scholarly journals Biomechanical Comparison of a New Memory Compression Alloy Plate versus Traditional Titanium Plate for Anterior Cervical Discectomy and Fusion: A Finite Element Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jiantao Liu ◽  
Runqing Wang ◽  
Hongbo Wang ◽  
Yanbiao Wang ◽  
Dongbo Lv ◽  
...  
Keyword(s):  
Finite Element ◽  
Anterior Cervical Discectomy ◽  
Plate Versus ◽  
Segmental Motion ◽  
Titanium Plate ◽  
Alloy Plate ◽  
Cervical Discectomy ◽  
Memory Compression ◽  
Flexion Extension ◽  
The Impact

Objective. To compare the biomechanical properties of a new memory compression alloy plate and traditional titanium plate after anterior cervical discectomy and fusion (ACDF). Methods. A finite element model of the C3-7 segments was developed and validated. The C5-6 disc was removed, and an intervertebral cage made of peek material was implanted. Then, a new memory compression alloy plate composed of Ti-Ni memory alloy and a traditional titanium plate were integrated at the C5-6 segment. All models were subjected to a load of 73.6 N to simulate the head weight and 1 Nm of flexion-extension, lateral bending, and axial rotation. The range of segmental motion (ROM) and stress on the prostheses, adjacent discs, and endplates were analyzed. Results. Compared with intact status, ACDF with the new prothesis and traditional titanium plate reduced the ROM of C5-6 in six directions by 95.2%-100% and increased that of adjacent discs (C4-5 and C6-7) by 4.8%-112.5%. Adjacent disc stress peaks were higher for the traditional titanium plate (0.7-4.2 MPa) than for the new prosthesis (0.6-4.1 MPa). Endplate stress peaks were the highest in ACDF with the new prosthesis (15.6-53.3 MPa), followed by ACDF with traditional titanium plate (5.0-29.4 MPa). Stress peaks were significantly lower for the new prothesis (12.8-52.3 MPa) than for the traditional titanium plate (397.0-666.1 MPa). Conclusions. The new prosthesis improved the immediate stability of the surgical site and had an elastic modulus that was smaller than that of traditional titanium plate, making it conducive to reducing stress shielding and the impact on the adjacent intervertebral disc.

scholarly journals Biomechanical Effect of Plate-to-Disc Distance on Surgical and Adjacent Segment in C5/C6 Anterior Cervical Discectomy and Fusion - A Finite Element Analysis

2020 ◽  
Author(s):  
Yuan Xue ◽  
Xing Guo ◽  
Jiaming Zhou ◽  
Yueyang Tian ◽  
Liang Kang
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Bone Graft ◽  
Anterior Cervical Discectomy ◽  
Von Mises Stress ◽  
Adjacent Segment ◽  
Titanium Plate ◽  
Cervical Discectomy ◽  
Cage Subsidence ◽  
Biomechanical Effect

Abstract Background: The PDD is an important factor affecting the degeneration of adjacent segments after ACDF. However, the most suitable PDD is controversial. This study examined the adjacent intervertebral disc stress, bone graft stress, titanium plate stress and screw stress to evaluate the biomechanical effect of different Plate-to-Disc Distance (PDD) on surgical segment and adjacent segment following C5/C6 anterior cervical discectomy and fusion (ACDF). Methods: We constructed 10 preoperative finite element models (FEM) of intact C4–C7 segments and validated them in the present study. We simulated ACDF surgery based on the 10 intact models in software. We designed three different distance of Plate-to-Disc titanium plates: L, long PDD (10 mm); S, short PDD (0 mm); and N, PDD (5 mm). The changes in C4/C5 and C6/C7 intervertebral disc stress, bone graft stress, titanium plate stress and screw stress were analyzed.Results: The von Mises stress of C4/C5 and C6/C7 intervertebral discs have no significant differences (P>0.05) in three different PDD groups. Titanium plate stress increased as the PDD decreased. The bone graft stress and screws stress decreased as the PDD decreased. The maximum stress of each part occurred was mostly in the conditions of rotation and lateral bending. Conclusions: The PDD has no effect on adjacent intervertebral disc stress, but it is an important factor that affecting the bone graft stress, titanium plate stress and screws stress after ACDF. Shorter PDD plate can provide better stability to reduce stress on screws and bone graft, that may be helpful to prevent cage subsidence, pseudarthrosis and instrument failure. This can serve as a reference for clinical choice of plate.

scholarly journals Biomechanical effect of different plate-to-disc distance on surgical and adjacent segment in anterior cervical discectomy and fusion - a finite element analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xing Guo ◽  
Jiaming Zhou ◽  
Yueyang Tian ◽  
Liang Kang ◽  
Yuan Xue
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Bone Graft ◽  
Anterior Cervical Discectomy ◽  
Von Mises Stress ◽  
Adjacent Segment ◽  
Titanium Plate ◽  
Cervical Discectomy ◽  
Cage Subsidence ◽  
Biomechanical Effect

Abstract Background The plate-to-disc distance (PDD) is an important factor affecting the degeneration of adjacent segments after anterior cervical discectomy and fusion (ACDF). However, the most suitable PDD is controversial. This study examined the adjacent intervertebral disc stress, bone graft stress, titanium plate stress and screw stress to evaluate the biomechanical effect of different PDD on surgical segment and adjacent segment following C5/C6 ACDF. Methods We constructed 10 preoperative finite element models of intact C4–C7 segments and validated them in the present study. We simulated ACDF surgery based on the 10 intact models in software. We designed three different distance of plate-to-disc titanium plates: long PDD (10 mm), medium PDD (5 mm) and short PDD (0 mm). The changes in C4/C5 and C6/C7 intervertebral disc stress, bone graft stress, titanium plate stress and screw stress were analyzed. Results The von Mises stress of C4/C5 and C6/C7 intervertebral discs had no significant differences (P > 0.05) in three different PDD groups. Titanium plate stress increased as the PDD decreased. The bone graft stress and screws stress decreased as the PDD decreased. The maximum stress of each part occurred was mostly in the conditions of rotation and lateral bending. Conclusions The PDD has no effect on adjacent intervertebral disc stress, but it is an important factor that affecting the bone graft stress, titanium plate stress and screws stress after ACDF. Shorter PDD plate can provide better stability to reduce stress on screws and bone graft, which may be helpful to prevent cage subsidence, pseudarthrosis and instrument failure. This can serve as a reference for clinical choice of plate.

Nonunion Rates After Anterior Cervical Discectomy and Fusion: Comparison of Polyetheretherketone vs Structural Allograft Implants

Neurosurgery ◽  
2021 ◽  
Author(s):  
Won Hyung A Ryu ◽  
Dominick Richards ◽  
Mena G Kerolus ◽  
Adewale A Bakare ◽  
Ryan Khanna ◽  
...  
Keyword(s):  
Smoking Status ◽  
Posterior Instrumentation ◽  
Patient Reported Outcome ◽  
Anterior Cervical Discectomy ◽  
Successful Outcome ◽  
Cervical Discectomy ◽  
Structural Allograft ◽  
Modifiable Factors ◽  
Patient Reported ◽  
The Impact

Abstract BACKGROUND Although advances in implant materials, such as polyetheretherketone (PEEK), have been developed aimed to improve outcome after anterior cervical discectomy and fusion (ACDF), it is essential to confirm whether these changes translate into clinically important sustained benefits. OBJECTIVE To compare the radiographic and clinical outcomes of patients undergoing up to 3-level ACDF with PEEK vs structural allograft implants. METHODS In this cohort study, radiographic and symptomatic nonunion rates were compared in consecutive patients who underwent 1 to 3 level ACDF with allograft or PEEK implant. Prospectively collected clinical data and patient-reported outcome (PRO) scores were compared between the allograft and PEEK groups. Regression analysis was performed to determine the predictors of nonunion. RESULTS In total, 194 of 404 patients met the inclusion criteria (79% allograft vs 21% PEEK). Preoperative demographic variables were comparable between the 2 groups except for age. The rate of radiographic nonunion was higher with PEEK implants (39% vs 27%, P = .0035). However, a higher proportion of nonunion in the allograft cohort required posterior instrumentation (14% vs 3%, P = .039). Patients with multilevel procedures and PEEK implants had up to 5.8 times the risk of radiographic nonunion, whereas younger patients, active smokers, and multilevel procedures were at higher risk of symptomatic nonunion. CONCLUSION Along with implant material, factors such as younger age, active smoking status, and the number of operated levels were independent predictors of fusion failure. Given the impact of nonunion on PRO, perioperative optimization of modifiable factors and surgical planning are essential to ensure a successful outcome.

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.

scholarly journals Impact of local steroid application on dysphagia following an anterior cervical discectomy and fusion: results of a prospective, randomized single-blind trial

2018 ◽  
Vol 29 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Brittany E. Haws ◽  
Benjamin Khechen ◽  
Ankur S. Narain ◽  
Fady Y. Hijji ◽  
Daniel D. Bohl ◽  
...  
Keyword(s):  
Controlled Trial ◽  
Anterior Cervical Discectomy ◽  
Retropharyngeal Abscess ◽  
Cervical Discectomy ◽  
Air Index ◽  
Estimated Blood Loss ◽  
Patient Reported ◽  
Chi Square Analysis ◽  
The Impact ◽  
Single Blind

OBJECTIVEIntraoperative local steroid application has been theorized to reduce swelling and improve swallowing in the immediate period following anterior cervical discectomy and fusion (ACDF). Therefore, the purpose of this study was to quantify the impact of intraoperative local steroid application on patient-reported swallow function and swelling after ACDF.METHODSA prospective, randomized single-blind controlled trial was conducted. A priori power analysis determined that 104 subjects were needed to detect an 8-point difference in the Quality of Life in Swallowing Disorders (SWAL-QOL) questionnaire score. One hundred four patients undergoing 1- to 3-level ACDF procedures for degenerative spinal pathology were randomized to Depo-Medrol (DEPO) or no Depo-Medrol (NODEPO) cohorts. Prior to surgical closure, patients received 1 ml of either Depo-Medrol (DEPO) or saline (NODEPO) applied to a Gelfoam carrier at the surgical site. Patients were blinded to the application of steroid or saline following surgery. The SWAL-QOL questionnaire was administered both pre- and postoperatively. A ratio of the prevertebral swelling distance to the anteroposterior diameter of each vertebral body level was calculated at the involved levels ± 1 level by using pre- and postoperative lateral radiographs. The ratios of all levels were averaged and multiplied by 100 to obtain a swelling index. An air index was calculated in the same manner but using the tracheal air window diameter in place of the prevertebral swelling distance. Statistical analysis was performed using the Student t-test and chi-square analysis. Statistical significance was set at p < 0.05.RESULTSOf the 104 patients, 55 (52.9%) were randomized to the DEPO cohort and 49 (47.1%) to the NODEPO group. No differences in baseline patient demographics or preoperative characteristics were demonstrated between the two cohorts. Similarly, estimated blood loss and length of hospitalization did not differ between the cohorts. Neither was there a difference in the mean change in the scaled total SWAL-QOL score, swelling index, and air index between the groups at any time point. Furthermore, no complications were observed in either group (retropharyngeal abscess or esophageal perforation).CONCLUSIONSThe results of this prospective, randomized single-blind study did not demonstrate an impact of local intraoperative steroid application on patient-reported swallowing function or swelling following ACDF. Neither did the administration of Depo-Medrol lead to an earlier hospital discharge than that in the NODEPO cohort. These results suggest that intraoperative local steroid administration may not provide an additional benefit to patients undergoing ACDF procedures.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: Class I.Clinical trial registration no.: NCT03311425 (clinicaltrials.gov)

scholarly journals Biomechanical Analysis of an Anterior Cervical Discectomy and Fusion Pseudarthrosis Model Revised With Machined Interfacet Allograft Spacers

2019 ◽  
Vol 10 (8) ◽  
pp. 973-981
Author(s):  
Raymond J. Hah ◽  
Ram Alluri ◽  
Paul A. Anderson
Keyword(s):  
Range Of Motion ◽  
Study Design ◽  
Axial Rotation ◽  
Biomechanical Analysis ◽  
Anterior Cervical Discectomy ◽  
Lateral Bending ◽  
Cervical Discectomy ◽  
Single Level ◽  
Flexion Extension ◽  
Potential Applications

Study Design: Biomechanics study. Objectives: To evaluate the biomechanical advantage of interfacet allograft spacers in an unstable single-level and 2-level anterior cervical discectomy and fusion (ACDF) pseudoarthrosis model. Methods: Nine single-level and 8 two-level ACDF constructs were tested. Range of motion in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) at 1.5 N m were collected in 4 testing configurations: (1) intact spine, (2) ACDF with interbody graft and plate/screw, (3) ACDF with interbody graft and plate/loosened screws (loose condition), and (4) ACDF with interbody graft and plate/loosened screws supplemented with interfacet allograft spacers (rescue condition). Results: All fixation configurations resulted in statistically significant decreases in range of motion in all bending planes compared with the intact spine ( P < .05). One Level. Performing ACDF with interbody graft and plate on the intact spine reduced FE, LB, and AR 60.0%, 64.9%, and 72.9%, respectively. Loosening the ACDF screws decreased these reductions to 40.9%, 44.6%, and 52.1%. The addition of interfacet allograft spacers to the loose condition increased these reductions to 74.0%, 84.1%, and 82.1%. Two Level. Performing ACDF with interbody graft and plate on the intact spine reduced FE, LB, and AR 72.0%, 71.1%, and 71.2%, respectively. Loosening the ACDF screws decreased these reductions to 55.4%, 55.3%, and 51.3%. The addition of interfacet allograft spacers to the loose condition significantly increased these reductions to 82.6%, 91.2%, and 89.3% ( P < .05). Conclusions: Supplementation of a loose ACDF construct (pseudarthrosis model) with interfacet allograft spacers significantly increases stability and has potential applications in treating cervical pseudarthrosis.

Changes in Swallowing After Anterior Cervical Discectomy and Fusion With Instrumentation: A Presurgical Versus Postsurgical Videofluoroscopic Comparison

2017 ◽  
Vol 60 (4) ◽  
pp. 785-793 ◽  
Author(s):  
Lydia Muss ◽  
Janina Wilmskoetter ◽  
Kerstin Richter ◽  
Constanze Fix ◽  
Soenke Stanschus ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Posterior Pharyngeal Wall ◽  
Anterior Cervical Discectomy ◽  
Future Research ◽  
Swallowing Function ◽  
Pharyngeal Wall ◽  
Cervical Discectomy ◽  
Functional Measures ◽  
Posterior Pharyngeal Wall Thickness ◽  
The Impact

Purpose The purpose of this study was to explore the impact of anterior cervical discectomy and fusion (ACDF) with anterior instrumentation on swallowing function and physiology as measured on videofluoroscopic swallowing studies. Method We retrospectively analyzed both functional measures (penetration-aspiration, residue) and physiological/anatomical measures (hyoid excursion, posterior pharyngeal wall thickness) in a series of 17 patients (8 men, 9 women, mean age 54 years). These measures were extracted from calibrated 5-ml boluses of thin radio-opaque liquids on both pre-ACDF and post-ACDF videofluoroscopies, thus controlling for individual variation and protocol variation. Results After ACDF surgery, we found significant within-subject worsening of Penetration-Aspiration Scale (Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996) scores, vallecular (but not piriform sinus) residue, superior (but not anterior) hyoid excursion, and posterior pharyngeal wall thickness. Results are discussed in the context of previous literature. Conclusions ACDF surgery can affect both physiological/anatomical and functional measures of swallowing. Future research should expand to other biomechanical and temporal variables, as well as greater bolus volumes and a wider array of viscosities and textures.

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