Table 5.

Results of Z-Test Statistical Comparisons.

Variable	Time point	ACI versus microfracture	OAT versus microfracture	ACI versus OAT
Tegner	1 year	P = 0.0016, Z = 3.2 (favors ACI)	P = 0.014, Z = 2.5 (favors OAT)	NS
	2 years	NS	NS	NS
	Final follow-up	NS	NS	NS
IKDC	1 year	NS	NS	NS
	2 years	P = 0.046, Z = 2.0 (favors ACI)	NS	NS
	Final follow-up	NS	NS	NS
Lysholm	1 year	P = 0.037, Z = 2.1 (favors Mfx)	P = 0.032, Z = 2.1 (favors Mfx)	NS
	2 years	NS	NS	NS
	Final follow-up	NS	NS	NS
KOOS	1 year	NS	NA	NA
	2 years	NS	NA	NA
	Final follow-up	NA	NA	NA
SF-36	1 year	NS	NS	NS
	2 years	NS	P < 0.001, Z = 3.5 (favors OAT)	NS
	Final follow-up	NS	P < 0.001, Z = 5.6 (favors OAT)	NS
Marx	1 year	NA	NS	NA
	2 years	NA	P < 0.001, Z = 3.5 (favors OAT)	NA
	Final follow-up	NA	P < 0.001, Z = 5.6 (favors OAT)	NA

Note: ACI = autologous chondrocyte implantation; OAT = osteochondral allograft transplantation; MFx = microfracture; NS = not significant; IKDC = International Knee Documentation Committee; KOOS = Knee Injury and Osteoarthritis Outcome Score; SF-36 = Short Form-36 Quality of Life Outcome Score; NA = not available.