Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disease that commonly affects the small joints of the hands and feet, and results in irreversible joint damage, deformity, and functional impairment.
Hand function is an important domain of the health status of RA patients. Assessment of hand function, therefore, is an essential part in the follow-up of RA patients and in gauging their response to treatment.
Numerous measures were developed to evaluate the hand function. One widely accepted measure includes simple clinical tests: Key grip, ball grasp, pen grasp, pinch grip and grip strength.
This study aims to determine the effect of hand deformities on hand function in a sample of patients with RA.
PATIENTS AND METHODS:
A cross-sectional study was conducted on 116 randomly selected patients fulfilling the 2010 ACR/EULAR criteria for Classification of RA. Patients with other conditions that can affect the hand function were excluded.
Patients were evaluated for age, hand deformities and Disease Activity Index (DAS28). A novel score was used to combine all hand deformities into one value.
Hand function was assessed by 3 subjective tests (key grip, pen grasp and ball grasp) and 2 objective tests (pinch strength and grip strength, measured by specialized dynamometers).
Objective hand function tests (mean grip strength and mean pinch strength) had significant moderate negative correlations with the score of hand deformities (p<0.001, r=-0.459 or better), while the mean ranks of impairment of subjective hand function tests (key grip, pen grasp and ball grasp) showed significant weak positive correlations with the score of hand deformities (p=0.002 or less, r=0.283 or more).
The presence and degree of hand deformities are significantly associated with poor hand function in patients with rheumatoid arthritis.