Table 1.

Summary of histological findings. ICRS II scores for patient repair tissue (italic) as well as healthy cartilage and marrow stimulation repair tissue for comparison. Some parameters could not be scored for the marrow stimulation repair tissue due to the loss of tissue architecture upon collection.

Histological parameter	Healthy cartilage biopsy score (positive control)	Marrow stimulation + chondral allograft repair tissue biopsy score	Marrow stimulation repair tissue biopsy score
Tissue morphology	100	91	56.5
Percentage
Hyaline cartilage	100	85	5
Hyaline-like cartilage	0	5	45
Fibrocartilage	0	5	40
Fibrous connective tissue	0	0	5
Bone	0	0	0
Degenerative tissue	0	5	5
Calcified cartilage	0	0	0
Total percentage	100	100	100
Matrix staining	90	85	69.9
Cell morphology	96	87.5	52.0
Chondrocyte clustering	100	30	95
Surface architecture	90	85	65
Basal integration	100	90	n/a
Formation of a tidemark	100	100	n/a
Subchondral bone abnormalities/marrow fibrosis	100	95	n/a
Inflammation	100	100	100
Abnormal calcification/ossification	100	100	100
Vascularization	100	100	80
Surface/superficial assessment	100	65	n/a
Mid/deep zone assessment	100	50	n/a
Overall assessment	98	60	n/a