Cerebrospinal fluid leakage ( 9.7 % vs 17.2 % , OR 0.53 [ 95 % CI 0.23-1 .15 ] , p = 0.108 ) and infection ( OR 0.18 [ 95 % CI 0.01-1 .18 ] , p = 0.077 ) occurred less frequently in the study group than in the control group .