Facet joint involvement in the inflammatory rheumatic disease

The involvement of facet joints (FJ) in patients with inflammatory rheumatic disorders remains underexplored. This review aims to look at FJ disease from a rheumatologist's perspective, with the emphasis given to the clinical presentations and patterns of FJ engagement in axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), rheumatoid arthritis (RA), and crystal-related arthropathies, and discussion of challenges in studying FJ in rheumatic disease.

A systematic PubMed search using the pertinent keywords was performed, relevant articles extracted, and the acquired data critically assessed, interpreted, and organized according to the authors' experience and judgment.

FJ involvement is common in patients with radiographic axSpA, occurs throughout the spine, but is more frequently seen in the thoracic segment. The existing data suggests that the FJ are primarily affected by the disease process, while altered spine biomechanics due to the presence of syndesmophytes at the same vertebral level contributes to the FJ fusion. Predominant involvement of FJ of the cervical spinal segment has been suggested in PsA; however, prevalence and clinical significance of FJ involvement in PsA is still markedly underexplored. RA-related FJ disease of the cervical spine in patients with poorly controlled RA is not uncommon and can be related to significant morbidity, while the burden of FJ involvement in the thoracic and lumbar spinal segments in RA is also underexplored. FJ disease is possible in the course of crystal-related arthropathies, but the high level of suspicion is a prerequisite for the timely diagnosis.

The involvement of FJ in the course of inflammatory rheumatic disease is not uncommon. Prospective studies are needed to understand the epidemiology and significance of FJ disease in inflammatory rheumatic conditions.