Parametric study of anterior percutaneous endoscopic cervical discectomy (APECD)

Abstract

Anterior percutaneous endoscopic cervical discectomy (APECD) is a common treatment for cervical spondylotic radiculopathy (CSR). In this study, the effects of various channel diameters and approach angles on cervical vertebrae on postoperative outcomes in APECD surgery were explored. A finite element model of intact cervical C₃-C₇ was constructed and then modified to obtain six surgical models. Range of motion (ROM) and intradiscal pressure (IDP) were calculated under different conditions of flexion (Fle), extension (Ext), lateral bending, and axial rotation. During Fle and bending to the left (LB), the ROM was closer to the intact model when the angle of approach was 90°. During bending to the left (LB) and rotation to the left (LR), the ROM changed considerably (43.2%, 33.7%, respectively) where the angle of approach was 45°. As the surgical channel diameter increased, the extent of the change in ROM compared with the intact model also increased. IDP decreased by 48% and 49%, respectively, compared with the intact model at the C₅-C₆ segment where the angle of approach was 45° and 60° during Fle, while it changed little at 90°, by less than 10%. The IDP was increased noticeably by 117.6%, 82.1%, and 105.8%, for channel diameters of 2, 3 and 4 mm, respectively. And declined noticeably during LB and LR (LB: 27.1%, 27.1%, 38.5%; LR: 37.4%, 35.5%, 48.7%). The results demonstrated that the shorter the surgical path, the smaller surgical diameter, the less the biomechanical influence on the cervical vertebra.

Keywords:

• Percutaneous endoscopy
• cervical discectomy
• parameterization
• biomechanics
• finite element

Acknowledgments

The authors would like to thank Chun-Jie Liu and Zi-Xuan Liu for her kind help for editing the manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was supported by the [National Natural Science Foundation of China] under Grant [No. 11602172, No. 11602063]; [Sichuan Science and Technology Program] under Grant [No. 2018SZ0035, No. 2018SZ0036]; [Tianjin Natural Science Foundation] under Grant [No. 18ZXSGSY00010, No. 18YFZCSY00890]; [Fundamental Reaearch Funds for Central Public Welfare Research Institutes] under Grant [118009001000160001]; and [Tianjin Development Program for Innovation and Entrepreneurship].

Notes on contributors

Meng-Si Sun

Meng-Si Sun is a B.E. student of the Department of Mechanical Engineering from Tianjin University of Technology.

Chen-Xi Yuchi

Chen-Xi Yuchi is a B.E. student of the Department of Mechanical Engineering from Tianjin University of Technology.

Xin-Yi Cai

Xin-Yi Cai is a B.E. student of the Department of Mechanical Engineering from Tianjin University of Technology.

Cheng-Fei Du

Cheng-Fei Du is a professor of the Department of Mechanical Engineering from Tianjin University of Technology.

Zhong-Jun Mo

Zhong-Jun Mo is a professor of the National Research Centre for Rehabilitation Technical Aids.