Abstract
Objective
To determine the reliability, reproducibility, variability and validity of the Osteoarthritis Research Society International (OARSI) Osteoarthritis Cartilage Histopathology (OACH) system and Mankin Histopathology – Histochemical Grading System (HHGS) when applied to the characterisation of the osteoarthritic human knee.
Method
Kellgren-Lawrence and Line Drawing Atlas (LDA) radiology scores clinically graded the knees of ten patients undergoing total knee arthroplasty due to osteoarthritis. The tibial plateaux were scored using the Modified Collins (MC) and Société Française d'Arthroscopie (SFA). Three observers, twice scored, using both the OACH and HHGS systems across a single complete medial and lateral tibial plateau transect taken to include the region with the most severe OA lesion. Intra and inter-observer reliability, reproducibility, variability and validity were quantified, and the correlation between the two histopathology scoring systems was calculated.
Results
We identified that both histopathology scoring systems are reliable and reproducible exhibiting similar variability, when applied to characterise OA specimens sampled from a well defined patient group with knee osteoarthritis. A strong correlation between the mean OACH and HHGS scores was identified (Spearman'sρ 0.973).
Conclusion
Both scoring systems provide useful measures in the characterisation of knee osteoarthritis. It is of note that an additional parameter within the OACH score over the HHGS that defines the extent of the disease, where the HHGS is a grade attributed to the most representative level of the biological aggression within the OA lesions. This study has confirmed the OACH system's utility in human knee OA and is supported by good correlation with the established Mankin HHGS.
