Synovitis of sternoclavicular and peripheral joints can be detected by ultrasound in patients with SAPHO syndrome

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.

Anatomical study of the sternoclavicular joint using high-frequency ultrasound

OBJECTIVES

The purpose of the present study was to determine whether ultrasound enables assessment of sternoclavicular structures.

METHODS

A preliminary study in 3 cadavers was followed by an ultrasound study, performed by 2 musculoskeletal radiologists working in consensus, in 59 patients without history of trauma, surgery or pain in the sternoclavicular joint. The visibility, echogenicity and thickness of the sternoclavicular structures were assessed.

RESULTS

The anterior sternoclavicular ligament and the interclavicular ligament could be seen in all patients (mean thickness: 1.4 mm and 1.3 mm, respectively). The articular disc was clearly seen in 66.1% of cases, and shoulder antepulsion enabled analysis in an additional 20.3%. Intra-articular joint gas was frequent (33.89% of cases), preventing analysis of the disc in 2 patients. Only the superficial anterior aspect of the clavicular and sternal articular cartilages could be assessed. Joint effusion was seen in 6.8% of cases. Clavicular osteophytes, sternal osteophytes and bone irregularities at the anterior sternoclavicular ligament insertion were detected in 33.9%, 16.9% and 16.9% of cases, respectively.

CONCLUSION

The anterior sternoclavicular ligament, interclavicular ligament and anterior intra-articular structures can be visualized by ultrasound. This means of assessment may have clinical applications, particularly in patients with trauma or microtrauma.

A case of hip joint septic arthritis due to haematogenous infection, which was misdiagnosed sternoclavicular joint septic arthritis as SAPHO syndrome

Anterior chest pain associated with sternoclavicular arthritis has been considered a symptom specific to SAPHO syndrome. Differentiating aseptic arthritis of the SAPHO syndrome from infectious sternoclavicular joint (SCJ) arthritis is often difficult. We reported a 55-year-old woman with left hip joint and right SCJ pain. Diagnosis and treatment were delayed because she was misdiagnosed with SAPHO syndrome, and haematogenous infection spread to the hip joint septic arthritis. She was diagnosed promptly after presenting to our hospital and underwent early debridement, and her hip joint and SCJ was found to have almost no dysfunction. Differentiation between sternoclavicular arthritis of the SAPHO syndrome and sternoclavicular septic arthritis is clinically important and requires careful attention.

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.

Diagnostic value of ultrasonography in synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome: A case report

RATIONALE

Synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is a rare condition that affects the skin, bones, and joints. Diagnosis of SAPHO syndrome is established based on clinical manifestations and imaging features on radiography or magnetic resonance imaging.

PATIENT CONCERNS

We report a 44-year-old male with a 20-year history of pustulosis who presented with pain in the lower extremities. Plain radiography demonstrated hyperostosis with subperiosteal erosions in the right tibia. Magnetic resonance imaging and computed tomography showed inflammatory accumulation, whereas musculoskeletal ultrasonography clearly depicted a periosteal reaction, osteitis, and enthesitis with abnormal blood flow in the surface of the right tibia.

DIAGNOSES

A diagnosis of SAPHO syndrome was made.

INTERVENTIONS

The patient was treated with combination therapy comprising prednisolone, methotrexate, and infliximab, which resulted in clinical improvement.

OUTCOMES

The elevated levels of C-reactive protein and matrix metalloproteinase-3 normalized, and the abnormal ultrasonographic findings disappeared.

LESSONS

The present case report demonstrates that multiple imaging modalities are important for the definitive diagnosis of SAPHO syndrome. Ultrasonography might be a useful tool for evaluating local musculoskeletal inflammation in patients with SAPHO syndrome.