HISTOLOGIC HISTOCHEMICAL GRADING SYSTEM FOR OSTEOARTHRITIC ARTICULAR-CARTILAGE - REPRODUCIBILITY AND VALIDITY/

Objective. To evaluate the reproducibility and validity of the histolo gic/histochemical grading system (HHGS) for osteoarthritis (OA) develo ped by Mankin and coworkers. Methods. Sections of human articular cart ilage from macroscopically normal and osteoarthritic femoral heads wer e graded by the HHGS (0-14 scale) twice by 3 observers, and intra-and interobserver reproducibility was determined. Results. The exact intra -and interobserver reproducibilities ranged from 22% to 33% and from 1 3% to 25%, respectively. Intra-and interobserver variation ranged from -7 to 5, Although scores were generally higher in cartilage from oste oarthritic joints-as compared with cartilage from normal joints, the d ifference reached statistical significance for only 2 observers. Addit ionally, the average scores from all observers were within the definit ive range for OA (>5) in 30% of sections from normal joints, and in on ly 47% of sections from OA joints. Conclusion. The results indicate th at the reproducibility and the validity of the HHGS are inadequate, an d an improved histopathologic grading system for OA is needed.