Background/Purpose:

Primary hand osteoarthritis (HOA) is a heterogeneous disease, with erosive and osteoproliferative changes of the finger joints. [1] Due to the lack of treatment options, HOA patients suffer from progressive functional impairment of the affected joints, which is associated with pain. Despite these severe functional changes, the impact of HOA on bone microstructure and biomechanics of the affected limb remains poorly investigated. Therefore we aimed to assess bone microstructure and biomechanical properties in HOA patients.

Methods:

HOA patients fulfilled the 1990 American College of Rheumatology criteria for the classification of hand osteoarthritis [2]. For comparison, sex- and age-matched healthy controls (HC), free of present or past signs of rheumatic diseases, osteoporosis, diabetes mellitus, renal or hepatic disease were analyzed. All participants received a high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT 1, Scanco, Switzerland) scan of the distal radius. Volumetric bone mineral density (vBMD) parameters such as total vBMD, trabecular vBMD, cortical vBMD (in mg HA/cm³) as well as micro-finite element analysis (µFEA) parameters such as stiffness (kN/mm) and failure load (N) were determined.

Results:

105 subjects were included (76 HC/29 HOA). Mean age was 55.6±13.3 (HC) and 60.5±66.9 years respectively (HOA), while 31 HC and 6 HOA were male. HOA patients revealed significantly decreased trabecular vBMD compared to HC (139±35 vs. 159±38, p=0.026), while cortical vBMD was comparable between HOA and HC. Microstructural parameters such as trabecular number (1.9±0.3 vs. 2.0±0.3 1/mm, p=0.027) or cortical thickness (0.06±0.01 vs. 0.07±0.01 mm, p=0.035) were significantly reduced in HOA. Regarding biomechanical bone properties HOA patients showed a significantly lower stiffness and failure load compared with HC (stiffness: 36.2±10.2 vs. 45.3±14.7, p=0.010; failure load: 1770±452 vs. 2164±679, p=0.009).

Conclusion:

This study shows that HOA affects bone microstructure and biomechanical properties of the affected limb. Impaired mobility might be an explanation for this strong reduction of biomechanical properties and trabecular bone density. These results underline the clinical importance of HOA-related functional impairment and suggest that HOA patients need to receive awareness for increased risk of fractures and anti-osteoporotic Treatment

1. Kloppenburg, M. and W.Y. Kwok, Hand osteoarthritis–a heterogeneous disorder. Nat Rev Rheumatol, 2011. 8(1): p. 22-31.

2. Altman, R., et al., The American College of Rheumatology criteria for the classification and reporting of osteoarthritis of the hand. Arthritis Rheum, 1990. 33(11): p. 1601-10.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-influence-of-hand-osteoarthritis-on-bone-microstructure-and-biomechanical-properties-of-radial-bone/