Danlu Tongdu tablets treat lumbar spinal stenosis through reducing reactive oxygen species and apoptosis by regulating CDK2/CDK4/CDKN1A expression

Lumbar spinal stenosis is caused by the compression of the nerve root or cauda equina nerve by stenosis of the lumbar spinal canal or intervertebral foramen,and is manifested as chronic low back and leg pain.Danlu Tongdu(DLTD)tablets can relieve chronic pain caused by lumbar spinal stenosis,but the molecular mechanism remains largely unknown.In this study,the potential molecular mechanism of DLTD tablets in the treatment of lumbar spinal stenosis was first predicted by the network pharmacology method.Results showed that DLTD functions in regulating anti-oxidative,apoptosis,and inflammation signaling pathways.Furthermore,the flow cytometry results showed that DLTD tablets efficiently reduced reactive oxygen species content and inhibited rat neural stem cell apoptosis induced by hydrogen peroxide.DLTD also inhibited the mitochondrial membrane potential damage induced by hydrogen peroxide.Elisa analysis showed that DLTD induced cell cycle-related protein,CDK2 and CDK4,and reduced CDKN1A protein expression level.Taken together,our study provided new insights of DLTD in treating lumbar spinal stenosis through reducing reactive oxygen species content,decreasing apoptosis by inhibiting CDKN1A and promoting CDK2 and CDK4 expression levels.

Correlation study between the changes of motor evoked potential and the improvement of spinal canal volume in minimally invasive transforaminal lumbar interbody fusion

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.

Spectrum of magnetic resonance imaging findings in congenital lumbar spinal stenosis

AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects with CLSS and 48 control subjects were retrospectively evaluated. In each examination, the five lumbar levels were assessed for the presence or absence of circumferential or shallow annular bulges, annular tears, anterior or posterior disc herniations, epidural lipomatosis, Schmorl's nodes,spondylolisthesis, pars defects, and stress reactions of the posterior vertebral elements. RESULTS: Compared to control individuals, subjects with CLSS exhibited increased incidence of circumferential and shallow annular bulges, annular tears, discherniations and spondylolisthesis(P < 0.05). CONCLUSION: CLSS is associated with increased incidence of degenerative changes in specific osseous and soft-tissue elements of the lumbar spine.

Evaluation of degree of nerve root injury by dermatomal somatosensory evoked potential following lumbar spinal stenosis

BACKGROUND： Computed Tomography （CT） and Magnetic Resonance Imaging （MRI） can display the site of lumbar spinal stenosis and predict nervous compression at the morphological level; however, pure morphological changes cannot reflect functional alterations in a compressed nerve root. Dermatomal somatosensory evoked potential （DSEP） provides a means to assess the functional state of a nerve root. OBJECTIVE： To evaluate the clinical significance of DSEP, assessing the degree of nerve root injury following lumbar spinal stenosis. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Orthopaedic Surgery, Hainan People＇s Hospital, China, between September 2004 and December 2007. PARTICIPANTS： Forty-seven patients diagnosed with lumbar spinal stenosis by CT or MRI were selected as the case group; fifty healthy subjects were collected as the control group. METHODS： A KEYPOINT myoelectric evoked potential apparatus （DANTEC Company, Denmark） was used to measure DSEP, and stimulative spots were determined in accordance with the skin key sensory spot standards established by The American Spinal Injury Association： L4 in the medial malleolus, L5 in the third metatarsophalangeal joint of the dorsum of foot and S1 in the lateral heel. The needle electrode used as the recording electrode was located at the Cz point of the cranium, and the reference electrode at the Fz point. MAIN OUTCOME MEASURES： Latency of the P40 peak of DSEP, P1-N1 amplitude, P40 waveform and differentiation and disappearance of various waves. RESULTS： The sensitivity and diagnostic concurrence with surgery of nerve root injury following lumbar spinal stenosis evaluated by DSEP was 95.7 %. P40 latencies at L4, L5 and S1 in the case group were significantly longer than in the control group （P 〈 0.05）, and the P1-N1 amplitude in the case group was significantly lower than the control group （P 〈 0.05-0.01）. Nerve root injury was categorized according to DSEP latency as follows： severe damage （disappearance of the P40 wave in 103 dermatomes）, moderate damage （prolongation of the P40 peak latency ≥ 3.0 times the standard deviation of the normal mean in 60 dermatomes） and mild damage （prolongation of the P40 peak latency ≥ 2.5 times the standard deviation of the normal mean in 31 dermatomes）. CONCLUSION： DSEP can be used to determine the severity of nerve root injury following lumbar spinal stenosis with high sensitivity and specificity.

Early Functional Outcome of Posterior Spinal Decompression for Lumbar Spinal Stenosis at a Tertiary Health Institution, South East Nigeria

Background: Surgical treatment of lumbar spinal stenosis by posterior spinal decompression may be indicated if non-surgical management for the symptoms of low back and lower limbs radicular pains is unsuccessful and/or in patients with persisting or worsening neurological deficits. It has been reported to be an effective treatment modality in well selected patients. This procedure is however not without possible complications which can adversely affect the outcome of treatment in the affected patients. This prospective study was therefore undertaken to evaluate the early functional outcome of posterior spinal decompression for lumbar spinal stenosis at our health institution. Method: All patients with symptomatic lumbar spinal stenosis admitted for posterior spinal decompression and who met the inclusion criteria were recruited with their written informed consent. The patients’ pain severity and functional disability were assessed preoperatively with visual analogue scale (VAS) and Oswestry Disability Index (ODI). The VAS and ODI were also used to reassess the patients postoperatively, at 2 weeks, 6 weeks and 12 weeks respectively. All intraoperative and/or postoperative complications were documented and the results were analyzed. Results: The patients’ mean preoperative lower back pain and leg pain VAS score was 8.26 ± 1.46 while the mean preoperative ODI was 62.4% ±13.56. The commonest combination of spinal decompressive procedure done in the patients was laminectomy + foraminotomy in 10 (25% patients). The most common decompressed spinal level was L4/L5 (89.7%);while almost equal number of patients had either one spinal level or two-spinal level decompression (43.6% and 46.1% respectively). Postoperative pain assessment showed a mean VAS of 3.79 ± 1.15, 2.55 ± 1.27 and 2.00 ± 1.41 at 2 weeks, 6 weeks and 12 weeks respectively (p = 0.000). Functional outcome assessment with ODI was 34% ± 11.79%, 24% ± 10.75% and 18.12% ± 10.61% at 2 weeks, 6 weeks and 12 weeks respectively (p = 0.000). The commonest surgical complication seen was dura tear which occurred in nine patients (23.1%). Conclusion: There was significant reduction in low back and radicular pains with consequent functional improvement in majority of the patients who had posterior spinal decompression for lumbar spinal stenosis at our health institution. There were few complications of which dura tear was the commonest.

Severe lumbar spinal stenosis combined with Guillain-Barrésyndrome:A case report

BACKGROUND Guillain-Barrésyndrome(GBS)is a rare disorder that typically presents with ascending weakness,pain,paraesthesias,and numbness,which mimic the findings in lumbar spinal stenosis.Here,we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARY A 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness.Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis.However,his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness.An electromyogram was performed.Based on his symptoms,physical examination,and electromyogram,he was diagnosed with GBS.After 5 d of intravenous immunoglobulin(0.4 g/kg/d for 5 d)therapy,he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias.He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSION GBS should be considered in the differential diagnosis of spinal disorder,even though magnetic resonance imaging shows severe lumbar spinal stenosis.This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms.

LUMBAR SPINAL STENOSIS: A REVIEW OF BIOMECHANICAL STUDIES

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.

Techniques of Surgery for Lumbar Spinal Stenosis: A Comparative Study

Aim: To compare between classic open surgeries and minimally invasive surgeries in Lumbar Spinal Stenosis. Methods: A comparative descriptive study, involved 117 patients suffering from lumbar canal stenosis, aged between 40 - 70 years;admitted to department of Neurosurgery from March 2011 till august 2016 in King Fahad Hospital in Saudi Arabia. Study groups are consisted of group A as patients managed with classical laminectomy, group B as patients managed with endoscopic spinal procedures and group C as patients managed with microscopic decompression facilitated by the Metrex Tubular System. SPSS was used in data entry and analysis, and ethical considerations taken into consideration and participants filled the required inform consents. Results: Age of particaoncet ranged from 45 - 63 years, Mean +/&#8210;50. The degenerative canal stenosis with acute disc single level (cauda equina syndrome) was the most common type of lumbar canal stenosis encountered in group A;the unilateral foraminal and lateral recess stenosis without disc prolapse was the most common type of lumbar canal stenosis encountered in group B;while the unilateral foraminal and lateral recess stenosis without disc prolapse was the most common type of lumbar canal stenosis encountered in group C. Classic laminectomy and disectomy used mostly in group A;endoscopic unilateral decompression lamino-foraminotomy without discectomy used mostly in group B and bilateral microscopic laminectomy without discectomy followed by unilateral microscopic laminoforaminotomy without discectomy used mostly in group C. Mean of operation duration was the highest in both gender of group A, followed by group B, then group C. Unintended durotomy was the most common intra operative complications occurred in the whole study especially in group A. Mean of blood lost was the highest in both gender of group A, followed by group B, then group C. Postop complications in the patients of study groups were the highest in group A (33.3%), followed by group B (8.5%) and then group C (2%). Conclusion: Microscopic decompression facilitated by the Metrex Tubular System is the most effective technique of Surgery for Lumbar Spinal Stenosis and the least intra-operative and post-operative complications.

Simulation of Lumbar Spinal Stenosis Using the Finite Element Method

Lumbar spine stenosis(LSS)is a narrowing of the spinal canal that results in pressure on the spinal nerves.This orthopedic disorder can cause severe pain and dysfunction.LSS is a common disabling problem amongst elderly people.In this paper,we developed a finite element model(FEM)to study the forces and the von Mises stress acting on the spine when people bend down.An artificial lumbar spine(L3)was generated from CT data by using the FEM,which is a powerful tool to study biomechanics.The proposed model is able to predict the effect of forces which apply to the lumbar spine.In addition,FEM allows us to investigate the tests into the lumbar spine instead of applying the tests to the real spine in humans.The proposed model is highly accurate and provides precise information about the lumbar spine(L3).We investigate the behavior of humans in daily life which effects to the lumbar spine in a normal person and a patient with LSS.The computational results revealed high displacement levels around the spinal canal and lower displacement levels in the spinal body when bending down.The total displacement of the axial load in a normal person was higher when compared with patients with LSS.Higher degree bends resulted in a lower total displacement when compared with lower degree bends,while the von Mises stress decreased as the bending degree increased.

Changes in Attitudes toward Lumbar Spinal Stenosis Treatment

As the environment surrounding healthcare continues to evolve, there is a need to revise outcome assessment criteria. A shift is being demanded in diagnosis and treatment outcome assessment practices from objective to subjective assessment and from evaluation by doctors to assessment that is based on the patient’s own perspective. Therefore, lumbar diseases must now be assessed from multiple perspectives. Some major indices for evaluation are pain and numbness, functional status, general health status, disability, and patient satisfaction. An effective assessment method for lumbar spinal stenos is that examines symptoms, quality of life, and healthcare economics as key assessment factor is reviewed.

Nonsurgical intervention for neuroclaudication due to lumbar spinal stenosis:Interpretation of the 2021 American Association for the Study of Pain Guidelines

Lumbar Spinal Stenosis(LSS)is the major cause of Neurogenic Claudication(NC).It is common in the elderly and has an increasing incidence.In 2021,the United States Association for the Study of Pain published new evidence-based clinical practice guidelines to provide more effective nonsurgical treatment of LSS-induced NC.Based on a thorough reading of the latest guidelines,combined with new clinical developments,and in collaboration with the 2011 North American Spine Society,NASS guidelines(hereinafter referred to as the 2011 Guidelines)were compared with the 2019 Danish Health Authority(DHA)Guidelines(hereinafter referred to as the 2019 Guidelines),and the clinical diagnosis and treatment of NC caused by LSS were reviewed and suggestions were put forward.

Observation on TCM syndromes effect of Shujinjianyao Pill in the Treatment of Lumbar Spinal Stenosis (Ganshenbuzu and Fengshiyuzu Syndrome)

Objective:To observe the TCM(Traditonal Chinese Medcine)syndromes effect and safety of Shujinjianyao Pill in the treatment of LSS(Lumbar Spinal Stenosis)(Ganshenbuzu and Fengshiyuzu Syndrome).Methods:120 LSS patients fit the inclusion criteria were separated into two groups,90 in the experimental group and 30 in the control group.No significant difference was existed in the basic data between the two groups.The experimental group was given Shujinjianyao Pill and Danlutongdu Tablet Simulator orally,while the control group was given Shujinjianyao Pill Simulator and Danlutongdu Tablet orally for 4 weeks.The VAS score,total TCM(Traditonal Chinese Medcine)syndrome score and single TCM symptom score on day 0,14 and 28 were observed,and adverse reactions were recorded.Result:There were significant differences in total TCM syndrome score between the two groups at baseline,14 day and 28 day(P<0.01).There was a significant difference in total TCM syndrome score between the two groups at 28 day(P<0.05).Significant differences were existed between this two groups in total effective rate of total TCM syndromes and waist-knee pain-weak in single TCM syndromes on the 28 day(P<0.05).There was no significant difference in the incidence of adverse events and serious adverse events between the two groups(P>0.05).Conclusion:Shujinjianyao Pill is effective on TCM syndromes in the treatment of Ganshenbuzu and fengshiyuzu syndrome LSS,especially in improving the score of total TCM syndromes and waist-knee pain-weak of single TCM syndrome,and has high safety.

Technical Nuances of Minimal Invasive Interlaminar Decompression in Lumbar Spinal Stenosis: The Role of Minimal Invasive Bilateral Approach

We report a series of patients operated for one or multilevel lumbar spinal stenosis (with and without spondylolisthesis) using the minimal invasive bilateral interlaminar decompression. We discuss our results, comparing this procedure (from a technical point of view) with the muscle-preserving interlaminar decompression (MILD) and the unilateral approach for bilateral decompression (ULBD). Clinical and outcome data of 62 consecutive patients were reviewed, using the Visual Analogue Scale for both low back pain (LBP) and legs pain and the Oswestry Disability Index (ODI) for the degree of disability. Mean age was 68.88 ± 9.54 years and mean follow-up (FU) was 16.38 ± 11.12 months. A statistically significant improvement of LBP, legs pain and ODI was globally observed. At latest FU, patients with multilevel lumbar spinal stenosis significantly improved all scores and patients with spondylolisthesis significantly decreased their disability. No major complications occurred. Two cerebrospinal fluid (CSF) collections were treated conservatively. No wound infection occurred. No progression of spondylolisthesis was observed. No reoperation was needed. Although efficacious in patients with lumbar spinal stenosis, MILD and ULBD can have both some limitations. MILD has been found to decrease lumbar function in multilevel decompression (increasing sagittal translation and lumbar lordosis probably due to the removal of half of the spinous processes) and ULBD shows some disadvantages due to the difficulty of manipulating instruments through a small portal and the inadequate decompression due to a minimal exposure. The minimal invasive bilateral interlaminar decompression (in this technique, the access is bilateral but the supraspinous and interspinous ligaments and the spinous processes are preserved) allows wide access (bilateral exposure) with minimal invasiveness and very low morbidity in patients with lumbar spinal stenosis at one or more levels.

Comparison of Physical Therapy Follow-Up of Patients with Operated and Non-Operated Lumbar Spinal Stenosis According to the Nottingham Health Profile-Pain Scale

Background: Lumbar spinal stenosis (LSS) continues to be a major problem in societies, causing job loss and lowering quality of life. There are two types of treatment methods, physical therapy and surgery. If patients with LSS avoid treatment, they are likely to experience neurological deterioration in later years. Objective: The study aimed to evaluate the effect of physical therapy applied after decompression surgery or the effect of only applied physical therapy in patients with lumbar spinal stenosis. Materials and Methods: The results of the physical therapy follow-up of patients who had surgery and did not have surgery due to lumbar spinal stenosis between July 2014 and December 2019 were compared with each other. All patients received physical therapy for 6 months. Included were 42 patients who underwent decompression surgery due to LSS; 56 patients were not operated. Clinical outcomes were measured using the Nottingham Health Profile-Pain (NHP-Pain) scale at the initial, first, third and sixth months. The results were compared statistically. Results: The age of the operated patients was 54.69 ± 8.42 (39 - 71), while the non-operated patients were 59.16 ± 14.04 (34 - 83). There was no significant difference in the statistical comparison (p = 0.053). While the body mass index (BMI) of the operated patients was 29.43 ± 4.99 (21 - 40), the BMI of the non-operated patients was 28.84 ± 4.62 (22 - 42). There was no significant difference in the statistical comparison (p = 0.552). The scores of a 6-month physical therapy follow-up of patients were evaluated according to the NHP-pain scale. The values of patients who underwent surgery, initial - 1st month (p < 0.001), 1st month - 3rd month (p = 0.028), 3rd month - 6th month (p = 0.389) follow-up of the intervals were compared statistically. The values of non-operated patients, initial - 1st month (p = 0.008), 1st month -3rd month (p = 0.013), 3rd month - 6th month (p = 0.025) were compared statistically. Patients with and without surgery had significantly different initial pain scores (p < 0.001). Conclusions: The NHP-Pain scores of the patients undergoing physical therapy with the operation were shown to provide more significant improvement than the group receiving only the physical therapy. Patients with LSS should be treated with an operation to obtain the maximum benefit of physical therapy.

Diagnosis and one stage surgical treatment of lower thoracic ossification of ligamentum flavum combined with lumbar spinal stenosis

Objective To study the diagnosis and treatment of lower thoracic ossification of ligamentum flavum(OLF) combined with lumbar spinal stenosis.Methods Retrospective analysis was carried out on 11 cases of lower thoracic OLF combined with

Spinal dural arteriovenous fistula 8 years after lumbar discectomy surgery: A case report and review of literature

BACKGROUND Spinal dural arteriovenous fistula(SDAVF)is an extremely rare vascular malformation of the central nervous system that is often confused with degenerative spinal disorders due to similar early symptoms and clinical features.Here,we report a case of SDAVF recurrence 8 years after lumbar spine surgery and summarize relevant literature.CASE SUMMARY A 54-year-old male was admitted to our hospital complaining of lower back pain,numbness in both lower extremities and intermittent claudication.Subsequent imaging identified lumbar spinal stenosis.Following surgical treatment,the patient’s symptoms significantly resolved,and he was able to perform daily activities.However,similar symptoms appeared 8 years later,followed by confirmation of SDAVF diagnosis.The patient underwent neurosurgery 7 mo after symptom onset.The follow-up period lasted 14 mo,and the patient remains with marginal neurological symptoms.CONCLUSION This case highlights the importance of prompt SDAVF diagnosis.Due to its nonspecific clinical presentation,the clinical experience of the surgeon and definitive imaging examination are indispensable.Additionally,timely neurosurgery is effective and may significantly improve patient outcomes.

Histological difference in ligament flavum between degenerative lumbar canal stenosis and non-stenotic group:A prospective,comparative study

BACKGROUND Ligament flavum(LF)hypertropy is the main etiopathogenesis of lumbar canal stenosis(LCS).The purely elastic LF undergoes a morphological adaptation including a reduction in the elastic fibers and a consequent increase in the collagen content,fibrosis,cicatrization,and calcification.However,the morphometric analysis can delineate the LF in patients with LCS from those without LCS,which would help in better understanding LCS pathogenesis.AIM To compare the histopathological changes in LF between the degenerative LCS and non-stenotic(non-LCS)group.METHODS The present prospective study was conducted in 82 patients who were divided into two groups,namely LCS and non-LCS.Demographic details of the patients such as duration of symptoms,level of involvement,and number of segments were recorded.The LF obtained from both groups was histopathologically examined for the fibrosis score,elastic fiber degeneration,calcification,and chondroid metaplasia.Morphometrical details included a change in elastin and collagen percentages,elastin/collagen ratio,elastic fiber fragmentation,and ligamentocyte numbers.All parameters were compared between the two groups by using the independent t test,Chi-square test,and Pearson’s correlation test.RESULTS Out of 82 cases,74 were analysed,34 in LCS and 40 in non-LCS group.The mean±SD age of presentation in LCS and non-LCS group was 49.2±8.9 and 43.1±14.3 respectively.The LCS group(n=34)exhibited significant differences in fibrosis(P=0.002),elastic fiber degeneration(P=0.01),%elastic fragmentation(66.5±16.3 vs 29.5±16.9),%elastic,content(26.9±6.7 vs 34.7±8.4),%collagen content(63.6±10.4 vs 54.9±6.4),reduction of elastic/collagen(0.4±0.1 vs 0.6±0.1),and ligamentocyte number(39.1±19.1 vs 53.5±26.9)as compared to non-LCS group(n=40).The calcification(P=0.08)and Pearson’s correlation between duration and loss of elastin was not significant.The difference in LF morphology is consistent in patient’s≥40 years of age among the groups as found in subgroup analysis.Similarly in the patents<40 and>40 in the non-LCS group.CONCLUSION LF is vital in the pathogenesis of LCS.The purely elastic LF undergoes a morphological adaptation that includes a reduction in the elastic fibers with a consequent increase in the collagen content,fibrosis,cicatrization,and calcification.The present study provides a detailed morphometric analysis to semiquantitatively delineate the LF changes in patients with LCS from those in patients without LCS.

Interspinous Process Implants Causes Wear of the Spinous Processes in Patients Treated for Spinal Stenosis—An Experimental Biomechanical Study with Comparison to Clinical Cases

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.

Mechanical properties of nerve roots and rami radiculares isolated from fresh pig spinal cords

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.

Correlation of lumbar lateral recess stenosis in magnetic resonance imaging and clinical symptoms

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.