Table 2 Evaluation of biopsy samples with a semi-quantitative four-point scoring system
Grade 0 | Grade 1 | Grade 2 | Grade 3 | |
|---|---|---|---|---|
Fiber structure | Straight, parallel, packed fibers, with slight waviness | Slight separation of fibers, increased waviness | Separation of fibers, deterioration of fibers | Complete loss of fiber structure and hyalinization |
Cellularity | < 100 cells/high-power field (HPF) | 100–199 cells/HPF | 200–299 cells/HPF | > 300 cells/HPF |
Vascularity | Vessels running parallel to the collagen fiber bundles in the septa | Slight increase in vessels, including transverse vessels in the tendon tissue | Moderate increase in vessels within the tendon tissue | Markedly increased vascularity with clusters of vessels |
Glycosaminoglycans | No alcianophilia | Slight alcianophilia between the collagen fibers | Moderate increase in alcianophilia | Markedly increased alcianophilia forming blue lakes |