Sacroiliitis: A Review on Anatomy, Diagnosis, and Treatment

Sacroiliitis is an inflammation of one or both of the sacroiliac (SI) joints, most often resulting pain in the lower back that can extend down the legs. Pain arising from the SI joint can be difficult to diagnose and treat due to the intricate surrounding ligamentous structure, nerve innervation, and its role in transferring weight from the upper body to the lower limbs. SI joint dysfunction accounts for up to 25% of cases of lower back pain and has a debilitating effect on patient functionality. This review aims to provide comprehensive coverage of all aspects of SI joint pain, with a specific focus on differential diagnosis and treatment.

Current literature on SI joint pain and inflammation, other etiologies of lower back pain, and new treatment options were compiled using the databases PubMed and Cochrane and used to write this comprehensive review. There were no restrictions when conducting the literature search with regard to publication date, study language, or study type.

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. Reduction in pain following the anesthetic is considered the golden standard for diagnosis. The treatment begins with the conservative approach of physical therapy and analgesics for symptom relief. However, refractory cases often require interventional methods such as corticosteroid injections, prolotherapy, radiofrequency ablation, and even SI joint fusion surgery.

SI joint pain is a complex problem that can present with varying patterns of pain due to uncertainty regarding its innervation and its prominent surrounding structure. It is therefore especially important to obtain a thorough history and physical on top of diagnostic tests such as a diagnostic block to properly identify the source of pain. Conservative treatment options with physical therapy and analgesics should be attempted first before interventional strategies such as ablation, injections, and prolotherapy can be considered. SI joint fusion surgery is a solution to cases in which previous methods do not provide significant relief.