Acquired hyperostosis syndrome--AHYS--(sternocostoclavicular hyperostosis, pustulotic arthro-osteitis, SAPHO-syndrome): bone scintigraphy of the anterior chest wall

Defining the imaging diagnostic criteria for adult chronic non-bacterial osteitis

Osteitis of the sternocostoclavicular (SCC) region, referred to as sternocostoclavicular hyperostosis (SCCH), is the clinical expression of chronic non-bacterial osteitis (CNO) in adults with this rare chronic auto-inflammatory disorder of the axial skeleton. The diagnosis is based on distinctive computerized tomography (CT) features of sclerosis and hyperostosis of the SCC region, and local increases in osteoid formation visualized by high radiopharmacon uptake on skeletal scintigraphy but clear radiologic diagnostic criteria are lacking. In a cross-sectional study, CT scans and whole-body skeletal scintigraphy images obtained in 169 patients seen at the Center for Bone Quality of the Leiden University Medical Center between 2008 and 2018 with a suspected diagnosis of CNO of the SCC region were re-evaluated by 2 skeletal radiologists and 2 nuclear physicians. The diagnosis was confirmed in 118 (70%) predominantly female patients (n = 103, 89.2%); median age at first symptoms 45 years (range 20-73). The diagnosis was excluded in the remaining 51 "non-CNO" patients. Increased radiopharmacon uptake at the SCC region was observed in 82% CNO patients, with the manubrium sterni having the highest predictive ability to discriminate on both imaging modalities. The prevalence of sclerosis of the clavicles, manubrium and first ribs was significantly higher in CNO patients (P < 0.001). Hyperostosis was not observed in non-CNO patients. 46 CNO versus only 2 non-CNO patients had costoclavicular ligament calcification. Our findings identify CT scan features of sclerosis and hyperostosis of manubrium sterni, medial end of clavicles and first ribs, and calcification of costoclavicular ligaments, associated with increased tracer uptake on skeletal scintigraphy at the SCC region, specifically manubrium sterni, as well-defined imaging diagnostic criteria for adult CNO. Pitfalls encountered in the diagnosis of CNO are highlighted. These defined imaging diagnostic criteria for adult CNO should facilitate the diagnosis of this rare auto-inflammatory bone disease across the spectrum of its early to late stages.

Clinical and therapeutic diversity in adult chronic nonbacterial osteomyelitis (CNO) of the sternocostoclavicular region: a meta-analysis

OBJECTIVES

Chronic nonbacterial osteomyelitis (CNO) is a rare inflammatory bone disease. The distinct CNO subtype that affects the anterior chest wall is descriptively named sternocostoclavicular hyperostosis (SCCH) and mainly occurs in adults. Literature on CNO/SCCH is scattered and lacks diagnostic and therapeutic consensus.

METHODS

Systematic review and meta-analysis aiming to characterize clinical presentation and therapeutic modalities applied in adult CNO/SCCH patients. Untransformed numerical data and double-arcsine transformed proportional data were pooled in a random effects model in R-4.0.5; proportions were reported with 95% CI.

RESULTS

Forty studies were included, containing data on 2030 and 642 patients for aim 1 and 2, respectively. A female predisposition (67%, 95% CI 60, 73) and major diagnostic delay (5 years 95% CI 3, 7) were noted. Clinical presentation included chest pain (89%, 95% CI 79, 96) and swelling (79%, 95% CI 62, 91). Patients suffered from pustulosis palmoplantaris (53%, 95% CI 37, 68), arthritis (24%, 95% CI 11, 39) and acne (8%, 95% CI 4, 13). Inflammatory markers were inconsistently elevated. Autoantibody and HLA-B27 prevalence was normal, and histopathology unspecific. Increased isotope uptake (99%, 95% CI 96, 100) was a consistent imaging finding. Among manifold treatments, pamidronate and biologicals yielded good response in 83%, 95% CI 60, 98 and 56%, 95% CI 26, 85, respectively.

CONCLUSION

CNO/SCCH literature proves heterogeneous regarding diagnostics and treatment. Timely diagnosis is challenging and mainly follows from increased isotope uptake on nuclear examination. Biopsies, autoantibodies and HLA status are non-contributory, and biochemical inflammation only variably detected. Based on reported data, bisphosphonates and biologicals seem reasonably effective, but due to limitations in design and heterogeneity between studies the precise magnitude of their effect is uncertain. Fundamentally, international consensus seems imperative to advance clinical care for CNO/SCCH.

Three patterns of osteoarticular involvement in SAPHO syndrome: a cluster analysis based on whole body bone scintigraphy of 157 patients

OBJECTIVES

To explore the patterns of osteoarticular involvement in SAPHO syndrome.

METHODS

Baseline clinical characteristics and imaging data of 99mTc-MDP whole-body bone scintigraphy (WBBS) were collected from 157 out of 164 patients diagnosed with SAPHO syndrome. The twelve most frequently involved osteoarticular sites were analysed by hierarchical cluster analysis with the Ward minimum-variance method.

RESULTS

Three distinctive patterns of osteoarticular involvement were identified: the spinal type (70 patients, 44.6%), with predominantly thoracic, lumbar or sacral vertebral lesions; the costal type (52 patients, 33.1%), with lesions of anterior ribs, particularly the first ribs; and the sternoclavicular type (35 patients, 22.3%), with predominantly sternal and bilateral sternoclavicular lesions, characterized by the typical bullhead sign. Notably, a total of 77 (49%) patients exhibited lesions of ribs on WBBS, of which 61.3% involved the first ribs. Interestingly, patients of spinal type were older at onset of cutaneous manifestations than those of sternoclavicular type (P = 0.036) and costal type (P = 0.035). The disease course was remarkably longer in sternoclavicular type than costal type (P = 0.001) and spinal type (P < 0.001).

CONCLUSION

The osteoarticular involvement in SAPHO syndrome can be categorized as three distinct patterns with different corresponding clinical features. The costal involvement in SAPHO syndrome, which was under-recognized previously, may define a distinct sub-type of the disease.

SAPHO: Treatment options including bisphosphonates

INTRODUCTION

Both the diagnosis and treatment of the syndrome of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) remain difficult. We describe a case series of 21 patients with SAPHO and their response to several pharmacological treatments.

METHODS

Clinical and biochemical data, along with medical imaging, were collected from the medical records of 21 patients, diagnosed as SAPHO during follow-up between 2005 and 2013. Symptoms and inflammatory markers were recorded twice, once at first patient presentation, and once at the end of follow-up. Synovitis, acne, pustulosis, hyperostosis, and osteitis were labeled as defining features. All treatment options were categorized according to their respective responses (full remission, partial remission, and no disease control).

RESULTS

There was a female predominance and a median age of 32 years (range: 12-54 years). Median follow-up duration was 45 months (range: 0-188 months). Total prevalence of defining features in this cohort increased for each defining feature during follow-up, except for acne. All patients reached full or partial remission at the end of follow-up. A total of 14 patients were treated with bisphosphonates. Of which 8 of them went into full or partial remission.

DISCUSSION AND CONCLUSION

In our case series, none of the patients had the full presentation of SAPHO at the first consultation. Some presented with symptoms suggestive for psoriatic arthritis. This explains why diagnosis of SAPHO can be challenging. Full remission was induced in the majority of individuals. Bisphosphonates seem to be a noteworthy treatment option. We suggest a prospective placebo-controlled clinical trial with bisphosphonates to confirm this observation.

Sternocostoclavicular hyperostosis: a review

Sternocostoclavicular hyperostosis (SCCH) is a chronic inflammatory disorder which presents with erythema, swelling, and pain of the sternoclavicular joint. Approximately one half of patients have acne or pustular lesions with the best described association being with palmoplantar pustulosis (PPP). Extrasternal articular disease occurs in about a quarter of patients. The inflammatory process spans several years and has periods of exacerbation followed by remission. The histologic picture demonstrates a sterile osteomyelitis of the sternum and medial end of the clavicle. The diagnosis of SCCH is confirmed radiographically by hyperostosis and sclerosis of the sternum with involvement of the first rib on computed tomography (CT). The focal uptake of radiopharmaceutical on bone scintigraphy called the 'bullhead' sign is highly sensitive of SCCH. Treatment is aimed at easing pain and modifying the inflammatory process. Evidence over the last two decades suggests a role for intravenous bisphosphonates and tumor necrosis factor alpha inhibitors. A low level of awareness of SCCH often leads to a delay in diagnosis. This translates into significant morbidity and brings a psychological burden. Untreated chronic inflammation of the sternoclavicular joint leads to restricted mobility and secondary degenerative joint changes. In the search for a diagnosis, patients often undergo multiple serologic and imaging studies and in the experience of the author are referred to multiple specialists before a correct diagnosis is made. Greater awareness of SCCH is needed to prevent the irreversible physical and psychological impairments associated with the disease.

The SAPHO syndrome--are microbes involved?

The syndrome of synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) includes a rare group of chronic, relapsing, inflammatory osteoarticular disorders that is conventionally associated with manifestations in the skin. Diagnostic dilemmas can arise due to incomplete manifestations or confusion generated through mimicking of other conditions, such as osteomyelitis. The aetiology of this syndrome remains unclear, but probably involves genetic, immunological and infectious mechanisms. The possible pathogenetic role of infectious agents in genetically predisposed individuals, resulting in a 'reactive osteitis', has been suggested because microbes such as Propionibacterium acnes have been recovered from bone biopsy samples. However, this hypothesis has not been demonstrated as yet. Current knowledge with regard to treatment of this syndrome is based on results reported from small case studies and, thus, is still empiric. The use of antibiotics, instituted based on the isolation of Propionibacterium acnes, has been reported to show conflicting results. Promising results for potential future application have recently been reported for treatment of SAPHO with bisphosphonates and antagonists of tumour necrosis factor-α. This review aims to evaluate the existing knowledge on the SAPHO syndrome and to provide information on symptoms, diagnosis and treatment options for this disease.

SAPHO: What radiologists should know

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) is an umbrella acronym for inflammatory clinical conditions whose common denominator is aseptic osteoarticular involvement with characteristic skin lesions. It involves all ages, can involve any skeletal site, and has variable imaging appearances depending on the stage/age of the lesion and imaging method. It mimics important differentials including infection and neoplasia. Awareness of the imaging features, especially in the spine, facilitates early diagnosis, prevents repeated biopsies, and avoids unnecessary surgery, while initiating appropriate treatment.

[The importance of bone scintigraphy in the diagnosis of SAPHO syndrome]

The SAPHO acronym corresponds to a group of benign conditions that combine osteoarticular and skin involvement whose diagnosis is mainly clinical and is supported by imaging findings. The bone scintigraphy has a relevant role due to its sensitivity and early detection ability. We present 8 patients with SAPHO syndrome whose clinical involvement began with skin manifestations. All of them had palmoplantar pustulosis, either of recent onset or outbreak evolution. Some had associated osteoarticular pain in shoulders, sternum, lumbar area or limbs. Bone scintigraphy with Tc-99m-diphosphonate showed pathological findings in all the patients, detecting sternoclavicular joint damage, this being the most frequent involvement in 7 of them, and also in other less usual localizations.

SAPHO Syndrome Diagnosis and Treatment: Report of Five Cases and Review of the Literature

Background:

The term “SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome” includes a variety of musculoskeletal disorders associated with skin conditions; Osteitis is the most prominent skeletal lesion, whereas palmoplantar pustulosis and acne are the main skin lesions. Diagnosing SAPHO syndrome is difficult, because this syndrome is often confused with suppurative osteomyelitis, which has similar clinical and pathologic findings. SAPHO diagnosis is even more difficult when atypical sites are involved and there are no skin lesions.

Patients and Methods:

This case series presents five patients (3 women, 2 men), ages 27 to 44 years, who came to the Orthopaedic Department outpatient clinic for evaluation of pain in the humerus, clavicle, sacroiliac joints, and/or distal radius, and were diagnosed with SAPHO syndrome. Clinical and radiologic findings, treatment and outcome data, with up to 4 years of follow-up are presented. An extensive discussion of the clinical presentation, published literature, treatment options and outcome of SAPHO syndrome is also included.

Results:

Once the diagnosis of SAPHO syndrome was established, treatment with antibiotics (clindamycin) and non steroid anti-inflammatory drugs (lornoxicam) was remarkably effective. All patients did well and remained symptom free for up to four years, after a 3-8 month course of treatment.

Interpretation:

SAPHO syndrome should be included in the differential diagnosis when evaluating patients with lytic, sclerotic, or hyperostotic bone lesions and pain. Prompt SAPHO syndrome recognition, followed by appropriate therapy with antibiotics and NSAIDs can produce rapid symptom resolution, while avoiding unnecessary procedures and longterm antibiotic therapy.

[A pregnant woman with a SAPHO syndrome]

The association SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis) and pregnancy is very rare. Only one case is indexed in the literature. We report the case of a pregnancy in a 27-year-old patient with a SAPHO syndrome and we expose its history and its obstetrical, medical and anaesthetic following. Under this multi-field following, there was no evolutionary push of the disease neither during the pregnancy, nor in immediate postpartum. We will expose the different possible treatments during the pregnancy.

Case reports: aseptic femoral osteitis and sternocostal hyperostosis from SAPHO syndrome

Synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome are characterized by peculiar bone lesions that commonly involve the anterior chest wall. Osteitis typically is the most prominent skeletal lesion seen in synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome. We present a patient with aseptic femoral osteitis and sternocostal hyperostosis. The classic clinical, radiographic, and histologic features of this syndrome are described. Diagnosis is difficult in patients with only one symptomatic bone. The lesion often is confused with suppurative osteomyelitis because of similar clinicopathologic findings. Although the optimal treatment is unclear, it is important to consider synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome in the differential diagnosis of any lytic, sclerotic, or hyperostotic bone lesion to avoid unnecessary long-term antibiotic therapy.

The skin is the clue

A 67-year-old woman presented with aseptic osteomyelitis and palmoplantar pustular psoriasis. The diagnosis of SAPHO syndrome was made. Treatment with pamidronate led to symptomatic improvement.

Dense bone around the sacroiliac joint: a radiological review of the differential diagnosis

Solitary osteosclerotic bone lesions around the sacroiliac (SI) joints are described as seen on plain radiographs or conventional tomography, with the descriptive attributes ranging from round to ovoid over square and triangular to multiform. The etiology of the solitary osteosclerotic lesions around the SI joint can often be concluded from the radiographic appearance, sometimes complemented by the presentation on CT and/or scintigraphy.