Both FNB groups ( 77 % ) were more likely to achieve 90 knee flexion compared with the control group ( 59 % ) ; odds ratio ( OR ) 2.3 , 95 % confidence interval ( 95 % CI ) 1.1 , 4.8 for single-injection FNB , and OR 2.3 , 95 % CI 1.1 , 4.9 for continuous FNB .