TELD with limited foraminoplasty has potential biomechanical advantages over TELD with large annuloplasty: an in-silico study

• Main Authors: Jingchi Li, Chen Xu, Xiaoyu Zhang, Zhipeng Xi, Mengnan Liu, Zhongxin Fang, Nan Wang, Lin Xie, Yueming Song
• Format: Article
• Language: English
• Published: BMC 2021-07-01
• Series: BMC Musculoskeletal Disorders
• Subjects: Biomechanical deterioration; Transforaminal endoscopic lumbar discectomy; Endoscopic dynamic drill; Facetectomy; Iatrogenic annulus injury
• Online Access: https://doi.org/10.1186/s12891-021-04504-1

Abstract Background Facetectomy, an important procedure in the in–out and out–in techniques of transforaminal endoscopic lumbar discectomy (TELD), is related to the deterioration of the postoperative biomechanical environment and poor prognosis. Facetectomy may be avoided in TELD with large annuloplasty, but iatrogenic injury of the annulus and a high grade of nucleotomy have been reported as risk factors influencing poor prognosis. These risk factors may be alleviated in TELD with limited foraminoplasty, and the grade of facetectomy in this surgery can be reduced by using an endoscopic dynamic drill. Methods An intact lumbo-sacral finite element (FE) model and the corresponding model with adjacent segment degeneration were constructed and validated to evaluate the risk of biomechanical deterioration and related postoperative complications of TELD with large annuloplasty and TELD with limited foraminoplasty. Changes in various biomechanical indicators were then computed to evaluate the risk of postoperative complications in the surgical segment. Results Compared with the intact FE models, the model of TELD with limited foraminoplasty demonstrated slight biomechanical deterioration, whereas the model of TELD with large annuloplasty revealed obvious biomechanical deterioration. Degenerative changes in adjacent segments magnified, rather than altered, the overall trends of biomechanical change. Conclusions TELD with limited foraminoplasty presents potential biomechanical advantages over TELD with large annuloplasty. Iatrogenic injury of the annulus and a high grade of nucleotomy are risk factors for postoperative biomechanical deterioration and complications of the surgical segment.