Radiological Analysis of Cerebrospinal Fluid Dynamics at the Craniovertebral Junction Using Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging in Patients with Cervical Spinal Canal Stenosis

OBJECTIVE

Spondylotic changes in the cervical spine cause degeneration, leading to cervical spinal canal stenosis. This stenotic change can affect cerebrospinal fluid (CSF) dynamics by compressing the dural sac and reducing space in the subarachnoid space. We examined CSF dynamics at the craniovertebral junction (CVJ) using time-spatial labeling inversion pulse magnetic resonance imaging (Time-SLIP MRI) in patients with cervical spinal canal stenosis.

METHODS

The maximum longitudinal movement of the CSF at the CVJ was measured as length of motion (LOM) in the Time-SLIP MRI of 56 patients. The sum of ventral and dorsal LOM was defined as the total LOM. Patients were classified into 3 groups depending on their spinal sagittal magnetic resonance imaging findings: control (n = 27, Kang classification grades 0 and 1), stenosis (n = 14, Kang classification grade 2), and severe stenosis (n = 15, Kang classification grade 3).

RESULTS

Time-SLIP MRI revealed pulsatile movement of the CSF at the CVJ. The mean total, ventral, and dorsal LOM was 14.2 ± 9, 8.1 ± 5.7, and 3.8 ± 2.9 mm, respectively. The ventral LOM was significantly larger than the dorsal LOM. The total LOM was significantly smaller in the severe stenosis group (6.1 ± 3.4 mm) than in the control (16.0 ± 8.4 mm) or stenosis (11 ± 5.4 mm) groups (P < 0.001, Kruskal-Wallis H-test). In 5 patients, postoperative total LOM was improved after adequate decompression surgery.

CONCLUSIONS

This study demonstrates that CSF dynamics at the CVJ are influenced by cervical spinal canal stenosis. Time-SLIP MRI is useful for evaluating CSF dynamics at the CVJ in patients with spinal canal stenosis.

A Convolutional Neural Network for Automated Detection of Cervical Ossification of the Posterior Longitudinal Ligament using Magnetic Resonance Imaging

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

We aimed to develop and validate a convolutional neural network (CNN) model to distinguish between cervical ossification of posterior longitudinal ligament (OPLL) and multilevel degenerative spinal stenosis using Magnetic Resonance Imaging (MRI) and to compare the diagnostic ability with spine surgeons.

SUMMARY OF BACKGROUND DATA

Some artificial intelligence models have been applied in spinal image analysis and many of promising results were obtained; however, there was still no study attempted to develop a deep learning model in detecting cervical OPLL using MRI images.

MATERIALS AND METHODS

In this retrospective study, 272 cervical OPLL and 412 degenerative patients underwent surgical treatment were enrolled and divided into the training (513 cases) and test dataset (171 cases). CNN models applying ResNet architecture with 34, 50, and 101 layers of residual blocks were constructed and trained with the sagittal MRI images from the training dataset. To evaluate the performance of CNN, the receiver operating characteristic curves of 3 ResNet models were plotted and the area under the curve were calculated on the test dataset. The accuracy, sensitivity, and specificity of the diagnosis by the CNN were calculated and compared with 3 senior spine surgeons.

RESULTS

The diagnostic accuracies of our ResNet34, ResNet50, and ResNet101 models were 92.98%, 95.32%, and 97.66%, respectively; the area under the curve of receiver operating characteristic curves of these models were 0.914, 0.942, and 0.971, respectively. The accuracies and specificities of ResNet50 and ResNet101 models were significantly higher than all spine surgeons; for the sensitivity, ResNet101 model achieved better values than that of the 2 surgeons.

CONCLUSION

The performance of our ResNet model in differentiating cervical OPLL from degenerative spinal stenosis using MRI is promising, better results were achieved with more layers of residual blocks applied.

Obesity increases the odds of intervertebral disc herniation and spinal stenosis; an MRI study of 1634 low back pain patients

PURPOSE

The objective of this study was to examine the relationships between BMI and intervertebral disc degeneration (DD), disc herniation (DH) and spinal stenosis (SS) using a large, prospectively recruited and heterogeneous patient population.

METHODS

Patients were recruited through the European Genodisc Study. An experienced radiologist scored MRI images for DD, DH and SS. Multivariate linear and logistic regression analyses were used to model the relationship between these variables and BMI with adjustment for patient and MRI confounders.

RESULTS

We analysed 1684 patients with a mean age of 51 years and BMI of 27.2 kg/m2.
The mean DD score was 2.6 (out of 5) with greater DD severity with increasing age (R2 = 0.44). In the fully adjusted model, a 10-year increase in age and a 5 kg/m2 increase in BMI were associated, respectively, with a 0.31-unit [95% CI 0.29,0.34] and 0.04-unit [CI 0.01,0.07] increase in degeneration. Age (OR 1.23 [CI 1.06,1.43]) and BMI (OR 2.60 [CI 2.28,2.96]) were positively associated with SS. For DH, age was a negative predictor (OR 0.70 [CI 0.64,0.76]) but for BMI (OR 1.19 [CI 1.07,1.33]), the association was positive. BMI was the strongest predictor of all three features in the upper lumbar spine.

CONCLUSIONS

While an increase in BMI was associated with only a slight increase in DD, it was a stronger predictor for DH and SS, particularly in the upper lumbar discs, suggesting weight loss could be a useful strategy for helping prevent disorders associated with these pathologies.

A possible correlation between facet orientation and development of degenerative cervical spinal stenosis

BACKGROUND

Previous studies have demonstrated the relationship between sagittal facet orientation and cervical degenerative spondylolisthesis. However, the associations between facet orientation and cervical spinal stenosis (CSS) have rarely been studied.

METHODS

One hundred twenty patients with CSS (CSS group) and 120 healthy participants (control group) were consecutively enrolled. The cervical facet angles and anteroposterior diameter (A-P diameter) of spinal canal at each subaxial cervical levels were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint.

RESULTS

The facet angles on the right side at C2- C3 and C3-C4 in CSS group and at C2- C3 in control group had significantly higher values than those of the other sides. Besides, the facet angles and A-P diameter of spinal canal in CSS group were significantly smaller than those in control group at all levels (p < 0.05).

CONCLUSIONS

Our study demonstrated that patients with CSS have smaller axial cervical facet joint angles compared to the healthy individuals. Further studies are needed to elicit the specific underlying mechanism between sagittalization of the cervical facet joints and the pathology of CSS.

Facet joint tropism, pelvic incidence and intervertebral height index: associations with facet joint osteoarthritis in lumbar spinal stenosis

BACKGROUND CONTEXT

Facet joint osteoarthritis (FJOA) is associated with lumbar disc degeneration and has a significant role in the development of lumbar spinal stenosis (LSS). The relationship between various radiographic parameters and the grade of FJOA is not well understood.

PURPOSE

To explore radiographical parameters associated with FJOA in LSS without lumbar dynamic instability.

STUDY DESIGN

Retrospective study analysis.

PATIENT SAMPLE

A total of 122 patients diagnosed with LSS who visited our hospital between January 2015 and July 2022.

OUTCOME MEASURES

We evaluated radiographic parameters of patients at L4-5 including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), grades of FJOA, facet joint orientation (FO), facet joint tropism (FT), intervertebral height index (IHI) and the relative cross-sectional area (RCSA) of paraspinal muscles.

METHODS

Patients diagnosed with LSS between January 2015 and July 2022 were enrolled. Demographic characteristics and radiographic parameters were collected. Spinopelvic parameters were measured through the preoperative lateral image of the whole spine, including LL, PI, pelvic tilt, and sacral slope. Lumbar computed tomography scan and magnetic resonance imaging were collected to measure the FO, FT, IHI, and the RCSA of paraspinal muscles respectively. Patients were divided into three groups according to the severity of FJOA graded by the Weishaupt classification: grade 0 and grade 1 were group A, grade 2 were group B, and grade 3 were group C. All variables were compared among the three groups, while the relationship between parameters and grades of FJOA were also analyzed.

RESULTS

A total of 122 patients were included. PI was significantly greater in group C compared to group A (p = 0.025) and group B (p=0.022). FT was significantly greater in group C compared to group A (p<.001) and group B (p<.001). The RCSA of multifidus in group A were significantly greater than that in group B (p=0.02) and C (p=0.002). Additionally, FO in group C were significantly lower than group A (p<.001) and group B (p=0.028). The IHI in group C was significantly lower than group A (p=0.017). The correlation analysis indicated that grades of FJOA was positively related to Age, BMI (body mass index), PI, LL and FT, while negatively related to IHI, FO, RCSA of multifidus and RCSA of psoas major. Furthermore, the logistics regression showed that FT, PI, and IHI were important influence factors for FJOA.

CONCLUSIONS

The current study confirmed that FT, PI and IHI were significantly associated with grades of FJOA at L4-5. Additionally, longitudinal studies are needed to understand the causal relationship between these parameters and FJOA.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis

OBEJECTIVE

To perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times.

SUBJECTS AND METHODS

The T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery.

RESULTS

The T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%).

CONCLUSION

Healthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

ACSM5 inhibits ligamentum flavum hypertrophy by regulating lipid accumulation mediated by FABP4/PPAR signaling pathway

BACKGROUND

Ligamentum flavum (LF) hypertrophy is the main cause of lumbar spinal canal stenosis (LSCS). Previous studies have shown that LF hypertrophy tissue exhibits abnormal lipid accumulation, but the regulatory mechanism remains unclear. The objective of this study was to explore the function and potential mechanism of ACSM5 in LF lipid accumulation.

METHODS

To assess the ACSM5 expression levels, lipid accumulation and triglyceride (TG) level in LF hypertrophy and normal tissue, we utilized RT-qPCR, western blot, oil red O staining, and TG assay kit. The pearson correlation coefficient assay was used to analyze the correlation between ACSM5 levels and lipid accumulation or TG levels in LF hypertrophy tissue. The role of ACSM5 in free fatty acids (FFA)-induced lipid accumulation in LF cells was assessed in vitro, and the role of ACSM5 in LF hypertrophy in mice was verified in vivo. To investigate the underlying mechanisms of ACSM5 regulating lipid accumulation in LF, we conducted the mRNA sequencing, bioinformatics analysis, and rescue experiments.

RESULTS

In this study, we found that ACSM5, which was significantly down-regulated in LF tissues, correlated with lipid accumulation. In vitro cell experiments demonstrated that overexpression of ACSM5 significantly inhibited FFA-induced lipid accumulation and fibrosis in LF cells. In vivo animal experiments further confirmed that overexpression of ACSM5 inhibited LF thickening, lipid accumulation, and fibrosis. Mechanistically, ACSM5 inhibited lipid accumulation of LF cells by inhibiting FABP4-mediated PPARγ signaling pathway, thereby improving hypertrophy and fibrosis of LF.

CONCLUSIONS

our findings elucidated the important role of ACSM5 in the regulation of LF lipid accumulation and provide insight into potential therapeutic interventions for the treatment of LF hypertrophy. This study further suggested that therapeutic strategies targeting lipid deposition may be an effective potential approach to treat LF hypertrophy-induced LSCS.

Manipulation of osteogenic and adipogenic differentiation of human degenerative disc and ligamentum flavum derived progenitor cells using IL-1β, IL-19, and IL-20

PURPOSE

To elucidate whether pro-inflammatory cytokines might influence the commitment of intervertebral disc (IVD)- and ligamentum flavum (LF)-derived progenitor cells toward either osteogenesis or adipogenesis, specifically Interleukin-1β (IL-1β), IL-19, and IL-20.

METHODS

Sixty patients with degenerative spondylolisthesis and lumbar or lumbosacral spinal stenosis were included in the study. Injuries to the spine, infections, and benign or malignant tumors were excluded. From nine patient samples, IVD- and LF-derived cells were isolated after primary culture, and two clinical samples were excluded due to mycoplasma infection. The effects of IL-1β, IL-19, as well as IL-20 in regulating osteogenic and adipogenic differentiation in vitro were investigated.

RESULTS

Primary IVD- and LF-derived cells were found to have a similar cell morphology and profile of surface markers (CD44, CD90, and CD105) as placenta-derived mesenchymal stem cells (MSCs). Primary IVD/LF cells have a high capacity to differentiate into osteocytes and adipocytes. IL-19 had a tendency to promote adipogenesis. IL-20 inhibited osteogenesis and promoted adipogenesis; IL-1β promoted osteogenesis but inhibited adipogenesis.

CONCLUSION

IL-1β, IL-19, and IL-20 impact the adipogenic and osteogenic differentiation of IVD-derived and LF-derived cells. Modulating the expression of IL-1β, IL-19, and IL-20 provides a potential avenue for controlling cell differentiation of IVD- and LF-derived cells, which might have beneficial effect for degenerative spondylolisthesis and spinal stenosis.

Redundant nerve roots indicate higher degree of stenosis in lumbar spine stenotic patients

OBJECTIVES

Redundant Nerve Root (RNR) is a tortuous and elongated radiological appearance of cauda equina on Magnetic Resonance Imaging (MRI) in Lumbar Spinal Canal Stenosis (LSCS) patients. This study evaluated preoperative spinal morphometry associated with the development of RNR.

METHODS

The retrospective cohort was conducted at The Aga Khan University Hospital, and included patients undergoing decompressive spinal surgery secondary to degenerative LSCS in 2015. The patients were divided into two groups with respect to the presence of preoperative RNR. Spinal morphometry was defined by several radiological parameters, including areas of dural sac (DSA), spinal canal, spinal foramen, facets, and spinal joints, and bilateral angles based on vertebral anatomy.

RESULTS

A total of 55 patients were enrolled with a mean age of 57.1 years, in which 22 (40%) expressed RNR in their MRI. The RNR group had significantly lower mean DSA (59.64 vs 84.01 mm2; p = 0.028), bilateral posterior facet angle (Right: 33.84 vs 46.21, p = 0.004; Left: 36.43 vs 43.80, p = 0.039) and higher bilateral anterior facet angles (Right: 54.85 vs 44.57, p = 0.026; Left: 55.27 vs 46.36, p = 0.050) compared to the non-RNR group. The other bidimensional and angular parameters did not observe any statistical difference between the two groups.

CONCLUSION

RNR was associated with a higher degree of stenosis in patients with LSCS. Bilateral anterior and posterior facets angles contribute to its development, indicating particular spinal morphology to be vulnerable to the stenotic disease.

Postoperative Dural Sac Cross-Sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

The aim was to investigate the association between postoperative dural sac cross-sectional area (DSCA) after decompressive surgery for lumbar spinal stenosis and clinical outcome. Furthermore, to investigate if there is a minimum threshold for how extensive a posterior decompression needs to be to achieve a satisfactory clinical result.

SUMMARY OF BACKGROUND DATA

There is limited scientific evidence for how extensive lumbar decompression needs to be to obtain a good clinical outcome in patients with symptomatic lumbar spinal stenosis.

MATERIALS AND METHODS

All patients were included in the Spinal Stenosis Trial of the NORwegian Degenerative spondylolisthesis and spinal STENosis (NORDSTEN)-study. The patients underwent decompression according to three different methods. DSCA measured on lumbar magnetic resonance imaging at baseline and at three months follow-up, and patient-reported outcome at baseline and at two-year follow-up were registered in a total of 393 patients. Mean age was 68 (SD: 8.3), proportion of males were 204/393 (52%), proportion of smokers were 80/393 (20%), and mean body mass index was 27.8 (SD: 4.2).The cohort was divided into quintiles based on the achieved DSCA postoperatively, the numeric, and relative increase of DSCA, and the association between the increase in DSCA and clinical outcome were evaluated.

RESULTS

At baseline, the mean DSCA in the whole cohort was 51.1 mm 2 (SD: 21.1). Postoperatively the area increased to a mean area of 120.6 mm 2 (SD: 46.9). The change in Oswestry disability index in the quintile with the largest DSCA was -22.0 (95% CI: -25.6 to -18), and in the quintile with the lowest DSCA the Oswestry disability index change was -18.9 (95% CI: -22.4 to -15.3). There were only minor differences in clinical improvement for patients in the different DSCA quintiles.

CONCLUSION

Less aggressive decompression performed similarly to wider decompression across multiple different patient-reported outcome measures at two years following surgery.

[Rare complication of echinococcosis in clinical practice]

The authors report retroperitoneal echinococcosis with destruction of the bodies and left transverse processes of L4-5 vertebrae, recurrence and pathological fracture of L4-5 vertebrae with secondary spinal stenosis and left-sided monoparesis. Retroperitoneal echinococcectomy, pericystectomy, decompressive laminectomy L5 and foraminotomy L5-S1 on the left were performed. Therapy with albendazole was prescribed in postoperative period.

Spinal Cord Sarcoidosis Occurring at Sites of Spondylotic Stenosis, Mimicking Spondylotic Myelopathy: A Case Series and Review of the Literature

Sarcoidosis is a multisystem granulomatous disease, with intramedullary spinal cord involvement seen in <1% of cases. This case series illustrates the clinical presentations and imaging findings of 5 patients with intramedullary spinal neurosarcoidosis occurring at sites of spondylotic spinal canal stenosis, which can be indistinguishable from spondylotic myelopathy with cord enhancement. Both entities are most common in middle-aged men and present with weeks to months of motor and sensory symptoms. On imaging, both can have focal spinal cord enhancement and longitudinally extensive signal abnormality centered at or just below the level of spinal canal stenosis. On the basis of our experience, we suggest that in patients with cord enhancement centered at or just below a site of spinal canal stenosis, consideration should be given to chest imaging and lymph node biopsy when applicable, to assess for the possibility of underlying sarcoidosis before surgical decompression.

The Relationship Between Wild-Type Transthyretin Amyloid Load and Ligamentum Flavum Thickness in Lumbar Stenosis Patients

BACKGROUND

One key contributor to lumbar stenosis is thickening of the ligamentum flavum (LF), a process still poorly understood. Wild-type transthyretin amyloid (ATTRwt) has been found in the LF of patients undergoing decompression surgery, suggesting that amyloid may play a role. However, it is unclear whether within patients harboring ATTRwt, the amount of amyloid is associated with LF thickness.

METHODS

From an initial cohort of 324 consecutive lumbar stenosis patients whose LF specimens from decompression surgery were sent for analysis (2018-2019), 33 patients met the following criteria: 1) Congo red-positive amyloid in the LF, 2) ATTRwt by mass spectrometry-based proteomics, and 3) an available preoperative magnetic resonance imaging. Histological specimens were digitized, and amyloid load was quantified through Trainable Weka Segmentation machine learning. LF thicknesses were manually measured on axial T2-weighted preoperative magnetic resonance imaging scans at each lumbar level, L1-S1. The sum of thicknesses at every lumbar LF level (L1-S1) equals "lumbar LF burden".

RESULTS

Patients had a mean age of 72.7 years (range = 59-87), were mostly male (61%) and white (82%), and predominantly had surgery at L4-L5 levels (73%). Amyloid load was positively correlated with LF thickness (R = 0.345, P = 0.0492) at the levels of surgical decompression. Furthermore, amyloid load was positively correlated with lumbar LF burden (R = 0.383, P = 0.0279).

CONCLUSIONS

Amyloid load is positively correlated with LF thickness and lumbar LF burden across all lumbar levels, in a dose-dependent manner. Further studies are needed to validate these findings, uncover the underlying pathophysiology, and pave the way toward using therapies that slow LF thickening.

The Utility of Flexion-Extension Radiographs in Degenerative Cervical Spondylolisthesis

STUDY DESIGN

Retrospective radiologic analysis.

OBJECTIVE

The aim was to investigate if lateral flexion-extension radiographs identify additional cases of degenerative cervical spondylolisthesis (DCS) that would be missed by obtaining solely neutral upright radiographs, and determine the reliability of magnetic resonance imaging (MRI) in diagnosis.

SUMMARY OF BACKGROUND DATA

DCS and instability can be a cause of neck pain, radiculopathy, and even myelopathy. Standard anteroposterior and lateral radiographs and MRI of the cervical spine will identify most cervical spine pathology, but spondylolisthesis and instability are dynamic issues. Standard imaging may also miss DCS in some cases.

METHODS

We compared the number of patients who demonstrated cervical spondylolisthesis on lateral neutral and flexion-extension radiographs in addition to MRI. We used established criteria to define instability as ≥2 mm of listhesis on neutral imaging, and ≥1 mm of motion between flexion-extension radiographs.

RESULTS

A total of 111 patients (555 cervical levels) were analyzed. In all, 41 patients (36.9%) demonstrated cervical spondylolisthesis on neutral and/or flexion-extension radiographs. Of the 77 levels of spondylolisthesis, 17 (22.1%) were missed on neutral radiographs ( P ,0.05). Twenty levels (26.0%) were missed when flexion-extension radiographs were used alone ( P =0.02). Twenty-nine levels (37.7%) of DCS identified on radiograph were missed by MRI ( P =0.004).

CONCLUSIONS

Lateral flexion-extension views can be useful in the diagnosis of DCS. These views provide value by identifying a significant cohort of patients that would be undiagnosed based on neutral radiographs alone. Moreover, MRI missed 38% of DCS cases identified by radiographs. Therefore, lateral radiographs can be a useful adjunct to neutral radiographs and MRI when instability is suspected or if these imaging modalities are unable to identify the source of a patient's neck or arm pain.

Jmjd3 Mediates Neuropathic Pain by Inducing Macrophage Infiltration and Activation in Lumbar Spinal Stenosis Animal Model

Lumbar spinal stenosis (LSS) is a major cause of chronic neuropathic back and/or leg pain. Recently, we demonstrated that a significant number of macrophages infiltrated into the cauda equina after compression injury, causing neuroinflammation, and consequently mediating neuropathic pain development and/or maintenance. However, the molecular mechanisms underlying macrophage infiltration and activation have not been elucidated. Here, we demonstrated the critical role of histone H3K27 demethylase Jmjd3 in blood-nerve barrier dysfunction following macrophage infiltration and activation in LSS rats. The LSS rat model was induced by cauda equina compression using a silicone block within the epidural spaces of the L5-L6 vertebrae with neuropathic pain developing 4 weeks after compression. We found that Jmjd3 was induced in the blood vessels and infiltrated macrophages in a rat model of neuropathic pain. The blood-nerve barrier permeability in the cauda equina was increased after compression and significantly attenuated by the Jmjd3 demethylase inhibitor, GSK-J4. GSK-J4 also inhibited the expression and activation of MMP-2 and MMP-9 and significantly alleviated the loss of tight junction proteins and macrophage infiltration. Furthermore, the activation of a macrophage cell line, RAW 264.7, by LPS was significantly alleviated by GSK-J4. Finally, GSK-J4 and a potential Jmjd3 inhibitor, gallic acid, significantly inhibited mechanical allodynia in LSS rats. Thus, our findings suggest that Jmjd3 mediates neuropathic pain development and maintenance by inducing macrophage infiltration and activation after cauda equina compression and thus may serve as a potential therapeutic target for LSS-induced neuropathic pain.

Early results of full-endoscopic decompression of lumbar central canal stenosis by outside-in technique: A clinical and radiographic study

Retrospective cohort study.Full-endoscopic decompression of lumbar spinal canal stenosis is being performed by endoscopic surgeons as an alternative to micro-lumbar decompression in the recent years. The outcomes of the procedure are reported by few authors only. The aim of this paper is to report the clinical and radiographic outcomes of full endoscopic lumbar decompression of central canal stenosis by outside-in technique at 1-year follow-up.We reviewed patients operated for lumbar central canal stenosis by full endoscopic decompression from May 2018 to November 2018. We analyzed the visual analogue scale scores for back and leg pain and Oswestry disability index at pre-op, post-op, and 1-year follow-up. At the same periods, we also evaluated disc height, segmental lordosis, whole lumbar lordosis on standing X-rays and canal cross sectional area at the affected level and at the adjacent levels on magnetic resonance imaging and the facet length and facet cross-sectional area on computed tomography scans. The degree of stenosis was judged by Schizas grading and the outcome at final follow-up was evaluated by MacNab criteria.We analyzed 32 patients with 43 levels (M:F = 14:18) with an average age of 63 (±11) years. The visual analogue scale back and leg improved from 5.4 (±1.3) and 7.8 (±2.3) to 1.6 (±0.5) and 1.4 (±1.2), respectively, and Oswestry disability index improved from 58.9 (±11.2) to 28 (±5.4) at 1-year follow-up. The average operative time per level was 50 (±16.2) minutes. The canal cross sectional area, on magnetic resonance imaging, improved from 85.78 mm2 (±28.45) to 150.5 mm2 (±38.66). The lumbar lordosis and segmental lordosis also improved significantly. The disc height was maintained in the postoperative period. All the radiographic improvements were maintained at 1-year follow-up. The MacNab criteria was excellent in 18 (56%), good in 11 (34%), and fair in 3 (9%) patients. None of the patients required conversion to open surgery or a revision surgery at follow-up. There was 1 patient with dural tear that was sealed with fibrin sealant patch endoscopically. There were 10 patients who had grade I stable listhesis preoperatively that did not progress at follow-up. No other complications like infection, hematoma formations etc. were observed in any patient.Full endoscopic outside-in decompression method is a safe and effective option for lumbar central canal stenosis with advantages of minimal invasive technique.

Prognostic value of cervical ligamentum flavum thickness as a morphological parameter to predict cervical stenosis

One of major causes of cervical central stenosis (CCS) is thickened change of cervical ligament flavum (CLF). The association of a morphological parameter called cervical ligament flavum thickness (CLFT) with CCS has not been reported yet. Thus, the purpose of this research was to investigate the relationship between CCS and CFJT.Data were obtained from 88 patients with CCS. A total of 87 normal controls also underwent cervical spine magnetic resonance imaging (CSMRI). All subjects underwent axial T2-weighted CSMRI. Using our picture archiving and communications system, thickness of ligament flavum of the cervical spine at C6/7 level was analyzed.The mean CLFT was 1.41 ± 0.24 mm in normal subjects and 2.09 ± 0.39 mm in patients with CCS. The CCS group was found to have significantly (P < .001) higher rate of CLFT than normal subjects. ROC curves were used to assess the usefulness of CLFT as a predictor of CCS. In the CCS group, the best practical cut off-point of CLFT was 1.71 mm (sensitivity = 90.9%; specificity = 90.8%), with AUC of 0.94 (95% confidence interval: 0.90--0.98).Greater CLFT values were associated with greater possibility of CCS. Thus, treating physician should carefully examine CLFT, as it can help diagnose CCS.

Evaluation of the effects of differences in silicone hardness on rat model of lumbar spinal stenosis

Lumbar spinal stenosis (LSS), one of the most commonly reported spinal disorders, can cause loss of sensation and dyskinesia. In currently used animal models of LSS, the spinal cord is covered entirely with a silicone sheet, or block-shaped silicone is inserted directly into the spinal canal after laminectomy. However, the effects of differences between these implant materials have not been studied. We assessed the degree of damage and locomotor function of an LSS model in Sprague-Dawley rats using silicone blocks of varying hardness (70, 80, and 90 kPa) implanted at the L4 level. In sham rats, the spinal cord remained intact; in LSS rats, the spinal cord was increasingly compressed by the mechanical pressure of the silicone blocks as hardness increased. Inflammatory cells were not evident in sham rats, but numerous inflammatory cells were observed around the implanted silicone block in LSS rats. CD68+ cell quantification revealed increases in the inflammatory response in a hardness-dependent manner in LSS rats. Compared with those in sham rats, proinflammatory cytokine levels were significantly elevated in a hardness-dependent manner, and locomotor function was significantly decreased, in LSS rats. Overall, this study showed that hardness could be used as an index to control the severity of nerve injury induced by silicone implants.

MicroRNA expression in the cerebrospinal fluid of dogs with and without cervical spondylomyelopathy

BACKGROUND

Osseous-associated cervical spondylomyelopathy (OA-CSM) is a common condition of the cervical vertebral column that affects giant dog breeds. MicroRNAs (miRNAs) are small RNAs that regulate gene expression, and recent data suggest that circulating miRNAs present in biological fluids may serve as potential biomarkers for disease. The miRNA profiles of cerebrospinal fluid (CSF) from healthy dogs and dogs clinically affected by OA-CSM have not been described.

OBJECTIVE

To characterize the expression levels of miRNAs present in the CSF of normal Great Danes and identify differentially expressed miRNAs in the CSF of Great Danes clinically affected with OA-CSM.

ANIMALS

Client-owned dogs: 12 control, 12 OA-CSM affected.

METHODS

Cerebrospinal fluid samples were collected prospectively. MicroRNA expression was evaluated using the NanoString nCounter platform and quantitative real-time PCR.

RESULTS

We identified 8 miRNAs with significant differential expression. MiR-299-5p and miR-765 had increased expression levels in the CSF of OA-CSM-affected dogs, whereas miR-494, miR-612, miR-302-d, miR-4531, miR-4455, and miR-6721-5p had decreased expression levels in OA-CSM affected dogs compared to clinically normal dogs. Quantitative real-time PCR was performed to validate the expression levels of 2 miRNAs (miR-494 and miR-612), and we found a 1.5-fold increase in miR-494 expression and a 1.2-fold decrease in miR-612 in the CSF of the OA-CSM affected group (P = .41 and .89, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Data generated from our study represent an initial characterization of the miRNA profile of normal canine CSF and suggest that a distinct CSF miRNA expression profile is associated with OA-CSM.

Cervical Spine Deformities in Children With Rhizomelic Chondrodysplasia Punctata

BACKGROUND

Cervical spine deformity in rhizomelic chondrodysplasia punctata (RCDP) has been described with different findings reported in the literature. However, available literature provides limited data from a few cases with magnetic resonance imaging (MRI) of the cervical spine. Our report describes the MRI findings in a group of children with RCDP, aiming to reach a better understanding of this pathology.

METHODS

An Institutional Review Board-approved RCDP Registry was created at our institution with the goal of identifying pertinent medical issues over the lifespan of individuals with RCDP. Records of children within the registry were evaluated, and magnetic resonance images obtained between 2004 and 2015, were available for review. The levels of spinal canal stenosis were recorded and the severity of the stenosis was decided based on adults' parameters. Cord compression and myelomalacia were confirmed on the axial images. Sagittal lumbar spine magnetic resonance images were also evaluated when available, and the presence of tethered cord and fatty filum was recorded.

RESULTS

Twenty-six children (15 boys and 11 girls) were identified in the RCDP Registry. Eleven children (6 boys and 5 girls) had sagittal MRI of the cervical spine available for review. Age at the time of MRI study was variable (1 wk to 32 mo). All patients except 1 had stenosis of the cervical spinal canal. Myelomalacia of the cord was noted only in this patient.

CONCLUSIONS

This study suggests that, in children with RCDP, cervical spinal stenosis and cord compression are a real risk, and children with this diagnosis should have monitoring for these issues. Tethered cord is also a possible finding that needs to be evaluated. Full sagittal spine MRI is necessary to detect the possible deformities at the cervical and lumbar levels.

Risk factors of degenerative lumbar scoliosis in patients with lumbar spinal canal stenosis

Lumbar spinal canal stenosis (LSCS) associated with degenerative scoliosis has being increasingly aware by the public and studied by many researchers. Degenerative changes leading to spinal stenosis can precede a spinal deformity which will develop into the de novo scoliosis. There are few studies focusing on the risk factors contributing to the degenerative lumbar scoliosis (DLS) in lumbar spinal stenosis patients.From September, 2017 to December, 2017, 181 patients who were diagnosed with LSCS in the outpatient department of our hospital were enrolled in this retrospective investigation. The patients were divided into 2 groups: DLS group (Cobb angle >10°) and LSCS group. Sex, age, smoking status (yes or no), occupation (heavy or light labor), body mass index (BMI), bone mineral density (BMD) and radiographic parameters including the lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), coronal vertical axis, and sagittal vertical axis (SVA) are all evaluated as potential risk factors. Multivariate logistic regression analysis and receiver-operating characteristic curves were used to identify potential risk factors.Forty-five of 181 patients were diagnosed with DLS and involved in the DLS group. There were significant differences between the 2 groups in BMI (P < .001), LL (P = .0046), BMD (P < .001), SVA (P < .001), and TK (P = .047). BMD < -1.85 g/cm (adjusted odds ratio [AOR] 0.030, 95% confidence interval [CI] 0.008-0.107, P < .001), BMI >25.57 kg/m (AOR 1.270, 95% CI 1.040-1.551, P = .019), and SVA >3.98 cm (AOR 3.651, 95% CI 2.226-5.990, P < .001) had good accuracy to predict the formation of degenerative lumbar scoliosis based on degenerative lumbar spinal stenosis.Degenerative lumbar scoliosis has a high incidence in degenerative lumbar spinal stenosis. BMD <-1.85 g/cm, BMI >25.57 kg/m, and SVA >3.98 cm were the potential risk factors for the formation of degenerative lumbar scoliosis based on degenerative lumbar spinal stenosis.

Comparison of the clinical and radiographic appearance of the cervical vertebrae with histological and anatomical findings in an eight-month old warmblood stallion suffering from cervical vertebral stenotic myelopathy (CVSM)

BACKGROUND

Cervical vertebral stenotic myelopathy (CVSM) remains one of the most important abnormalities of the cervical spine resulting in neurological deficits in horses. The aim of the following study was to compare the results of the clinical and neurological examination, the results of myelography and the post mortem anatomical and histological appearance of the spinal cord and cervical vertebrae in a horse with CVSM.

CASE PRESENTATION

The following study describes a clinical case of an eight-month-old stallion with ataxia. Plain cervical radiographs indicated narrowing of the spinal canal. Conservative therapy using NSAIDs did not result in any improvement in the gait of the horse. Due to economic constraints, surgical intervention was excluded. The owner chose to humanely euthanise the horse. Immediately after euthanasia, post mortem myelography was performed, and measurements of the myelographic dye column were taken. They revealed a 67% DMC reduction and a 64% DD reduction at the C3/C4 level. Afterwards, an anatomical dissection was performed. The cervical vertebrae and vertebral canal were macroscopically inspected and measured and indicated a 44% narrowing of the canal at the C3/C4 level. The spinal cord was removed and underwent histological evaluation after staining. Microscopic lesions were visible at the level of the compression and included axonal degeneration with partial or complete loss of myelin in the white matter of the lateral and dorsal funiculi as well as the formation of dysfunctional so-called "spongy structures". An increase in the number of microglial cells and collagen was also observed. The formation of glial scars was excluded. Immunohistochemical studies revealed a negative transmembrane glycoprotein CD68(-) - monocyte response and a negative tumor necrosis alpha TNFα (-) reaction.

CONCLUSIONS

CVSM may be difficult to diagnose, even for experienced veterinary surgeons. Currently, an ex vivo histopathologic examination of the spinal cord is thought to be the gold standard in the diagnosis of CVSM. Our histological examination revealed no CVSM-specific glial scar formation and a CD68(-) negative and TNF-α negative reaction, which have not been previously reported. Histological lesions in CVSM may vary depending show inter-individual variability and on the treatment, which further hinders ex-vivo diagnostics.

Percutaneous endoscopic treatment for cervical ligamentum flavum gouty tophus: A case report

RATIONALE

Cervical ligamentum flavum gout (CLFG) is relatively rare, and its clinical manifestations are complicated; hence, it is often confused with ligamentum flavum ossification. Gout tophi may relate to certain risk factors, such as renal insufficiency and lack of long-term effective uric acid treatment.

PATIENT CONCERNS

A 73-year-old man had a half-year history of left upper extremity pain and numbness, which was aggravated 6 months ago.

DIAGNOSES

Computed tomography (CT) indicated spinal stenosis at the level of C5/6. Cervical stenosis was believed to be mostly related to the ossification of ligamentum flavum. The histological examination of the material removed during the surgery revealed fibrous tissues with pools of amorphous debris having a foreign body giant cell reaction, which is typical of urate gout.

INTERVENTIONS

We performed complete decompressions for this case with CLFG using posterior percutaneous endoscopic technique.

OUTCOMES

The patient experienced a progressive improvement in the left upper extremity pain after the surgery, and no signs of cerebrospinal fluid leakage, infection, or other complications were experienced.

LESSONS

The clinician should include spinal gout in the differential diagnosis when dealing with patients with hyperuricemia, renal insufficiency, and axial pain with or without neurologic deficits. We have applied the percutaneous endoscopic technique for the treatment of spinal gout. It performed direct decompression with minimizing trauma and instability, which could be used as an alternative choice.

Decreased catalase expression is associated with ligamentum flavum hypertrophy due to lumbar spinal canal stenosis

BACKGROUND

This is an immunohistologic study of gene expression between patients and controls.This study aims to evaluate expression of the catalase gene in hypertrophied ligamentum flavum (LF) specimens obtained from patients with lumbar spinal canal stenosis (LSCS).LSCS is one of the most common spinal disorders. It is well known that LF hypertrophy plays an important role in the onset of LSCS. Although degenerative changes, aging, and mechanical stress are all thought to contribute to hypertrophy and fibrosis of the LF, the precise pathogenesis of LF hypertrophy remains unknown. Previous genetic studies have tried to determine the mechanism of LF hypertrophy. However, the association between catalase gene expression and LF hypertrophy has not yet been explored.

METHODS

LF specimens were surgically obtained from 30 patients with spinal stenosis (LSCS group) and from 30 controls with lumbar disc herniation (LDH group). LF thickness was measured at the thickest point using calipers to an accuracy of 0.01 mm during surgical intervention. The extent of LF elastin degradation and fibrosis were graded (grades 0-4) by hematoxylin and eosin staining and Masson trichrome staining, respectively. The resulting LF measurements, histologic data, and immunohistologic results were then compared between the 2 groups.

RESULTS

The average LF thickness was significantly higher in the LSCS group than in the LDH group (5.99 and 2.95 mm, respectively, P = .004). Elastin degradation and fibrosis of the LF were significantly more severe in spinal stenosis samples than in the disc herniation samples (3.04 ± 0.50 vs 0.79 ± 0.60, P = .007; 3.01 ± 0.47 vs 0.66 ± 0.42, P = .009, respectively). Significantly lower expression of catalase was observed in the perivascular area of LF samples obtained from patients with LSCS compared with controls (61.80 ± 31.10 vs 152.80 ± 41.13, respectively, P = .009).

CONCLUSION

Our findings suggest that decreased expression of catalase is associated with LF hypertrophy in patients with LSCS.

Facet joint hypertrophy is a misnomer: A retrospective study

One of the major causes of lumbar spinal canal stenosis (LSCS) has been considered facet joint hypertrophy (FJH). However, a previous study asserted that "FJH" is a misnomer because common facet joints are no smaller than degenerative facet joints; however, this hypothesis has not been effectively demonstrated. Therefore, in order to verify that FJH is a misnomer in patients with LSCS, we devised new morphological parameters that we called facet joint thickness (FJT) and facet joint cross-sectional area (FJA).We collected FJT and FJA data from 114 patients with LSCS. A total of 86 control subjects underwent lumbar magnetic resonance imaging (MRI) as part of routine medical examinations, and axial T2-weighted MRI images were obtained from all participants. We measured FJT by drawing a line along the facet area and then measuring the narrowest point at L4-L5. We measured FJA as the whole cross-sectional area of the facet joint at the stenotic L4-L5 level.The average FJT was 1.60 ± 0.36 mm in the control group and 1.11 ± 0.32 mm in the LSCS group. The average FJA was 14.46 ± 5.17 mm in the control group and 9.31 ± 3.47 mm in the LSCS group. Patients with LSCS had significantly lower FJTs (P < .001) and FJAs (P < .001).FJH, a misnomer, should be renamed facet joint area narrowing. Using this terminology would eliminate confusion in descriptions of the facet joint.

Clinical classification criteria for neurogenic claudication caused by lumbar spinal stenosis. The N-CLASS criteria

BACKGROUND CONTEXT

Because imaging findings of lumbar spinal stenosis (LSS) may not be associated with symptoms, clinical classification criteria based on patient symptoms and physical examination findings are needed.

PURPOSE

The objective of this study was to develop clinical classification criteria that identify patients with neurogenic claudication (NC) caused by LSS.

STUDY DESIGN

This study is a two-stage process that includes Phase 1, the Delphi process, and Phase 2, the cross-sectional study.

PATIENT SAMPLE

Outpatients were recruited from spine clinics in five countries.

OUTCOME MEASURE

The outcome measure includes items from the patients' history and physical examination.

METHODS

In Phase 1, a list of potential predictors of NC caused by LSS was based on the available literature and was evaluated through a Delphi process involving 17 spine specialists (surgeons and non-surgeons) from eight countries. In Phase 2, 19 different clinical spine specialists from five countries identified patients they classified as having (1) NC caused by LSS, (2) radicular pain caused by lumbar disc herniation (LDH), or (3) non-specific low back pain (NSLBP) with radiating leg pain. The patients completed survey items and the specialists documented the examination signs. Coefficients from general estimating equation models were used to select predictors, to generate a clinical classification score, and to obtain a receiver operating characteristic curve. Conduction of the Delphi process, data management, and statistical analysis were partially supported by an unrestricted grant of less than 15,000 US dollars from Merck Sharp & Dohme. No fees were allocated to participating spine specialists.

RESULTS

Phase 1 generated a final list of 46 items related to LSS. In Phase 2, 209 patients with leg pain caused by LSS (n=63), LDH (n=89), or NSLBP (n=57) were included. Criteria that independently predicted NC (p<.05) were age over 60 years, positive 30-second extension test, negative straight leg test, pain in both legs, leg pain relieved by sitting, and leg pain decreased by leaning forward or flexing the spine. A classification score using a weighted set of these criteria was developed. The proposed N-CLASS score ranged from 0 to 19 and had an area under the curve of 0.92, and the cutoff (>10/19) to obtain a specificity of >90.0% resulted in a sensitivity of 82.0%.

CONCLUSIONS

Clinical criteria independently associated with neurogenic claudication due to LSS were identified. The use of these symptom and physical variables as a classification score for clinical research could improve homogeneity among enrolled patients.

Kinetic and kinematic variables affecting trunk flexion during level walking in patients with lumbar spinal stenosis

Lumbar spinal stenosis causes cauda equina and nerve root compression, resulting in neurological symptoms. Although trunk flexion during level walking may alleviate these symptoms by enabling spinal canal decompression, some patients do not use this strategy. We aimed to identify the kinetic and kinematic variables that affect trunk flexion in patients during level walking. Gait was recorded in 111 patients using a three-dimensional motion capture system and six force plates. From the data recorded, walking velocity, bilateral step length, cycle time, maximum trunk flexion angle, forward pelvic tilt angle, pelvic rotation angle, maximum and minimum joint angles, and moment and power of the lower limb were calculated. Then a step-wise multiple regression analysis was conducted to identify kinetic and kinematic variables affecting trunk flexion. The maximum hip extension angle (β = 0.416), maximum hip flexion moment (β = -0.348), and step length (β = 0.257) were identified as variables significantly affecting the trunk flexion angle. The coefficient of determination adjusted for the degree of freedom was 0.294 (p < 0.05). Our results suggest that patients with lumbar spinal stenosis choose one of two strategies to alleviate symptoms during walking. One strategy is gait with trunk flexion posture to increase step length and hip extension angle. The other strategy is gait with trunk upright posture to decrease step length and hip extension angle.

Bilateral decompression and intervertebral fusion via unilateral fenestration for complex lumbar spinal stenosis with a mobile microendoscopic technique

For complex lumbar spinal stenosis, using of endoscopy technique may provide clear vision with less invasive dissection of paravertebral muscle. The objective of this study was to evaluate the feasibility and clinical efficacy of bilateral decompression and intervertebral fusion via unilateral fenestration for complex lumbar spinal stenosis using mobile microendoscopic discectomy (MMED) technique.A total of 61 patients with complex lumbar spinal stenosis (lumbar canal stenosis combined with degenerative spondylolisthesis, instability, and scoliosis) were treated with this procedure. Patients with isolated lumbar spinal stenosis or spondylolisthesis greater than grade II were excluded. The index levels included L4/5 in 52 patients, L5/S1 in 6 patients, L3-L5 in 2 patients and L4-S1 in 1 patient. The preoperative Oswestry Disability Index (ODI) score was 42.6 ± 10.2, lumbar visual analog scale (VAS) score was 6.1 ± 4.2, and leg VAS score was 7.1 ± 5.1. During the operation, ipsilateral enlarged fenestration was made using the MMED technique. The disc and cartilage endplate were thoroughly removed, and the contralateral ligamentum flavum and the inner layer of lamina were undercut to release the contralateral nerve root. The intervertebral space was released and prepared, followed by bone grafting and cage insertion. Percutaneous pedicle system was used for reduction and fixation. The operative time and blood loss were recorded, and patients were followed-up for at least 3 years (36-48 months, average 41 months) to evaluate the clinical efficacy.The procedure was successful in all patients, with no nerve injury or conversion to open operation. The mean operative time was 120 minutes (range, 100-180 minutes), with a mean blood loss of 100 mL (range, 50-200 mL). Postoperative x-ray and CT showed sufficient decompression and improvement of spinal alignment. At 3 years after surgery, the ODI scores, lumbar and leg VAS scores decreased from preoperative 42.6 ± 10.2, 6.1 ± 4.2, and 7.1 ± 5.1 to 8.6 ± 7.0, 1.8 ± 1.3, and 0.9 ± 0.6, respectively (P = .00 for each comparison). The clinical results were excellent in 36 cases, good in 23, and fair in 2, according to the MacNab scale.The procedure of bilateral decompression and intervertebral fusion via unilateral fenestration using the MMED technique can provide satisfactory clinical results for complex lumbar spinal stenosis.

Dural sac area is a more sensitive parameter for evaluating lumbar spinal stenosis than spinal canal area: A retrospective study

Narrowing of the dural sac cross-sectional area (DSCSA) and spinal canal cross-sectional area (SCCSA) have been considered major causes of lumbar central canal spinal stenosis (LCCSS). DSCSA and SCCSA were previously correlated with subjective walking distance before claudication occurs, aging, and disc degeneration. DSCSA and SCCSA have been ideal morphological parameters for evaluating LCCSS. However, the comparative value of these parameters is unknown and no studies have evaluated the clinical optimal cut-off values of DSCSA and SCCSA. This study assessed which parameter is more sensitive.Both DSCSA and SCCSA samples were collected from 135 patients with LCCSS, and from 130 control subjects who underwent lumbar magnetic resonance imaging (MRI) as part of a medical examination. Axial T2-weighted MRI scans were acquired at the level of facet joint from each subject. DSCSA and SCCSA were measured at the L4-L5 intervertebral level on MRI using a picture archiving and communications system.The average DSCSA value was 151.67 ± 53.59 mm in the control group and 80.04 ± 35.36 mm in the LCCSS group. The corresponding average SCCSA values were 199.95 ± 60.96 and 119.17 ± 49.41 mm. LCCSS patients had significantly lower DSCSA and SCCSA (both P < .001). Regarding the validity of both DSCSA and SCCSA as predictors of LCCSS, Receiver operating characteristic curve analysis revealed an optimal cut-off value for DSCSA of 111.09 mm, with 80.0% sensitivity, 80.8% specificity, and an area under the curve (AUC) of 0.87 (95% confidence interval, 0.83-0.92). The best cut off-point of SCCSA was 147.12 mm, with 74.8% sensitivity, 78.5% specificity, and AUC of 0.85 (95% confidence interval, 0.81-0.89).DSCSA and SCCSA were both significantly associated with LCCSS, with DSCSA being a more sensitive measurement parameter. Thus, to evaluate LCCSS patients, pain specialists should more carefully investigate the DSCSA than SCCSA.

Visualization of lumbar nerves using reduced field of view diffusion tensor imaging in healthy volunteers and patients with degenerative lumbar disorders

OBJECTIVE

We investigated high resolution diffusion tensor imaging (DTI) of lumbar nerves with reduced field of view (rFOV) using 3 T MRI.

METHODS

DTI measured with rFOV was compared with conventional FOV (cFOV) 3.0 T MRI in 5 healthy volunteers and 10 patients with degenerative lumbar disorders. The intracanal, foramina and extraforamina of the L5 nerve were established as the regions of interest and fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) values were measured. Image quality for tractography and FA maps and ADC maps, interindividual and intraindividual reliability of FA and ADC, and signal-to-noise (SNR) were studied.

RESULTS

Both of image qualities with tractography, FA map and ADC map showed that lumbar nerves were more clearly imaged with the rFOV. Intraindividual reliability was higher with rFOV compared with the conventional method for ADC values, while interindividual reliability was higher for both FA values and ADC values with the rFOV method over the conventional method (p < 0.05). Significantly higher SNR was obtained with rFOV compared with cFOV in the spinal canal (p < 0.05).

CONCLUSION

rFOV enabled clearer imaging of the lumbar nerve, allowing for more accurate measurement of FA and ADC values. Significantly higher SNR was obtained with rFOV compared with cFOV in the spinal canal. To our knowledge, this research showed for the first time the usefulness of rFOV in patients with degenerative lumbar disorders. High resolution DTI using rFOV may become useful in clinical applications because visualization of nerve entrapments and quantification of DTI parameters may allow more accurate diagnoses of lumbar nerve dysfunction. Advances in knowledge: Compared with traditional methods, rFOV allows for clear imaging of the lumbar nerve and enables accurate measurements of the FA and ADC values. High-resolution DTI with rFOV may be used to visualize nerve entrapments and allow for more accurate diagnosis of DTI parameter quantification with opportunities for clinical applications.

The functional relevance of diffusion tensor imaging in comparison to conventional MRI in patients with cervical compressive myelopathy

OBJECTIVE

To determine the functional relevance of diffusion tensor imaging (DTI) metrics and conventional MRI (signal intensity change in T2, compression ratio) by measuring the correlation of these parameters with clinical outcome measured by the modified Japanese Orthopedic Association (mJOA) score.

MATERIALS AND METHODS

A total of 20 cervical myelopathy (CM) patients participated in this prospective cohort study. The severities of CM were assessed using the mJOA score. Conventional MRIs (T2-weighted images) measuring the signal changes of spinal cords and the degree of compression at the lesion level and DTI metrics [fractional anisotropy (FA), apparent diffusion coefficient (ADC)] at each lesion and below each lesion (C7/T1) level were acquired using a 3-T Achieva MRI. These parameters were correlated with the mJOA scores to determine the functional relevance.

RESULTS

Ninety percent of CM patients showed signal changes and 30 % of patients noted a more than 40% canal compression ratio in conventional MRIs at the lesion level; however, these findings were not correlated with the mJOA score (p < 0.05). In contrast, FA values on DTI showed high sensitivity to CM (100%), which was well correlated with the mJOA score (p = 0.034, r = 0.475) below the lesion level (C7/T1).

CONCLUSIONS

This study showed a meaningful symptomatic correlation between mJOA scores and FA values below the lesion levels in CM patients. It could give us more understanding of the pathological changes in spinal cords matched with various clinical findings in CM patients than the results from conventional MRI.

Neurosurgical aspects of dialysis-related spinal amyloidosis: Report of three cases and a review of the literature

BACKGROUND AND PURPOSE

Osteoarticular manifestations of beta-2 microglobulin amyloidosis are often diagnosed in long-term dialyzed patients. However, spinal involvement is rare (10-25% of patients), and generally not associated with neurological deterioration. Compression of the spinal cord or roots is extremely rare, and probably under-recognized.

METHODS

The authors describe three cases of spinal stenosis presenting with neurological signs in long-term dialyzed patients, prospectively collected over 2 years in two different institutions and treated by surgical decompression. In all three cases, the main cause of neural compression was amyloid deposition in the spine, either extradurally in the ligamentum flavum or intradurally.

RESULTS

All patients improved after surgery and did not present any postoperative complications. However, two out of three patients with amyloid in the cervical spine required surgical revision to obtain a satisfactory decompression of the spinal cord.

DISCUSSION

The authors discuss spinal amyloidosis which is a well-known complication of long-term dialysis. However, neurological complications such as spinal cord or radicular symptoms have been rarely reported and, when present in dialyzed patients, are symptoms that are often attributed to other causes. To our knowledge, this is the first case series that demonstrates the relationship between neurological deterioration and amyloid depositions in the spinal canal that occur in long-term dialyzed patients. The prevalence of spinal stenosis related to the presence of amyloid in this specific subgroup of patients is probably underestimated.

Expression of the JAK/STAT signaling pathway in the ligamentum flavum of patients with lumbar spinal canal stenosis

BACKGROUND

Ligamentum flavum (LF) hypertrophy is an important cause of lumbar spinal canal stenosis (LSS), one of the most common spinal disorders in the elderly. Although many cytokines are reported to be associated with LF hypertrophy, the intracellular signaling system is rarely discussed. The purpose of this study was to identify the JAK/STAT signaling pathway and to examine the role of the JAK/STAT systems in the hypertrophied LF.

METHODS

The LF of 10 LSS patients was analyzed and the expression of JAK1, STAT3, phosphorylated (p)-STAT3, and actin was examined by Western blot analysis. The expression of p-STAT3 was also examined by immunostaining and its positive cell ratio was compared between LSS and non-LSS samples. We measured the thickness of the LF on magnetic resonance images and studied the relationship between its thickness and the expression of p-STAT3.

RESULTS

JAK1, STAT3, and p-STAT3 were detected in almost all samples by Western blot analysis. Immunoreactivity against p-STAT3 was observed mainly in endothelial- and fibroblast-like cells. The expression of p-STAT3 was significantly higher in LSS than non-LSS samples; it was significantly stronger on the dorsal than the dural side of the LF and positively correlated with the thickness of the LF on the dorsal side.

CONCLUSIONS

The JAK/STAT signaling pathway is positively correlated with the thickness of the LF. Our findings suggest that JAK1 and STAT3 molecules are involved in and regulate LF hypertrophy.

Experimental Spinal Stenosis in Cats: New Insight in Mechanisms of Hydrocephalus Development

In our new experimental model of cervical stenosis without inflammation we have tested hypothesis that cranio-spinal communication impairment could lead to hydrocephalus development. Spinal and cranial cerebrospinal fluid (CSF) space separation was obtained with positioning of plastic semiring in epidural space at C2 level in cats. Brain ventricles planimetry, and CSF pressure recording in lateral ventricle (LV) and lumbar subarachnoid space (LSS) were performed in acute and subchronic experiments. In all experiments opening CSF pressures were normal. However, in acute experiments, an infusion of artificial CSF into the LV led to increase of CSF pressure and significant gradient pressure development between LV and LSS due to limited pressure transmission. After 3 or 6 weeks spinal cord atrophy was observed at the site of cervical stenosis, and pressure transmission from LV to LSS was improved as a consequence of spinal tissue atrophy. Planimetry of both the coronal brain slices and the ventricles' surface showed that control ventricular surface was 0.6 ± 0.1% (n = 5), and 1.6 ± 0.2% (n = 4) in animals with subchronic cervical stenosis (P < 0.002). These results support the mentioned hypothesis claiming that CSF volume cranio-spinal displacement impairment could start pathophysiological processes leading to development of hydrocephalus.

How I do it? Biportal endoscopic spinal surgery (BESS) for treatment of lumbar spinal stenosis

BACKGROUND

Prevalent endoscopic spine surgeries have shown limitations especially in spinal stenosis (Ahn in Neurosurgery 75(2):124-133, 2014). Biportal endoscopic surgery is introduced to manage central and foraminal stenosis with its wide range of access angle and clear view.

METHODS

The authors provide an introduction of this technique followed by a description of the surgical anatomy with discussion on its indications and advantages. In particular, tricks to avoid complications are also presented.

CONCLUSIONS

Effective circumferential and focal decompression were achieved in most cases without damage to the spinal structural integrity with preservation of muscular and ligamentous attachments. The biportal endoscopic spinal surgery (BESS) may be safely used as an alternative minimally invasive procedure for lumbar spinal stenosis (Figs. 1 and 2).

Predictive Factors for Subjective Improvement in Lumbar Spinal Stenosis Patients with Nonsurgical Treatment: A 3-Year Prospective Cohort Study

Objective

To assess the predictive factors for subjective improvement with nonsurgical treatment in consecutive patients with lumbar spinal stenosis (LSS).

Materials and Methods

Patients with LSS were enrolled from 17 medical centres in Japan. We followed up 274 patients (151 men; mean age, 71 ± 7.4 years) for 3 years. A multivariable logistic regression model was used to assess the predictive factors for subjective symptom improvement with nonsurgical treatment.

Results

In 30% of patients, conservative treatment led to a subjective improvement in the symptoms; in 70% of patients, the symptoms remained unchanged, worsened, or required surgical treatment. The multivariable analysis of predictive factors for subjective improvement with nonsurgical treatment showed that the absence of cauda equina symptoms (only radicular symptoms) had an odds ratio (OR) of 3.31 (95% confidence interval [CI]: 1.50–7.31); absence of degenerative spondylolisthesis/scoliosis had an OR of 2.53 (95% CI: 1.13–5.65); <1-year duration of illness had an OR of 3.81 (95% CI: 1.46–9.98); and hypertension had an OR of 2.09 (95% CI: 0.92–4.78).

Conclusions

The predictive factors for subjective symptom improvement with nonsurgical treatment in LSS patients were the presence of only radicular symptoms, absence of degenerative spondylolisthesis/scoliosis, and an illness duration of <1 year.

The Relation Between Sacral Angle and Vertical Angle of Sacral Curvature and Lumbar Disc Degeneration: A Case-Control Study

The purpose of this study is to determine the reliability and validity of a goniometric measurement of the vertical angle of the sacrum and sacral angle (SA), and their relationships to lumbar degeneration.A herniated lumbar disc is one of the most frequent medical issues. Investigators in a number of studies have reported associated risk factors for prevalent disc degeneration. Atypical lumbosacral angles and curvature are thought to contribute to the degradation of the spine by many researchers. This study analyzed 360 patients referred to our clinic from 2013 to 2015 due to low back pain. A cross-sectional case-control study was designed in order to compare the sagittal alignment of the lumbosacral area in 3 groups of patients suffering from LBP. A total 120 patients were in a control group with a normal lumbar magnetic resonance imaging (MRI), 120 patients had lumbar disk herniation (LDH), and 120 patients had spinal stenosis. From the sagittal plan of lumbar MRI, SA and vertical angle of sacral curvature (VASC) were determined and then analyzed.The means of VASC in these groups were: 38.98 (SD: 6.36 ± 0.58), 40.89 (SD: 7.69 ± 0.69), and 40.54 (SD: 7.13 ± 0.92), respectively (P = 0.089). Moreover, studies of SA in 3 groups showed that the means of SA were: 39.30 (SD: 6.69 ± 0.63), 40.52 (SD: 7.47 ± 0.65), and 35.63 (SD: 6.07 ± 0.79), respectively. Relation between SA and spinal stenosis was just statistically significant (P ≤ 0.05).One significant limitation of our study is the lack of standing MRI for increased accuracy of measurement. However, we were reluctant to give patients needless exposure to radiation from conventional X-ray, and instead used MRI scans. We did not find any significant correlation between the VASC and LDH in lumbar MRI. Also, SA is not an independent risk factor for LDH in men and women. We suggested that there are several biomechanical factors involved in LDH.

Comparison of the Dynesys Dynamic Stabilization System and Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

BACKGROUND

There have been few studies comparing the clinical and radiographic outcomes between the Dynesys dynamic stabilization system and posterior lumbar interbody fusion (PLIF). The objective of this study is to compare the clinical and radiographic outcomes of Dynesys and PLIF for lumbar degenerative disease.

METHODS

Of 96 patients with lumbar degenerative disease included in this retrospectively analysis, 46 were treated with the Dynesys system and 50 underwent PLIF from July 2008 to March 2011. Clinical and radiographic outcomes were evaluated. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD).

RESULTS

The mean follow-up time in the Dynesys group was 53.6 ± 5.3 months, while that in the PLIF group was 55.2 ± 6.8 months. At the final follow-up, the Oswestry disability index and visual analogue scale score were significantly improved in both groups. The range of motion (ROM) of stabilized segments in Dynesys group decreased from 7.1 ± 2.2° to 4.9 ± 2.2° (P < 0.05), while that of in PLIF group decreased from 7.3 ± 2.3° to 0° (P < 0.05). The ROM of the upper segments increased significantly in both groups at the final follow-up, the ROM was higher in the PLIF group. There were significantly more radiographic ASDs in the PLIF group than in the Dynesys group. The incidence of complications was comparable between groups.

CONCLUSIONS

Both Dynesys and PLIF can improve the clinical outcomes for lumbar degenerative disease. Compared to PLIF, Dynesys stabilization partially preserves the ROM of the stabilized segments, limits hypermobility in the upper adjacent segment, and may prevent the occurrence of ASD.

Degenerative Pathways of Lumbar Motion Segments--A Comparison in Two Samples of Patients with Persistent Low Back Pain

Background

Magnetic resonance imaging (MRI) is used to identify spinal pathoanatomy in people with persistent low back pain. However, the clinical relevance of spinal degenerative MRI findings remains uncertain. Although multiple MRI findings are almost always present at the same time, research into the association with clinical outcomes (such as pain) has predominantly focused on individual MRI findings. This study aimed to: (i) investigate how multiple MRI lumbar spine findings cluster together within two different samples of patients with low back pain, (ii) classify these clusters into hypothetical pathways of degeneration based on scientific knowledge of disco-vertebral degeneration, and (iii) compare these clusters and degenerative pathways between samples.

Methods

We performed a secondary cross-sectional analysis on two dissimilar MRI samples collected in a hospital department: (1) data from the spinal MRI reports of 4,162 low back pain patients and (2) data from an MRI research protocol of 631 low back pain patients. Latent Class Analysis was used in both samples to cluster MRI findings from lumbar motion segments. Using content analysis, each cluster was then categorised into hypothetical pathways of degeneration.

Results

Six clusters of MRI findings were identified in each of the two samples. The content of the clusters in the two samples displayed some differences but had the same overall pattern of MRI findings. Although the hypothetical degenerative pathways identified in the two samples were not identical, the overall pattern of increasing degeneration within the pathways was the same.

Conclusions

It was expected that different clusters could emerge from different samples, however, when organised into hypothetical pathways of degeneration, the overall pattern of increasing degeneration was similar and biologically plausible. This evidence of reproducibility suggests that Latent Class Analysis may provide a new approach to investigating the relationship between MRI findings and clinically important characteristics such as pain and activity limitation.

[A RARE CAUSE OF THORACIC MYELOPATHY: THE OSSIFICATION OF THE LIGAMENTUM FLAVUM]

Ossification of the ligamentum flavum (OLF) is a rare cause of thoracic myelopathy. Mostly described in Japan and East Asia, a number of cases have recently been reported in western subjects. We present the case of a patient, an asymptomatic carrier of lumbar canal stenosis, presenting with a slowly progressive posterior cord compression and a T12 sensitive level. The diagnosis of thoracic OLF was retrospectively made thanks to medical imaging. We reviewed the literature and focused on the epidemiology, physiopathology, presentation, treatment and prognosis of the thoracic OLJ with or without lumbar spinal stenosis.

Thoracic Meningioma In Combination With Severe Lumbar Spinal Stenosis Presenting With Atypical Neurological Deficit

We report on a case of a 47-year-old female patient with a long history of low back pain irradiating bilaterally to the legs. Twenty days before admission to our clinic, she had developed progressive weakness in the legs, more pronounced on the left side. The initial neurological examination revealed signs of damage to both the cauda equina and the spinal cord. The neuroimaging studies (computed tomography, myelography and magnetic-resonance tomography) found spinal stenosis most severe at L4-L5 level, and right lateral thoracic intradural-extramedullary tumor at T9-T10 level. The patient underwent two neurosurgical procedures. The first stage included microsurgical resection of the thoracic lesion and the second stage aimed at decompressing the lumbar spinal stenosis. To avoid missing a diagnosis of thoracic lesions, it is necessary to perform a thorough neurological examination of the spinal cord motor and sensory functions. In addition, further MRI examination of upper spinal segment is needed if the neuroimaging studies of the lumbar spine fail to provide reasonable explanation for the existing neurological symptoms.

The Lumbar Spine as a Dynamic Structure Depicted in Upright MRI

Spinal canal stenosis is a dynamic phenomenon that becomes apparent during spinal loading. Current diagnostic procedures have considerable short comings in diagnosing the disease to full extend, as they are performed in supine situation. Upright MRI imaging might overcome this diagnostic gap.This study investigated the lumbar neuroforamenal diameter, spinal canal diameter, vertebral body translation, and vertebral body angles in 3 different body positions using upright MRI imaging.Fifteen subjects were enrolled in this study. A dynamic MRI in 3 different body positions (at 0° supine, 80° upright, and 80° upright + hyperlordosis posture) was taken using a 0.25 T open-configuration scanner equipped with a rotatable examination bed allowing a true standing MRI.The mean diameter of the neuroforamen at L5/S1 in 0° position was 8.4 mm on the right and 8.8 mm on the left, in 80° position 7.3 mm on the right and 7.2 mm on the left, and in 80° position with hyperlordosis 6.6 mm (P < 0.05) on the right and 6.1 mm on the left (P < 0.001).The mean area of the neuroforamen at L5/S1 in 0° position was 103.5 mm on the right and 105.0 mm on the left, in 80° position 92.5 mm on the right and 94.8 mm on the left, and in 80° position with hyperlordosis 81.9 mm on the right and 90.2 mm on the left.The mean volume of the spinal canal at the L5/S1 level in 0° position was 9770 mm, in 80° position 10600 mm, and in 80° position with hyperlordosis 9414 mm.The mean intervertebral translation at level L5/S1 was 8.3 mm in 0° position, 9.9 mm in 80° position, and 10.1 mm in the 80° position with hyperlordosis.The lordosis angle at level L5/S1 was 49.4° in 0° position, 55.8° in 80° position, and 64.7 mm in the 80° position with hyperlordosis.Spinal canal stenosis is subject to a dynamic process, that can be displayed in upright MRI imaging. The range of anomalies is clinically relevant and dynamic positioning of the patient during MRI can provide essential diagnostic information which are not attainable with other methods.

[Degenerative and age-related alterations of the spine]

Degenerative alterations of the spine occur in an individual-specific manner with increasing age. This is not only dependent on external factors, such as hard physical labor over many years but can also be genetically influenced as demonstrated in recent studies. The spinal cord is well-protected within the spinal canal but can be impaired by degenerative alterations of the intervertebral discs and functional spinal segments. Depositions or narrowing of nerve structures can cause lasting pain or focal neurological deficits, such as paralysis or sensitivity disorders. These complaints can slowly develop over years, e.g. by a gradually increasing bony narrowing of the spinal canal (spinal canal stenosis) or can occur suddenly, e.g. an acute herniated disc. However, low back pain is much more common and occurs in approximately 80 % of people sometime during their lifetime. It is necessary to recognize the normal age-related anatomical alterations in magnetic resonance imaging (MRI), particularly for intervertebral discs in order to interpret these correctly. Knowledge of the spectrum of the various age-related degenerative processes which can occur in intervertebral discs and vertebral bodies is necessary to be able to differentiate them from pathological alterations. This is important because therapy decisions are often made as a direct result of MRI.

Efficacy of percutaneous epidural neuroplasty does not correlate with dural sac cross-sectional area in single level disc disease

PURPOSE

Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationship between the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectional area in single level disc disease.

MATERIALS AND METHODS

This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromise by disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom's criteria at 1, 3, 6, 12, and 24 months after treatment.

RESULTS

The demographic data showed no difference between groups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom's criteria after PEN were also not different according to dural sac cross-sectional area by disc material.

CONCLUSION

PEN is an effective procedure in treating single level lumbar disc herniation without affecting dural sac cross-sectional area.

Magnetic Resonance Imaging Findings in Lumbar Disc Degeneration in Symptomatic Patients

BACKGROUND

The sequel of disc degeneration is one of the leading causes of functional incapacity that leads to chronic disability. The study aims to evaluate the MRI findings of degenerative changes in symptomatic patients.

METHODS

The study was a retrospective study for the duration of 3 years. Symptomatic patients undergoing MRI of LS spine were included in the study. Patients undergoing MRI for neurological symptoms alone and acute trauma or suspected infection or tumor were excluded from the study. MRI of patients was evaluated for degenerative changes and their sequel. Data was entered in a predesigned proforma and analysis was done with SPSS version 19.0.

RESULTS

A total of 2037 MRIs of LS spine of symptomatic patients were included in the study. Degenerative changes were demonstrated in 1906 (93.8 %) patients, which comprised 1039 (54.5 %) males and 867 (45.4 %) females. Disc bulge along with disc desiccation was the most common degenerative findings noted in 1667 (81.8 %). Disc herniation was seen in 1032(50.6%), neural foraminal stenosis in 1220 (59.8 %), central spinal canal in 1136 (55.8%) and nerve root compression in 650 (31.9%). Disc bulge, neural foraminal stenosis, central spinal canal stenosis was significantly more common in patients older than 40 years. Disc herniation was however significantly more frequent in patients younger than 40 years.

CONCLUSIONS

Degenerative changes are common in symptomatic patients and increase in frequency with aging. Disc herniation is however more common in younger patients.

Role of modified open-door laminoplasty in the treatment of multilevel cervical spinal stenosis: a retrospective analysis of 43 cases

BACKGROUND AND PURPOSE

Symptomatic degenerative multilevel cervical spinal stenosis--beside other methods--is often treated using the open-door laminoplasty. This procedure aims to decompress the spinal cord and preserve the stability of the cervical spine. The efficiency and safety of the method was proved by numerous Japanese and American studies, also the technique related complications are well known. We treated 43 patients with symptomatic multilevel cervical spine stenosis using the open-door laminoplasty as a surgical procedure of choice in the National Institute of Clinical Neurosciences between 2009 and 2012. In this article we analyse our results and the related literature is discussed.

METHODS

Symptomatic patients with a minimum of three-segment cervical spine stenosis and radiologically proved myelopathy or with electrophisiologically verified subclinical myelopathy were selected for laminoplasty. Patients in whom cervical kyphosis was present were operated on using laminectomy and posterior fusion. Postoperative control CT, MRI and/or X-ray images were made after the surgery and at six weeks, three, six and 12 months after the operation and in the same time neurological evaluation was performed. The modified Japanase Orthopaedic Association (mJOA) scale value was assigned to patients preoperatively, six weeks, three, six and 12 months after the operation. The statistical difference between the groups of data was tested by chi square test.

RESULTS

The average follow-up time was 27 months (minimum seven, maximum 42). According to the mJOA scale, 26 patient's condition (61%) improved, in 13 cases (30%) remained unchanged, and in one case (2%) we detected neurological deterioration. We lost three patients during the follow up period. The median of mJOA preoperatively was 12 (minimum eight, maximum 18), while six week postoperative mJOA was 14 (minimum 10, maximum 17). Three, six and 12 months mean value of mJOA was 14 which shows that the improvement in patients' condition remained stable at one year after surgery. The difference was statistically significant (p < 0.05). The canal's average anteroposterior diameter on CT was 8.29 ± 0.92 mm at the level of C III, while after the operation we measured 15.16 ± 1.02 mm; 7.54 ± 0.62 mm at the level of C IV before, and 15.29 ± 0.2 mm after; 9.05 ± 0.48 mm at the level of C V before and 17.23 ± 0.4 mm after the surgery. The differences proved to be significant (p = 0.0001).

CONCLUSION

According to our experiences the modified open-door laminoplasty is an efficient and safe method for the treatment of symptomatic multilevel cervical spinal stenosis.

[Comparative study between plate-graft, cage-plate and peek cage in cervical arthrodesis for cervical stenosis]

INTRODUCTION

A variety of systems have been developed to fix and perform arthrodesis of the cervical spine, with the advantages of reducing the risk of pseudoarthrosis, extrusion and graft collapse and achieving a more precise sagittal alignment. We therefore need to compare the results of the following approaches to patients with cervical stenosis: plate-graft, cage-plate and PEEK cage.

MATERIAL AND METHODS

Prospective, interventional, comparative trial involving three groups: group I, arthrodesis with plate-graft; group II, cage-plate, and group III, PEEK cage. The pre- and postoperative assessments included the cervical disability scale, the pain visual analog scale (VAS), and cervical spine X-rays. The results were analyzed with non-parametric tests such as the Wilcoxon sign test and the Kruskal-Wallis test for the comparison of more than two groups. Significance level was 0.05.

RESULTS

The sample included a total of 37 patients: n = 12 in group I, with 22 levels; n = 11 in group II, with 19 levels, and n = 14 in group III, with 25 levels. Patient age ranged between 60 and 80. One year after surgery there was an improvement in cervical disability and the pain VAS score, with a statistically significant difference among the three groups (p = 0.001). However, radiographic measurements at that time showed a significant improvement in segmental lordosis (p = 0.02) only in plate-graft patients.

CONCLUSIONS

The plate-graft approach provides better clinical and radiographic results compared to the cage-plate and PEEK cage techniques, at the one-year follow- up.

Paraplegia after epidural-general anesthesia in a Morquio patient with moderate thoracic spinal stenosis

PURPOSE

We describe an instance in which complete paraplegia was evident immediately postoperatively after apparently uneventful lumbar epidural-general anesthesia in a patient with Morquio Type A syndrome (Morquio A) with moderate thoracic spinal stenosis.

CLINICAL FEATURES

A 16-yr-old male with Morquio A received lumbar epidural-general anesthesia for bilateral distal femoral osteotomies. Preoperative imaging had revealed a stable cervical spine and moderate thoracic spinal stenosis with a mild degree of spinal cord compression. Systolic blood pressure (BP) was maintained within 20% of the pre-anesthetic baseline value. The patient sustained a severe thoracic spinal cord infarction. The epidural anesthetic contributed to considerable delay in the recognition of the diagnosis of paraplegia.

CONCLUSION

This experience leads us to suggest that, in patients with Morquio A, it may be prudent to avoid the use of epidural anesthesia without very firm indication, to support BP at or near baseline levels in the presence of even moderate spinal stenosis, and to avoid flexion or extension of the spinal column in intraoperative positioning. If the spinal cord/column status is unknown or if the patient is known to have any degree of spinal stenosis, we suggest that the same rigorous BP support practices that are typically applied in other patients with severe spinal stenosis, especially stenosis with myelomalacia, should apply to patients with Morquio A and that spinal cord neurophysiological monitoring should be employed. In the event that cord imaging is not available, e.g., emergency procedures, it would be prudent to assume the presence of spinal stenosis.

Preoperative MRI findings predict two-year postoperative clinical outcome in lumbar spinal stenosis

PURPOSE

To study the predictive value of preoperative magnetic resonance imaging (MRI) findings for the two-year postoperative clinical outcome in lumbar spinal stenosis (LSS).

METHODS

84 patients (mean age 63±11 years, male 43%) with symptoms severe enough to indicate LSS surgery were included in this prospective observational single-center study. Preoperative MRI of the lumbar spine was performed with a 1.5-T unit. The imaging protocol conformed to the requirements of the American College of Radiology for the performance of MRI of the adult spine. Visual and quantitative assessment of MRI was performed by one experienced neuroradiologist. At the two-year postoperative follow-up, functional ability was assessed with the Oswestry Disability Index (ODI 0-100%) and treadmill test (0-1000 m), pain symptoms with the overall Visual Analogue Scale (VAS 0-100 mm), and specific low back pain (LBP) and specific leg pain (LP) separately with a numeric rating scale from 0-10 (NRS-11). Satisfaction with the surgical outcome was also assessed.

RESULTS

Preoperative severe central stenosis predicted postoperatively lower LP, LBP, and VAS when compared in patients with moderate central stenosis (p<0.05). Moreover, severe stenosis predicted higher postoperative satisfaction (p = 0.029). Preoperative scoliosis predicted an impaired outcome in the ODI (p = 0.031) and lowered the walking distance in the treadmill test (p = 0.001). The preoperative finding of only one stenotic level in visual assessment predicted less postoperative LBP when compared with patients having 2 or more stenotic levels (p = 0.026). No significant differences were detected between quantitative measurements and the patient outcome.

CONCLUSIONS

Routine preoperative lumbar spine MRI can predict the patient outcome in a two-year follow up in patients with LSS surgery. Severe central stenosis and one-level central stenosis are predictors of good outcome. Preoperative finding of scoliosis may indicate worse functional ability.

Epidural adhesiolysis: an evidence-based review

First described over 25 years ago, epidural lysis of adhesions (LOA) involves the mechanical dissolution of epidural scar tissue, which may directly alleviate pain and facilitate the spread of analgesic substances to area(s) of pain generation. Although it most commonly performed for lumbar failed back surgery syndrome, there is a growing body of evidence that suggests it may be effective for spinal stenosis and radicular pain stemming from a herniated disc. There is weak positive evidence that LOA is more effective than conventional caudal epidural steroid injections for failed back surgery syndrome and spinal stenosis, and that LOA is more effective than sham adhesiolysis and conservative management for lumbosacral radiculopathy. For cervical disc herniation and spinal stenosis, there is only anecdotal evidence suggesting effectiveness and safety. Factors that may contribute to the enhanced efficacy compared to traditional epidural steroid administration include the high volume administered, the use of hypertonic saline, and to a lesser extent the use of hyaluronidase and a navigable catheter to mechanically disrupt scar tissue and guide medication administration. Although LOA is widely considered a safe intervention, the complication rates are higher than for conventional epidural steroid injection.