Table 5.

Summary of key changes reported in the articular cartilage across the four different animal models over time.

Time Point	ACLT	Meniscectomy	Combination	Impact
Early	Higher occurrence of degradation in medial hemijoint	Greater damage observed in medial hemijoint accompanied by a decrease in GAG coverage	Damage to superficial layer of tissue in both hemijoints	Surface damage observed in tissue along with a decrease in GAG coverage and mechanical properties
Mid-Early	Significant morphological, mechanical and histological changes in medial hemijoint	Degeneration of tissue integrity in medial hemijoint	Equal damage to both hemijoints, significant decrease in mechanical properties in lateral hemijoint medial hemijoint	Increase in tissue permeability and decrease in GAG content
Mid-Late	Continued degradation of tissue integrity, mechanical properties and GAG content in medial hemijoint	Continued damage and loss of GAG in medial hemijoint	Continued tissue degeneration across both hemijoints and decrease in mechanical properties in lateral hemijoint	Damage to tissue accompanied by an increase in permeability and loss of GAG coverage
Late	Further degradation of all three parameters in medial hemijoint. Significant morphological changes observed in lateral hemijoint	Damage observed across both hemijoints, with greater loss of tissue integrity from tissue previously covered by the meniscus.	Further degeneration across both hemijoints, decrease in mechanical properties in lateral hemijoint and loss of GAG coverage in both hemijoints	Further tissue degradation accompanied by decrease in modulus and an increase in permeability as well as loss of GAG content