Abstract
A novel scoring system for the grading of osteoarthritis has been developed.
Scoring systems for the measurement of Osteoarthritis (OA) are essential for the understanding of the osteoarthritic process. OA is a mutifactorial degenerative joint disease affecting not only hyaline cartilage but also the surrounding tissues and particularly the subchondral bone. It as questionable as to why the articular cartilage remains the sole component used for histopathological assessment. The intimate relationship between the subchondral bone and overlying cartilage provide major difficulty in their independent measurement.
A new scoring system has been developed to incorporate the subchondral bone into the assessment process and relating it to the structure of the overlying hyaline cartilage, which together permit a more accurate description of the degree of degenerate change.
The new scoring system was developed from the analysis of 26 operative specimens from tibial plateau (TP) from patients who underwent total knee replacement (TKR). Multiple osteochondral plugs were taken from weight-bearing regions of the whole TP. The specimens were fixed and decalcified before being sectioned and stained with Masson's trichrome.
Using a standard imaging system (Photoshop) the areas of bone and hyaline cartilage were identified and measured. Further parameters 1) cartilage thickness 2) tidemark integrity, 3) surface integrity 4) cartilage morphology were measured using a numeric measurement scale.
The scoring system indicated a relationship between the area of subchondral bone and the hyaline cartilage degeneration. The overall sum of scores was also successful in distinguishing between the milder and more severe samples of OA. More comprehensive inter and intra observer variability needs to be tested in order validate the system. Quantifying changes to the subchondral bone may also serve beneficial to clinicians, as it is possible that monitoring these changes clinically could lead to early identification of OA.
