Osteoarthritis (OA) of the hand is associated with changes in bone mass and structure, and bone strength in men, according to study results published in Journal of Bone and Mineral Research.
Using high-resolution peripheral quantitative computed tomography (HR-pQCT), the investigators of this study aimed to evaluate the effect of hand OA on bone microarchitecture and biomechanical properties.
Patients with OA (n=29; 79.3% women) and healthy control participants (n=76; 60.5% women) were enrolled as part of the Erlangen Imaging Cohort. Participants underwent HR-pQCT of the second and third metacarpophalangeal joints in the dominant hand as well as the distal radius in the same arm. Total, trabecular, and cortical volumetric bone mineral densities (vBMDs) were measured. In addition, the researchers assessed microstructural attributes and conducted microfinite element analysis to determine bone strength.
Compared with healthy control participants, patients with OA had lower trabecular vBMD (196.9±34.5 vs 162.5±37.7 mg HA/cm3; P <.001) and higher cortical vBMD values (581.0±77.2 vs 645.9±63.9 mg HA/cm3; P =.02). After adjustment, OA was independently associated with changes in the multivariate metacarpophalangeal 2 outcome matrix (P <.001). Total, trabecular, and cortical vBMD in the distal radius were also numerically lower in patients with hand OA compared with healthy control participants; however, regression analysis did not reveal a significant effect of OA (P =.47).
Researchers noted that differences in the multivariate outcome matrix for the distal radius could be explained by differences in sex and age of the populations (P <.001 for both); significant study group-gender interaction were observed (P =.044), which was primarily driven by a reduced trabecular vBMD in men (P =.02). Similarly, mean values of stiffness and failure load were lower in the radius of patients with OA compared with healthy control participants, which was not explained by an association with OA. However, a difference in failure load was observed between men with OA and healthy men (mean difference, -514 N; 95% CI, -1084 to -9 N; P =.05) after adjusting for functional status.
Researchers noted that the small number of men included in their OA patient group represented a limitation of the study, and that gender interactions should be confirmed in a larger cohort.
“[Hand] OA is associated with reduced trabecular and increased cortical vBMD in the [metacarpophalangeal] 2 head and a reduction in radial trabecular vBMD and bone strength in [men],” the researchers concluded. “The findings of very substantial deficits in trabecular bone and bone strength could have a possible impact on the assessment of fracture risk…in clinical routine.”
Simon D, Tascilar K, Unbehend S, et al. Bone mass, bone microstructure and biomechanics in patients with hand osteoarthritis [published online May 12, 2020]. J Bone Miner Res. doi:10.1002/jbmr.4046