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

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jingchi Li ◽  
Chen Xu ◽  
Xiaoyu Zhang ◽  
Zhipeng Xi ◽  
Mengnan Liu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Postoperative Complications ◽  
Poor Prognosis ◽  
Adjacent Segment Degeneration ◽  
Iatrogenic Injury ◽  
Adjacent Segment ◽  
Fe Model ◽  
High Grade ◽  
Endoscopic Lumbar Discectomy ◽  
Adjacent Segments

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.

scholarly journals TESSYS Technique With Small Grade of Facetectomy Has Potential Biomechanical Advantages Compared to the In-Out TED With Intact Articular Process : An In-Silico Study

2021 ◽  
Author(s):  
Jingchi Li ◽  
Chen Xu ◽  
Xiaoyu Zhang ◽  
Zhipeng Xi ◽  
Mengnan Liu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Postoperative Complications ◽  
Poor Prognosis ◽  
Degenerative Change ◽  
Element Model ◽  
Iatrogenic Injury ◽  
Articular Process ◽  
Endoscopic Discectomy ◽  
In Silico Study ◽  
Adjacent Segments

Abstract Background: The facetectomy was reported as an important procedure in both in-out and out-in (i.e. transforaminal endoscopic spine system (TESSYS)) techniques in the transforaminal endoscopic discectomy (TED), and which was also related to the deterioration of postoperative biomechanical environment and related poor prognosis. Recently, the facetectomy was reported to be avoided in the modified in-out TED, but iatrogenic injury of annulus and related larger grades of nucleotomy can also be seen as risk factors for the prognosis deterioration. Meanwhile, above mentioned risk factors can be alleviated in TESSYS TED, and the grade of facetectomy can also be reduced in this surgery with the use of endoscopic dynamic drill. Methods: To evaluate the risk of biomechanical deterioration and related postoperative complications of these two surgical modified strategies in TED, an intact lumbo-sacral finite element model and the corresponding model with adjacent segments degeneration have been constructed and validated, modified in-out and TESSYS TED have been simulated in these models. Then, the change of biomechanical indicators have been computed to evaluate the risk of postoperative complications in the surgical segement. Results: Compared with intact FEA models, the tendency of biomechanical deterioration in TESSYS TED models was generally slight. By contrast, obvious biomechanical deterioration can be observed in models with modified in-out TED. The degenerative change in adjacent segments magnifies rather than alters the overall tendency of biomechanical change. Conclusions: Modified TESSYS TED with a small grade of facetectomy has potential biomechanical advantages compared with the in-out TED with intact articular process (i.e. without facetectomy). The iatrogenic injury of annulus and larger grade of nucleotomy can be seen as risk factors for postoperative biomechanical deteriorations and complications in the surgical segment.

A Computational Biomechanical Investigation of Posterior Dynamic Instrumentation: Combination of Dynamic Rod and Hinged (Dynamic) Screw

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Deniz U. Erbulut ◽  
Ali Kiapour ◽  
Tunc Oktenoglu ◽  
Ali F. Ozer ◽  
Vijay K. Goel
Keyword(s):  
Peak Stress ◽  
Adjacent Segment Degeneration ◽  
Dynamic Stabilization ◽  
Adjacent Segment ◽  
Fe Model ◽  
Rigid Fixation ◽  
Segmental Motion ◽  
Rigid Rod ◽  
Adjacent Segments

Currently, rigid fixation systems are the gold standard for degenerative disk disease treatment. Dynamic fixation systems have been proposed as alternatives for the treatment of a variety of spinal disorders. These systems address the main drawbacks of traditional rigid fixation systems, such as adjacent segment degeneration and instrumentation failure. Pedicle-screw-based dynamic stabilization (PDS) is one type of these alternative systems. The aim of this study was to simulate the biomechanical effect of a novel posterior dynamic stabilization system, which is comprised of dynamic (hinged) screws interconnected with a coiled, spring-based dynamic rod (DSDR), and compare it to semirigid (DSRR and RSRR) and rigid stabilization (RSRR) systems. A validated finite element (FE) model of L1-S1 was used to quantify the biomechanical parameters of the spine, such as range of motion, intradiskal pressure, stresses and facet loads after single-level instrumentation with different posterior stabilization systems. The results obtained from in vitro experimental intact and instrumented spines were used to validate the FE model, and the validated model was then used to compare the biomechanical effects of different fixation and stabilization constructs with intact under a hybrid loading protocol. The segmental motion at L4–L5 increased by 9.5% and 16.3% in flexion and left rotation, respectively, in DSDR with respect to the intact spine, whereas it was reduced by 6.4% and 10.9% in extension and left-bending loads, respectively. After instrumentation-induced intradiskal pressure at adjacent segments, L3-L4 and L5-S1 became less than the intact in dynamic rod constructs (DSDR and RSDR) except in the RSDR model in extension where the motion was higher than intact by 9.7% at L3-L4 and 11.3% at L5-S1. The facet loads were insignificant, not exceeding 12N in any of the instrumented cases in flexion. In extension, the facet load in DSDR case was similar to that in intact spine. The dynamic rod constructions (DSDR and RSDR) led to a lesser peak stress at screws compared with rigid rod constructions (DSRR and RSRR) in all loading cases. A dynamic construct consisting of a dynamic rod and a dynamic screw did protect the adjacent level from excessive motion.

scholarly journals Biomechanical Evaluation of Different Surgical Approaches for the Treatment of Adjacent Segment Diseases After Primary Anterior Cervical Discectomy and Fusion: A Finite Element Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Wencan Ke ◽  
Chao Chen ◽  
Bingjin Wang ◽  
Wenbin Hua ◽  
Saideng Lu ◽  
...  
Keyword(s):  
Finite Element ◽  
Revision Surgery ◽  
Anterior Cervical Discectomy ◽  
Surgical Approaches ◽  
Adjacent Segment ◽  
Fe Model ◽  
Element Analysis ◽  
Cervical Discectomy ◽  
Computed Tomography Images ◽  
Adjacent Segments

Symptomatic adjacent segment disease (ASD) is a common challenge after anterior cervical discectomy and fusion (ACDF). The objective of this study was to compare the biomechanical effects of a second ACDF and laminoplasty for the treatment of ASD after primary ACDF. We developed a finite element (FE) model of the C2-T1 based on computed tomography images. The FE models of revision surgeries of ACDF and laminoplasty were simulated to treat one-level and two-level ASD after primary ACDF. The range of motion (ROM) and intradiscal pressure (IDP) of the adjacent segments, and stress in the cord were analyzed to investigate the biomechanical effects of the second ACDF and laminoplasty. The results indicated that revision surgery of one-level ACDF increased the ROM and IDP at the C2–C3 segment, whereas two-level ACDF significantly increased the ROM and IDP at the C2–C3 and C7-T1 segments. Furthermore, no significant changes in the ROM and IDP of the laminoplasty models were observed. The stress in the cord of the re-laminoplasty model decreased to some extent, which was higher than that of the re-ACDF model. In conclusion, both ACDF and laminoplasty can relieve the high level of stress in the spinal cord caused by ASD after primary ACDF, whereas ACDF can achieve better decompression effect. Revision surgery of the superior ACDF or the superior and inferior ACDF after the primary ACDF increased the ROM and IDP at the adjacent segments, which may be the reason for the high incidence of recurrent ASD after second ACDF.

Paraspinal muscle, facet joint, and disc problems: risk factors for adjacent segment degeneration after lumbar fusion

2016 ◽  
Vol 16 (7) ◽  
pp. 867-875 ◽  
Author(s):  
Jong Yeol Kim ◽  
Dal Sung Ryu ◽  
Ho Kyu Paik ◽  
Sang Soak Ahn ◽  
Moo Sung Kang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Facet Joint ◽  
Lumbar Fusion ◽  
Adjacent Segment Degeneration ◽  
Paraspinal Muscle ◽  
Adjacent Segment

Surgical complications of posterior lumbar interbody fusion with total facetectomy in 251 patients

2006 ◽  
Vol 4 (4) ◽  
pp. 304-309 ◽  
Author(s):  
Shinya Okuda ◽  
Akira Miyauchi ◽  
Takenori Oda ◽  
Takamitsu Haku ◽  
Tomio Yamamoto ◽  
...  
Keyword(s):  
Postoperative Complications ◽  
Surgical Complications ◽  
Interbody Fusion ◽  
Intraoperative Complications ◽  
Posterior Lumbar Interbody Fusion ◽  
Clinical Results ◽  
Neurological Complications ◽  
Adjacent Segment Degeneration ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion

Object Previous studies of surgical complications associated with posterior lumbar interbody fusion (PLIF) are of limited value due to intrastudy variation in instrumentation and fusion techniques. The purpose of the present study was to examine rates of intraoperative and postoperative complications of PLIF using a large number of cases with uniform instrumentation and a uniform fusion technique. Methods The authors reviewed the hospital records of 251 patients who underwent PLIF for degenerative lumbar disorders between 1996 and 2002 and who could be followed for at least 2 years. Intraoperative, early postoperative, and late postoperative complications were investigated. Intraoperative complications occurred in 26 patients: dural tearing in 19 patients and pedicle screw malposition in seven patients. Intraoperative complications did not affect the postoperative clinical results. Early postoperative complications occurred in 19 patients: brain infarction occurred in one, infection in one, and neurological complications in 17. Of the 17 patients with neurological complications, nine showed severe motor loss such as foot drop; the remaining eight patients showed slight motor loss or radicular pain alone, and their symptoms improved within 6 weeks. Late postoperative complications occurred in 17 patients: hardware failure in three, nonunion in three, and adjacent-segment degeneration in 11. Postoperative progression of symptomatic adjacentsegment degeneration was defined as a condition that required additional surgery to treat neurological deterioration. Conclusions The most serious complications of PLIF were postoperative severe neurological deficits and adjacent-segment degeneration. Prevention and management of such complications are necessary to attain good long-term clinical results.

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