resonance imaging help the clinician?

Spondylodiscitis is a complex disease whose diagnosis and management are still challenging. The differentiation between infectious and non-infectious aetiology is mandatory to avoid delays in the treatment of life-threatening infectious conditions. Imaging methods, in particular magnetic resonance imaging (MRI), play a key role in differential diagnosis. MRI provides detailed anatomical information, especially regarding the epidural space and spinal cord, and may allow differential diagnosis by assessing the characteristics of certain infectious and inflammatory/degenerative lesions. In this article, we provide an overview of the radiological characteristics and differentiating features of non-infectious inflammatory spinal disorders and infectious spondylodiscitis, focussing on MRI results and presenting relevant clinical and pathological features that help early diagnosis.

Review article: the current status of CT-guided needle biopsy of the spine

CT-guided percutaneous needle biopsy of the spine is a well-described technique for determining the nature of indeterminate vertebral lesions or establishing a diagnosis of spinal infection, the high diagnostic accuracy and the safety of the procedure having been extensively documented. The purpose of the current article is to review the literature to date on CT-guided spinal biopsy. Specifically, indications for spinal biopsy, techniques for optimising yield, detail of the approaches for various spinal levels which is dependent upon both the region within the spinal column and lesion location within the vertebra (body vs. neural arch), determinants of biopsy outcome and complications are covered. It is hoped that the review will be of particular benefit to junior radiologists who are required to perform this procedure.

Tripterygium wilfordii Hook F. in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: a clinical trial

OBJECTIVE

This study aimed to investigate the efficacy and safety of Tripterygium wilfordii Hook F. (TwHF) in the treatment of osteoarticular lesions in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

METHODS

Eligible SAPHO patients were recruited to this single-center trial to receive 12-week TwHF treatment. Two dose groups (1.0-mg/kg/day group and 1.5-mg/kg/day group) were designed and patients were allocated (1:1) to these two groups. The primary endpoint was the change from baseline in Ankylosing Spondylitis Disease Activity Score on the basis of C-reactive protein level (ASDAS) at week 12.

RESULTS

All the 30 included patients completed the trial. At week 12, both dose groups showed significant change from baseline in ASDAS (1.0-mg/kg/day group: - 1.34 (1.10), p = 0.000; 1.5-mg/kg/day group: - 1.53 (1.19), p = 0.000). Similar improvement was also found in the Visual Analogue Scale in global osteoarticular pain, Bath Ankylosing Spondylitis Disease Activity Index, and other efficacy measures. The results showed a fast-acting characteristic of TwHF that the maximum efficacy was achieved within the first 2-4 weeks and maintained at a stable level for the rest of the study. No significant differences were observed between the two dose groups under the current sample size. TwHF was well tolerated that no severe adverse events or irregular menstruation were recorded, except for one patient who developed severe alanine aminotransferase elevation at the last follow-up and has stopped the TwHF treatment after the 12-week follow-up.

CONCLUSIONS

TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

TRIAL REGISTRATION

ChiCTR1900025912 Key points • This is the first clinical trial to evaluate Tripterygium wilfordii Hook F. (TwHF) in the treatment of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. • Twelve-week TwHF treatment in both dose groups designed (1.0-mg/kg/day group and 1.5-mg/kg/day group) was well tolerated and could lead to significant disease remission of SAPHO syndrome. • No significant differences were observed between the two dose groups under the current sample size. • TwHF should be considered for the treatment of osteoarticular lesions in SAPHO syndrome in clinical practice because of significant efficacy, reliable safety, and high socioeconomic value.

Acne in the first three decades of life: An update of a disorder with profound implications for all decades of life

Acne vulgaris is a chronic, inflammatory, skin condition that involves the pilosebaceous follicles and is influenced by a variety of factors including genetics, androgen-stimulation of sebaceous glands with abnormal keratinization, colonization with Cutibacterium acnes (previously called Propionibacterium acnes), and pathological immune response to inflammation. Acne can occur at all ages and this discussion focuses on the first three decades of life. Conditions that are part of the differential diagnosis and/or are co-morbid with acne vulgaris are also considered. Acne in the first year of life includes neonatal acne (acne neonatorum) that presents in the first four weeks of life and infantile acne that usually presents between 3 and 6 months of the first year of life with a range of 3 to 16 months after birth. Acne rosacea is a chronic, inflammatory, skin condition that is distinct from acne vulgaris, typically presents in adults, and has four main types: erythemato-telangiectatic, papulopustular, phymatous and ocular. Treatment options for acne vulgaris include topical retinoids, topical benzoyl peroxide, antibiotics (topical, oral), oral contraceptive pills, isotretinoin, and others. Management must consider the increasing impact of antibiotic resistance in the 21st century. Psychological impact of acne can be quite severe and treatment of acne includes awareness of the potential emotional toll this disease may bring to the person with acne as well as assiduous attention to known side effects of various anti-acne medications (topical and systemic). Efforts should be directed at preventing acne-caused scars and depigmentation on the skin as well as emotional scars within the person suffering from acne.

New Insights into Adult and Paediatric Chronic Non-bacterial Osteomyelitis CNO

Purpose of Review

To describe in detail the clinical synopsis and pathophysiology of chronic non-bacterial osteomyelitis and SAPHO syndrome.

Recent Findings

Chronic non-bacterial osteomyelitis (CNO) has been identified as a disease entity for almost 50 years. This inflammatory bone disorder is characterized by osteolytic as well as hyperostotic/osteosclerotic lesions. It is chronic in nature, but it can present with episodic flairs and phases of remission, which have led to the denomination “chronic recurrent osteomyelitis”, with its severe multifocal form “chronic recurrent multifocal osteomyelitis” (CRMO). For almost three decades, an infectious aetiology had been considered, since especially Propionibacterium acnes had been isolated from bone lesions of individual patients. However, this concept has been challenged since long-term antibiotic therapy did not alter the course of disease and modern microbiological techniques (including PCR) failed to confirm bone infection as an underlying cause. Over recent years, a profound dysregulation of cytokine expression profiles has been demonstrated in innate immune cells of CNO patients. A hallmark of monocytes from CNO patients is the failure to produce immune regulatory cytokines interleukin-10 (IL-10) and IL-19, which have been linked with genetic and epigenetic alterations. Subsequently, a significant upregulation of pro-inflammatory, NLRP3 inflammasome-dependent cytokines (IL-1β and TNF-α), has been demonstrated.

Summary

The current knowledge on CNO, the underlying molecular pathophysiology, and modern imaging strategies are summarized; differential diagnoses, treatment options, outcome measures, as well as quality of life studies are discussed.

The comparison analysis of clinical and radiological features in SAPHO syndrome

OBJECTIVES

The aim was to comparatively assess the clinical and imaging features in patients with SAPHO syndrome.

METHODS

The clinical data, laboratory results, imaging data of forty-six SAPHO patients were reviewed and the SAPHO patients were divided into spinal involvement group and non-spinal involvement group. Fifty patients with ankylosing spondylitis were recruited as control group. The clinical and radiological features of them were analyzed and compared.

RESULTS

Thirty-four of 46 (73.9%) of all the SAPHO patients had spinal involvement. The lesions exhibited as abnormal hyper-intensity signal in vertebral bodies, vertebral body erosion or collapse, bone marrow edema, endplate inflammation, spondyldiscitis, paravertebral ossification, and facet joint involvement. Compared with patients in non-spinal involvement group, the age at disease onset was older (P = 0.033), the disease duration was longer (P = 0.048), and CRP level was elevated (P = 0.047) in patients in spinal involvement group. Compared with patients with ankylosing spondylitis, SAPHO patients were more likely to have cervical vertebra involvement (P = 0.024), endplate inflammation (P = 0.019), and spondyldiscitis (P = 0.001), but less multiple vertebral body and facet joint involvement (P = 0.002). Patients regularly received DMARDS or biologics treatment had symptoms relieved and lesions turned into chronic stage or better than before.

CONCLUSIONS

A total of 73.9% of the SAPHO patients had spinal involvement and the involvement could affect any part of the spine. Cervical vertebral involvement, endplate inflammation, and sponlypodiscitis were more common in SAPHO than in patients with ankylosing spondylitis. In SAPHO patients with spinal involvement, the disease duration was longer and the inflammatory reaction was more intensive. DMARDs and biologics may help to prevent the disease progress.

KEY POINTS

• To the best of our knowledge, this paper is the first one to comparatively study the clinical and radiological features of SAPHO syndrome, especially the characteristics of spinal involvement.

Pamidronate in chronic non-bacterial osteomyelitis: a randomized, double-blinded, placebo-controlled pilot trial

OBJECTIVE

This is the first randomized double-blinded, placebo-controlled pilot trial to investigate the efficacy of pamidronate in reducing radiological and clinical disease activity in chronic non-bacterial osteomyelitis (CNO).

METHOD

Patients received pamidronate or placebo at baseline and weeks 12 and 24. Whole-body magnetic resonance imaging was performed at baseline and weeks 12 and 36, and computed tomography of the anterior chest wall (ACW) at baseline and week 36. Radiological disease activity was systematically scored in the ACW and spine. Patient-reported outcomes [visual analogue scale (VAS) pain, VAS global health, Health Assessment Questionnaire (HAQ), EuroQol-5 Dimensions (EQ-5D), and 36-item Short-Form Health Survey (SF-36)] and biomarkers of bone turnover and inflammation were assessed at baseline and weeks 1, 4, 12, 24, and 36. Data are expressed as median [interquartile range].

RESULTS

Fourteen patients were randomized and 12 were analysed. From baseline to week 36, the radiological disease activity score in the ACW decreased from 5 [4-7] to 2.5 [1-3] in the pamidronate group, but did not change in the placebo group (p = 0.04). From baseline to week 36, VAS pain and VAS global health tended to decrease more in the pamidronate than in the placebo group (p = 0.11, p = 0.08). Physical functioning (HAQ) and health-related quality of life (EQ-5D, SF-36) did not change. Biomarkers of bone turnover decreased only in the pamidronate group (p ≤ 0.02).

CONCLUSION

Pamidronate may improve radiological and clinical disease activity in CNO. Methods to score radiological disease activity in adult CNO were suggested. Clinical Trials: NCT02594878.

Imaging features in patients with SAPHO/CRMO: a pictorial review

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and chronic recurrent multifocal osteomyelitis (CRMO) have been described as disorders of chronic osteoarthritic inflammation frequently associated with skin manifestations, and SAPHO and CRMO (SAPHO/CRMO) are rare autoinflammatory disorders of unknown etiology. SAPHO tends to occur in adults and CRMO predominantly occurs in children and adolescents. SAPHO/CRMO can affect any skeletal region (e.g., anterior chest wall, spine, or long bones). As SAPHO/CRMO are diagnoses of exclusion, the diagnoses might be difficult if skin manifestations are not clearly evident. However, knowledge of the imaging findings of skeletal disorders is helpful for correcting the diagnosis and avoiding unnecessary invasive procedures, as well as in facilitating early diagnosis and adequate treatment. This pictorial review describes the appearance of increased skeletal uptake for SAPHO/CRMO on bone scintigraphy along with findings from radiography, computed tomography, and magnetic resonance imaging.

A retrospective study of bone scintigraphy in the follow-up of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome: is it useful to repeat bone scintigraphy for disease assessment?

OBJECTIVES

To investigate the value of repeated bone scintigraphy in the follow-up of patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to characterize the changing pattern of osteoarticular lesions revealed by bone scintigraphy.

METHOD

Twenty-four patients with SAPHO syndrome who had repetitively undergone bone scintigraphy and tests of inflammatory markers (erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP)) were included in this retrospective study. The change in accumulation number was recorded as the difference in the number of accumulation sites between consecutive bone scintigraphy. The visual analog scale (VAS) for pain and medications prescribed were also reviewed. The relationships of the change in accumulation number with medication prescribed and change in ESR or CRP were analyzed.

RESULTS

Twenty-four and 23 patients had follow-up tests of ESR and CRP, from which 30 and 28 follow-up data were obtained, containing the corresponding changes in ESR and CRP, respectively. A decrease in total accumulation number observed by bone scintigraphy was rarely observed, while decreases in ESR, CRP, and VAS were predominant. The accumulation number had significantly increased over time (follow-up with ESR: r = 0.389, p = 0.034; follow-up with CRP: r = 0.438, p = 0.020), in accordance with an "imprinting" pattern, while the inflammatory markers and VAS for pain predominantly decreased. There was no significant association between the change in accumulation number (local/total) and the change in ESR or CRP values (p > 0.05) or medications used for SAPHO (p > 0.05).

CONCLUSIONS

This retrospective cohort study of 24 SAPHO patients demonstrated an "imprinting" pattern on bone scintigraphy, without a correlation to the decrease in inflammatory markers, patient disease assessment, or treatment type. Thus, repeated bone scintigraphy did not contribute an additional clinical value for the follow-up of patients with SAPHO.Key Points• In a cohort of 24 SAPHO patients, repeated bone scintigraphy revealed a continuous increase in tracer accumulation number, indicating an "imprinting" pattern.• The change in tracer accumulation number, defined as the difference in the number of accumulation sites between consecutive bone scintigraphy measurements, was inconsistent with the change in ESR, CRP, or VAS for pain.• The medications prescribed for SAPHO did not seem to contribute to a decrease in accumulation number.• Repeated bone scintigraphy did not seem to be useful for the assessment of disease activity in patients with SAPHO.

Long-term remarkable remission of SAPHO syndrome in response to short-term systemic corticosteroids treatment in an immunoglobulin E elevated patient: A case report

RATIONALE

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare auto-inflammatory disease with no standardized treatment. Systemic corticosteroids are only transiently effective, but long-term use would bring complications and would not bring long-term remission. Bone scintigraphy is a first-line method for systematic evaluation of osteoarticular lesions but seems to show an "imprinting" pattern.

PATIENT CONCERNS

A 31-year-old female patient presented significant palmoplantar pustulosis and nail lesion as well as typical tracer accumulation feature on bone scintigraphy with normal hypersensitivity C-reactive protein and erythrocyte sedimentation rate, but an elevated serum immunoglobulin E level.

DIAGNOSIS

The diagnosis was made by dermatological manifestations and classical sign in bone scintigraphy in accordance with the diagnostic criteria proposed in 1988.

INTERVENTIONS

Methylprednisolone was given with a primary dose of 40 mg/day for 1 week followed with a subsequent 20 mg/day oral prednisone for another 1 week and then reduced in a rate of 5 mg/week until the eventual cessation.

OUTCOMES

Long-term remarkable remission on clinical manifestations, MRI performance, and quantitative analysis of bone scintigraphy was achieved.

LESSONS

Identification of specific subtype of SAPHO patient according to skin and nail manifestations as well as immunoglobulin E level may guide the selection of short-term systemic corticosteroids strategy, leading to remarkable long-term remission. Besides, the lesions on bone scintigraphy can hardly disappear in SAPHO patients, and instead, the quantitative analysis of bone scintigraphy and MRI performances may better reflect the change of disease condition and serve as indicator for treatment efficiency.

Stress fracture of the midshaft clavicle associated with sternocostoclavicular hyperostosis-Case report

•

Stress fractures of the midshaft of the clavicle caused by sternocostoclavicular hyperostosis are very rare.

•

The differential diagnosis of sternocostoclavicular hyperostosis might be difficult.

•

Sternocostoclavicular hyperostosis in the patient was suspected of having either SAPHO syndrome or ankylosing spondylitis.

•

The patient was treated conservatively and the shoulder function was satisfactory at the final follow-up.

Introduction

Stress fracture is generally a result of cumulative and repetitive stress in athletes, which accelerates the normal remodeling process of bones, and the most frequently involved areas are the tibia and metatarsal bones. Therefore, stress fractures of the midshaft of the clavicle are very rare.

Presentation of case

A 58-year-old female was admitted to our hospital because of pain in the middle of the right clavicle. Based on laboratory and radiographic inspection, it was concluded that the stress fracture of the midshaft of the clavicle in this case was caused by sternocostoclavicular hyperostosis (SCCH). Because the clavicular fracture had no displacement or callus formation, conservative treatment with a clavicle band was undertaken. Shoulder function at the final follow-up visit was satisfactory.

Discussion

SCCH is a rare chronic inflammatory disorder of the axial skeleton and ossifying diathesis associated with a predominantly osteogenic response. Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and ankylosing spondylitis (AS) should be considered in the differential diagnosis of SCCH. If a patient with this type of fracture has no history of traumatic injury or sports activity, the differential diagnosis might be very difficult.

Conclusion

We report the case of a female who had a stress fracture of the midshaft of the clavicle associated with SCCH in SAPHO or AS. Although the patient was treated conservatively, and the shoulder function was satisfactory at the final follow-up visit, re-fracture may occur in the future.

SAPHO syndrome with pathological fractures of vertebral bodies: a case report

Background

It’s difficult to diagnose and treat synovitis-acne-pustulosis-hyperostosis-osteomyelitis (SAPHO) syndrome due to its rare and unknown pathogenesis. There is no effective treatment for SAPHO syndrome and the consequences of empirical treatment are unpredictable. This study reports a case of a young female diagnosed as SAPHO syndrome with pathological fractures of vertebral bodies.

Case presentation

A 29-year-old female complained of the right sternoclavicular joint and back pain accompanied limited activities and cutaneous lesions. Laboratory assays revealed abnormal inflammatory factors. Multiple imaging studies illustrated bone lesions and pathological fractures of vertebral bodies. A diagnosis of SAPHO syndrome was made. The patient was treated with Compound Troxerutin and Poreine Cerebroside Injection, non-steroidal anti-inflammatory drugs (NSAIDs), bisphosphonates, corticosteroids and the thoracolumbar brace. The patient was followed up for 6 months and showed improved results.

Conclusions

The case supports that multiple image inspections and laboratory tests contribute to diagnose SAPHO syndrome, and combination therapies of Compound Troxerutin and Poreine Cerebroside Injection, NSAIDs, bisphosphonates, corticosteroids and the thoracolumbar brace in the treatment of SAPHO syndrome with pathological fractures of vertebral bodies are crucial to regain health.

Complete resolution and remodeling of chronic recurrent multifocal osteomyelitis on MRI and radiographs

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition thought to be under-diagnosed, with a true prevalence of more than the 1 in 10,000 estimated. It is a condition that is classically described as polyostotic with a relapsing and remitting course, preferentially affecting the metaphyses of tubular bones in the pediatric population. Lesions have characteristic appearances of cortical hyperostosis and mixed lytic/sclerotic medullary appearances radiographically, with active osteitis and periostitis best seen with fluid-sensitive sequences on magnetic resonance imaging (MRI). There are reports of lesions resolving on follow-up radiographs and MRI scans, but no supporting images. In particular, although the marrow appearances and degree of osteitis have been shown to improve on MRI, complete resolution and remodeling back to normal has never been demonstrated. We present a case of a lesion that has completely healed and remodeled back to normal appearances on both radiographs and MRI, and consider this the standard for the often loosely used terms "normalization" and "resolution". We discuss the implications of this for our understanding of the natural history of CRMO, and how this adds weight to the condition being significantly under-diagnosed. It provides a "gold standard" to be aimed for when assessing treatments for CRMO, and the optimal outcomes that are possible. It also provides further insight into the potential of pediatric bone to recover and remodel when affected by inflammatory conditions.

Imaging for Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis (SAPHO) Syndrome

Multifocal osteomyelitis and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome constitute a spectrum of disease that includes inflammatory bone lesions and dermatologic findings. Radiographic features resemble those of the spondyloarthropathies with anterior chest wall involvement. Early radiographic findings are osteodestructive with lytic lesions. Bone scintigraphy of the sternoclavicular region classically yields a 'bull's head' pattern of radionuclide uptake. Magnetic resonance imaging (MRI) can demonstrate corner lesions of vertebral bodies. Ultrasound often reveals peripheral enthesitis. Late radiographic features are usually osteoproliferative. PET/CT can identify chronic lesions. Differential diagnostic considerations include osteomyelitis and malignancy, which often prompt bone biopsy.

Computed Tomography and MR Imaging in Spondyloarthritis

This article provides an overview of the computed tomography (CT) and MR imaging appearances suggestive of spondyloarthritis, with a specific emphasis on the MR imaging findings of vertebral and sacroiliac involvement, and presents relevant clinical features that assist early diagnosis. CT is a sensitive imaging modality for the assessment of structural bone changes, but its clinical utility is limited. MR imaging is the modality of choice for early diagnosis, because of its ability to depict inflammation long before structural bone damage occurs, for monitoring of disease activity, and for evaluating therapeutic response.

Whole-spine Computed Tomography Findings in SAPHO Syndrome

OBJECTIVE

We evaluated the whole-spine computed tomography (CT) findings in patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome to improve our understanding of this rare disease.

METHODS

Whole-spine CT images obtained in 69 patients with SAPHO were reviewed. For each individual, a total of 25 vertebrae were evaluated for the distribution of affected vertebrae, CT manifestations of vertebral lesions, symmetry and location of distribution of the lesions on vertebrae, involvement pattern, and narrowing of adjacent intervertebral disc space. Paravertebral ligamentous ossifications, apophyseal joint disorders, and costovertebral joint disorders were also evaluated.

RESULTS

All the 69 patients with SAPHO exhibited abnormalities on whole-spine CT. Sixty-four had vertebral lesions, 52 had paravertebral ossifications, and 47 had both. The vertebral lesions were observed in 441 vertebrae, with a predilection for thoracic spine. The lesions exhibited a mixture of cortical erosion, reactive osteosclerosis of surrounding cancellous bone, and syndesmophyte. They may be confined to the vertebral corner (65.1%) or be extensive, involving the endplate (34.9%). Corner lesions could start in any part of the epiphyseal ring. The lesions were asymmetrically distributed. The affected vertebrae were more consecutively involved in a "kissing" appearance (78.2%). Intervertebral disc spaces were usually normal or mildly narrowed. There were 320 foci of paravertebral ossifications observed, with a predilection for the supraspinous ligament. Paravertebral ossifications were delicate and segmental. Ossifications throughout annulus fibrosis and apophyseal joint were not observed.

CONCLUSION

Our investigation of the distributional, morphological features and the involvement pattern of spinal lesions in patients with SAPHO demonstrated distinct CT characteristics.

SAPHO Syndrome: Imaging Findings of Vertebral Involvement

BACKGROUND AND PURPOSE

Imaging findings in patients with a combination of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) are often misinterpreted as discitis/osteomyelitis or metastases, resulting in multiple biopsies and delayed diagnosis. We have incidentally noted a semicircular morphology in vertebral body imaging in several cases of SAPHO syndrome with vertebral involvement. Our goal was to evaluate the prevalence of this distinctive morphology in these patients.

MATERIALS AND METHODS

A retrospective review of patients with SAPHO syndrome diagnosed between July 1998 and August 2013 was conducted. A descriptive analysis of MR imaging, CT, radiography, bone scanning, and PET imaging was performed for the presence and distribution of vertebral body signal intensity or attenuation changes and/or enhancement; contiguous vertebral body involvement; vertebral body collapse; endplate irregularity; disc space, facet, and spinous process involvement; subligamentous thickening; and paraspinal soft-tissue involvement.

RESULTS

Eighteen patients (16 women [89%]; mean age, 52.9 years) with SAPHO and spine involvement were included. Contiguous involvement of ≥2 vertebral bodies was found in 16 patients (89%), with a curvilinear or "semicircular" pattern involving portions of adjacent vertebral bodies in 10 (63%, P = .14). Most intervertebral discs demonstrated absence of abnormal T2 hyperintensity (73%) and enhancement (89%). Subligamentous thickening was present in 12 (67%). Paraspinal soft-tissue involvement was present in 6 (33%).

CONCLUSIONS

SAPHO syndrome should be included in the differential diagnosis in a patient with a curvilinear or semicircular pattern of vertebral involvement, contiguous vertebral body involvement, and absence of intervertebral disc edema and enhancement.

Spinal fractures in patients with ankylosing spondylitis

The ankylosed spine is prone to fracture even after minor trauma due to its changed biomechanical properties. The two central features of ankylosing spondylitis (AS) that promote the pathological remodeling of the spine are inflammation and new bone formation. AS is also associated with osteoporosis that is attributed to an uncoupling of the bone formation and bone resorption processes. Therefore, bone resorption occurs and promotes weakening of the spine as well as increased risk of vertebral fractures which can be hugely different in terms of clinical relevance. Even in the presence of symptomatic clinical vertebral fractures, the diagnosis can be overruled by attributing the pain to disease activity. Furthermore, given the highly abnormal structure of the spine, vertebral fracture diagnosis can be difficult on the basis of radiography alone. CT can show the fractures in detail. Magnetic resonance imaging is considered the method of choice for the imaging of spinal cord injuries, and a reasonable option for exclusion of occult fractures undetected by CT. Since it is equally important for radiologists and clinicians to have a common knowledge base rather than a compartmentalized view, the aim of this review article was to provide the required clinical knowledge that radiologists need to know and the relevant radiological semiotics that clinicians require in diagnosing clinically significant injury to the ankylosed spine.

SAPHO syndrome presenting as an osteolytic lesion of the neck

We report a case of acute-onset multifocal vertebral osteitis with a marked impact on the patient's general health. The radiological, scintigraphic and magnetic resonance findings made it necessary to carry out a differential diagnosis to distinguish it from an infiltrative neoplastic process and determine whether it had an infectious or an inflammatory etiology. The presence of noninfectious multifocal osteitis and sternoclavicular arthritis and the subsequent development of plantar pustulosis pointed to SAPHO syndrome. Treatment with infliximab led to improvement in the clinical symptoms, laboratory values and radiological abnormalities.