Cement augmentation of the proximal femoral nail antirotation for the treatment of two intertrochanteric fractures - a comparative finite element study

BMC Musculoskeletal Disorders

Yongze Zheng¹  Ziling Lin²  Xinmin Chen³  Jingxiong Wu⁴  Liqin Zheng⁵  Xingpeng He⁵ 

[1] Department of Orthopedic, Puning Hospital of Traditional Chinese Medicine;Department of Orthopedic, The First Affiliated Hospital of Guangzhou University of Chinese Medicine;Department of Orthopedic, Zhongxiang People’s Hospital;Department of Osteoarticular Surgery, Integrated Traditional Chinese and Western Medicine Hospital of Pengjiang District of Jiangmen City;The First Clinical Medical College, Guangzhou University of Chinese Medicine;

关键词: Bone cement augmentation;    Proximal femoral nail antirotation;    Intertrochanteric fracture;    Finite element analysis;   

DOI  :  10.1186/s12891-021-04878-2

来源: DOAJ

【 摘 要 】

Abstract Background There are concerns regarding initial stability and cutout effect in proximal femoral nail antirotation (PFNA) treating intertrochanteric fractures. No study have used finite element analysis (FEA) to investigate the biomechanics. This study aimed to compare the cutout effect, stress and displacement between stable (AO31-A1.3) and unstable (AO31-A2.2) intertrochanteric fractures treated by cement augmented PFNA. Methods Four femoral finite element models (FEMs) were constructed and tested under the maximum loading during walking. Non-augmented and augmented PFNA in two different intertrochanteric fractures were respectively simulated, assuming Tip Apex Distance (TAD) < 25 mm within each FEM. The cutout effect, stress and displacement between femur and PFNA were compared in each condition. Results Cutout effect was observed in both non-augmented femoral head and was more apparently in unstable intertrochanteric fracture model. After reinforced by bone cement, no cutout effect occurred in two models. Stress concentration were observed on medial part of intertrochanteric region and the proximal part of helical blade before augmented while were observed on femoral shaft and the conjunction between blade and nail after augmented in both FEMs. Displacement mainly appeared on femoral head and the helical blade tip before augmented while distributed moderately on intertrochanteric region and the upper part of nail after augmented in both FEMs. The maximum stress and displacement value of femur decreased both in stable and unstable model after augmented but was more significantly in the unstable one. The maximum stress and displacement value of PFNA increased both in stable and unstable model after augmented but was more significantly in the unstable one. Conclusion Our FEA study indicated that the cement augmentation of the PFNA biomechanically enhances the cutout resistance in intertrochanteric fracture, this procedure is especially efficient for the unstable intertrochanteric fracture.

【 授权许可】

Unknown