Effects of Removal of Uncinate Process in a Cervical Disc Replacement Model: A Finite Element Based Study

2007 ◽  
Author(s):  
A. Faizan ◽  
V. K. Goel ◽  
M. Krishna ◽  
T. Friesem
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
General Procedure ◽  
Total Disc Replacement ◽  
Uncinate Process ◽  
Disc Replacement ◽  
Cervical Disc ◽  
Fe Model ◽  
Disc Space ◽  
Cervical Disc Replacement

Anterior surgical approach is commonly used for Total Disc Replacement (TDR) surgeries in the cervical spine. The general procedure includes removal of the nucleus and anterior annulus of the intervertebral disc. Resection of Anterior Longitudinal Ligaments (ALL) is often performed to enter the disc space. The cervical spine also contains a unique anatomical feature called Luschka’s joints. These “joints” are actually fissures in the disc which run approximately parallel to the uncinate processes. These joints are thought to provide biomechanical stability to the cervical spine. However, sometimes surgeons have to sacrifice the uncinate processes at the involved level as well. We hypothesized that the cervical spine loses stability if the uncinate processes are removed along with disc replacement. We used a Finite Element (FE) model of cervical spine to prove the hypothesis (Fig1).

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.

Effects of Treatment for Cervical Disc Degenerative Disease in Military Populations

2011 ◽  
Author(s):  
Joseph Cochran ◽  
Jamie L. Baisden ◽  
Narayan Yoganandan ◽  
Frank A. Pintar
Keyword(s):  
Finite Element ◽  
Degenerative Disease ◽  
Disc Replacement ◽  
Cervical Disc ◽  
Cervical Disc Replacement ◽  
Bony Fusion ◽  
Bryan Disc ◽  
Cadaver Studies ◽  
External Forces ◽  
Military Patients

Numerous clinical and biomechanical evaluations of cervical disc replacement and anterior cervical discectomy and fusion as treatment of cervical disc herniation have been performed. Military patients represent a unique patient population as they may be subject to large external forces in theatre. Military patients are more susceptible to degenerative disease of the cervical spine, and if treated with single-level bony fusion, the treated level may be subject to large forces postoperatively. Literature reviews were conducted to determine patient outcomes following cervical disc replacement compared to bony fusion surgery; compare cadaver studies that evaluated the two conditions; and finite element modeling studies. In the civilian population, patients treated with each type of surgery have clinical improvement that is at least equivalent in the 2- and 5-year follow-up periods. Based on the finite element and cadaver biomechanical studies, semiconstrained devices, ProDisc-C and Prestige, are less mobile and a larger load is placed on the core of the device in comparison to the more mobile and unconstrained Bryan disc.

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)

Early results after ProDisc-C cervical disc replacement

2005 ◽  
Vol 2 (4) ◽  
pp. 403-410 ◽  
Author(s):  
Rudolf Bertagnoli ◽  
James J. Yue ◽  
Frank Pfeiffer ◽  
Andrea Fenk-Mayer ◽  
James P. Lawrence ◽  
...  
Keyword(s):  
Cervical Spondylosis ◽  
Total Disc Replacement ◽  
Disc Replacement ◽  
Definitive Treatment ◽  
Cervical Disc ◽  
Content Type ◽  
Cervical Disc Replacement ◽  
Arm Pain ◽  
Early Results ◽  
Fine Print

Object. Cervical anterior decompression and total-disc replacement is currently being investigated as an alternative treatment in patients with symptomatic intervertebral cervical spondylosis with and without radiculopathy. The authors prospectively investigated the safety and efficacy of using the ProDisc-C disc for cervical arthroplasty in the treatment of symptomatic cervical spondylosis. Methods. Sixteen patients in whom a diagnosis of symptomatic cervical spondylosis had been established were prospectively treated with complete anterior cervical discectomy and ProDisc-C cervical disc arthroplasty. Overall 12 single- and four two-level procedures were performed (20 prostheses). Patients underwent pre- and multiple postoperative assessments (3 and 6 weeks and 3, 6, and 12 months). The median age of all patients was 50 years (range 32–60 years). Levels of surgery included seven C5–6, six C6–7, and three C4–5. Neck and arm pain as well as disability scores were significantly improved by 3 months and remained significantly improved at 1 year. No additional fusion surgeries were necessary at the affected or unaffected levels. Radiography revealed an affected disc motion from 4 to 12°. No surgery- or device-related complications were documented. Conclusions. Analysis of preliminary results involving ProDisc-C arthroplasty indicates significant improvement in pain and functional outcome scores. No spontaneous fusions at the level of surgery or at adjacent levels were noted. Long-term follow-up studies will be necessary before more definitive treatment recommendations can be formulated.

Biomechanical Analysis of Cervical Finite Element Model

2013 ◽  
Vol 273 ◽  
pp. 845-850
Author(s):  
Dong Mei Wu ◽  
Li Tao Zhang ◽  
Jun Zhao
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Cervical Vertebrae ◽  
Element Model ◽  
Biomechanical Analysis ◽  
Cervical Disc ◽  
Control Group ◽  
Cervical Disc Replacement ◽  
Surgery Group

The finite element method is often used in the field of biomechanical analysis. It can study the mechanical response of the internal organization without any experiments on the human body. The paper studies the biomechanics of the cervical spine by the method of finite element analysis. Firstly, the finite element model of the cervical spine including cervical vertebrae and soft tissue is constructed. Secondly, biomechanical analysis of cervical finite element model which is validated to be reasonable and reliable is completed. The results of the control group, the anterior cervical decompression and fusion surgery group, and the artificial cervical disc replacement surgery group are obtained to study the motion degree and ligament force of cervical spine. Thirdly, the summary of the biomechanical analysis of cervical finite element model is concluded.

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