1.Comparing adjacent segment biomechanics between anterior and posterior cervical fusion using patient-specific finite element modeling
Balaji HARINATHAN ; Davidson JEBASEELAN ; Narayan YOGANANDAN ; Aditya VEDANTAM
Asian Spine Journal 2024;18(6):777-793
Methods:
Patient-specific finite element modeling (FEM) of the cervical spine and spinal cord were created. Surgical simulation was performed for multi-segment anterior cervical discectomy fusion (ACDF) (C4–C7) and posterior cervical laminectomy with fusion (PCLF) (C5–6 laminectomy and C4–C7 fusion). Physiological motions were simulated by applying a 2 Nm moment and 75 N force.
Results:
At the superior adjacent segment, the ACDF model exhibited a higher range of motion (ROM) during neck flexion compared to PCLF. Conversely, in neck extension, PCLF showed a higher ROM than ACDF. At the superior adjacent segment, the ACDF model showed greater spinal cord stress during flexion. During extension, PCLF was associated with greater spinal cord stress. At the inferior adjacent segment, ACDF was associated with greater spinal cord stress than PCLF during flexion. At the superior adjacent segment, ACDF also led to increased intradiskal pressure and capsular ligament strain during flexion, whereas PCLF showed these increases during extension.
Conclusions
Our findings indicate the differential effect of ACDF and PCLF on biomechanics at the cervical spine’s adjacent segments, with the patient-specific model with ACDF showing greater changes and potential for degeneration. This study highlights the utility of patient-specific FEMs in enhancing surgical decision-making through personalized medicine.
2.Comparing adjacent segment biomechanics between anterior and posterior cervical fusion using patient-specific finite element modeling
Balaji HARINATHAN ; Davidson JEBASEELAN ; Narayan YOGANANDAN ; Aditya VEDANTAM
Asian Spine Journal 2024;18(6):777-793
Methods:
Patient-specific finite element modeling (FEM) of the cervical spine and spinal cord were created. Surgical simulation was performed for multi-segment anterior cervical discectomy fusion (ACDF) (C4–C7) and posterior cervical laminectomy with fusion (PCLF) (C5–6 laminectomy and C4–C7 fusion). Physiological motions were simulated by applying a 2 Nm moment and 75 N force.
Results:
At the superior adjacent segment, the ACDF model exhibited a higher range of motion (ROM) during neck flexion compared to PCLF. Conversely, in neck extension, PCLF showed a higher ROM than ACDF. At the superior adjacent segment, the ACDF model showed greater spinal cord stress during flexion. During extension, PCLF was associated with greater spinal cord stress. At the inferior adjacent segment, ACDF was associated with greater spinal cord stress than PCLF during flexion. At the superior adjacent segment, ACDF also led to increased intradiskal pressure and capsular ligament strain during flexion, whereas PCLF showed these increases during extension.
Conclusions
Our findings indicate the differential effect of ACDF and PCLF on biomechanics at the cervical spine’s adjacent segments, with the patient-specific model with ACDF showing greater changes and potential for degeneration. This study highlights the utility of patient-specific FEMs in enhancing surgical decision-making through personalized medicine.
3.Comparing adjacent segment biomechanics between anterior and posterior cervical fusion using patient-specific finite element modeling
Balaji HARINATHAN ; Davidson JEBASEELAN ; Narayan YOGANANDAN ; Aditya VEDANTAM
Asian Spine Journal 2024;18(6):777-793
Methods:
Patient-specific finite element modeling (FEM) of the cervical spine and spinal cord were created. Surgical simulation was performed for multi-segment anterior cervical discectomy fusion (ACDF) (C4–C7) and posterior cervical laminectomy with fusion (PCLF) (C5–6 laminectomy and C4–C7 fusion). Physiological motions were simulated by applying a 2 Nm moment and 75 N force.
Results:
At the superior adjacent segment, the ACDF model exhibited a higher range of motion (ROM) during neck flexion compared to PCLF. Conversely, in neck extension, PCLF showed a higher ROM than ACDF. At the superior adjacent segment, the ACDF model showed greater spinal cord stress during flexion. During extension, PCLF was associated with greater spinal cord stress. At the inferior adjacent segment, ACDF was associated with greater spinal cord stress than PCLF during flexion. At the superior adjacent segment, ACDF also led to increased intradiskal pressure and capsular ligament strain during flexion, whereas PCLF showed these increases during extension.
Conclusions
Our findings indicate the differential effect of ACDF and PCLF on biomechanics at the cervical spine’s adjacent segments, with the patient-specific model with ACDF showing greater changes and potential for degeneration. This study highlights the utility of patient-specific FEMs in enhancing surgical decision-making through personalized medicine.
4.A Comparison Study of Four Cervical Disk Arthroplasty Devices Using Finite Element Models
Yuvaraj PURUSHOTHAMAN ; Hoon CHOI ; Narayan YOGANANDAN ; Davidson JEBASEELAN ; Jamie BAISDEN ; Shekar KURPAD
Asian Spine Journal 2021;15(3):283-293
Methods:
A validated C2–T1 finite element model was subjected to flexion-extension. CDAs were simulated at the C5–C6 level with the Secure-C, Mobi-C, Prestige LP, and Prodisc C prosthetic disks. We used a hybrid loading protocol to apply sagittal moments. Normalized motions at the index and adjacent levels, and intradiscal pressures and facet column loads were also obtained.
Results:
The ranges of motion at the index level increased after CDA. The Mobi-C prosthesis demonstrated the highest amount of flexion, followed by the Secure-C, Prestige LP, and Prodisc C. The Secure-C demonstrated the highest amount of extension, followed by the Mobi-C, Prodisc C, and Prestige LP. The motion decreased at the rostral and caudal adjacent levels. Facet forces increased at the index level and decreased at the rostral and caudal adjacent levels following CDA. Intradiscal pressures decreased at the adjacent levels for the Mobi-C, Secure-C, and Prodisc C. Conversely, the use of the Prestige LP increased intradiscal pressure at both adjacent levels.
Conclusions
While all artificial disks were useful in restoring the index level motion, the Secure-C and Mobi-C translating abilities allowed for lower intradiscal pressures at the adjacent segments and may be the driving mechanism for minimizing adjacent segment degenerative arthritic changes. The facet joint integrity should also be considered in the clinical decision-making process for CDA selection.
5.A Comparison Study of Four Cervical Disk Arthroplasty Devices Using Finite Element Models
Yuvaraj PURUSHOTHAMAN ; Hoon CHOI ; Narayan YOGANANDAN ; Davidson JEBASEELAN ; Jamie BAISDEN ; Shekar KURPAD
Asian Spine Journal 2021;15(3):283-293
Methods:
A validated C2–T1 finite element model was subjected to flexion-extension. CDAs were simulated at the C5–C6 level with the Secure-C, Mobi-C, Prestige LP, and Prodisc C prosthetic disks. We used a hybrid loading protocol to apply sagittal moments. Normalized motions at the index and adjacent levels, and intradiscal pressures and facet column loads were also obtained.
Results:
The ranges of motion at the index level increased after CDA. The Mobi-C prosthesis demonstrated the highest amount of flexion, followed by the Secure-C, Prestige LP, and Prodisc C. The Secure-C demonstrated the highest amount of extension, followed by the Mobi-C, Prodisc C, and Prestige LP. The motion decreased at the rostral and caudal adjacent levels. Facet forces increased at the index level and decreased at the rostral and caudal adjacent levels following CDA. Intradiscal pressures decreased at the adjacent levels for the Mobi-C, Secure-C, and Prodisc C. Conversely, the use of the Prestige LP increased intradiscal pressure at both adjacent levels.
Conclusions
While all artificial disks were useful in restoring the index level motion, the Secure-C and Mobi-C translating abilities allowed for lower intradiscal pressures at the adjacent segments and may be the driving mechanism for minimizing adjacent segment degenerative arthritic changes. The facet joint integrity should also be considered in the clinical decision-making process for CDA selection.