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Titanium mesh cage is one of the fusion devices used in anterior cervical corpectomy and fusion (ACCF). It can not only immediately rebuild the stability of cervical spine during the operation, maintain the height and physiological curvature of intervertebral vertebrae, but also avoid the complications of bone donor area caused by autologous bone extraction. Therefore, titanium mesh cage has become the most commonly used internal plant in ACCF. However, there exist many problems in traditional titanium cage, such as stress shielding and titanium cage sinking, which will affect the surgical effect to a certain extent, and even lead to serious postoperative complications requiring revision surgery. At present, a variety of new titanium cages have been invented, which can solve the problems caused by traditional titanium cage to a certain extent. Biomechanical evaluation and its testing methods are an indispensable process for judging whether a new type of spinal fusion cage can be used in clinical practice. This article reviews the biomechanical studies related to cervical spine anatomy, the biomechanical properties of traditional titanium cages and new titanium cages, so as to provide new ideas for the improvement of traditional titanium cages and the development of new titanium cages.
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<p><b>OBJECTIVE</b>To study the change trend of cervical range of motion(ROM) after single-level anterior cervical corpectomy and fusion(ACCF) in treating cervical spondylotic myelopathy.</p><p><b>METHODS</b>The clinical data of 23 patients with cervical spondylotic myelopathy was retrospectively analyzed from February 2015 to April 2016. There were 11 males and 12 females, with an average age of (54.6±13.3) years. All the patients were diagnosed as cervical spondylotic myelopathy by interrogation, physical examination and radiology, and were treated by ACCF. The Coda motion system was applied to assess the cervical range of motion pre-and post-operation. JOA and VAS scores were used to evaluate the clinical outcomes.</p><p><b>RESULTS</b>The mean follow-up time was (9.4±1.6) months. Cervical ROM in all directions at 3 months postoperatively were significantly lower except for the left rotation(<0.05). There was significant difference of cervical ROM in all directions between preoperative and 6 months postoperatively(>0.05). The right lateral bending and the left rotation at 9 months postoperatively increased significantly(<0.05). Postoperative extension at 6 months was significantly better than that of 3 months postoperatively(<0.05). The extension, left and right lateral bending and left rotation at 9 months postoperatively were significantly better than of 6 months postoperatively(<0.05). Postoperative JOA scores at each time points were significantly higher than that of preoperative(<0.05) and VAS scores at each time points were significantly lower than that of preoperative(<0.05).</p><p><b>CONCLUSIONS</b>The change trend of three-dimensional cervical ROM after single-level ACCF revealed that the ROM decreased in short term, and later increased and was better than the preoperative level. Meanwhile, the neurological function improved significantly. But the short-term and long-term change trend of ROM postoperatively and the change trend of ROM after multi-level ACCF need to be further studied.</p>
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<p><b>OBJECTIVE</b>To compare the clinical effects between anterior cervical discectomy and fusion(ACDF) combined with anterior cervical corpectomy and fusion(ACCF) and cervical posterior single open-door laminoplasty with mini-titanium plate fixation in treating three-segment cervical spondylotic myelopathy.</p><p><b>METHODS</b>The clinical data of 63 patients (39 males and 24 females) with three-segment cervical spondylotic myelopathy underwent surgical treatment from March 2014 to March 2016 were retrospectively analyzed. Among them, 43 cases were treated by ACDF combined with ACCF(anterior group), and 20 cases were treated by cervical posterior single open-door laminoplasty with mini-titanium plate fixation(posterior group). Operative time, intraoperative blood loss, postoperative complications were compared between two groups. And according to JOA score to evaluate the clinical effect.</p><p><b>RESULTS</b>All the patients were follow-up from 16 to 40 months with an average of 25.8 months. Operative time of anterior group and posterior group were (123.70±6.21) min and(118.70±5.41) min, respectively, there was no significant difference between two groups(>0.05). Intraoperative blood loss of anterior group and posterior group were (85.23±7.51) ml and (107.18±9.41) ml, respectively, there was significant difference between two groups(<0.05). In anterior group, axial symptoms occurred in 6 cases, dysphagia in 1 case, and no C₅ nerve root palsy, hoarseness and choking cough were found, the incidence rate of complication was 16.3%(7/43); and in posterior group, axial symptoms occurred in 5 cases, C5 nerve root palsy in 1 case, and no dysphagia, hoarseness and choking cough were found, the incidence rate of complication was 30.0%(6/20); there was significant defference in incidence rate of complication between two group(<0.05). At 1 week after operation and final follow-up, the JOA scores of anterior group were obviously better than that of posterior group(<0.05).</p><p><b>CONCLUSIONS</b>Above-mintioned two surgical treatment for cervical spondylotic myelopathy can provide instantly stability, the method of ACDF combined with ACCF was obviously better that of the method of cervical posterior single open-door laminoplasty in intraoperative blood loss, the incidence rate of complications, clinical effect.Thus, for the treatment of three-segment cervical spondylotic myelopathy, the method of ACDF combined with ACCF would be firstly chosen.</p>
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft, and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery. Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh, bone graft, plate and screw fixation was established，and C3-7 segment intact model of cervical vertebra was also constructed. The torque moment of 0.5, 1.0, 1.5, 2.0 N﹒m was applied to the ACCF surgery model. The ROM, maximum stress in facet joint and stress distributions on internal fixation devices under flexion, extension, lateral bending and torsion movement were analyzed. Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery. In the case of 1.0 N﹒m torque moment and 50 N preload, the ROM of reconstructed C5, C3-4, C6-7 and C3-7 segment was reduced by 81%, 62%, 58% and 80% compared with the intact model. The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased. The stress of titanium mesh was mainly distributed on the compression side of movement, and high stress was located in the roots of screws. Conclusions ACCF surgery can promote the stability of cervical spine, decrease the stress in facet joint of operation segment, and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy. The research results will provide some theoretical basis for clinical application of ACCF.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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OBJECTIVE: To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group. METHODS: Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group. RESULTS: In all cases, the artificial disc and vertebra system maintained intervertebral motion and reestablished vertebral height at the operative level. After its implantation, there was no significant difference in the range of motion (ROM) of C3-7 in all directions in the non-fusion group compared with the intact group (p>0.05), but significant differences were detected in flexion, extension and axial rotation compared with the fusion group (p<0.05). The ROM of adjacent segments (C3-4, C6-7) of the non-fusion group decreased significantly in some directions compared with the fusion group (p<0.05). Significant differences in the C4-6 ROM in some directions were detected between the non-fusion group and the intact group. In the fusion group, the C4-6 ROM in all directions decreased significantly compared with the intact and non-fusion groups (p<0.01). The stability index ROM (SI-ROM) of some directions was negative in the non-fusion group, and a significant difference in SI-ROM was only found in the C4-6 segment of the non-fusion group compared with the fusion group. CONCLUSION: An artificial disc and vertebra system could restore vertebral height and preserve the dynamic function of the surgical area and could theoretically reduce the risk of adjacent segment degeneration compared with the anterior fusion procedure. However, our results should be considered with caution because of the low power of the study. The use of a larger ...
Subject(s)
Adult , Female , Humans , Male , Cadaver , Prostheses and Implants , Spinal Cord Diseases/surgery , Spinal Fusion/instrumentation , Cervical Vertebrae/surgery , Decompression, Surgical , Prosthesis Implantation , Spinal Fusion/methodsABSTRACT
OBJECTIVE: To investigate the causes for failed anterior cervical surgery and the outcomes of secondary laminoplasty. METHODS: Seventeen patients failed anterior multilevel cervical surgery and the following conservative treatments between Feb 2003 and May 2011 underwent secondary laminoplasty. Outcomes were evaluated by the Japanese Orthopaedic Association (JOA) Scale and visual analogue scale (VAS) before the secondary surgery, at 1 week, 2 months, 6 months, and the final visit. Cervical alignment, causes for revision and complications were also assessed. RESULTS: With a mean follow-up of 29.7+/-12.1 months, JOA score, recovery rate and excellent to good rate improved significantly at 2 months (p0.05). Mean VAS score decreased postoperatively (p0.05). The causes for secondary surgery were inappropriate approach in 3 patients, insufficient decompression in 4 patients, adjacent degeneration in 2 patients, and disease progression in 8 patients. Complications included one case of C5 palsy, axial pain and cerebrospinal fluid leakage, respectively. CONCLUSION: Laminoplasty has satisfactory results in failed multilevel anterior surgery, with a low incidence of complications.
Subject(s)
Humans , Asian People , Cerebrospinal Fluid , Decompression , Disease Progression , Follow-Up Studies , Incidence , Paralysis , SpondylosisABSTRACT
Objective To investigate the clinical therapeutic effects of different surgical treatments on cervical spondylotic my-elopathy and the occurrence of postoperative complications .Methods 65 patients with cervical spondylotic myelopathy admitted in our department between January 2010 and January 2013 were retrospectively analyzed ;and among them ,31 underwent anterior cer-vical discectomy and fusion(ACDF) and 34 underwent anterior cervical corpectomy and fusion (ACCF);the general surgical condi-tions ,JOA scores and functional grades of Nurick ,incidences of dysphagia and so on in the patients of the two groups were investi-gated .Results The operative time and intra-operative blood loss of the patients of the ACDF group were better than those of the ACCF group[(88 .70 ± 9 .03)min ,(125 .46 ± 12 .62)min ,(94 .26 ± 10 .34)mL ,(133 .98 ± 12 .09)mL] ,and the differences were sta-tistically significant(P0 .05);but the differences between the preoperative and postoperative JOA scores and functional grade of Nurick in 6 months after the surgeries and those before the surgeries of the same groups were statistically significant (P<0 .05) .At the same observation time points ,the incidences of dysphagia and the thicknesses of soft tissue before the cervical vertebra in the operated segment of the observation group were all lower than those of the control group ,and the differences were statistically significant (P<0 .05);in the patients of either group ,no loosening ,translocation or non-fusion of the bone graft was observed .Conclusion The two surgeries in treatment of cervical spondylotic myelopathy van both obtain satisfying clinical therapeutic effects ,but ACDF has a lower incidence of postop-erative complications ,and doctors should choose a suitable surgery based on the actual conditions .