“…Among clinical studies utilizing PENG block ( n = 29), most are low-quality case reports/series [ 1 , 2 , 3 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ], but one cohort study [ 59 ] and eight randomized controlled trials [ 4 , 5 , 60 , 61 , 62 , 63 , 64 , 65 ] appeared in the literature after late 2020. Definite post-procedural quadriceps weakness after PENG block was reported in two case reports [ 2 , 3 ] and two RCTs [ 4 , 5 ] (group A).…”