What are the diagnosis and treatment options for sacroiliitis (inflammation of the sacroiliac joint)?

From the Guidelines

Sacroiliitis diagnosis should start with conventional radiography of the SI joints, and if necessary, MRI of the SI joints should be used as an alternative first imaging method, especially in young patients and those with short symptom duration, as recommended by the EULAR guidelines 1.

Diagnosis

Diagnosis of sacroiliitis typically begins with a physical examination where a healthcare provider checks for pain in the sacroiliac joints through specific maneuvers like FABER test or direct pressure.

• Imaging studies are crucial, with MRI being the gold standard as it can detect inflammation early.
• X-rays may show joint changes in advanced cases, while CT scans provide detailed bone structure.
• Blood tests for inflammatory markers (ESR, CRP) and HLA-B27 genetic testing may support diagnosis, especially when associated with conditions like ankylosing spondylitis.

Treatment

Treatment follows a stepwise approach starting with non-pharmacological measures like physical therapy and exercise to maintain joint mobility and strengthen supporting muscles.

• For pain management, NSAIDs like ibuprofen (400-800mg three times daily) or naproxen (500mg twice daily) are first-line medications.
• If these prove insufficient, corticosteroid injections directly into the sacroiliac joint can provide temporary relief, as supported by the ASAS-EULAR management recommendations 1.
• For persistent cases, especially those associated with autoimmune conditions, disease-modifying antirheumatic drugs (DMARDs) like methotrexate (15-25mg weekly) or biologics such as TNF inhibitors (adalimumab, etanercept, infliximab) may be prescribed, with consideration of the patient's CRP levels and MRI findings 1.
• In severe cases unresponsive to other treatments, radiofrequency ablation to deaden pain-transmitting nerves or, rarely, surgical fusion of the sacroiliac joint might be considered. Early diagnosis and treatment are essential to prevent chronic pain and disability, as sacroiliitis often indicates underlying inflammatory conditions that require comprehensive management.

From the Research

Diagnosis of Sacroilitis

• Sacroilitis is an inflammation of one or both of the sacroiliac (SI) joints, often resulting in pain in the lower back that can extend down the legs 2.
• The diagnosis protocol of SI joint pain arising from sacroiliitis usually begins with the presentation of lower back pain and confirmatory diagnostic testing through fluoroscopy joint block 2.
• Reduction in pain following the anesthetic is considered the golden standard for diagnosis 2.
• Imaging modalities such as radiography, magnetic resonance imaging (MRI), computed tomography (CT), single-photon emission computed tomography (SPECT)/CT, positron emission tomography (PET)/CT, and ultrasonography can be used to improve diagnostic accuracy 3.
• MRI has the ability to visualize both the inflammatory and destructive aspects of sacroiliitis and is a crucial element in the diagnosis and classification of axial spondyloarthritis (axSpA) 4.

Treatment of Sacroilitis

• The treatment of sacroilitis begins with the conservative approach of physical therapy and analgesics for symptom relief 2.
• Refractory cases often require interventional methods such as corticosteroid injections, prolotherapy, radiofrequency ablation, and even SI joint fusion surgery 2.
• Treatment options range from physical therapy and medications to invasive methods like joint injections and surgery 5.
• Future management looks promising with advanced imaging, regenerative medicine, and biologic therapies, especially for conditions like ankylosing spondylitis 5.
• Conservative treatment options with physical therapy and analgesics should be attempted first before interventional strategies such as ablation, injections, and prolotherapy can be considered 2.
• SI joint fusion surgery is a solution to cases in which previous methods do not provide significant relief 2.

Challenges in Diagnosis and Treatment

• Sacroiliitis can be difficult to distinguish from other etiologies of lower back and buttock pain due to diverse patient presentations and a lack of highly sensitive and specific diagnostic modalities 3.
• The MRI appearance of several potential differential diagnoses may resemble axSpA sacroiliitis, making diagnosis challenging 4.
• Awareness of the typical manifestations of sacroiliitis, along with recognition of its diverse presentations and cognizance of the limitations of today's imaging modalities, are critical to good clinical practice 6.