Objective:To compare the complications in young adults with femoral neck fracture after internal fixation with compression buttress screws (CBS) versus 3 parallel partially threaded cannulated screws (PTS).Methods:A prospective study was conducted of the 120 young adults with femoral neck fracture who had been treated from July 2016 to December 2017 at Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital. Of them, 60 were subjected to PTS fixation (control group) and 60 to CBS fixation (observation group) according to their will. In the control group, there were 38 males and 22 females with an age of (46.1±7.6) years, and 17 cases of types Ⅰ-Ⅱ and 43 cases of type Ⅲ by the modified Pauwels classification; in the observation group, there were 42 males and 18 females with an age of (44.8±8.1) years, and 11 cases of types Ⅰ-Ⅱ and 49 cases of type Ⅲ. The 2 groups were compared in postoperative complications. A stratified analysis was performed according to the modified Pauwels classification.Results:Comparability was indicated between the 2 groups because there was no significant difference in their baseline demographic information ( P>0.05). The incidences of fixation failure (8.3%, 5/60), nonunion (5.0%, 3/60), femoral neck shortening<10 mm(10.0%, 6/60) and lateral withdrawal (11.7%, 7/60) in the observation group were significantly lower than those in the control group [38.3% (23/60), 28.3% (17/60), 41.7% (25/60) and 71.7% (43/60), respectively] ( P<0.05). There was no significant difference in the incidence of avascular necrosis of the femoral head or of medial migration between the 2 groups ( P>0.05). The stratified analysis showed that the incidences of fixation failure and nonunion in the observation group were significantly lower than in the control group for fractures of the modified Pauwels type Ⅲ ( P<0.05). The incidences of femoral neck shortening<10 mm and fixation loosening in the control group were significantly higher than in the observation group for fractures of all the modified Pauwels types ( P<0.05). Conclusion:Compared with conventional PTS fixation, CBS fixation can significantly reduce postoperative complications in young adults with femoral neck fracture, especially those with high energy fracture of the modified Pauwels type Ⅲ.