| Query | 
        Inclusion Criteria | 
        Criteria applied | 
        Number of articles | 
        Reference numbers of articles    meeting inclusion criteria | 
       
      
        | (1)    Waiting list VAS | 
        A:    Must report a mean VAS pain score or mean WOMAC pain score, standard    deviation, and sample size. | 
        None | 
        6 | 
        [10 - 14] | 
       
      
        | A | 
        3 | 
        [3,10,11,] | 
       
      
        | (2)  knee VAS | 
        E:    Treatment group must receive femoral nerve block, either single-injection or    continuous. | 
        None | 
        9 | 
        [15-23] | 
       
      
        | E | 
        9 | 
        [15-23] | 
       
      
        | F:    Control group must receive intravenous opioids alone. | 
        E,    F | 
        7 | 
        [15-23] | 
       
      
        | G:    Must report mean VAS pain score, standard deviation, and sample size for both    treatment and control groups. | 
        E,    F, G | 
        2 | 
        [15, 22] | 
       
      
        | (3)    Waiting list duration | 
        H:    Must report a mean duration of time spent on waiting list and standard    deviation. | 
        None | 
        8 | 
        [10, 24-30] | 
       
      
        | H | 
        3 | 
        [10, 24, 28] | 
       
      |