UC San Diego
Quantitative polarized light microscopy analysis of medial femoral condyles from rabbits that underwent anterior cruciate ligament transection
- Author(s): Goldberg, Iliya
- Goldberg, Iliya
- et al.
Osteoarthritis (OA) is a disease characterized by the gradual degeneration of articular cartilage, however the onset and early progression of OA are difficult to predict and diagnose. Abnormal joint movements and laxity as a result of an anterior cruciate ligament (ACL) tears have been determined as a major cause of posttraumatic OA in the knee. This thesis aims to further understanding the early structural, cellular and matrix alterations that occur after trauma to the ACL Rabbits that underwent ACL transections (ACLT) were sacrificed four weeks after surgery and their knees harvested. Selected sagittal knee sections were chosen from regions most prone to cartilage degeneration as determined by images of india ink retention and previous ACLT studies. The three quantitative polarized light microscopy (qPLM) parameters include parallelism index (PI), which corresponds to the local anisotropy of the collagen fibers, [alpha], which corresponds to the group-averaged orientation of the fibers, and I⁻, the optical retardance based on the birefringence signal from the collagen. qPLM parameters and standard histochemistry were used to characterize the cartilage zones, based on the collagen network organization, in the non-operated samples and compared to the ACLT knees. Higher qPLM weighted scores, based on zonal area, a greater number of chondrocyte clusters and clones, a reduction in proteoglycan content in superficial and middle zone, and an increase in surface irregularities were noted when comparing the non-operated controls to the ACLT knees. Lastly, correlations between the overall qPLM area-weighted score and deep zone subscores with proteoglycan content were determined