Background Left-handedness is less common than right-handedness. Studies suggest that approximately 10% of the world population is left-handed.
Objectives The present study is designed to assess the correlation of handedness with, ultrasound changes, of the proximal interphalangeal joints (PIP).
Methods Case control study of healthy asymptomatic left-handed volunteers (Group1) and age-matched control right-handed group (Group2). Ultrasonography (Esaote MyLab 60 machine and a 13-18 MHz linear array transducer) was performed on PIP by a rheumatologist with theoretical and practical training in musculoskeletal ultrasonography and blinded to the dominant side. For each patient, 10 joints were assessed (8 PIP and 2 IPs). In B mode, effusion was defined with the OMERACT criteria.
Results Nine left-handed volunteers and 10 right-handed controls were included: 17 men and 2 women with no history of rheumatologic or traumatic disease. The average age of group 1 was 20 years and group 2 was 27.3 years. There was no significant difference in the proportion of PIP effusion between the two groups (OR=1). There were no significantly greater changes in the dominant hand with 9 affected PIP in both hands (p=0.6). However, the PIP1 and 2 were most severely affected (p=0.01 and 0.008) in the 2 groups. There was no correlation with gender, age or professional activity.
Conclusions It is the first descriptive study of the normal PIP in left handed subject. It appears that the possible existence of a physiological effusion of the PIP of healthy subjects didn't depend on the dominant side.
Disclosure of Interest None declared