Table 3.

Clinical, arthroscopic, and histologic data

Study	Primary clinical outcome*	Secondary clinical outcome*	Arthroscopic findings†	Histologic findings	Independent observer	Additional findings
Gudas et al. [19]	HSS (p < 0.01)OAT  = 91.1 ± 4.1MFx = 80.6 ± 4.6	ICRS (p < 0.001)OAT = 89 ± 4MFx = 75 ± 4Percent return to sportOAT = 93%MFx = 52%	Percent with CRA 8–12 (p = 0.004)OAT = 79%MFx = 45%	OAT: 100% hyaline cartilageMFx: 57% fibrocartilage43% fibroelastic tissue	Yes	Patients younger than 30 years had better HSS score in both groups (p = 0.008)Patients with a traumatic defect had better HSS scores that those with osteochondritis dessicans in both groups (p = 0.004)Lesions > 2 cm2 in central medial femoral condyle had lower HSS scores in MFx group (p < 0.05) but no significant difference in OAT group
Bartlett et al. [1]	Improvement in Mod Cinn (p = 0.32)MACI = 19.6ACI-C†† = 17.5	VAS (NS)MACI = 4.1ACI-C = 4.3Stanmore (NS)MACI = 2.1ACI-C = 2.2	Percent with CRA 8–12 (p = 0.3)MACI = 66.6%ACI-C = 79.2%	Percent with hyalinelike or mixed hyaline/fibrocartilagelike (NS)MACI = 36.4%ACI-C = 42.9%	No	Patients younger than 35 years had better clinical outcome (p = 0.03)
Knutsen et al. [29]	SF-36 PC (p = 0.01)MFx = 46 ± 2ACI-P = 42 ± 2	Lysholm (NS)MFx = 75 ± 4ACI-P = 71 ± 5VAS (NS)MFx = 31 ± 4ACI-P = 35 ± 5	CRA (p = 0.17)MFx = 9.1ACI-P = 8.1	Percent with hyalinelike or mixed hyaline/fibrocartilagelike (p = 0.08)MFx = 29%ACI-P = 50%	Yes	Patients younger than 30 years (p = 0.007) and patients with Tegner scores > 4 (p = 0.0005) had better SF-36 scores in both groupsHigher SF-36 scores in MFx group associated with lesion < 4 cm2 (p = 0.003)
Visna et al. [45]	Lysholm (p = 0.001)MACI = 86 ± 9Abrasion = 74 ± 11	IKDC (p < 0.05)MACI = 76 ± 13Abrasion = 68 ± 10 Tegner (p < 0.01)MACI = 5.9 ± 0.8Abrasion = 4.2 ± 1.1	CRAMACI = 8.5Abrasion = NR	Histology on four samples revealed evidence of hyaline-like cartilage; fibroblastlike cells (in two)	No
Bentley et al. [2]	Mod Cinn > 55 (p = 0.27)ACI = 88%OAT = 69%	Medial femoral condyle lesions ONLYMod Cinn > 55 (p = 0.03)ACI = 88%OAT = 74%	Percent with CRA 8–12 (p < 0.01)ACI = 82%OAT = 34%	Percent with hyalinelike or mixed hyaline/fibrocartilagelikeACI = 74%OAT = NR	No	Seven poor results, all in OAT groupTechnique documented placing plugs slightly prominently
Horas et al. [24]	Lysholm (p < 0.05)OAT = 74 ± 6ACI-P = 67 ± 8	Tegner (NS)OAT = 5 ± 1ACI-P = 5 ± 1Meyers (NS)OAT = 17 ± 2ACI-P = 16 ± 3	No objective data	OAT patients with hyaline cartilage not integrated into surrounding cartilage; ACI-P specimens with mainly fibrocartilage, focalized areas of hyalinelike cartilage deep	No

*Values expressed as mean ± standard deviation when available; clinical outcome measures used: HSS = Hospital for Special Surgery clinical score (higher score indicates increased function); ICRS = International Cartilage Repair Society clinical score (higher score indicates increased function); Mod Cinn = Modified Cincinnati score (higher score indicates increased function); VAS = visual analog scale (higher score indicates increased pain); Stanmore score (lower score indicates increased function); SF-36 PC = SF-36 Physical Component score (higher score indicates increased function); Lysholm score (higher score indicates increased function); IKDC = International Knee Documentation Committee subjective score (higher score indicates increased function); Tegner activity score (higher score indicates increased level of activity); Meyers rating scale (higher score indicates increased function); ^†CRA = International Cartilage Repair Society cartilage repair assessment (higher score indicates more normal cartilage; 12 = normal cartilage); OAT = osteochondral autograft transplantation; MFx = microfracture; MACI = matrix-induced autologous chondrocyte implantation; ACI-C = autologous chondrocyte implantation–collagen cover; ACI-P = autologous chondrocyte implantation–periosteal cover; NS = not statistically significant; NR = not reported.