P016 - MicroCT Analysis of Subchondral Bone Reveals Disorganized Architecture after Cartilage Damage
- R. Danilkowicz (Durham, US)
- R. Danilkowicz (Durham, US)
- N. Allen (Durham, US)
- B. Wesorick (Durham, US)
- S. Adams (Morrisville, US)
Abstract
Purpose
There are numerous treatment modalities of the ankle and knee that work to address cartilage damage. The purpose of our study is to determine the extent of damage in the subchondral bone after chondral injuries as it relates to the bony architecture to provide evidence for why certain treatment modalities may fail.
Methods and Materials
Samples were fixed in 10% formalin for 48 h then transferred to 70% ethanol. Quantitative three-dimensional evaluation of the samples was undertaken by μCT using a Viva CT 80 (Scanco, Brüttisellen, Switzerland) at 55 kVp and 145 μA with a resolution of 15.6 μm voxel size. A hydroxyapatite calibration phantom was used to scale values of linear attenuation for the calcified tissues to bone density values (mg/cm3). Calcified tissues were segmented using a thresholding procedure in which bone was defined by a threshold above 500mg HA/cm3.
Results
Of the four diseased samples, the average relative bone volume (%) was 11.86. Comparatively, the four allograft controls contained a relative bone volume (%) of 16.54. Two diseased samples did not have allograft controls for direct comparison.
Conclusion
Damaged subchondral bone is a known source of continued pain, declining results, requirement for additional procedures, and OA progression after injury. This study is the first of its kind to utilize microCT to analyze damaged osteochondral samples in an attempt to quantify the damage.