scholarly journals Investigation into Cervical Spine Biomechanics Following Single, Multilevel and Hybrid Disc Replacement Surgery with Dynamic Cervical Implant and Fusion: A Finite Element Study

2022 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Muzammil Mumtaz ◽  
Iman Zafarparandeh ◽  
Deniz Ufuk Erbulut
Keyword(s):  
Cervical Spine ◽  
Standard Procedure ◽  
Total Disc Replacement ◽  
Disc Replacement ◽  
Von Mises Stress ◽  
Adjacent Segment ◽  
Fusion Model ◽  
Hybrid Surgery ◽  
Maximum Increase ◽  
Flexion Extension

Cervical fusion has been a standard procedure for treating abnormalities associated with the cervical spine. However, the reliability of anterior cervical discectomy and fusion (ACDF) has become arguable due to its adverse effects on the biomechanics of adjacent segments. One of the drawbacks associated with ACDF is adjacent segment degeneration (ASD), which has served as the base for the development of dynamic stabilization systems (DSS) and total disc replacement (TDR) devices for cervical spine. However, the hybrid surgical technique has also gained popularity recently, but its effect on the biomechanics of cervical spine is not well researched. Thus, the objective of this FE study was to draw a comparison among single-level, bi-level, and hybrid surgery with dynamic cervical implants (DCIs) with traditional fusion. Reductions in the range of motion (ROM) for all the implanted models were observed for all the motions except extension, compared to for the intact model. The maximum increase in the ROM of 42% was observed at segments C5–C6 in the hybrid DCI model. The maximum increase in the adjacent segment’s ROM of 8.7% was observed in the multilevel fusion model. The maximum von Mises stress in the implant was highest for the multilevel DCI model. Our study also showed that the shape of the DCI permitted flexion/extension relatively more compared to lateral bending and axial rotation.

scholarly journals Investigation Into Cervical Spine Biomechanics Following Single, Multilevel and Hybrid Disc Replacement Surgery With Dynamic Cervical Implant and Fusion: A Finite Element Study

2021 ◽  
Author(s):  
Muzammil Mumtaz ◽  
Iman Zafarparandeh ◽  
Deniz Ufuk Erbulut
Keyword(s):  
Cervical Spine ◽  
Standard Procedure ◽  
Total Disc Replacement ◽  
Disc Replacement ◽  
Von Mises Stress ◽  
Adjacent Segment ◽  
Fusion Model ◽  
Hybrid Surgery ◽  
Maximum Increase ◽  
Flexion Extension

Cervical fusion has been a standard procedure for treating the abnormalities associated with the cervical spine. However, the reliability of anterior cervical discectomy and fusion (ACDF) has become arguable due to its adverse effects on the biomechanics of adjacent segments. One of the drawbacks associated with ACDF is adjacent segment degeneration (ASD) which has served as the base for the development of dynamic stabilization systems (DSS) and total disc replacement (TDR) devices for cervical spine. However, the hybrid surgical technique has also gained popularity recently but their effect on the biomechanics of cervical spine is not well researched. Thus, the objective of this FE study was to draw the comparison among single, bi-level and hybrid surgery with DCI implant with traditional fusion. Reduction in range of motion (ROM) for all the implanted models was observed for all the motions except extension, compared to intact model. The maximum increase in ROM of 42% was observed at C5-C6 level in Hybrid-DCI model. The maximum increase in adjacent segment’s ROM of 8.7% was observed in multilevel fusion model. The maximum von Mises stress in the implant was highest for the multilevel DCI model. Our study also showed that the shape of DCI implant permits flexion/extension relatively more compared to lateral bending and axial rotation.

scholarly journals Are Controversial Issues in Cervical Total Disc Replacement Resolved or Unresolved?: A Review of Literature and Recent Updates

2018 ◽  
Vol 12 (1) ◽  
pp. 178-192 ◽  
Author(s):  
Chun-Kun Park ◽  
Kyeong-Sik Ryu
Keyword(s):  
Surgical Outcomes ◽  
Wear Debris ◽  
Total Disc Replacement ◽  
Young Patients ◽  
Disc Replacement ◽  
Adjacent Segment ◽  
Controversial Issues ◽  
Hybrid Surgery ◽  
Cervical Total Disc Replacement

<p>Since the launch of cervical total disc replacement (CTDR) in the early 2000s, many clinical studies have reported better outcomes of CTDR compared to those of anterior cervical discectomy and fusion. However, CTDR is still a new and innovative procedure with limited indications for clinical application in spinal surgery, particularly, for young patients presenting with soft disc herniation with radiculopathy and/or myelopathy. In addition, some controversial issues related to the assessment of clinical outcomes of CTDR remain unresolved. These issues, including surgical outcomes, adjacent segment degeneration (ASD), heterotopic ossification (HO), wear debris and tissue reaction, and multilevel total disc replacement (TDR) and hybrid surgeries are a common concern of spine surgeons and need to be resolved. Among them, the effect of CTDR on patient outcomes and ASD is theoretically and clinically important; however, this issue remains disputable. Additionally, HO, wear debris, multilevel TDR, and hybrid surgery tend to favor CTDR in terms of their effects on outcomes, but the potential of these factors for jeopardizing patients' safety postoperatively and/or to exert harmful effects on surgical outcomes in longer-term follow-up cannot be ignored. Consequently, it is too early to determine the therapeutic efficacy and cost-effectiveness of CTDR and will require considerable time and studies to provide appropriate answers regarding the same. For these reasons, CTDR requires longer-term follow-up data.</p>

Early development and progression of heterotopic ossification in cervical total disc replacement

2012 ◽  
Vol 16 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Soo Eon Lee ◽  
Chun Kee Chung ◽  
Tae Ahn Jahng
Keyword(s):  
Clinical Outcome ◽  
Heterotopic Ossification ◽  
Total Disc Replacement ◽  
Disc Replacement ◽  
Adjacent Segment ◽  
Segmental Motion ◽  
Cervical Total Disc Replacement ◽  
The Mean ◽  
Grade Iii

Object The purpose of cervical total disc replacement (TDR) is to decrease the incidence of adjacent segment disease through motion preservation. Heterotopic ossification (HO) is a well-known complication after hip and knee arthroplasties. There are few reports regarding HO in patients undergoing cervical TDR, however; and the occurrence of HO and its effects on cervical motion have rarely been reported. Moreover, temporal progression of HO has not been fully addressed. One goal of this study involved determining the incidence of HO following cervical TDR, as identified from plain radiographs, and demonstrating the progression of HO during the follow-up period. A second goal consisted of determining whether segmental motion could be preserved and identifying the relationship between HO and clinical outcomes. Methods The authors conducted a retrospective clinical and radiological study of 28 consecutive patients who underwent cervical TDR with Mobi-C prostheses (LDR Medical) between September 2006 and October 2008. Radiological outcomes were evaluated using lateral dynamic radiographs obtained preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. The occurrence of HO was interpreted on lateral radiographs using the McAfee classification. Cervical range of motion (ROM) was also measured. The visual analog scale (VAS) and Neck Disability Index (NDI) were used to evaluate clinical outcome. Results The mean follow-up period was 21.6 ± 7.0 months, and the mean occurrence of HO was at 8.0 ± 6.6 months postoperatively. At the last follow-up, 18 (64.3%) of 28 patients had HO: Grade I, 6 patients; Grade II, 8 patients; Grade III, 3 patients; and Grade IV, 1 patient. Heterotopic ossification progression was proportional to the duration of follow-up; HO was present in 3 (10.7%) of 28 patients at 1 month; 7 (25.0%) of 28 patients at 3 months; 11 (42.3%) of 26 patients at 6 months; 15 (62.5%) of 24 patients at 12 months; and 17 (77.3%) of 22 patients at 24 months. Cervical ROM was preserved in Grades I and II HO but was restricted in Grades III and IV HO. Clinical improvement according to the VAS and NDI was not significantly correlated with the occurrence of HO. Conclusions The overall incidence of HO after cervical TDR was relatively high. Moreover, HO began unexpectedly to appear early after surgery. Heterotopic ossification progression was proportional to the time that had elapsed postoperatively. Grade III or IV HO can restrict the cervical ROM and may lead to spontaneous fusion; however, the occurrence of HO did not affect clinical outcome. The results of this study indicate that a high incidence of HO with the possibility of spontaneous fusion is to be expected during long-term follow-up and should be considered before performing cervical TDR.

Remaining Cervical Spine Movement Under Different Immobilization Techniques

2020 ◽  
Vol 35 (4) ◽  
pp. 382-387 ◽  
Author(s):  
Davut D. Uzun ◽  
Matthias K. Jung ◽  
Jeronimo Weerts ◽  
Matthias Münzberg ◽  
Paul A. Grützner ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Standard Procedure ◽  
Human Motion ◽  
Cervical Collar ◽  
Vacuum Mattress ◽  
Flexion Extension ◽  
Immobilization Techniques ◽  
Spine Board ◽  
Spine Movement ◽  
Belt System

AbstractBackground:Immobilization of the cervical spine by Emergency Medical Services (EMS) personnel is a standard procedure. In most EMS, multiple immobilization tools are available.The aim of this study is the analysis of residual spine motion under different types of cervical spine immobilization.Methods:In this explorative biomechanical study, different immobilization techniques were performed on three healthy subjects. The test subjects’ heads were then passively moved to cause standardized spinal motion. The primary endpoints were the remaining range of motion for flexion, extension, bending, and rotation measured with a wireless human motion detector.Results:In the case of immobilization of the test person (TP) on a straight (0°) vacuum mattress, the remaining rotation of the cervical spine could be reduced from 7° to 3° by additional headblocks. Also, the remaining flexion and extension were reduced from 14° to 3° and from 15° to 6°, respectively. The subjects’ immobilization was best on a spine board using a headlock system and the Spider Strap belt system (MIH-Medical; Georgsmarienhütte, Germany). However, the remaining cervical spine extension increased from 1° to 9° if a Speedclip belt system was used (Laerdal; Stavanger, Norway). The additional use of a cervical collar was not advantageous in reducing cervical spine movement with a spine board or vacuum mattress.Conclusions:The remaining movement of the cervical spine is minimal when the patient is immobilized on a spine board with a headlock system and a Spider Strap harness system or on a vacuum mattress with additional headblocks. The remaining movement of the cervical spine could not be reduced by the additional use of a cervical collar.

scholarly journals Four-year results of a prospective single-arm study on 200 semi-constrained total cervical disc prostheses: clinical and radiographic outcome

2016 ◽  
Vol 25 (5) ◽  
pp. 556-565 ◽  
Author(s):  
Hans-Jörg Meisel ◽  
Lubomír Jurák ◽  
Jussi Antinheimo ◽  
Ricardo Arregui ◽  
Bernhard Bruchmann ◽  
...  
Keyword(s):  
Total Disc Replacement ◽  
Neck Disability Index ◽  
Disc Replacement ◽  
Cervical Disc ◽  
Adjacent Segment ◽  
Radiographic Outcome ◽  
Cervical Disc Replacement ◽  
Arm Pain ◽  
Facet Joint Degeneration

OBJECTIVE Recent studies have described encouraging outcomes after cervical total disc replacement (cTDR), but there are also critical debates regarding the long-term effects of heterotopic ossification (HO) and the prevalence of adjacent-level degeneration. The aim in this paper was to provide 4-year clinical and radiographic outcome results on the activ C disc prosthesis. METHODS A total of 200 subjects underwent single-level activ C (Aesculap AG) implantation between C-3 and C-7 for the treatment of symptomatic degenerative disc disease. Clinical and radiographic assessments were performed preoperatively, intraoperatively, at discharge, and again at 6 weeks, 6 months, 1 year, 2 years, and 4 years. Radiographic evaluations were done by an independent core laboratory using a specific software for quantitative motion analysis. RESULTS Neck Disability Index (NDI) and visual analog scale (VAS) score for neck and arm pain decreased significantly from baseline to the 4-year follow-up. The mean improvement for NDI was 20, for VAS severity and frequency of neck pain 26.4 and 28, and for VAS severity and frequency of arm pain 30.7 and 35.1, respectively. The neurological situation improved for the majority of patients (86.4%); 76.1% of cases were asymptomatic. Subsequent surgical interventions were reported in 7% of the cases, including device removals in 3%. In 2.5% a subsidence greater than 3 mm was recorded; 1 of these cases also had a migration greater than 3 mm. No device displacement, expulsion, disassembly, loose or fractured device, osteolysis, or facet joint degeneration at the index level was observed. Segmental lordotic alignment changed from −2.4° preoperatively to −6.2° at 4 years, and postoperative height was maintained during the follow-up. Advanced HO (Grade III and IV) was present in 27.1% of the cases; 82.4% showed segmental mobility. A progression of radiographic adjacent-segment degeneration occurred in 28.2%, but only 4.5% required surgical treatment. CONCLUSIONS The activ C is a safe and effective device for cervical disc replacement confirming the encouraging results after cTDR. Clinical trial registration no.: NCT02492724 (clinicaltrials.gov)

FINITE ELEMENT ANALYSIS OF CERVICAL SPINE WITH DIFFERENT CONSTRAINED TYPES OF TOTAL DISC REPLACEMENT

2014 ◽  
Vol 14 (03) ◽  
pp. 1450038 ◽  
Author(s):  
CHIEN-YU LIN ◽  
SHIH-YOUENG CHUANG ◽  
CHANG-JUNG CHIANG ◽  
YANG-HWEI TSUANG ◽  
WENG-PIN CHEN
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Vertebral Body ◽  
Facet Joint ◽  
Total Disc Replacement ◽  
Axial Rotation ◽  
Disc Replacement ◽  
Normal Person ◽  
Fe Model ◽  
Segmental Motion

Various designs of cervical total disc replacement (CTDR) have been introduced and employed in an attempt to avoid disadvantages of the fusion surgery. The purposes of this study were to evaluate the effects of the range of motion (ROM), the instantaneous center of rotation (ICR) and the facet joint force (FJF) with different constrained types of CTDR devices. A three-dimensional finite element (FE) model of intact cervical spine (C3-7) was made from CT scans of a normal person and validated. Postoperative FE models simulating CTDR implantation at the C5-6 disc space were made for CTDR-I (constrained design) and CTDR-II (nonconstrained design), respectively. Hybrid protocol (intact: 1 Nm) with a compressive follower load of 73.6 N was applied at the superior endplate of the C3 vertebral body. The inferior endplate of C7 vertebral body was constrained in all directions. At the index level, CTDR-I showed a higher increase in segmental motion and FJF than CTDR-II in extension, lateral bending and axial rotation. The CTDR-II with an elastomer-type core reproduced a near physiological ICR of the intact model in extension and axial rotation. Abnormal kinetic and kinematic changes related to the CTDR may induce surgical level problems and cause long-term failure of spinal surgery.

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