Axial Involvement in Psoriatic Arthritis: A Cross-sectional Clinical and Radiologic Studies

This study aimed to investigate spinal involvement in psoriatic arthritis (PsA) patients using clinical and radiographic methods.

A cross-sectional clinical study was conducted on 50 PsA patients diagnosed according to the CASPAR criteria. Clinical examinations and functional assessments were performed. A radiographic assessment of the spine was performed.

Out of 50 PsA patients (mean age of 45.50 ± 9.90 years), (males and females constituted 27 (54.0%) and 23 (46.0%) respectively), 76% had radiological axial involvement; (26%) with inflammatory axial pain and (50%) without inflammatory axial pain (subclinical). Three axial radiographic patterns were detected including spondylitis without sacroiliitis (15.78%), spondylitis with sacroiliitis (78.94%), and sacroiliitis without spondylitis (5.26%). In axial PsA patients, males were more affected than females (χ²=11.679, p = 0.003), with older age (H = 15.817, p < 0.001) and higher body mass index (BMI) (F = 5.145, p = 0.010), increased psoriasis duration (H = 9.826, p = 0.007) and severity (Η=25.171, p < 0.001), and more spinal movement limitations than PsA patients without axial involvement (F = 26.568, p < 0.001). Cervical involvement was higher than lumbar involvement. Axial radiographic severity assessed by the PsA Spondylitis Radiology Index was associated with increased disability as assessed by the Health assessment questionnaire (r_s = 0.533, p = 0.001) and decreased quality of life assessed by short form-36 score (r_s = -0.321, p = 0.050).

This study shows that a high percentage of PsA patients had axial involvement with a high percentage of them having asymptomatic radiological findings. The cervical spine is more frequently and severely affected than the lumbar spine. Axial PsA occurs in males more than females with characteristic older age and higher BMI, increased psoriasis duration, and more limitation of spinal mobility.