Comparison of phalangeal bone mineral content and density between the dominant and non-dominant sides

Compared to the non-dominant side, higher bone mineral content (BMC) and density (BMD) have been demonstrated in the forearm bones in the dominant side. Clinicians are compelled to scan the dominant side when deformities or artifacts are found in the non-dominant side. This study was done to evaluate the differences in phalangeal BMC and BMD, measured using accuDXA, between the dominant and non-dominant hands. Design and participants A group of 333 subjects, comprising 267 healthy volunteers (185 women and 82 men) and 66 women with rheumatoid arthritis. Phalangeal BMD and BMC, were measured using accuDEXA, both in the non-dominant and dominant hands. Main results BMC and BMD showed strong correlations between the two sides (r = 0.95, p < 0.001 for both). Compared to the non-dominant side, dominant side BMC was 5% higher (mean values =1.54 and 1.47, mean difference = 0.064, 95% CI for the mean difference = 0.048-0.081 g, p < 0.001) and BMD was 4% higher (mean values = 0.480 and 0.463, mean difference = 0.018, 95% CI for the mean difference = 0.014-0.021 g/cm2, p < 0.001). In the subgroup analysis, percentage differences of BMD between the two sides were found to be similar among men (n=82), women (n=251), people below 50 years (n=24), people above 50 years (n=122) and also among patients with rheumatoid arthritis (n=66). Conclusions When the non-dominant hand is not suitable for scanning, the clinician should consider scanning the dominant hand instead. However, the differences in BMD between the two hands should be taken into consideration when interpreting results.