What is the approach to treating sacroillitis?

Approach to Sacroiliitis

Initial Treatment

Start with NSAIDs at optimal anti-inflammatory doses as first-line therapy for active sacroiliitis, and if inadequate response after 2-4 weeks, add a TNF inhibitor rather than continuing NSAID monotherapy alone. 1, 2

• NSAIDs are strongly recommended over no treatment, providing both analgesic and anti-inflammatory benefits for sacroiliac joint inflammation 1, 2
• Common NSAIDs used include indomethacin, naproxen, and diclofenac at full anti-inflammatory doses 3
• Evaluate treatment response after 2-4 weeks of optimal NSAID dosing 2

Escalation to Biologic Therapy

For patients with active sacroiliitis despite NSAIDs, adding a TNF inhibitor is strongly recommended over continued NSAID monotherapy. 1, 2

• TNF inhibitors (etanercept, adalimumab, infliximab, golimumab) have demonstrated significant benefit in controlling sacroiliac inflammation 1, 2
• This is a strong recommendation despite low-quality evidence, based on established efficacy in adult spondyloarthritis trials 1, 2
• TNFi should be added promptly rather than prolonging ineffective NSAID monotherapy 1

Alternative Second-Line Options

Sulfasalazine is conditionally recommended only for patients with contraindications to TNF inhibitors or who have failed multiple TNFi agents. 1, 2

• This recommendation is conditional based on limited efficacy demonstrated in randomized controlled trials 1
• Consider sulfasalazine for patients with class-effect adverse events to TNFi who cannot receive additional TNFi 1

Methotrexate monotherapy is strongly recommended against for treating sacroiliitis. 1, 2

• Adult spondyloarthritis data demonstrates lack of effectiveness for axial disease 1
• Methotrexate may have utility only as adjunct therapy in patients with concomitant peripheral polyarthritis or to prevent anti-drug antibodies against monoclonal TNFi 1, 2

Adjunctive Therapies

Glucocorticoids

Bridging therapy with oral glucocorticoids (<3 months) is conditionally recommended during initiation or escalation of therapy, particularly for high disease activity, limited mobility, or significant symptoms. 1, 2

• This provides rapid symptom control while waiting for DMARD or biologic effect 1, 2
• Keep duration under 3 months due to known risks of glucocorticoid use 1

Intraarticular glucocorticoid injections of the sacroiliac joints are conditionally recommended as adjunct therapy. 1, 2

• Injections should be performed under fluoroscopic guidance or CT guidance for accurate placement 3, 4
• This is particularly useful for unilateral or asymmetric sacroiliitis 4

Physical Therapy

Physical therapy is conditionally recommended for patients with sacroiliitis who have or are at risk for functional limitations. 1, 2

• PT helps maintain range of motion, strengthen periarticular muscles, and reduce stiffness 2
• Activity modification may reduce mechanical factors contributing to microtrauma and repetitive stress 1

Treatment Algorithm Summary

1. Week 0: Initiate NSAID at optimal anti-inflammatory dose 1, 2
2. Week 2-4: Assess response; if inadequate, add TNF inhibitor 2
3. Consider bridging: Short-course oral glucocorticoids (<3 months) for severe symptoms during therapy initiation 1, 2
4. If TNFi fails: Switch to alternative TNFi or consider non-TNFi biologic (though pediatric data limited) 1
5. If multiple TNFi failures or contraindications: Consider sulfasalazine 1, 2
6. Throughout: Incorporate physical therapy for functional limitations 1, 2

Critical Pitfalls to Avoid

• Do not use methotrexate monotherapy for sacroiliitis—it lacks efficacy for axial disease despite effectiveness in peripheral arthritis 1, 2
• Do not delay TNFi addition if NSAIDs are inadequate after 2-4 weeks—prompt escalation prevents joint damage 1, 2
• Do not continue prolonged oral glucocorticoids beyond 3 months due to toxicity risks 1
• Do not assume all lower back pain is sacroiliitis—diagnostic confirmation with imaging (MRI showing bone marrow edema) or fluoroscopy-guided diagnostic block is essential 4, 5