Comparison of effectiveness of two cannulated screw configurations in the treatment of femoral neck fractures in young adults

Abstract

To investigate and analyze the effectiveness of internal fixation with the two different cannulated screw implanting methods of rhomboid and inverted triangle in the treatment of femoral neck fracture in young adults. The clinical data of 38 young adults with femoral neck fracture who met the selection criteria between January 2018 and August 2019 were retrospectively analyzed. According to the different methods of cannulated screw implanting, the patients were divided into two groups, 19 cases in each group. The trial group was treated with closed reduction and cannulated screw rhombic distribution internal fixation, while the control group was treated with closed reduction and cannulated screw inverted triangular distribution internal fixation. There was no significant differences in patients' gender, age, cause of injury, Garden classification of fracture, and time from injury to operation between the two groups ( P>0.05). The fracture healing time, the incidence of nonunion, femoral neck shortening, and femoral head necrosis were recorded and compared between the two groups; the effectiveness was evaluated by Harris score and visual analogue scale (VAS) score at last follow-up. The incisions of the two groups healed by first intention. All patients were followed up 12-24 months with an average of 15.5 months. There were 1 case of fracture nonunion and 2 cases of shortening of femoral neck in the trial group; while there were 2 cases of fracture nonunion, 1 case of necrosis of femoral head, and 6 cases of femoral neck shortening in the control group; the difference in the incidence of complications (15.8% vs. 47.4%) between the two groups was significant ( χ 2=4.385, P=0.036). The remaining 18 cases in the trial group and 17 cases in the control group all achieved osteonal union, and the healing time was (14.8±1.6) weeks and (15.9±1.3) weeks, respectively, showing no significant difference between the two groups ( t=1.265, P=0.214). At last follow-up, Harris score and VAS score of the trial group were 88.9±4.3 and 1.1±0.7, respectively, while those of the control group were 86.9±5.9 and 1.3±0.9, respectively, showing no significant difference ( t=0.603, P=0.550; t=1.152, P=0.257). Hip function was evaluated in accordance with Harris score, the results were excellent in 12 cases, good in 6 cases, and fair in 1 case in the trial group, the excellent and good rate was 94.74%; the results were excellent in 10 cases, good in 7 cases, and fair in 2 cases in the control group, the excellent and good rate was 89.47%; there was no significant difference in the excellent and good rate between the two groups ( χ 2=0.368, P=0.544). The short-term effectiveness of the two kinds of cannulated screw implanting methods is clear, rhomboid fixation of 4 screws has strong stability with stress distribution, which can effectively reduce the incidence of femoral neck shortening, fracture nonunion, femoral head necrosis, and other complications.