Psoriatic arthritis (PsA) is associated with a distinct pattern of bone pathology, which influences the clinical picture of the disease. High-resolution computed tomography (CT) has contributed to understanding structural bone changes in PsA. Periarticular bone erosions in PsA are characterized by periosteal responses around the cortical break, distinguishing them from bone erosions in rheumatoid arthritis. Furthermore, a large number of enthesophytes can be found in CT studies of joints of PsA patients and in psoriasis patients without clinical arthritis. This latter observation supports the idea that articular changes start in psoriasis before joint disease commences. Moreover, enthesophytes are not influenced by methotrexate treatment and tumour necrosis factor inhibition. Finally, studies of systemic bone loss by high-resolution CT revealed significant alterations of the bone architecture in PsA but not in patients with skin disease only. In summary, CT has made valuable contributions in understanding the structural bone changes in PsA.
Periarticular bone structure in rheumatoid arthritis patients and healthy individuals assessed by high resolution computed tomography
