Prevalence of Coxitis and its Correlation with Inflammatory Activity in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterised by intra-articular and extra-articular manifestations but very rarely with coxitis.

This study aimed to investigate the prevalence of coxitis, clinical changes, and its correlation with the parameters of inflammatory activity.

A cohort of 951 patients diagnosed with ACR/EULAR (American College of Rheumatology/European League against Rheumatism) 2010 criteria was enrolled in this prospective, observational and analytic research study. The CBC (Complete Blood Count), ESR (Erythrocyte sedimentation rate), CRP(C - reactive protein), Anti CCP (Antibodies to cyclic citrullinated peptides), X-ray examination of palms and pelvis, and the activity of the disease as measured by DAS - 28 (28 - joint disease activity score) were carried out in all subjects. Independent samples t-test was used to compare the group's characteristics, whereas Pearson correlation test was used to analyse the correlation between study variables.

Of the total number of the subjects, 730 (76.8 %) were females, whereas 221 (23.2%) were males. The average age was 51.3, y/o while the most of them were between 40 - 49 y/o (32.6%). The prevalence of coxitis was 14.2%, mostly found in males (19.46%). The echosonografic prevalence of changes was 21.45%, while the radiological changes were 16.3%; in both cases, the changes were more expressed in males. The analysis showed that inflammatory parameters were significantly higher in patients with coxitis.

Coxitis has high economic cost because it ends up with a mandatory need for a total hip joint prosthesis. Thus the results of this study can serve to plan and initiate early preventive measures.