The observation of hip joint cartilage of elderly people based on EPIC Micro-CT

The objective of this study was to observe the age-related changes of sulfated glycosaminoglycan (sGAG) content and surface roughness of hip joint cartilage of elderly people based on Equilibrium Partitioning of an Ionic Contrast Agent (EPIC) Micro-CT. 35 human hip cartilage-bone samples were prepared from hip-fracture patients whose age were from 50 to 100 years old and divided into 5 groups (10 years as an age group). They were first immersed in 20% concentration of the contrast agent Meglumine Diatrizoate (MD) for 6 hours at 37°C, and scanned by Micro-CT after taken out from the contrast agent. The X-ray mean attenuation and hip joint cartilage surface roughness were calculated. The results showed the X-ray mean attenuation of the entire hip joint cartilage increased about 17.44% from the 50 age group to the 80 age group (from 1294.61±97.77HU to 1520.39±184.56HU), but it decreased about 6.43% in the 90 age group compared to the 80 age group (from 1520.39±184.56HU to 1422.55±106.37HU). Moreover, the X-ray mean attenuations of the superficial layer, middle layer and radical layer of cartilage declined successively in the different age groups. Regarding of the superficial layer and middle layer from the 50 age group to the 80 age group, they rose about 31.21 % and 43.02% respectively (from 1472.40±138.96HU to 1931.99±199.69HU and 1271.83±58.36HU to 1819.07±213.55HU), and also reduced 4.64% and 6.03% separately in the 90 age group (from 1931.99±199.69HU to 1798.12±153.32HU, and 1819.07±213.55HU to 1653.22±169.46HU), while the radical layer showed no significant change along with age increase. The hip joint cartilage surface roughness changes only 5.31% with age increase (from 13.64±5.17μm to 14.36±5.21μm).