ABSTRACT
Objective:To investigate the clinical efficacy of proximal femoral nail anti-rotation (PFNA) assisted by the "3-2-1" surface positioning method in the treatment of femoral subtrochanteric fractures.Methods:A total of 97 patients with subtrochanteric fractures admitted to the Second Hospital of Fuzhou from January 2015 to December 2020 were retrospectively analyzed. They were divided into two groups according to whether the "3-2-1" surface positioning method (3 longitudinal axes, 2 preset incisions, and 1 auxiliary incision) was used. There were 44 patients in the surface positioning group, including 25 males and 19 females, aged 61.59±18.43 years (range, 22-90 years). According to the Seinsheimer classification, there were 13 cases of type II, 11 cases of type III, 6 cases of type IV, and 14 cases of type V. The mechanism of injury was low energy injury in 26 cases and high energy injury in 18 cases. There were 53 patients in the traditional positioning group, including 30 males and 20 females, aged 56.38±17.24 years (range, 24-90 years). According to the Seinsheimer classification, there were 9 cases of type II, 22 cases of type III, 9 cases of type IV, and 13 cases of type V. According to the mechanism of injury, there were 30 cases of low energy injury and 23 cases of high energy injury. The length of incision, operation time, and blood loss were recorded. At 1, 3, 6, and 12 months after operation, the anteroposterior and lateral X-ray films of the hip were taken to evaluate the imaging indicators (neck-shaft angle, anteroposterior and lateral displacement, and angulation), fracture healing, and complications (infection, malunion, loosening and breakage of the internal fixation, and periprosthetic fracture). The Harris hip score and EuroQol five dimensions questionnaire (EQ-5D) were evaluated.Results:All patients successfully completed the operation and were followed up for 15.12±1.54 months (range, 12-18 months). The operation time, incision length, dominant blood loss and hidden blood loss in the surface positioning group were 1.78(1.50, 2.00) h, 8(8, 9) cm, 300(200, 400) ml and 843(629, 1 130) ml, respectively, which were less than 2.10(1.69, 2.38) h, 10(9, 12) cm, 400(300, 500) ml and 1 030(954, 1 266) ml in the traditional positioning group, and the difference was statistically significant ( P<0.05). The neck-shaft angle in the surface positioning group was 135.54°±2.83°, which was larger than 132.33°±3.37° in the traditional positioning group, and the difference was statistically significant ( t=5.02, P<0.001). The anterolateral and lateral displacement and lateral image angle in the surface positioning group were 4.70±1.60 cm, 4.52±1.71 cm and 9.36°±2.94°, respectively, which were lower than 6.14±2.57 cm, 5.98±2.70 cm and 11.46°±4.68° in the traditional positioning group, and the difference was statistically significant ( P<0.05). One year after operation, the Harris hip score and EQ-5D score of the surface positioning group were 92(84, 99) points and 0.90(0.73, 1.00) points, respectively, which were higher than 88(74, 96) points and 0.81(0.72, 0.94) points of the traditional positioning group ( P<0.05). Conclusion:The "3-2-1" surface positioning method assisted PFNA internal fixation in the treatment of femoral subtrochanteric fracture can improve the quality of reduction, reduce intraoperative blood loss, and improve hip function and quality of life.
ABSTRACT
Objective To investigate the biomechanical properties of our self-designed 4 cannulated screws in 4 configurations for fixation of extremely unstable femoral neck fractures.Methods Twelve adult cadaveric femoral specimens were randomly divided into 4 equal groups (n =3) and made into models of extremely unstable femoral neck fracture combined with comminution (Pauwels type Ⅲ).Group A was subjected to fixation in configuration of “double axial compressions plus double stabilizations”,group B to configuration of “positive triangle parallel compression plus small angle screwing”,group C to configuration of “inverted triangle parallel compression plus small angle screwing”,and group D to configuration of “diamond pattern screwing”.Static compression tests,cyclic loading tests and limit load tests were carried out for the 4 groups on a biomechanical testing machine.Results For groups A,B C and D,the axial compression stiffness was respectively 995.29 ±34.16 N/mm,509.89 ± 138.90 N/mm,559.28 ± 111.25 N/mm and 610.18 ±232.35 N/mm,and the limit load was respectively 3,225.33 ±461.31 N,2,008.67 ±237.27 N,2,705.67 ±496.39 N and 2,395.33 ±403.71 N,showing significant differences between the 4 groups (P ＜ 0.05).For groups A,B C and D,the displacement was respectively 0.46 ± 0.10 mm,1.47 ± 0.72 mm,1.14 ±0.24 mm and 1.22 ±0.22 mm,and the limit stiffness was respectively 1,139.28 ±342.09 N/mm,843.56 ±408.91 N/mm,585.98 ± 81.60 N/mm and 729.96 ±251.37 N/mm,showing no significant differences between the 4 groups (P ＞ 0.05).Conclusions In the fixation of extremely unstable femoral neck fracture with our self-designed 4 cannulated screws,the configuration of “double axial compressions plus double stabilizations” may lead to the greatest biomechanical advantage while the configuration of “positive triangle parallel compression plus small angle screwing” may result in the poorest biomechanical properties.