Key factors for increased tip-apex distance when treating intertrochanteric fractures with InterTAN nails

Naifeng Zhu; Lianxia Wu; Xiaofeng Han; Zhonglai Qian

doi:10.3389/fbioe.2024.1426307

Key factors for increased tip-apex distance when treating intertrochanteric fractures with InterTAN nails

Front Bioeng Biotechnol. 2024 Nov 1:12:1426307. doi: 10.3389/fbioe.2024.1426307. eCollection 2024.

Authors

Naifeng Zhu^{1

2}, Lianxia Wu³, Xiaofeng Han², Zhonglai Qian¹

Affiliations

¹ Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China.
² Department of Orthopaedics, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
³ School of Social Development, Population Research Institute, East China Normal University, Shanghai, China.

Abstract

Background: The tip-apex distance is a key factor in predicting implant cut-out after intramedullary fixation for intertrochanteric fractures. This study aimed to evaluate the factors associated with an increased tip-apex distance when treating intertrochanteric fractures using an InterTAN nail.

Methods and material: We retrospectively analyzed patients with intertrochanteric fractures who underwent InterTAN nail insertion between January 2017 and March 2022 at our hospital. Medical and radiological data were collected. Measurements of preoperative factors and postoperative factors were performed accordingly. Multivariate logistic regression analysis was performed to determine the statistically significant variables of the tip-apex distance.

Results: This study included 102 patients with intertrochanteric fractures. The average tip-apex distance measured 22.4 ± 7.1 mm, ranging from 9.3 to 48.0 mm. The length of the femoral neck on the non-fractured side, lag screw placement in the sagittal plane (center-inferior, superior) and coronal plane (posterior), and the angle between the line of the proximal nail axis and the femoral long axis were identified to be statistically significant factors for the tip-apex distance.

Conclusion: To obtain a shorter tip-apex distance, we recommend a medial trochanteric entry point to minimize the angle between the line of the proximal nail axis and the femoral long axis. Additionally, sufficiently deep central insertion of the lag screw was advised in both the sagittal and coronal planes.

Keywords: InterTAN; cut-out; implant failure; intertrochanteric fracture; tip-apex distance.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. National Natural Science Foundation (12171158), Fundamental Research Funds for the Central Universities in China (2020ECNU-HLYT048; 2022QKT001).