High-resolution peripheral quantitative CT imaging: Cortical porosity, poor trabecular bone microarchitecture, and low bone strength in lung transplant recipients.

Abstract

To characterize bone microarchitecture and quantify bone strength in lung transplant (LT) recipients by using high-resolution (HR) peripheral quantitative computed tomographic (CT) imaging of the ultradistal radius. After study approval by the local ethics committee, all participants provided written informed consent. Included were 118 participants (58 LT recipients [mean age, 46.8 years ± 1.9; 30 women, 28 men] and 60 control participants [mean age, 39.9 years ± 1.9; 41 women, 19 men]) between April 2010 and May 2012. HR peripheral quantitative CT of the ultradistal radius was performed and evaluated for bone mineral density and trabecular and cortical bone microarchitecture. Mechanical competence was quantified by microfinite element analysis. Differences between LT recipients and control participants were determined by using two-way factorial analysis of covariance with age adjustment. Total and trabecular bone mineral density were significantly lower (-13.4% and -16.4%, respectively; P = .001) in LT recipients than in healthy control participants. LT recipients had lower trabecular number (-9.7%; P = .004) and lower trabecular thickness (-8.1%; P = .025). Trabecular separation and trabecular network heterogeneity were higher (+24.3% and +63.9%, respectively; P = .007 and P = .012, respectively) in LT recipients. Moreover, there was pronounced cortical porosity (+31.3%; P = .035) and lower cortical thickness (-10.2%, P = .005) after LT. In addition, mechanical competence was impaired, which was reflected by low stiffness (-15.0%; P < .001), low failure force (-14.8%; P < .001), and low bone strength (-14.6%; P < .001). Men and women with recent LT showed severe deficits in cortical and trabecular bone microarchitecture. Poor bone microarchitecture and low bone strength are likely to contribute to high fracture susceptibility observed in LT recipients.