Mechanisms, impact and prevention of pathological bone regeneration in spondyloarthritis.

PURPOSE OF REVIEW: To discuss different aspects of new bone formation in patients with spondyloarthritis based on emerging data from clinical trials, prospective cohort studies and translational laboratory investigations.

RECENT FINDINGS: New bone formation potentially leading to ankylosis of the spine and sacroiliac joints remains an important concern for patients with axial spondyloarthritis. New therapeutic strategies, in particular targeting of interleukin-17, have emerged in addition to the antitumor necrosis factor drugs, but we still fail to fully understand the mechanisms of structural disease progression. A new paradigm is developing in which sustained and effective suppression of inflammation likely inhibits this structural disease progression. Biomechanical factors, in particular changes in bone microarchitecture in the vertebrae, and the need for core stability could provide a new framework to understand the relationship between bone remodeling and inflammation and to develop long-term strategies.

SUMMARY: New bone formation leading to ankylosis remains a hallmark of axial spondyloarthritis and should be further investigated. The clinical data that progressively become available support the concept that effective and sustained therapy will be beneficial for the patients not only in short-term, but also in long-term outcomes.