TABLE 3.

Treatment Characteristics^a

	General Study Population	Patients Requiring Revision Surgery	% of Revision Surgery With Regard to Entire Cohort	P Value
Type of surgery				.2914
ACI	1100 (41.37)	50 (4.54)	1.88
Bone marrow  stimulation	497 (18.69)	15 (3.02)	0.56
ACI with  subchondral  bone  reconstruction	195 (7.33)	6 (3.08)	0.23
Osteochondral  autograft	58 (2.18)	3 (5.17)	0.11
MACI	92 (3.46)	2 (2.17)	0.08
Defect  debridement	127 (4.78)	1 (0.79)	0.04
Multiple	211 (7.94)	3 (1.42)	0.11
Other	291 (10.94)	8 (2.75)	0.30
No. of previous knee operative procedures				.0203
None	1275 (47.95)	29 (2.27)	1.09
1 procedure	759 (28.54)	29 (3.82)	1.09
2 procedures	299 (11.24)	17 (5.69)	0.64
>2 procedures	203 (7.63)	12 (5.91)	0.45
Not reported	35 (1.32)	1 (2.86)	0.04
No. of surgeries for cartilage defect				.0749
None	1998 (75.14)	59 (2.95)	2.22
1 surgery	416 (15.64)	20 (4.81)	0.75
2 surgeries	83 (3.12)	6 (7.23)	0.23
>2 surgeries	30 (1.13)	2 (6.67)	0.08
Not reported	44 (1.65)	1 (2.27)	0.04

^aData are shown as n (%) unless otherwise indicated. ACI, autologous chondrocyte implantation; MACI, matrix-induced autologous chondrocyte implantation.