Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed co...Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed comparing the clinical effectiveness of unilateral versus bilateral fixation in the surgical management of lumbar spinal canal stenosis. Objective: Evaluate the impact on quality of life and clinical efficacy of unilateral spondylodesis compared to bilateral spondylodesis in the surgical management of lumbar spinal canal stenosis at the Yaounde Central Hospital. Methods: This was a retrospective descriptive cross-sectional study for a period of 4 years, from June 2015 to June 2019. It involved all patients operated for lumbar canal stenosis and who underwent spondylodesis or spinal fusion at the neurosurgery department of the Yaounde Central Hospital. Results: A total of 68 participants were recruited during our study period. 32 (47%) of the study population were in the 50 - 60 age group, with a mean age of 56.98 years ranging from 41 to 75 years. Females, housewives and farmers were the most affected. In our study, 72% of patients had unilateral spondylodesis and 28% had bilateral fusion. Preoperatively, 71% of patients had insurmountable pain, refractory to medical treatment. At 3 months postoperatively, 73.7% of patients with bilateral setup had moderate pain compared to 69% of those with unilateral setup. At 6 months postoperatively, 79% of patients with bilateral fusion had mild pain compared to 82% of patients with unilateral setup. At 1 year postoperatively, all patients had mild pain. Preoperatively, 66.2% of patients were unable to walk and 19.1% of patients were bedridden according to the Oswestry score. At 3 months postoperatively, 10.2% of patients with unilateral setup were unable to walk compared to 10.5% of patients with bilateral fixation, while 67.3% of patients with unilateral fixation had moderate disability compared to 52.6% of patients with bilateral fixation. At 6 months postoperatively, 51% of patients with unilateral setup had moderate disability compared to 47.4% of patients with bilateral fixation, while 42.9% of patients with unilateral fixation had mild disability compared to 42.1% of patients with bilateral fixation. At 1 year postoperatively, 81.6% of patients who underwent unilateral fixation had only mild disability compared to 73.7% of patients with bilateral fixation. Conclusion: The assessment of quality of life according to the set-up used shows similar results at 3 months, 6 months and 1 year, with no statistically significant differences. Single-sided pedicle screw fixation combined with transforaminal lumbar interbody fusion or mounting has the advantage of being faster, with less bleeding and is less expensive compared to bilateral fixation.展开更多
Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after...Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.展开更多
Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as t...Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as three-dimensional finite element models. three-dimensional kinematic measurement, cadeveric evaluation, and imaging assessment was applied to correlate lumbar biomechanics and lumbar spinal stenosis. Surgery of lumbar spinal stenosis has been improved. Results. The stresses significantly concentrate on the posterolateral part of the annulus fibrosus of disc, the posterior surface of vertebral body, the pedicle, the interarticularis and the facet joints. This trend is intensified by disc degeneration and lumbar backward extension. Posterior element resection has a definite effect upon the biomechanical behavior of lumbar vertebrae. The improved operations proved satis- factory. Conclusion. Stress concentration in the lumbar vertebrae is of importance to the etiology of degenerative lumbar spinal stenosis, and disc degeneration is the initial key of this process. Then these will be aggravated by backward extension. Functional radiography and myelography are of assistance to the diagnosis o f the lumbar spinal stenosis. For the surgical treatment of the lumbar spinal stenosis, destruction of the posterior element should be avoid as far as possible based upon the thorough decompression. Maintaining the lumbar spine in flexion by fusion after decompression has been proved a useful method. When developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy is recommend for decompression.展开更多
Introduction: Gout is defined as an arthritic condition resulting from the deposition of monosodium urate crystals in and/or around joints, following long-standing hyperuricemia. This may cause gouty arthritis in join...Introduction: Gout is defined as an arthritic condition resulting from the deposition of monosodium urate crystals in and/or around joints, following long-standing hyperuricemia. This may cause gouty arthritis in joints and tophi in soft tissues. Spinal gout is rare and never mentioned in our context. It can appear as acute back pain, radiculopathy, spinal cord compression, spondylodiscitis or neoplasic/infectious epiduritis. Our aim was to share our surgical experience and proceed of a Literature review. Cases Presentation: Between January and August 2022, two patients male were surgically cared, aged of 42 and 60 years old. The gout was unknown in the youngest and poorly followed in the eldest. There was no past medical history of tuberculosis or immunodeficiency in both. The early diagnosis retained was unspecific lumbar spondylodiscitis due to clinical features: Patients complained both of lower back pain with initial fever. It was of a progressive left L5S1 deficit with erectile defect and dysuria in the first case and a progressive paraplegia without sphincter disorders in the second case. We proceeded with a lumbar laminectomy with a biopsy on both patients. The spinal tophus was ligamentous in one case and arthro-ligamentous in the other. There was a progressive motor recovery from postoperative Day-2 till postoperative Month-1. A probabilistic antituberculosis treatment was promptly initiated postoperatively based on radioclinic features while waiting for histologic proof. The Polymerase Chain Reaction (PCR) of Mycobacterium tuberculosis was negative and the histology was of a chronic calcified osteitis with dense fibrosis in both. The anti-gout treatment was implemented after 15 days with blood test evidence. A rheumatologic follow-up was also initiated and adjuvant physio-therapy. The results were very satisfactory from 4 - 6 months with independent walking. Discussion Conclusion: Spinal Gout may be suggested in 40-male-old faced with any acute rachialgia with neuro deficit with dubious neuro-imaging.展开更多
Objective:To investigate the relationship between morphological abnormalities and spinal cord deficit in thoracolumbar burst fractures. Methods: Seventy-eight patients with thoracolumbar burst fractures were retrospec...Objective:To investigate the relationship between morphological abnormalities and spinal cord deficit in thoracolumbar burst fractures. Methods: Seventy-eight patients with thoracolumbar burst fractures were retrospectively reviewed to calculate the stenotic ratio of spinal canal based on the midsagittal diameters and the hyphosis angle according to Cobb. The ASIA scoring of motor function of lower extremities was recorded . Results: The differences (P > 0.05) of the stenotic ratio of spinal canal and the kyphosis angle were not significant between patients without neurological deficit, with incomplete and complete lesions. No significant correlation(P > 0.05) between the stenotic ratio of spinal canal and the kyphosis angle, and ASIA scoring was noted. Conclusion:The severity of spinal cord injuries in thoracolumbar burst fractures is not predicted according to the percentage of canal stenosis or the degree of kyphesis induced by thoracolumbar burst fractures.展开更多
There are few biomechanical studies on Interspinous Process Implants (IPD);however none investigate the amount of wear on spinous processes. Therefore the objective of the present study was to investigate the effect o...There are few biomechanical studies on Interspinous Process Implants (IPD);however none investigate the amount of wear on spinous processes. Therefore the objective of the present study was to investigate the effect of repetitive loading of the IPD Aperius on the spinous processes in a biomechanical porcine model. For comparison, three patients treated surgically with the same device have been followed for one to two years clinically and with image analyses (X-rays, MRI, CT-scans). Four lumbar spines from 6 months old porcine were divided into seven segments, which received IPD. The segments were exposed to 20,000 cyclical loads. Afterwards the deformation (wear) of the segments was registered. The wear of the spinous processes was measured in mm on a following CT-scan. Additionally, the wear of the ex-vivo was compared to that of the spinous processes investigated by CT-scans or X-ray in three patients treated surgically with the same interspinous implant. The mean maximal deformation of porcine specimens was 1.79 mm (SD 0.25) with the largest deformation occurring in the first quarter of the loading (<5000 cycles). The mean wear of the spinous processes after loading was 6.57 mm. A similar level of wear (mean 12.7 mm) of the spinous processes was detected in the patients. The Aperius IPD creates significant wear on the spinous processes in an experimental biomechanical study. Similar wear of the spinous processes is also present in patients treated with the same device post-operatively. How these findings influence the short and long term result of this implant device remains to be investigated in further biomechanical as well as clinical studies. For future development of this type of devices a proper selection of materials and design is essential to minimize wear effects on the spinous processes and thereby increases the possibilities for the devices to function as suggested.展开更多
No reports have described experiments designed to determine the strength characteristics of spinal nerve roots and rami radiculares for the purpose of explaining the complexity of symptoms of medullary cone lesions an...No reports have described experiments designed to determine the strength characteristics of spinal nerve roots and rami radiculares for the purpose of explaining the complexity of symptoms of medullary cone lesions and cauda equina syndrome. In this study, to explain the pathogenesis of cauda equina syndrome, monoaxial tensile tests were performed to determine the strength characteristics of spinal nerve roots and rami radiculares, and analysis was conducted to evaluate the stress-strain relationship and strength characteristics. Using the same tensile test device, the nerve root and ramus radiculares isolated from the spinal cords of pigs were subjected to the tensile test and stress relaxation test at load strain rates of 0.1, 1, 10, and 100 s-1 under identical settings. The tensile strength of the nerve root was not rate dependent, while the ramus radiculares tensile strength tended to decrease as the strain rate increased. These findings provide important insights into cauda equina symptoms, radiculopathy, and clinical symptoms of the medullary cone.展开更多
AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were ...AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study.On magnetic resonance images(MRI) the lateral recesses(LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale(Grade 0-3) as normal,not deviated,deviated or compressed.Patient symptoms and disability were assessed using ODI.The Spearman's rank correlation coefficient was used for statistical analysis(P < 0.05).RESULTS Approximately half of the LR revealed stenosis(grade 1-3;52% at level L4/5 and 42% at level L5/S1) with 2.2% and 1.9% respectively reveal a nerve root compression.The ODI score ranged from 0%-91.11% with an arithmetic mean of 34.06% ± 16.89%.We observed a very weak statistically significant positive correlation between ODI and LRS at lumbar levels L4/5 and L5/S1,each bilaterally(L4/5 left:rho < 0.105,P < 0.01;L4/5 right:rho < 0.111,P < 0.01;L5/S1 left:rho 0.128,P < 0.01;L5/S1 right:rho < 0.157,P < 0.001).CONCLUSION Although MRI is the standard imaging tool for diagnosing lumbar spinal stenosis,this study showed only a weak correlation of LRS on MRI and clinical findings.This can be attributed to a number of reasons outlined in this study,underlining that imaging findings alone are not sufficient to establish a reliable diagnosis for patients with LRS.展开更多
目的探讨创伤性中下段腰椎(L_(2)-L_(5))骨折后神经功能损伤的影像学风险因素。方法回顾性分析该院2019年1月~2022年10月收治的71例创伤性中下段腰椎(L_(2)-L_(5))骨折患者资料,根据ASIA分级进行神经功能评估,将患者分为损伤组31例和未...目的探讨创伤性中下段腰椎(L_(2)-L_(5))骨折后神经功能损伤的影像学风险因素。方法回顾性分析该院2019年1月~2022年10月收治的71例创伤性中下段腰椎(L_(2)-L_(5))骨折患者资料,根据ASIA分级进行神经功能评估,将患者分为损伤组31例和未损伤组40例。统计两组患者的人口学资料和临床资料,并在矢状位和轴位腰椎CT片上测量以下影像学指标:椎管侵占率、椎体前缘高度比、椎弓根内侧间距比值、伤椎Cobb角和是否存在椎板垂直骨折等。对两组患者的上述资料进行比较,将P<0.05的相关因素纳入到多因素Logistic回归模型进行处理;采用ROC曲线确定独立影响指标的最佳截断值,采用曲线下面积(area under the curve,AUC)对其预测价值进行评价。结果71例中,31例(43.7%)出现神经功能障碍,ASIA分级为A级3例(4.2%),B级5例(7.0%),C级3例(4.2%),D级20例(28.2%);其中,有24例(33.8%)存在下肢无力,16例(22.5%)存在自主神经功能障碍。损伤组和未损伤组患者的损伤水平、骨折AO分型、椎管侵占率、椎体前缘高度比、椎弓根内侧间距比值、椎板垂直骨折的占比等数据,差异有统计学意义(P<0.05)。经Logistic回归模型分析,损伤水平(P=0.021)、椎管侵占率(P=0.007)、椎体前缘高度比(P=0.036),均是与患者神经功能损伤相关的独立影响因素。ROC曲线分析得出,仅椎管侵占率具备良好的鉴别能力(AUC=0.874,95%CI=0.791~0.957),其最佳截断值为47%,灵敏度为90.3%,特异度为80%。结论损伤水平、椎管侵占率和椎体前缘高度比,均是创伤性中下段腰椎(L_(2)-L_(5))骨折后神经功能损伤的影像学风险因素,其中椎管侵占率与患者神经功能损伤的相关性最强,最佳截断值为47%。展开更多
文摘Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed comparing the clinical effectiveness of unilateral versus bilateral fixation in the surgical management of lumbar spinal canal stenosis. Objective: Evaluate the impact on quality of life and clinical efficacy of unilateral spondylodesis compared to bilateral spondylodesis in the surgical management of lumbar spinal canal stenosis at the Yaounde Central Hospital. Methods: This was a retrospective descriptive cross-sectional study for a period of 4 years, from June 2015 to June 2019. It involved all patients operated for lumbar canal stenosis and who underwent spondylodesis or spinal fusion at the neurosurgery department of the Yaounde Central Hospital. Results: A total of 68 participants were recruited during our study period. 32 (47%) of the study population were in the 50 - 60 age group, with a mean age of 56.98 years ranging from 41 to 75 years. Females, housewives and farmers were the most affected. In our study, 72% of patients had unilateral spondylodesis and 28% had bilateral fusion. Preoperatively, 71% of patients had insurmountable pain, refractory to medical treatment. At 3 months postoperatively, 73.7% of patients with bilateral setup had moderate pain compared to 69% of those with unilateral setup. At 6 months postoperatively, 79% of patients with bilateral fusion had mild pain compared to 82% of patients with unilateral setup. At 1 year postoperatively, all patients had mild pain. Preoperatively, 66.2% of patients were unable to walk and 19.1% of patients were bedridden according to the Oswestry score. At 3 months postoperatively, 10.2% of patients with unilateral setup were unable to walk compared to 10.5% of patients with bilateral fixation, while 67.3% of patients with unilateral fixation had moderate disability compared to 52.6% of patients with bilateral fixation. At 6 months postoperatively, 51% of patients with unilateral setup had moderate disability compared to 47.4% of patients with bilateral fixation, while 42.9% of patients with unilateral fixation had mild disability compared to 42.1% of patients with bilateral fixation. At 1 year postoperatively, 81.6% of patients who underwent unilateral fixation had only mild disability compared to 73.7% of patients with bilateral fixation. Conclusion: The assessment of quality of life according to the set-up used shows similar results at 3 months, 6 months and 1 year, with no statistically significant differences. Single-sided pedicle screw fixation combined with transforaminal lumbar interbody fusion or mounting has the advantage of being faster, with less bleeding and is less expensive compared to bilateral fixation.
基金National Natural Science Foundation of China(No.82160435)。
文摘Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.
基金This project was supported by the National Natural ScienceFoundation of China.
文摘Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as three-dimensional finite element models. three-dimensional kinematic measurement, cadeveric evaluation, and imaging assessment was applied to correlate lumbar biomechanics and lumbar spinal stenosis. Surgery of lumbar spinal stenosis has been improved. Results. The stresses significantly concentrate on the posterolateral part of the annulus fibrosus of disc, the posterior surface of vertebral body, the pedicle, the interarticularis and the facet joints. This trend is intensified by disc degeneration and lumbar backward extension. Posterior element resection has a definite effect upon the biomechanical behavior of lumbar vertebrae. The improved operations proved satis- factory. Conclusion. Stress concentration in the lumbar vertebrae is of importance to the etiology of degenerative lumbar spinal stenosis, and disc degeneration is the initial key of this process. Then these will be aggravated by backward extension. Functional radiography and myelography are of assistance to the diagnosis o f the lumbar spinal stenosis. For the surgical treatment of the lumbar spinal stenosis, destruction of the posterior element should be avoid as far as possible based upon the thorough decompression. Maintaining the lumbar spine in flexion by fusion after decompression has been proved a useful method. When developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy is recommend for decompression.
文摘Introduction: Gout is defined as an arthritic condition resulting from the deposition of monosodium urate crystals in and/or around joints, following long-standing hyperuricemia. This may cause gouty arthritis in joints and tophi in soft tissues. Spinal gout is rare and never mentioned in our context. It can appear as acute back pain, radiculopathy, spinal cord compression, spondylodiscitis or neoplasic/infectious epiduritis. Our aim was to share our surgical experience and proceed of a Literature review. Cases Presentation: Between January and August 2022, two patients male were surgically cared, aged of 42 and 60 years old. The gout was unknown in the youngest and poorly followed in the eldest. There was no past medical history of tuberculosis or immunodeficiency in both. The early diagnosis retained was unspecific lumbar spondylodiscitis due to clinical features: Patients complained both of lower back pain with initial fever. It was of a progressive left L5S1 deficit with erectile defect and dysuria in the first case and a progressive paraplegia without sphincter disorders in the second case. We proceeded with a lumbar laminectomy with a biopsy on both patients. The spinal tophus was ligamentous in one case and arthro-ligamentous in the other. There was a progressive motor recovery from postoperative Day-2 till postoperative Month-1. A probabilistic antituberculosis treatment was promptly initiated postoperatively based on radioclinic features while waiting for histologic proof. The Polymerase Chain Reaction (PCR) of Mycobacterium tuberculosis was negative and the histology was of a chronic calcified osteitis with dense fibrosis in both. The anti-gout treatment was implemented after 15 days with blood test evidence. A rheumatologic follow-up was also initiated and adjuvant physio-therapy. The results were very satisfactory from 4 - 6 months with independent walking. Discussion Conclusion: Spinal Gout may be suggested in 40-male-old faced with any acute rachialgia with neuro deficit with dubious neuro-imaging.
文摘Objective:To investigate the relationship between morphological abnormalities and spinal cord deficit in thoracolumbar burst fractures. Methods: Seventy-eight patients with thoracolumbar burst fractures were retrospectively reviewed to calculate the stenotic ratio of spinal canal based on the midsagittal diameters and the hyphosis angle according to Cobb. The ASIA scoring of motor function of lower extremities was recorded . Results: The differences (P > 0.05) of the stenotic ratio of spinal canal and the kyphosis angle were not significant between patients without neurological deficit, with incomplete and complete lesions. No significant correlation(P > 0.05) between the stenotic ratio of spinal canal and the kyphosis angle, and ASIA scoring was noted. Conclusion:The severity of spinal cord injuries in thoracolumbar burst fractures is not predicted according to the percentage of canal stenosis or the degree of kyphesis induced by thoracolumbar burst fractures.
文摘There are few biomechanical studies on Interspinous Process Implants (IPD);however none investigate the amount of wear on spinous processes. Therefore the objective of the present study was to investigate the effect of repetitive loading of the IPD Aperius on the spinous processes in a biomechanical porcine model. For comparison, three patients treated surgically with the same device have been followed for one to two years clinically and with image analyses (X-rays, MRI, CT-scans). Four lumbar spines from 6 months old porcine were divided into seven segments, which received IPD. The segments were exposed to 20,000 cyclical loads. Afterwards the deformation (wear) of the segments was registered. The wear of the spinous processes was measured in mm on a following CT-scan. Additionally, the wear of the ex-vivo was compared to that of the spinous processes investigated by CT-scans or X-ray in three patients treated surgically with the same interspinous implant. The mean maximal deformation of porcine specimens was 1.79 mm (SD 0.25) with the largest deformation occurring in the first quarter of the loading (<5000 cycles). The mean wear of the spinous processes after loading was 6.57 mm. A similar level of wear (mean 12.7 mm) of the spinous processes was detected in the patients. The Aperius IPD creates significant wear on the spinous processes in an experimental biomechanical study. Similar wear of the spinous processes is also present in patients treated with the same device post-operatively. How these findings influence the short and long term result of this implant device remains to be investigated in further biomechanical as well as clinical studies. For future development of this type of devices a proper selection of materials and design is essential to minimize wear effects on the spinous processes and thereby increases the possibilities for the devices to function as suggested.
文摘No reports have described experiments designed to determine the strength characteristics of spinal nerve roots and rami radiculares for the purpose of explaining the complexity of symptoms of medullary cone lesions and cauda equina syndrome. In this study, to explain the pathogenesis of cauda equina syndrome, monoaxial tensile tests were performed to determine the strength characteristics of spinal nerve roots and rami radiculares, and analysis was conducted to evaluate the stress-strain relationship and strength characteristics. Using the same tensile test device, the nerve root and ramus radiculares isolated from the spinal cords of pigs were subjected to the tensile test and stress relaxation test at load strain rates of 0.1, 1, 10, and 100 s-1 under identical settings. The tensile strength of the nerve root was not rate dependent, while the ramus radiculares tensile strength tended to decrease as the strain rate increased. These findings provide important insights into cauda equina symptoms, radiculopathy, and clinical symptoms of the medullary cone.
文摘AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study.On magnetic resonance images(MRI) the lateral recesses(LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale(Grade 0-3) as normal,not deviated,deviated or compressed.Patient symptoms and disability were assessed using ODI.The Spearman's rank correlation coefficient was used for statistical analysis(P < 0.05).RESULTS Approximately half of the LR revealed stenosis(grade 1-3;52% at level L4/5 and 42% at level L5/S1) with 2.2% and 1.9% respectively reveal a nerve root compression.The ODI score ranged from 0%-91.11% with an arithmetic mean of 34.06% ± 16.89%.We observed a very weak statistically significant positive correlation between ODI and LRS at lumbar levels L4/5 and L5/S1,each bilaterally(L4/5 left:rho < 0.105,P < 0.01;L4/5 right:rho < 0.111,P < 0.01;L5/S1 left:rho 0.128,P < 0.01;L5/S1 right:rho < 0.157,P < 0.001).CONCLUSION Although MRI is the standard imaging tool for diagnosing lumbar spinal stenosis,this study showed only a weak correlation of LRS on MRI and clinical findings.This can be attributed to a number of reasons outlined in this study,underlining that imaging findings alone are not sufficient to establish a reliable diagnosis for patients with LRS.
文摘目的探讨创伤性中下段腰椎(L_(2)-L_(5))骨折后神经功能损伤的影像学风险因素。方法回顾性分析该院2019年1月~2022年10月收治的71例创伤性中下段腰椎(L_(2)-L_(5))骨折患者资料,根据ASIA分级进行神经功能评估,将患者分为损伤组31例和未损伤组40例。统计两组患者的人口学资料和临床资料,并在矢状位和轴位腰椎CT片上测量以下影像学指标:椎管侵占率、椎体前缘高度比、椎弓根内侧间距比值、伤椎Cobb角和是否存在椎板垂直骨折等。对两组患者的上述资料进行比较,将P<0.05的相关因素纳入到多因素Logistic回归模型进行处理;采用ROC曲线确定独立影响指标的最佳截断值,采用曲线下面积(area under the curve,AUC)对其预测价值进行评价。结果71例中,31例(43.7%)出现神经功能障碍,ASIA分级为A级3例(4.2%),B级5例(7.0%),C级3例(4.2%),D级20例(28.2%);其中,有24例(33.8%)存在下肢无力,16例(22.5%)存在自主神经功能障碍。损伤组和未损伤组患者的损伤水平、骨折AO分型、椎管侵占率、椎体前缘高度比、椎弓根内侧间距比值、椎板垂直骨折的占比等数据,差异有统计学意义(P<0.05)。经Logistic回归模型分析,损伤水平(P=0.021)、椎管侵占率(P=0.007)、椎体前缘高度比(P=0.036),均是与患者神经功能损伤相关的独立影响因素。ROC曲线分析得出,仅椎管侵占率具备良好的鉴别能力(AUC=0.874,95%CI=0.791~0.957),其最佳截断值为47%,灵敏度为90.3%,特异度为80%。结论损伤水平、椎管侵占率和椎体前缘高度比,均是创伤性中下段腰椎(L_(2)-L_(5))骨折后神经功能损伤的影像学风险因素,其中椎管侵占率与患者神经功能损伤的相关性最强,最佳截断值为47%。
