Failure analysis in proximal femoral nail antirotation fixation for intertrochanteric fractures
10.3760/cma.j.cn115530-20200808-00511
- VernacularTitle:股骨近端防旋髓内钉固定治疗股骨转子间骨折的失效原因分析
- Author:
Xiaotao ZHAO
;
Dianying ZHANG
;
Kai YU
;
Xiaomeng ZHANG
- From:
Chinese Journal of Orthopaedic Trauma
2021;23(3):202-208
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the causes and risk factors for failure of internal fixation with proximal femoral nail antirotation (PFNA) in the treatment of femoral intertrochanteric fractures.Methods:A retrospective analysis was conducted of the 568 patients with femoral intertrochanteric fracture who had been treated with PFNA fixation at Department of Orthopaedic Surgery, The Fifth Central Hospital of Tianjin from March 2013 to March 2018. They were 348 males and 220 females, aged from 44 to 93 years (average, 74.6 years). According to the fracture stability classification, the patients were divided into a stable group of 424 cases and an unstable group of 144 cases. According to the AO classification, the stable group had type 31-A1 and type 31-A2.1 while the unstable group type 31-A2.2, type 31-A2.3 and type 31-A3. The 2 groups were compared in terms of reduction quality, rate of internal fixation failure, and function of the affected hip. Single factor and multi-factor binary logistic regression analyses were conducted to determine the risk factors responsible for failure of PFNA fixation of femoral intertrochanteric fracture.Results:There were no significant differences in the preoperative general data between the 2 groups, showing comparability between groups ( P> 0.05). Internal fixation failure occurred in 19 cases, which was caused by spiral blade withdrawal in 13 cases, femoral neck shortening in 17 cases, hip varus in 14 cases, and spiral blade cut-out in 14 cases. The failure rate for the stable group was 1.2% (5/424), significantly lower than that for the unstable group [9.7%,(14/144)] ( P<0.05). The Harris hip score at the last follow-up for the stable group [98(95,100)] was significantly higher than that for the unstable group [84 (82, 87)] ( P<0.05). There was no significant difference in reduction quality between the 2 groups ( P>0.05). The multivariate analysis showed that osteoporosis ( OR=7.283, 95% CI: 1.626 to 32.623, P=0.009) and unstable fracture ( OR=11.607, 95% CI: 4.039 to 33.355, P<0.001) were risk factors responsible for the failure of PFNA fixation of femoral intertrochanteric fracture. Conclusions:PFNA fixation for unstable intertrochanteric fracture can lead to a high failure rate. It forms a lever like structure so that the main stress is shifted to the internal fixation. Its lever fulcrum is located at the angle of intramedullary fixation so that a long arm forms at the load-bearing side, leading to a high failure rate. The weight-free time should be longer for patients with osteoporosis and unstable fracture after operation.
