A new fluoroscopic view for evaluation of anteromedial cortex reduction quality during cephalomedullary nailing for intertrochanteric femur fractures: the 30\xb0 oblique tangential projection

Shi-Yi Chen,Sun-Jun Hu,Zhen Wei,Shou-Chao Du,Rujan Tuladhar,Shi-Min Chang,Wen-Feng Xiong

doi:10.1186/s12891-020-03668-6

Shi-Yi Chen, Sun-Jun Hu + Show 5 more

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https://doi.org/10.1186/s12891-020-03668-6

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Abstract

BackgroundAnteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation. This paper introduces the oblique fluoroscopic projection as a novel method to evaluate the quality of anteromedial cortical apposition.MethodsThree proximal femur specimens were marked with steel wires along five anatomic landmarks: Greater trochanter, Lesser trochanter, Intertrochanteric line, Anterolateral tubercle and the Anteromedial cortical line. After obtaining the standard femoral neck AP and lateral fluoroscopic images, the C-arm was rotated by every 5°increments until a clear tangential view of the antero-medial-inferior corner cortex was observed. 98 cases of intertrochanteric hip fractures were enrolled from April 2018 to October 2019. After fixation with the nails, the intra-operative anteromedial cortex reduction quality was evaluated from the AP, the true lateral, and the new anteromedial oblique fluoroscopic images. The fluoroscopic results were compared with the post-operative 3D-CT reconstruction images.ResultsThe specimen study showed that internal rotation of the C-arm to approximately 30 ° can remove all the obscure shadows and clearly display the antero-medial-inferior cortical tangent line. Clinically,the positive, neutral and negative apposition of different cortices via intra-operative fluoroscopic images showed79, 19 and 0 cases of medial cortical apposition in AP views; 2, 68 and 28 cases of anterior cortices in lateral views;and 22, 51 and 25cases of anteromedial cortical apposition in oblique views respectively. The post-operative 3D-CT reconstruction images revealed that the final anteromedial cortical contact was noted in 62 cases (63.3%), and lost in 36 cases (36.7%). The overall coincidence rate between intra-operative fluoroscopy and post-operative 3D-CT was 63.3% (62/98) in AP view,79.6% (78/98) in lateral view, and 86.7% (85/98) in oblique view(p < 0.001). Negative cortical apposition in oblique view was highly predictive of a final loss of cortical support on 3D CT (24/25 cases, 96%).And non-negative cortical apposition in oblique view was highly associated with true cortical support on 3D CT images (61/73 cases, 83.6%) (p < 0.001).ConclusionsBesides the AP and lateral projections, an anteromedial oblique view of 30° certifies to be a very useful means for evaluation of the fracture reduction quality of anteromedial cortical apposition.

Highlights

Anteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation
The aim of this study was to introduce a new method of anteromedial oblique fluoroscopic view, which can be used to judge the quality of anteromedial cortical reduction in pertrochanteric fractures, and to signify its value in clinical applications
Clinical study The evaluation of the cortical apposition observed in the intra-operative fluoroscopic images were noted to be 79 positive, 19 neutral and no negative positions in the AP view,two positive, 68 neutral and 28 negative positions in the lateral view, and 22 positive, 51neutral and25 negative positions in the oblique view respectively

Summary

Introduction

Anteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation. The quality of the fracture reduction is the first prerequisite in the treatment of pertrochanteric fracture. In 2015, Chang et al [5] firstly introduced the concept of anteromedial cortical support reduction, which allowed the head-neck fragment contact with the anteromedial cortex of the femoral shaft via limited and controlled sliding. As the reduction of the displaced lesser trochanter is difficult in the unstable 31A2 pertrochanteric fracture type, the cortex-to-cortex apposition which stands as a non-anatomic functional buttress reduction is an important element to effectively support the head-neck fragment, i.e. the anteromedial cortices of the inferior corner become the key position for the cortex-to-cortex support and fracture reduction

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