Narrowing Of Spinal Canal Research Articles

Preoperative Computed Tomography Myelography Parameters as Predictors of Outcome in Patients With Degenerative Cervical Myelopathy: Results of a Systematic Review.

Study Design:Systematic review.Objectives:To determine the preoperative computed tomography (CT) myelogram imaging parameters in patients diagnosed with degenerative cervical myelopathy (DCM) that correlate with severity of DCM and predict postoperative patients’ functional outcome.Methods:An electronic database search was performed using Ovid Medline and Embase. CT myelogram studies investigating the correlation between imaging characteristics and DCM severity or postoperative outcomes were included. Two independent reviewers performed citation screening, selection, qualitative assessment, and data extraction using an objective and blinded protocol.Results:A total of 5 studies (402 patients) were included in this review and investigated the role of preoperative CT myelogram parameters in predicting the functional outcome after surgical treatment of DCM. All studies were retrospective cohort studies. CT myelogram characteristics included the transverse area of the spinal cord at maximum level of compression, spinal canal narrowing, number of blocks, spinal canal diameter, and flattening ratio. There is low evidence suggesting that patients with a preoperative transverse area of the spinal cord >30 mm2 at the level of maximum compression have better postoperative recovery and outcome. We found no studies investigating the correlation between preoperative CT myelogram parameters and DCM severity.Conclusions:Patients with greater transverse area of spinal cord at the level of maximum compression on the preoperative CT myelogram are more likely to have better neurological outcome after surgery. There is insufficient evidence to suggest that any of the other CT myelogram parameters investigated are predictors of postoperative outcomes in patients with DCM.

Cervical neurapraxia in college football players with cervical spinal canal narrowing (P6.162)

Cervical neurapraxia in college football players with cervical spinal canal narrowing (P6.162)

Atlanto-axial subluxation with cervical myelopathy operated with occipital C2 fusion: A case report

Background: Atlantoaxial subluxation with cervical myelopathy is a rare condition that can occur mainly by trauma followed by Rheumatoid arthritis, Grisel syndrome, Down’s syndrome and various other metabolic disorders. It is characterized by excessive movement of atlas (C1) over axis (C2) either by bony or ligamentous abnormality. Due to its laxity the spinal cord may get damaged and cause neurologic symptoms. Reduction and fixation is needed for such instability.
 Case Report: This 55-year-old gentleman was apparently all right 4 years back when he gradually developed difficulty in walking and imbalance. Bilateral Babinski sign was positive, All deep tendon reflexes were brisk; muscle tone was increased with clasp-knife spasticity present in all four limbs. Ankle and patellar clonus was present bilaterally. His X-ray cervical spine showed C1-C2 subluxation in flexion and extension views. Magnetic resonance imaging (MRI) of Cranio-vertebral junction. Mild subluxation of atlantoaxial joint (3.1 mm) with posterior displacement of dens causing narrowing of bony cervical spinal canal with reduced distance between posterior aspect of dens of C2 and anterior aspect of posterior arch of C1 vertebrae was noticed. Atlas was also slightly displaced anteriorly in relation to baso-occiput. We managed this patient with occipital cervical fusion after reduction from a posterior approach using screws and rods construct and fusion with bone graft from iliac crest. Post operatively the patient was able to walk without any support and tone of the muscles in lower limb decreased, no tingling or numbness are present, no signs of local infection or inflammation.
 Conclusion: We suggest to operate atlanto-axial subluxation and cervical myelopathy with occipital C2 fusion.

Nursing Review Section of Surgical Neurology International Part 2: Lumbar Spinal Stenosis.

Background:The lumbar spine includes 5 lumbar vertebral bodies, L1, L2, L3, L4, and L5. At each level, there is a disc space defined by the two bones (vertebral bodies) in the back; for example, there is a disc space at the L5-S1 level etc. The normal front to back (anterior to posterior or AP diameter) measurement of the spinal canal is typically 18-20 mm, but some patients have narrowing called spinal stenosis.Methods:Lumbar stenosis is defined by two major types. Central stenosis compresses the midline (in the middle) sac of nerve tissue (dural or thecal sac containing the lumbar nerve roots). Lateral recess stenosis (off to the sides) compresses the individual exiting nerve roots.Results:At each lumbar level, there may be compression of the nerve tissue centrally (dura also called cauda equina) or the nerve roots (on one or both sides). Compression may occur due to soft or calcified discs in the front (anteriorly) of the spine at different levels or from behind (posteriorly) due to arthritic enlargement (hypertrophy) or calcification (ossification) of the yellow ligament, facet joints, and/or bones (laminae). Surgery to remove bone and arthritic structures from the back of the spinal canal to decompress nerve tissue is called a laminectomy.Conclusions:Patients with narrowing of the lumbar spinal canal may have central or lateral recess stenosis that compresses the thecal sac and/or exiting nerve roots at any of 5 levels. Laminectomy, performed at single or multiple levels, decompresses lumbar spinal stenosis.

PARAMETERS OF NUCLEAR MAGNETIC RESONANCE IN PATIENTS WITH CONGENITAL NARROWING OF THE LUMBAR SPINAL CANAL

ABSTRACT Objective: To compare the morphological parameters of magnetic resonance in patients with congenital narrowing of the lumbar spinal canal with patients with low back pain. Methods: A descriptive, retrospective, observational study was conducted with measurements in the axial and sagittal magnetic resonance sections of the vertebral body and canal of the lumbar spine of 64 patients with diagnosis of low back pain, which were compared with resonance images taken from 31 Mexican patients with congenital narrowing of the lumbar spinal canal. Results: The results show that patients with congenital narrowing of the lumbar spinal canal in the axial sections have a difference in diameters, being L2<13.9 mm, L3<13.3 mm, L4<12.9 mm, L5<13.1 mm, compared with controls L2<20.5 mm, L3<20.5 mm, L4<19.3 mm, L5<18.1 mm with p = 0.000. Conclusions: We found different measurements in the Mexican population compared to those found by similar studies. With the parameters obtained, it would be possible to make the proper diagnosis, surgical planning, and treatment.

A novel MRI classification system for congenital functional lumbar spinal stenosis predicts the risk for tandem cervical spinal stenosis.

The purpose of this study was to develop a simple and clinically useful morphological classification system for congenital lumbar spinal stenosis using sagittal MRI, allowing clinicians to recognize patterns of lumbar congenital stenosis quickly and be able to screen these patients for tandem cervical stenosis. Forty-four subjects with an MRI of both the cervical and lumbar spine were included. On the lumbar spine MRI, the sagittal canal morphology was classified as one of three types: Type I normal, Type II partially narrow, Type III globally narrow. For the cervical spine, the Torg-Pavlov ratio on X-ray and the cervical spinal canal width on MRI were measured. Kruskal-Wallis analysis was done to determine if there was a relationship between the sagittal morphology of the lumbar spinal canal and the presence of cervical spinal stenosis. Subjects with a type III globally narrow lumbar spinal canal had a significantly lower cervical Torg-Pavlov ratio and smaller cervical spinal canal width than those with a type I normal lumbar spinal canal. A type III lumbar spinal canal is a globally narrow canal characterized by a lack of spinal fluid around the conus. This was defined as "functional lumbar spinal stenosis" and is associated with an increased incidence of tandem cervical spinal stenosis.

Surgery for ventral intradural thoracic spinal tumors with a posterolateral transpedicular approach.

Surgery for ventrally seated thoracic tumors requires an anatomically specific approach that is distinct from cervical or lumbar spinal cord surgery as the narrower spinal canal of the thoracic spinal cord makes it sensitive to surgical procedures. However, reports describing this operative technique are few. To obtain a wide operative field and minimize thoracic spinal cord retraction, we employed a posterolateral transpedicular approach in ventral-located tumors and investigated the efficacy and limitations of this technique. Eighteen patients with lesions (meningioma or neurinoma) located in the ventral intradural thoracic region were surgically treated between 2009 and 2014. The relationship among the clinical outcome, tumor location, and postoperative spinal alignment was analyzed. Postoperative neurological function improved in all patients, namely those with meningioma (p = 0.012) and schwannoma (p = 0.018). One patient who underwent removal of two facet joints suffered a postoperative compression fracture. Removal of two facet joints and pedicles resulted in a worsening of spinal alignment (p = 0.03), while this was not the case for the removal of one facet joint and pedicle (p = 0.72). This case series clarified the benefits of the posterolateral transpedicular approach for resection of ventral intradural extramedullary tumors. Removal of one pedicle and facet joint seems to be more beneficial.

Difference in canal encroachment by the fusion mass between anterior cervical discectomy and fusion with bone autograft and anterior plating, and stand-alone cage

We conducted a prospective randomized study comparing stand-alone cage and bone autograft and plate implants in anterior cervical discectomy and fusion (www.clinicaltrials.gov, NCT01011569). Our interim analysis showed autologous bone graft with plating was superior to a stand-alone cage for segmental lordosis. During this analysis, we noted a difference in canal encroachment by the fusion mass between the two fusion groups. A narrow cervical spinal canal is an important factor in the development of cervical spondylotic myelopathy, therefore this unexpected potential risk of spinal cord compression necessitated another interim analysis to investigate whether there was a difference in canal encroachment by the fusion mass between the two groups. Patients had a minimum 1year of follow-up. The Neck Disability Index, neck and arm pain Visual Analog Scales and lateral radiographs, including bone fusion patterns, were evaluated. Twenty-seven (16 males, 11 females, mean age 54.8years) and 31 (24 males, seven females, mean age 54.5years) patients were in the cage and plate group, respectively. Both groups improved after surgery. Fusion began at 2.6months and 1.3months and finished at 6.7months and 4.0months in 24 (88.9%) and 28 (90.3%) patients in the cage and plate group, respectively. Encroachment into the spinal canal by the fusion mass was significantly different between the fusion types, occuring in 21 (77.8%) patients in the cage group versus six (19.4%) in the plate group (p=0.003). There was a high incidence of spinal canal encroachment by the fusion mass in the stand-alone cage group, possibly limiting use in narrow spinal canals.

Cervical spinal canal narrowing in idiopathic syringomyelia.

The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7.

CT-Myelogram Predictors of Outcome in Patients with Cervical Spondylotic Myelopathy: Results of a Systematic Review

Introduction Magnetic resonance imaging (MRI) is used routinely to diagnose cervical spondylotic myelopathy (CSM). However, in cases where MRI is contraindicated, CT myelogram remains the preferable imaging modality for the diagnosis of CSM. There remains no confirmed consensus on the use of specific CT myelogram parameters and their relationship with regards to CSM disease severity, clinical presentation and prognosis after surgical treatment. The purpose of this study is to determine the CT myelogram imaging parameters in patients diagnosed with CSM that correlate with severity of CSM and predict postoperative patient outcome Materials and Methods An electronic database search was performed using Ovid Medline and Embase. CT mylogram studies investigating the correlation between imaging characteristics and CSM severity or postoperative outcomes were included. Two independent reviewers performed citation screening, selection, qualitative assessment and data extraction using an objective and blinded protocol. All authors involved in the study have no disclosures related to present study. No funding was needed for this study. Results We found no studies investigating the correlation between CT myelogram parameters and CSM severity. A total of 5 studies (402 patients) were included in this review and investigated the role of CT myelogram parameters in predicting outcome after surgical treatment. All studies were retrospective cohort studies. CT mylogram characteristics included the transverse area of the spinal cord at maximum level of compression, spinal canal narrowing, number of blocks, spinal canal diameter and flattening ratio. There is low evidence suggesting that patients with a transverse area of the spinal cord &gt;30 mm2 at the level of maximum compression have better postoperative recovery and outcome. Conclusion Patients with greater transverse area of spinal cord at the level of maximum compression on CT myelogram are more likely to have better neurological outcome after surgery. There is insufficient evidence to suggest that any of the other CT mylogram parameters investigated are predictors of postoperative outcomes in patients with CSM.

Histopathological Features of Facet Osteoarthritis in Patients with Lumbar Spinal Stenosis

Introduction Lumbar spinal stenosis (LSS) is a degenerative, age-related narrowing of the lower spinal canal that causes pressure on the nerves, leading to pain and reduced mobility. Hypertrophy of ligament flava and facet joints combined with disc protrusions are a causative for LSS. Osteoarthritic changes to the facet joint, including joint space narrowing, subchondral cysts and osteophyte formation are commonly detected using magnetic resonance imaging (MRI) and computed tomography (CT) scanning. However, the pathomechanisms of facet joint osteoarthritis (OA) at a cellular and molecular level are poorly understood and have been scarcely studied. In this study we sought to investigate the histological features and to uncover cellular pathomechanisms of facet joint OA. Material and Methods Fifteen patients undergoing surgical decompression due to degenerative LSS were included in this study (9 female/6 male, median age 66, range 49–85). Routine preoperative X-ray and MRI scanning of the lumbar spine was performed in all subjects. Severity of facet joint OA was assessed in MRI images using the Weishaupt grading system for the lumbar spine. The medial portion of facet joints was collected during surgical decompression of the spinal canal and processed for tissue histology. Tissue morphology was evaluated using haematoxylin and eosin (HE), Safranin-O and van Gieson's stains. The presence of macrophages, blood vessels and nerve fibers was investigated using immunohistological staining for their respective markers CD68, CD34 and PGP9.5. Functional osteoclasts were visualized using tartrate-resistant acid phosphatase (TRAP) staining. Subchondral bone area fraction (B.Ar/T.Ar) was determined using the ImageJ-plugin BoneJ. Results OA was evident in MRI images characterized by joint space narrowing, bone edema and cysts and hypertrophy of articular processes. The severe OA phenotype in facet joints from LSS patients was confirmed at a histological level by complete loss of proteoglycan staining, CD34+ vessel penetration, and fissuring of cartilage tissue. Subchondral B.Ar/T.Ar ranged between 0.6 and 0.8. In all samples, subchondral marrow spaces contained CD34+ blood vessels and CD68+ mononuclear macrophages. CD68+ multinucleated osteoclasts were detected in resorption pits at the bone surface in 80 percent of the patients. Functionality of osteoclasts was confirmed by positive staining of multinucleated bone cells for TRAP in serial sections. Osteoblast activity was demonstrated in 60 percent of the patients and predominantly characterized by large areas of intramembranous bone formation near the osteochondral junction. Formation of an osteoclast-rich pannus-like tissue was seen in one sample. Innervation of subchondral marrow spaces by PGP9.5-positive nerve fibers was scarce and exclusively found in the vicinity of arterioles. Conclusion Facet joints in LSS patients display radiological and histopathological features of OA. Two major OA phenotypes can be distinguished based upon cellular pathomechanisms in subchondral bone tissue: 1) osteoblast-rich intramembranous bone formation and 2) osteoclast/macrophage rich remodeling. Osteoimmunological mechanisms, specifically the interaction of CD68+ macrophages with bone-resident cells, play a – previously unknown – role in regulating subchondral bone sclerosis in progressive osteoarthritis. Targeting osteoimmunology might hold potential as a disease-modifying treatment for osteoarthritis.

Use of an Interspinous Device above the Level of Interbody Fusion: Does it Reduce the Worsening of Adjacent Segment Degeneration?

Introduction Lumbar fusion in degenerative conditions has universally provided good results. However, adjacent segment degeneration, either afresh or worsening of a low grade degeneration in the segment above has been indicated for the pain and low functional outcome on long term follow-ups. Interspinous implants have been used to off load the facets and prevent spinal canal narrowing in stenosis with good results. This paper analyses the novel idea of using an interspinous device above the level of fusion to decelerate the physiologic process and reduce the incidence of adjacent segment degeneration (ASD). Material and Methods 12 patients were analyzed in the study. The inclusion criteria for the study was degeneration of the disc above the level of intended fusion with no or less than 50% disc height reduction and no nerve root compression. Patients with more than 50% height reduction or severe arthritic facet joints underwent fusion at two levels and were excluded from the study. Patients with failed back syndrome and significant osteoporosis were also excluded from the study. Coflex (Paradigm) interspinous device was used in the level above the fusion in all cases. Clinical and radiographic criteria for ASD was assessed at the latest followup. VAS and ODI functional outcome was analyzed. Results 12 patients with mean age of 63 years who underwent surgery between September 2012 and March 2014 were analyzed in the study. Mean followup was 27 months (Range 18–36 months). Single level fusion was performed in 9 cases and Two level fusion in 3 cases. Coflex device was implanted at L3–4 in 8 cases and L4–5 in 4 cases. All 12 patients had a good fusion in the 6 months radiograph. Disc height improvement was seen in the level above, with no evidence of stenosis or listhesis at the latest followup. Worsening of already existant ASD in one patient was noticed but did not require surgical intervention. VAS and ODI showed significant ( p &lt; 0.05) improvement postoperatively. No infection or reoperation was needed in any of the 12 patients. Conclusion ASD remains a significant reason causing failed back syndrome requiring reoperations in lumbar fusion. Use of interspinous device not only preserves a motion segment from fusion, but also shows promise in reducing the incidence of degeneration above the level of fusion. Further studies with larger sample size and long term followup is necessary to support the conclusion.

A comparison of two methods to evaluate a narrow spinal canal: routine magnetic resonance imaging versus three-dimensional reconstruction

Background ContextIn routine clinical practice, the presence of lumbar spinal stenosis (LSS) is assessed on axial magnetic resonance images (MRI) typically acquired using a preselected spine sagittal angle. Given the natural lordosis of the lumbar spine, not all axial slices will be parallel to the disc and perpendicular to the spinal canal and, thus, are not optimal for the assessment of dural sac cross-sectional area (DCSA). PurposeThe objective of this study was to compare DCSA measurements from routinely acquired clinical images with three-dimensional (3D)-reconstructed images. Study DesignThis is a cross-sectional study. Patient SampleThe sample consists of 390 patients referred for lumbar imaging with some aspect of anatomical LSS found, with no prior back surgery, 40 years of age or older, and with available volumetric MR images to allow 3D reconstruction of the spine. Outcome MeasuresThe outcome of interest in this study was dural sac cross sectional area. MethodsSpine images were 3D reconstructed at the level of the disc, perpendicular to the spinal canal. Dural sac cross-sectional area was measured for both 3D-reconstructed and routinely acquired clinical images using the slice orientation captured. ResultsDural sac cross-sectional area for the lower lumbar levels (L4–L5 and L5–S1) was significantly different between routinely acquired clinical images and 3D-reconstructed images, with a standard error of measurement of 12.98 and 19.73 mm2, respectively. ConclusionsWhen canal size is of interest, particularly when LSS affecting the lower lumbar levels is of concern, 3D reconstruction of clinical images should be considered.

THORACOLUMBAR BURST FRACTURE: STRUCTURAL CHANGES AND CLINICAL OUTCOME OF TREATMENT

ABSTRACT Objective: To evaluate the correlation between structural changes in burst fractures of thoracic and lumbar spine with clinical outcome of the treatment. Methods: A retrospective study in 25 patients with fractures of thoracic and lumbar spine burst fractures without neurological deficit. Eleven patients underwent conservative treatment and for the remaining the treatment was surgical. All patients were followed up for at least 24 months. The cases were evaluated by a protocol that included: posttraumatic measurement of kyphosis, vertebral body collapse and narrowing of the spinal canal, the visual analog scale of pain, and the quality of life questionnaire SF-36 at the follow-up. For statistical analysis, the significance level was 5% and the software SPSS 18.0 was used. Results: No statistically significant difference was observed when comparing the clinical outcomes of one treatment over another. Similarly, there was no statistically significant correlation between kyphosis and post-traumatic narrowing of the spinal canal with clinical worsening in the follow-up, regardless of the treatment used. We found a positive correlation (p&lt;0.05) between initial collapse and SF-36 domains in both groups (operated and non-operated). Conclusion: There was no significant superiority of one treatment over the other, and no correlation was found between kyphosis and spinal canal narrowing in burst fractures of the thoracic and lumbar spine without neurological deficit. However, there was correlation between initial collapse and clinical outcome in some domains of the SF-36 questionnaire.

Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8years (range 18.8 to 87.7). Five fractures (24%) were U-shaped, six (29%) H-shaped, four (19%) Y-shaped, and six (29%) burst. Nine patients (43%) had central canal narrowing, and 19 (90%) had neural foramina narrowing. Eleven patients (52%) had kyphotic angulation between major fracture fragments, and seven patients (33%) had either anterior (24%) or posterior (10%) displacement of the proximal fracture fragment. Fourteen patients (67%) had associated pelvic fractures, and 20 (95%) had associated non-pelvic fractures. Two patients (10%) had associated urethral injuries, and one (5%) had an associated colon injury. Seven patients (33%) had associated nerve injuries. Six patients (29%) had surgical fixation while 15 (71%) were managed non-operatively. On trauma MDCT examinations, patients with SPD have characteristic fracture patterns. It is important to differentiate SPD from other pelvic ring injuries due to high rate of associated injuries. Although all SPD injuries are unstable and need fixation, the decision for operative management in an individual patient depends on the systemic injury pattern, specific fracture pattern, and the ability to attain stable screw fixation.

Clinical management of patients with vertebral lumbosacral radiculopathy. Description clinical cases

Lumbosacral radiculopathy one of the most difficult choices vertebrogenic pain syndromes characterized especially intense and prolonged pain, usually accompanied by a sharp restriction of mobility, and is the most common cause of disability. Most of the destruction of roots of spinal nerves caused by vertebral reasons the presence of a herniated disc, degenerative changes in the intervertebral joints, narrow spinal canal. This article describes a clinical case of practice management of patients with chronic vertebral lumbosacral radiculopathy. The main causes of pain in the lower back, the main approaches to the diagnosis and treatment of chronic pain. Special attention is paid to the differential diagnosis of chronic pain in his back and leg.

Gait Analysis Using a Support Vector Machine for Lumbar Spinal Stenosis

Lumbar spinal canal stenosis (LSS) is diagnosed based on physical examination and radiological documentation of lumbar spinal canal narrowing. Differential diagnosis of the level of lumbar radiculopathy is difficult in multilevel spinal stenosis. Therefore, the authors focused on gait analysis as a classification method to improve diagnostic accuracy. The goal of this study was to identify gait characteristics of L4 and L5 radiculopathy in patients with LSS and to classify L4 and L5 radiculopathy using a support vector machine (SVM). The study group comprised 13 healthy volunteers (control group), 11 patients with L4 radiculopathy (L4 group), and 22 patients with L5 radiculopathy (L5 group). Light-emitting diode markers were attached at 5 sites on the affected side, and walking motion was analyzed using video recordings and the authors' development program. Potential gait characteristics of each group were identified to use as SVM parameters. In the knee joint of the L4 group, the waveform was similar to that of normal gait, but knee extension at initial contact was slightly greater than that of the other groups. In the ankle joint of the L5 group, the one-peak waveform pattern with disappearance of the second peak was present in 10 (45.5%) of 22 cases. The total classification accuracy was 80.4% using the SVM. The highest and lowest classification accuracies were obtained in the control group (84.6%) and the L4 group (72.7%), respectively. The authors' walking motion analysis system identified several useful factors for differentiating between healthy individuals and patients with L4 and L5 radiculopathy, with a high accuracy rate.

Spinal cord evolution in early Homo

The discovery at Nariokotome of the Homo erectus skeleton KNM-WT 15000, with a narrow spinal canal, seemed to show that this relatively large-brained hominin retained the primitive spinal cord size of African apes and that brain size expansion preceded postcranial neurological evolution. Here we compare the size and shape of the KNM-WT 15000 spinal canal with modern and fossil taxa including H. erectus from Dmanisi, Homo antecessor, the European middle Pleistocene hominins from Sima de los Huesos, and Pan troglodytes. In terms of shape and absolute and relative size of the spinal canal, we find all of the Dmanisi and most of the vertebrae of KNM-WT 15000 are within the human range of variation except for the C7, T2, and T3 of KNM-WT 15000, which are constricted, suggesting spinal stenosis. While additional fossils might definitively indicate whether H. erectus had evolved a human-like enlarged spinal canal, the evidence from the Dmanisi spinal canal and the unaffected levels of KNM-WT 15000 show that unlike Australopithecus, H. erectus had a spinal canal size and shape equivalent to that of modern humans. Subadult status is unlikely to affect our results, as spinal canal growth is complete in both individuals. We contest the notion that vertebrae yield information about respiratory control or language evolution, but suggest that, like H. antecessor and European middle Pleistocene hominins from Sima de los Huesos, early Homo possessed a postcranial neurological endowment roughly commensurate to modern humans, with implications for neurological, structural, and vascular improvements over Pan and Australopithecus.

Significant Blood Loss in Lumbar Fusion Surgery for Degenerative Spine

Lumbar fusion is a widely used procedure for degenerative spine diseases but frequently is accompanied with substantial surgical blood loss. We aimed to investigate the risk factors for significant intraoperative blood loss and the influence of excessive bleeding on postoperative complications in patients undergoing fusion for degenerative lumbar spines. For this retrospective study, we enrolled 199 patients who had undergone lumbar fusion surgery for degeneration. The definition of significant blood loss at operation was 500 mL or more in blood volume. The patients were subdivided into 2 groups on the basis of whether significant blood loss was present (n = 107) or not (n = 92). The incidence of significant blood loss during lumbar fusion was 53.8%. In the multivariate logistic regression model, the independent risk factors for significant blood loss included body mass index (P = 0.027), extreme spinal canal narrowing (P = 0.023), spine fusion segments >1 level (P = 0.008), and transforaminal lumbar interbody fusion (P = 0.006). Significant blood loss in lumbar fusion was associated with a greater incidence of postoperative complications (P = 0.002). The length of hospital stay for patents with excessive bleeding was prolonged significantly (P = 0.045). Because substantial bleeding in lumbar fusion is associated with a greater incidence of morbidities and prolonged length of hospital stay, attention to the risk factors for significant blood loss is important in the preoperative assessment and postoperative guidance for the level of care.

Acquired lumbar spinal stenosis.

Lumbar spinal stenosis is the most frequent reason for spinal surgery in patients over age 65 years. In this condition, narrowing of the lumbar spinal canal and nerve root canals leads to painful, debilitating compression of spinal nerves and blood vessels. As the population ages, an increasing number of patients will be diagnosed and treated for lumbar spinal stenosis by primary care providers. This article reviews the pathophysiology, diagnosis, and management of lumbar spinal stenosis in adults over age 50 years.