Table 1.

Semiquantitative histomorphometric score modified by those of Svensson, Soslowsky, and Cook.

Parameter	Grade 0	Grade 1	Grade 2	Grade 3
Fiber structure, Svensson and Soslowsky scores	Normal appearance with collagen straight parallel and packed fibers, tangentially oriented with slight waviness	Mild changes with collagen fibers <25% slightly separated with increased waviness	Moderate changes with collagen fibers ≥25% and ≤50% disorganized, separated, and deteriorated	Marked changes with collagen fibers >50% structurally disorganized, and hyalinized
Cellularity (aspect), Cook scores	Inconspicuous elongated spindle nuclei with no obvious cytoplasm	Increased roundness: nucleus becomes more ovoid to round in shape without conspicuous cytoplasm	Increased roundness and size: the nucleus is round, slightly enlarged, and a small amount of cytoplasm is visible	Nucleus is round and large with abundant cytoplasm and lacuna formation
Vascularity, Svensson scores	Vessels run inconspicuous coursing 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 vessels
Cartilage formation	No cartilage formation	Isolated hyaline cartilage nodules	Moderate cartilage formation of 25–50%	Extensive cartilage formation, more than 50% of the field involved