. Author manuscript; available in PMC: 2018 Feb 1.

Published in final edited form as: Knee Surg Sports Traumatol Arthrosc. 2015 Sep 26;25(2):532–537. doi: 10.1007/s00167-015-3799-x

Table 1.

Predictors of intervention for arthrofibrosis following ACL injury

	Number at risk	Hazard ratio (95% Confidence Intervals) from univariate Cox models

Age, years	1,841	0.89 (0.62, 1.25)

Women (vs. men)	1,841	2.59 (1.21, 5.82)

Calendar year (per calendar year)	1,841	0.98 (0.92, 1.04)

1990-1994	405	1 (ref)
2006-2010	419	0.90 (0.34, 2.36)

Meniscal injury	1,100	0.91 (0.43, 1.96)

ACL reconstruction	1,355	5.29 (2.01, 17.08)

BTB^* autograft (vs hamstring autograft)	1,130	1.08 (0.31,6.78)

Allograft vs autograft	1,355	0.28 (0.02,1.37)

Timing of ACL reconstruction
Non-operative	486	1 (reference)
Within 4 weeks	198	3.57 (0.86, 13.97)
After 4 weeks	1,157	6.40 (2.27, 22.63)

Bone patellar tendon bone