1.C5 Palsy of Patients with Proximal-Type Cervical Spondylotic Amyotrophy
Yasuaki IMAJO ; Norihiro NISHIDA ; Masahiro FUNABA ; Yuji NAGAO ; Hidenori SUZUKI ; Takashi SAKAI
Asian Spine Journal 2022;16(5):723-731
Methods:
Sixty patients with PCSA who underwent surgical treatment of the cervical spine were enrolled. The radiological findings on plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) were evaluated. The cervical lordotic angles, C2–C7 sagittal vertical axis (SVA), and T1 slope were assessed on a lateral radiograph in the neutral position. CT was used to assess the width of the intervertebral foramen and the anterior protrusion of the superior articular process on the axial view. MRI was used to determine the number of levels of compression (NLC) and the presence of a high-intensity area in the spinal cord in the T2- weighted midsagittal view. The preoperative and postoperative strengths of the most atrophic muscles were evaluated using manual muscle testing. Improvements in strength were classified as excellent (five grades recovered), good (more than one grade recovered), fair (no improvement), or poor (worsened).
Results:
The prevalence of C5 palsy was 17% (10/60). Patients with poor outcomes had higher NLC and Δ C2–C7 SVA than patients with excellent, good, and fair outcomes (p =0.015; odds ratio [OR], 5.758; 95% confidence interval [CI], 1.397−23.726 for a change of 10% and p =0.048; OR, 1.068; 95% CI, 0.992−1.141 for a change of 10%, respectively).
Conclusions
ΔC2–C7 SVA and NLC may be used as prognostic factors for achieving a poor outcome following surgery in patients with PCSA. More focus is needed on preventing the increase in ΔC2–C7 SVA.
2.Patient-specific mechanical analysis of pedicle screw insertion in simulated osteoporotic spinal bone models derived from medical images
Norihiro NISHIDA ; Hidenori SUZUKI ; Hanvey TETSU ; Yuki MORISHITA ; Yogesh KUMARAN ; Fei JIANG ; Masahiro FUNABA ; Kazuhiro FUJIMOTO ; Yusuke ICHIHARA ; Takashi SAKAI ; Junji OHGI
Asian Spine Journal 2024;18(5):621-629
Methods:
Male and female patients with computed tomography data were selected. Dimensions of the first thoracic (T1), fourth lumbar (L4), and fifth lumbar (L5) vertebrae were measured, and bone models consisting of the cancellous and cortical bones made from polyurethane foam were created. PS with diameters of 4.5 mm, 5.5 mm, and 6.5 mm were used. T1 PS were 25 mm long, and L4 and L5 PS were 40 mm long. The bone models were secured with cement, and the MIT was measured using a calibrated torque wrench. After MIT testing, the PS head was attached to the machine’s crosshead. POS was then calculated at a crosshead speed of 5 mm/min until failure.
Results:
The L4 and L5 were notably larger in female bone models, whereas the T1 vertebra was larger in male bone models. Consequently, the MIT and POS for L4 and L5 were higher in female bone models across all PS diameters than in male bone models. Conversely, the MIT for T1 was higher in male bone models across all PS; however, no significant differences were observed in the POS values for T1 between sexes.
Conclusions
The mechanical properties of the proposed bone models can vary based on the vertebral structure and size. For accurate 3D surgical and mechanical simulations in the creation of custom-made medical devices, bone models must be constructed from patientspecific medical images.
3.Patient-specific mechanical analysis of pedicle screw insertion in simulated osteoporotic spinal bone models derived from medical images
Norihiro NISHIDA ; Hidenori SUZUKI ; Hanvey TETSU ; Yuki MORISHITA ; Yogesh KUMARAN ; Fei JIANG ; Masahiro FUNABA ; Kazuhiro FUJIMOTO ; Yusuke ICHIHARA ; Takashi SAKAI ; Junji OHGI
Asian Spine Journal 2024;18(5):621-629
Methods:
Male and female patients with computed tomography data were selected. Dimensions of the first thoracic (T1), fourth lumbar (L4), and fifth lumbar (L5) vertebrae were measured, and bone models consisting of the cancellous and cortical bones made from polyurethane foam were created. PS with diameters of 4.5 mm, 5.5 mm, and 6.5 mm were used. T1 PS were 25 mm long, and L4 and L5 PS were 40 mm long. The bone models were secured with cement, and the MIT was measured using a calibrated torque wrench. After MIT testing, the PS head was attached to the machine’s crosshead. POS was then calculated at a crosshead speed of 5 mm/min until failure.
Results:
The L4 and L5 were notably larger in female bone models, whereas the T1 vertebra was larger in male bone models. Consequently, the MIT and POS for L4 and L5 were higher in female bone models across all PS diameters than in male bone models. Conversely, the MIT for T1 was higher in male bone models across all PS; however, no significant differences were observed in the POS values for T1 between sexes.
Conclusions
The mechanical properties of the proposed bone models can vary based on the vertebral structure and size. For accurate 3D surgical and mechanical simulations in the creation of custom-made medical devices, bone models must be constructed from patientspecific medical images.
4.Patient-specific mechanical analysis of pedicle screw insertion in simulated osteoporotic spinal bone models derived from medical images
Norihiro NISHIDA ; Hidenori SUZUKI ; Hanvey TETSU ; Yuki MORISHITA ; Yogesh KUMARAN ; Fei JIANG ; Masahiro FUNABA ; Kazuhiro FUJIMOTO ; Yusuke ICHIHARA ; Takashi SAKAI ; Junji OHGI
Asian Spine Journal 2024;18(5):621-629
Methods:
Male and female patients with computed tomography data were selected. Dimensions of the first thoracic (T1), fourth lumbar (L4), and fifth lumbar (L5) vertebrae were measured, and bone models consisting of the cancellous and cortical bones made from polyurethane foam were created. PS with diameters of 4.5 mm, 5.5 mm, and 6.5 mm were used. T1 PS were 25 mm long, and L4 and L5 PS were 40 mm long. The bone models were secured with cement, and the MIT was measured using a calibrated torque wrench. After MIT testing, the PS head was attached to the machine’s crosshead. POS was then calculated at a crosshead speed of 5 mm/min until failure.
Results:
The L4 and L5 were notably larger in female bone models, whereas the T1 vertebra was larger in male bone models. Consequently, the MIT and POS for L4 and L5 were higher in female bone models across all PS diameters than in male bone models. Conversely, the MIT for T1 was higher in male bone models across all PS; however, no significant differences were observed in the POS values for T1 between sexes.
Conclusions
The mechanical properties of the proposed bone models can vary based on the vertebral structure and size. For accurate 3D surgical and mechanical simulations in the creation of custom-made medical devices, bone models must be constructed from patientspecific medical images.
5.Patient-specific mechanical analysis of pedicle screw insertion in simulated osteoporotic spinal bone models derived from medical images
Norihiro NISHIDA ; Hidenori SUZUKI ; Hanvey TETSU ; Yuki MORISHITA ; Yogesh KUMARAN ; Fei JIANG ; Masahiro FUNABA ; Kazuhiro FUJIMOTO ; Yusuke ICHIHARA ; Takashi SAKAI ; Junji OHGI
Asian Spine Journal 2024;18(5):621-629
Methods:
Male and female patients with computed tomography data were selected. Dimensions of the first thoracic (T1), fourth lumbar (L4), and fifth lumbar (L5) vertebrae were measured, and bone models consisting of the cancellous and cortical bones made from polyurethane foam were created. PS with diameters of 4.5 mm, 5.5 mm, and 6.5 mm were used. T1 PS were 25 mm long, and L4 and L5 PS were 40 mm long. The bone models were secured with cement, and the MIT was measured using a calibrated torque wrench. After MIT testing, the PS head was attached to the machine’s crosshead. POS was then calculated at a crosshead speed of 5 mm/min until failure.
Results:
The L4 and L5 were notably larger in female bone models, whereas the T1 vertebra was larger in male bone models. Consequently, the MIT and POS for L4 and L5 were higher in female bone models across all PS diameters than in male bone models. Conversely, the MIT for T1 was higher in male bone models across all PS; however, no significant differences were observed in the POS values for T1 between sexes.
Conclusions
The mechanical properties of the proposed bone models can vary based on the vertebral structure and size. For accurate 3D surgical and mechanical simulations in the creation of custom-made medical devices, bone models must be constructed from patientspecific medical images.