Hip Involvement Common in Axial Spondyloarthritis, Linked to Disease Severity

Hip involvement is a frequent manifestation of axial spondyloarthritis (axSpA), often associated with increased disease severity and a longer duration of illness, according to recent research. A study conducted at a rheumatology outpatient clinic in Rabat, Morocco, investigated the prevalence and characteristics of hip involvement in patients with confirmed ankylosing spondylitis.

What is Axial Spondyloarthritis?

Axial spondyloarthritis is a chronic inflammatory disease primarily affecting the spine. It can cause pain and stiffness in the back and hips. The Spondylitis Foundation provides comprehensive information on the condition.

Study Findings on Hip Involvement

Researchers analyzed data from 137 patients with ankylosing spondylitis followed between 2019 and 2023. Radiographic evidence of hip involvement – defined as hip pain linked to inflammation and supported by imaging with a Bath Ankylosing Spondylitis Radiology Hip Index (BASRI) score of at least 2 – was found in 19 patients (13.90%).

• Hip involvement was present on one side in nine patients and on both sides in ten.
• Men and patients with longer disease durations were more likely to experience hip involvement.
• A higher incidence of uveitis (eye inflammation) was observed in those with hip involvement, suggesting a connection to more severe disease features.
• The risk of hip involvement increased over time, reaching 18.6% in male patients after 10 years and 48.8% after 20 years of disease duration.

Connection to Disease Activity and Damage

Patients with hip involvement exhibited higher scores on measures of disease activity, including the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS). They also showed greater structural damage, as indicated by higher modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) values. Research published in Mediterr J Rheumatol highlights these associations.

Prevalence Compared to Other Studies

The study authors noted that the prevalence of hip involvement in their outpatient cohort was lower than rates reported in studies conducted at university hospital settings. This suggests that the setting of care may influence observed prevalence rates.

Difficult-to-Treat Spondyloarthritis in Morocco

Managing spondyloarthritis in Morocco can be challenging due to delays in diagnosis, the prevalence of active and severe disease forms, limited access to certain biologic agents, and a lack of universal social insurance coverage. A real-world study emphasizes these factors.

Key Takeaways

• Hip involvement is a common feature of axial spondyloarthritis.
• It is linked to longer disease duration and greater disease severity.
• Men and those with prolonged illness are at higher risk.
• Hip involvement may be associated with other inflammatory conditions, such as uveitis.