Anteroposterior Diameter Of Spinal Canal Research Articles

Sex Disparity in the Canal-to-Body Ratio of the Cervical Spine Indicating the Prevalence of Cervical Myelopathy: A Cross-Sectional Study

Abstract Background A narrow spinal canal and large vertebral body have been thought to be risk factors for cervical myelopathy. It is generally known that males are more likely to develop cervical myelopathy than females. Thus, sex is also a factor that contributes to myelopathy. The anteroposterior (AP) diameter of the cervical spinal canal is well-established as a primary factor of myelopathy. Objective To investigate the sex discrepancy in the canal-to-body ratio of the cervical spine on magnetic resonance imaging (MRI). Materials and Methods This cross-sectional study included 59 males and 59 females, all aged between 20 and 40 years. Morphological parameters, including height, AP diameter of the vertebral body, and AP diameter of the spinal canal, were measured on sagittal T2-weighted MRI cervical spine images for each participant. The canal-to-body ratio, obtained by dividing the spinal canal's AP diameter by the vertebral body's AP diameter, served as a key metric. The average canal-to-body ratio values compared between male and female groups at each spinal level (C3–C7) elucidate potential gender-related differences. Results The height and the AP diameter of the vertebral body were larger in males than in females throughout C3–C7. There was a statistically significant difference between males and females. The AP diameter of the spinal canal was similar for both genders, with no statistically significant difference between them. The mean canal-to-body ratio was significantly larger in females than in males, with a statistically significant difference between males and females at each spinal level. Conclusion Females had a larger canal-to-body ratio, and men had a significantly lower one. The canal-to-body ratio method was thought to be superior to the absolute value of the AP diameter of the spinal canal for the diagnosis of canal stenosis.

The apparent diffusion coefficient based on small-field DWI is superior to T2-weighted imaging in evaluating neurological dysfunction of degenerative cervical myelopathy.

To investigate the clinical application of zonally magnified oblique multislice (ZOOM) imaging technology in patients with degenerative cervical myelopathy (DCM) and compare it with T2WI imaging. A total of 111 patients diagnosed with DCM were recruited. According to mJOA, patients with DCM were divided into ND + group with neurological dysfunction and ND- group without neurological dysfunction. Routine MRI and ZOOM-DWI were performed on 3.0T MRI to obtain sagittal T2WI and apparent diffusion coefficient (ADC) diagram. ADC values of the narrow segment and its adjacent upper and lower segments were measured, and compared between the ND + and ND- groups. The correlation between ADC value of cervical spinal cord and mJOA score was analyzed. Additionally, ROC curves were plotted to calculate the AUC values. The comparison between ND + and ND- groups shows that there are significant differences in mJOA score, T2WI, anteroposterior diameter of spinal canal, ADC values of narrow, upper and lower segment (P < 0.05). In ND + group, there is a significant difference between ADC values of the narrow and its upper and lower segments (P < 0.001), while with no significant difference in ADC values of the upper and lower segments (P > 0.05). Results of correlation analysis indicate that in the ND + group, neurological dysfunction evaluated by mJOA scores is correlated with increased ADC values of the narrow segment (r = -0.52, P < 0.001), but not significantly correlated with ADC values of the upper and lower segments. Furthermore, T2WI, anteroposterior diameter of the spinal canal, and cervical cord ADC values all has diagnostic efficacy in evaluating neurological dysfunction in DCM (AUC > 0.5, P < 0.05), with the ADC value of the narrow segment being optimal. The ADC value of spinal cord obtained by small-field ZOOM-DWI can be used to evaluate neurological dysfunction in DCM, and is superior to traditional T2WI.

Do we know the normal anterior-posterior diameters of the spinal cord and canal in newborns?

Aim: We aim to reveal the normal anterior-posterior diameter of the spinal cord and canal at cervical, thoracic and lumbar levels in newborn with sonographic measurements and to create a reference value. Also, we aim to reveal whether the anterior-posterior diameter at these levels will vary with the newborn's head circumference, gender, height and weight. Thus, we aim to be one of the pioneering studies in the literature&#x0D; Material and Method: Statistical analysis was performed to determine normal anterior-posterior diameter for the spinal canal and spinal cord at each vertebral level, and their correlations with birth weight, length and head circumference.&#x0D; Results: 188 newborns were included. The mean anteroposterior spinal canal diameter in male newborns was significantly higher compared to females (9.27±0.83 vs 9.00±0.79, p=.020). There was a positive correlation between spinal cord anterior-posterior diameter and head circumference at thoracic level, which was statistically significant. There was a positive correlation between spinal canal diameter and height at thoracic level. There was a positive correlation between spinal canal diameter and weight at lumbar level. &#x0D; Conclusion: The establishment of the normal values for anterior-posterior diameters of the spinal cord in healthy newborns may contribute the current literature data.

Application of unilateral biportal endoscopy technique in single-segment thoracic ossification of ligamentum flavum

To investigate the safety and effectiveness of unilateral biportal endoscopy (UBE) technique in the treatment of single-segment thoracic ossification of ligamentum flavum (TOLF). Between August 2020 and December 2021, 11 patients with single-segment TOLF were treated with UBE technique. There were 6 males and 5 females, with an average of 58.2 years (range, 49-72 years). The responsible segment was T 6, 7 in 1 case, T 7, 8 in 1 case, T 8, 9 in 2 cases, T 9, 10 in 2 cases, T 10, 11 in 2 cases, and T 11, 12 in 3 cases. Imaging examination showed that the ossification were located on the left side in 4 cases, on the right side in 3 cases, and on bilateral sides in 4 cases. The main clinical symptoms were chest and back pain or lower limb pain, all accompanied by lower limb numbness and fatigue. The disease duration ranged from 2 to 28 months (median, 17 months). The operation time, postoperative hospital stay, and complications were recorded. Visual analogue scale (VAS) score was used to evaluate the chest and back pain and low limb pain, and Oswestry disability index (ODI) and Japanese Orthopedic Association (JOA) score were used to evaluate functional recovery before operation and at 3 days, 1 month, 3 months after operation, and last follow-up. The anteroposterior diameter of the coronal spinal canal was measured by CT before and after operation to evaluate the effect of surgical decompression. All operations were successfully completed. The operation time was 50-105 minutes, with an average of 80.0 minutes. No postoperative complication such as dural sac tear, cerebrospinal fluid leakage, spinal nerve injury, or infection occurred. The postoperative hospital stay was 2-5 days, with an average of 3.1 days. All incisions healed by first intention. All patients were followed up 6-22 months, with an average of 14.8 months. CT measurement at 3 days after operation showed that the anteroposterior diameter of the spinal canal was (8.63±1.61) mm, which was significantly larger than that before operation [(3.67±1.37) mm] ( t=-12.181, P<0.001). The VAS score of chest and back pain and lower limb pain and ODI at each time point after operation were significantly lower than those before operation ( P<0.05). The above indexes were further improved after operation, except that there was no significant difference between at 3 months after operation and at last follow-up ( P>0.05), the differences between other time points were significant ( P<0.05). There was no recurrence during the follow-up period. UBE technique is a safe and effective method to treat single-segment TOLF, but its long-term effectiveness needs to be further studied.

Correlation between clinical scoring systems and quantitative MRI parameters in degenerative lumbar spinal stenosis

BackgroundMany quantitative MRI parameters and clinical scores have been used patients with lumbar spinal stenosis (LSS). However, the correlation between clinical scores and MRI parameters is not very clear. The objective of the study was to find out the correlation between commonly used clinical scoring systems and quantitative MRI parameters. MethodsEighty two patients (more than 40 years) with clinical and radiological characteristics of degenerative LSS completed 10 clinical questionnaires which included Oswestry disability index (ODI), Swiss spinal stenosis (SSS) questionnaire, Quebec pain disability scale (QPD), Visual analogue scale (VAS), modified Japanese orthopaedic association scale (mJOA), Pain disability index (PDI), Short form health survey (SF-36), Self-paced walking test (SPWT), Euro quality of life-5D (EQ-5D) and Neurogenic claudication outcome score (NCOS). Lumbosacral MRIs were performed and 8 quantitative parameters namely transverse & AP diameter of dural sac (TDD, APDD), anteroposterior diameter of spinal canal (APDS), ligamentous interfacet distance (LID), mid-sagittal diameter of thecal sac (MSDT), cross-sectional area dural sac (CSAD), lateral recess depth and angle (LRD, LRA) were measured at the maximum stenotic level at the level of the disc. The clinical and radiological parameters were then statistically analysed. ResultsThere were 51 females and 31 males in the study with a mean age of 53.0253.02 ± 9.18 years. NCOS score had a moderate correlation with CSAD, LID and TDS (p<0.05,0.7>r ≥ 0.3). MSDT showed a moderate negative correlation with SSS, VAS, ODI and QPD (p<0.05,0.7>r ≥ 0.3). LRD had a moderate negative correlation with ODI and VAS score (p<0.05,0.7>r ≥ 0.3). LRA had a moderate correlation with the EQ-5D and ODI (p<0.05,0.7>r ≥ 0.3). The CSAD had a moderate negative correlation with PDI (r = −0.383, p = 0.000). For all other comparisons, there was poor or no correlation. MRI parameters showed poor or no correlation with most of components of SF-36 score. ConclusionsA poor correlation or no correlation was noted for most of the MRI parameters when compared to commonly used clinical scores. Hence, poor MRI's don't necessarily mean poor clinical scores in LSS. The role of MRI parameters should be supplementary and overreliance on them in LSS management should be avoided.

Outcome of Long-Segment Fixation versus Inclusion of the Fractured Level in Short-Segment Fixation for Thoracolumbar Junction Fractures.

Objective The aim of this study was to compare the radiological outcomes of long-segment fixation and short-segment fixation, including the fracture level in patients treated for thoracolumbar junction fractures. Methods Data collected from records of patients with thoracolumbar junction fractures who were operated at our department. Neurological evaluation was done using American Spinal Injury Association classification score. Radiological parameters used were the Cobb's angle, vertebral body compression ratio, the anteroposterior spinal canal diameter, and the anterior and the posterior vertebral body heights. Patients were divided into two groups: group A included patients who underwent long-segment fixation and group B included patients who underwent short-segment fixation with inclusion of the fracture level. Results The mean preoperative Cobb angle was 22.51 degrees in group A and 19.37 degrees in group B. Both groups showed improvement in the postoperative Cobb angle as the mean in group A was 14.17 degrees and in group B was 11.77 degrees. The mean preoperative compression ratio in group A was 82.8%, while in group B it was 76%. The postoperative mean in group A was 89.2%, while in group B, it was 84%. The mean preoperative anterior vertebral body height of the fractured vertebra in group A was 16.7 mm, while in group B, it was 15.18 mm. The mean preoperative posterior vertebral body height in group A was 16.33 mm and that of group B was 19.41 mm. The mean postoperative anterior vertebral body height in group A was 17.66 mm and that of group B was 17.10 mm. The mean postoperative posterior vertebral body height in group A was 17.11 mm and that of group B was 20.79 mm. Conclusion Posterior short-segment fixation with additional screws at the fracture level provides similar-if not better-clinical and radiological outcomes to long-segment fixation in the treatment of thoracolumbar junction fractures.

Unilateral Approaches for Posterior Spinal Canal Decompression in Cervical Spondylotic Myelopathy—An Evaluation of Conceptual Feasibility

Patients with cervical spondylotic myelopathy (CSM) can be treated with posterior approaches for spinal canal decompression. We compared the patients' outcome after 2 different unilateral and a bilateral posterior approach for decompression to elucidate feasibility and potential procedure-related differences. Medical records of 98 patients with CSM undergoing posterior decompression between 2012 and 2018 were assessed. Patients were divided into 3 groups: (1) unilateral interlaminar fenestration with over-the-top "undercutting" (laminotomy) for compression limited to a ligamentum flavum hypertrophy, (2) unilateral hemilaminectomy for lateralized compression with a combination of ligamentous hypertrophy and osseus stenosis, and (3) laminectomy/laminoplasty for circular osseous-ligamentous spinal canal narrowing. The mean age was 73 years (m:f = 1.4:1), and most frequent symptoms (mean duration: 15 months) were ataxia (69%) and sensory changes (57%). Main location of stenoses (median Naganawa Score = 3; mean anteroposterior spinal canal diameter = 7.7 ± 2.2 mm) was C3 to C6. Thirty-one percent of the patients were assigned for a laminotomy procedure, 20% for a hemilaminectomy, and 49% for a laminectomy/laminoplasty. There were no significant differences of patients' characteristics, blood loss, and operation time between the 3 groups. Independent from the mode of surgery, the spinal canal was significantly widened (median Naganawa Score = 0; mean anteroposterior diameter = 11.4 ± 3.6 mm) and myelopathy (mJOA Score) improved ( P &lt; .001); a higher body mass index was significantly correlated with a worse mJOA improvement (r = 0.293/ P = .003). Quality of life (Short-Form 36v2 Health Survey/Neck Disability Index) and reduction of the neck pain level were similar in the 3 groups at last follow-up (mean: 28 months). To minimize patients' periprocedural burden in CSM with dorsal compression, individual tailoring of the posterior approach according to the underlying compressive pathology achieves sufficient decompression and comparable long-term results.

Morphometric analysis of lumbar vertebrae using CT scans in Nepalese population

Introduction: Understanding anatomy of the lumbar vertebrae is necessary to achieve clinical success during surgery, for the development of the spinal implants and instruments and to understand changes in elderly and in male and female patients. Methods: A cross-sectional study was done in 50 patients in Nepal to study the lumbar morphometric analysis of the vertebral body, intervertebral disc and spinal canal. Patients who underwent CT IVU for nephrolithiasis at our center were included for analysis of the lumbar morphometry. All the traumatic cases and pathological lesions, such as infection, tumor were excluded from the study. Patients having low backache due to probable intervertebral disc pathology were also excluded from the study. Data analysis was done from Microsoft excel and the mean, standard deviation and range were calculated. Results: The anterior-posterior diameter of the vertebral body, varied from 25.97 mm at L1 to 29.39 mm at L5. The transverse diameter of the body ranged from 31.55 mm at L 1 to 44.13mm at L5. There were changes in height of body. First from L1 - L3 there was increase in height and from L4-L5 there was decrease in height with least height at L5 (22.71mm). According to our study the L1 vertebra has narrowest transverse diameter of spinal canal(21.25mm) whereas L4 has narrowest antero-posterior diameter of spinal canal(12.37mm). Conclusion: In the lumbar area, detailed anatomical knowledge is critical for performing a safe operation. These findings give guidance to the surgeons during various approach while performing operative procedure like pedicle screws, vertebral body screws, cages and laminar hooks.

Study of pedicles and spinal canal diameters at the level of lumbar vertebral in normal adult Saudi population using computed tomography

The values of normal transverse (interpedicular) and sagittal (midsagittal) diameters are different at various levels of lumbar spinal canal in individuals of the same race and differ at identical levels in individuals of various races. The aim of the study was to determine normal reference range of the lumbar spinal canal dimensions and to evaluate lumbar pedicle dimensions with respect to spinal level, age, gender in Saudi population by using Computed Tomography. This study was conducted in Najran province (K.S.A), archival abdominal CT scan images from PACS in hospitals were used. The data of this study was collected from 210 (102 male and 108 female) normal Saudi adults individuals with different ages, gender over a period of 20 months (2019 - 2021). The mean spinal canal transverse distance (SCTR) showed steady decrease from L1 to L4, as there was an increasing in (SCTR) at L5 relative to L4, The mean spinal canal anteroposterior diameter (SCAP) showed a decrease from L1 to L3, and then a gradual increase from L4 to L5 (Fig.4-10). This pattern was observed in males only as there was an increase of female (SCAP) at L2 and L5, and no significant gender difference was noted at any lumbar level for (SCAP) The mean pedicle width (PW) showed steady increase from L1 to L5. While the mean pedicle height (PH) showed a gradual decrease from L1 to L5. The study conclude that Computed tomography is a reliable method for determining the morphological measurements of the spinal canal and pedicles diameter.

Morphometry of Dry Sub Axial Vertebra: A Nepalese Study

There is paucity in literature describing the morphology of sub-axial vertebra of the local population. Available studies are limited to the body, intervertebral disk, spinal canal and Torg’s ratio of the cervical vertebra. Therefore, the present study aims to document various morphological parameters of sub axial vertebra. Sixty-four dry sub-axial vertebrae of the Nepalese population were studied using Vernier Calipers calibrated to 0.1 mm accuracy. Paired parameters of pedicle, lamina, uncinate process, the distance of the apex of the uncinate process to intervertebral foramen and foramen transversarium were measured. Similarly, unpaired parameters including spinous process length, vertebral foramen anteroposterior width, vertebral foramen transverse diameter and Torg’s ratio were evaluated. Except the height of left lamina of C3 to C6 vertebrae, none of the parameters showed significant side differences. Significant higher values of C7 were noted against C3-C6 on vertebral body height, vertebral body anteroposterior diameter, spinous process length and vertebral foramen anteroposterior diameter. Population data of sub-axial vertebra available in literature showed mixed results with ours. Interestingly, our observations either compared to (lamina, uncinate process, anteroposterior diameter of spinal canal and Torg’s ratio) or were larger (Pedicle and spinous process) than the Indian study with pedicle axis length being largest among all the compared studies. The information of this study may be used as a reference database for our local setting and could be of value in preoperative planning and in designing implants.

Radiation Protection: Do We Need to Scan the Whole Lumbar Spine in Suspected Lumbar Spine Stenosis?

Objectives: To test two hypotheses that the scan length could be reduced in patients younger than an age threshold below which lumbar stenosis in the two upper lumbar levels never occurs, and that an anteroposterior spinal canal diameter cut-off at the level of the L3 pedicles could rule out a congenital stenosis at the L1 and/or L2 levels. Methods: MR examinations of 55 healthy volunteers and 200 patients with suspected spinal canal stenosis were included. The anteroposterior diameter of the spinal canal was measured at each pedicle and each disk levels by two readers who also subjectively assessed the presence of stenosis. Results: Degenerative spinal canal stenosis never occurs at the upper two lumbar disk levels in patients younger than 55 years. The anteroposterior diameter of the spinal canal diminished from L1 to L3 in both healthy volunteers and patients. An anteroposterior diameter of the spinal canal at the L3 pedicles level ≥11 mm excluded a diameter &lt;10 mm at L1 and/or L2 pedicles levels. Conclusion: A substantial reduction of the radiation dose from CT could be achieved by limiting the scan length from L3 to S1 in patients younger than 55 years provided that the anteroposterior diameter of the spinal canal is &gt;11 mm at the L3 pedicles level.

Influence of K-line on intraoperative and hidden blood loss in patients with ossification of the posterior longitudinal ligament when undergoing unilateral open-door laminoplasty

BackgroundThe K-line is a virtual straight line that connects the midpoints of the anteroposterior spinal canal diameter from C2 to C7 on a cervical lateral X-ray film. Patients with cervical ossification of the posterior longitudinal ligament (OPLL), in which the peak of the OPLL exceeds the K-line (K-line [-]), are less likely to experience sufficient decompression after laminoplasty compared with patients for whom the OPLL does not exceed the K-line (K-line [+]). This retrospective study investigated the influence of K-line position relative to the OPLL on intraoperative and hidden blood loss during unilateral open-door laminoplasty for OPLL.MethodsData were retrospectively analyzed of 108 patients with OPLL who underwent unilateral open-door laminoplasty between April 2015 and March 2018. Patient cases were categorized as K-line (+) or (-). The evaluated perioperative parameters were haematocrit, haemoglobin, intraoperative and hidden blood loss, surgical time, postoperative drainage, and complications. Radiological parameters included ossification occupancy ratio and C2-7 lordosis.ResultsThe K-line (+) and K-line (-) groups were statistically comparable with regard to age, gender, body mass index, OPLL classification, medication history, C2-7 lordosis, postoperative haemoglobin and haematocrit, postoperative drainage, hidden blood loss, and complications. The occupying ratio of the K-line (-) group was significantly greater than that of the K-line (+) group (49.5 ± 15.3% cf. 42.3 ± 10.1%; P = 0.006), and the intraoperative blood loss was also significantly higher (286 ± 110.5 mL cf. 205.5 ± 98.3 L, P = 0.003). The hidden blood loss of the K-line (-) group was higher than that of the K-line (+), but not significantly (295.5 ± 112.6 mL cf. 265.6 ± 103.8 mL; P = 0.072).ConclusionIntraoperative and hidden blood loss associated with unilateral open-door laminoplasty can be predicted by the spatial relationship of the K-line and osteophyte. This relationship is a simple and practical index that may help surgeons determine the appropriate surgical strategy for patients with OPLL.

Individualized artificial titanium alloy spinal lamina with 3D printing technology

Background: Laminectomy and decompression is a common procedure for treating spine diseases. However, due to the lack of a posterior, bony braced structure, the dural sac and nerve roots can adhere to the surrounding tissues, and scar formation can occur in muscle and soft tissues. This can cause new compression post surgery, and failure of the operation. Objective: This study aimed to produce an individualized titanium alloy spine lamina using 3D printing technology, and to evaluate its effectiveness by implantation in human cadaveric spines. Methods: Six adult lumbar cadaver specimens were used, and computed tomography (CT) was used to obtain DICOM medical digital image standard data. The lumbar vertebrae structure was reconstructed by three-dimensional (3D) modeling software, and then simulated lumbar laminectomy was performed. Based on the characteristics of the original lamina, an artificial spine lamina was designed, including suture holes at the posterior ligament attachment point and a locking screw hole for fixation. A titanium alloy spine lamina was fabricated by 3D printing, and a guide plate to assist artificial lamina implantation was designed. Using the guide plated, L4 lumbar vertebrae segment laminectomy was performed on the 6 lumbar spine specimens, titanium alloy spine lamina were implanted and fixed with cortical bone trajectory screws. After implantation, CT was performed to record the length of the screw, the trajectory of the screw in the pedicle, and changes of bony spinal canal volume and anteroposterior diameter of the spinal canal. Results: The morphology of artificial spine lamina matched that of the original lamina. The artificial lamina was easy to implant, and matched the original lamina. The laminas were fixed by 12 cortical screws (diameter, 4.5 mm; median length, 34.67 ± 1.97 mm). CT scan indicated that all screws passed through the pedicle cortex by &lt; 2 mm (2 screws penetrated the inner wall). The bony canal volume of the L4 vertebral pedicle was 311.23 ± 38.17 mm2 before operation and 356.17 ± 43.11 mm2 after operation, and there was statistical difference (P &lt; 0.001). The anteroposterior diameter of spinal canal was 17.82 ± 2.03 mm before surgery and 20.67 ± 2.38 mm after surgery, and they were statistically different (P &lt; 0.001). Conclusion: An individualized artificial titanium alloy spine lamina designed and produced with 3D printing technology can be used to reconstruct the structure of the posterior spine complex after lumbar laminectomy. The artificial lamina can increase the volume of the spinal canal and provide a posterior ligament reconstruction attachment point.

Percutaneous endoscopic lumbar discectomy combined with oblique lateral interbody fusion for degenerative lumbar diseases with ruptured disc herniation

Objective To investigate the preliminary clinical and radiographic outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with oblique lateral interbody fusion (OLIF) for the degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation. Methods Data of 11 patients with degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation who had undergone PELD combined with OLIF between March 2017 to July 2018 in our spine surgery center were retrospectively analyzed. There were 5 males and 6 females with an average age of 61.2±6.8 years old. All the patients were diagnosed with degenerative lumbar diseases including lumbar spondylolisthesis (7 cases), lumbar spinal stenosis (3 cases) and segmental instability (1 case). The patients were treated with PELD combined with OLIF. The visual analogue scale (VAS) scores of low back pain and lower limb pain and the Oswestry disability index (ODI) of lumbar function, spinal canal anteroposterior diameter, intervertebral disc height, vertical diameter of intervertebral foramen, segmental angle and the whole lumbar lordotic angle were collected. Results All patients received PELD with local anesthesia before OLIF with general anesthesia. The mean operation time was 52.3±13.2 min and the mean blood loss was 10.9±4.7 ml for PELD. The mean operation time was 56.8±18.0 min and the mean blood loss was 65.5±24.6 ml for OLIF. All patients were followed up for an average of 11.2 months. At the latest follow-up, the mean VAS score for back pain was 1.3±0.8, the mean VAS score for leg pain 1.1±0.5, the mean ODI 14.6%±5.3%, thus all of those were improved significantly compared to those of pre-operation (t=10.37, 16.49, 8.73; P< 0.05). The radiographic results showed the mean pre-operative intervertebral disc height, vertical diameter of intervertebral foramen, spinal canal anteroposterior diameter, segmental angle, and lumbar lordosis angle was 7.1±1.2 mm, 15.3±2.2 mm, 6.2±1.3 mm, 10.2°±3.5°, 16.2°±6.2°, and thus all of those were increased significantly to the latest follow-up 11.5±1.8 mm, 19.2±2.6 mm, 10.4±2.5 mm, 19.3°±7.8°, 27.4°±8.3°, respectively (t=5.83, 4.21, 6.59, 10.32, 7.65; P< 0.05). One of the patients had weakness of flexor hip strength and one had a transient paresthesia immediately post-operation. All symptoms were relieved within 1 month. Another one case had cage subsidence and encountered serious back pain after 1 month, and alleviated after percutaneous pedicle screw fixation. Conclusion PELD combined with OLIF can overcome the limitations of OLIF with indirect decompression effects, resulting in successful direct neural decompression without posterior decompressive procedures and providing a satisfactory outcome for the patients with degenerative lumbar diseases with ruptured disc herniation. Key words: Lumbar vertebrae; Intervertebral disc degeneration; Endoscopy; Spinal fusion; Surgical procedures, minimally invasive

Interobserver Reliability When Classifying MR Imaging of the Lumbar Spine: Written Instructions Alone Do Not Suffice.

Purpose:Numerous classification systems have been proposed to analyze lumbar spine MRI scans. When evaluating these systems, most studies draw their conclusions from measurements of experienced clinicians. The aim of this study was to evaluate the impact of specific measurement training on interobserver reliability in MRI classification of the lumbar spine.Methods:Various measurement and classification systems were assessed for their interobserver reliability in 30 MRIs from patients with chronic lumbar back and sciatic pain. Two observers were experienced spine surgeons. The third observer was an inexperienced medical student who, prior to the study measurements, in addition to being given the detailed written instructions also given to the surgeons, obtained a list of 20 reference measurements in MRI scans from other patients to practice with.Results:Excellent agreement was observed between the medical student and the spine surgeon who had also created the reference measurements. Between the two spine surgeons, agreement was markedly lower in all systems investigated (e.g., antero-posterior spinal canal diameter intraclass correlation coefficient [ICC] [3.1] = 0.979 vs. ICC [3.1] = 0.857).Conclusion:These data warrant the creation of publicly available standardised measurement examples of accepted classification systems to increase reliability of the interpretation of MR images.

MODIFIED LAMINOPLASTY AFTER EXCISION OF CERVICAL SCHWANNOMA WITH LARGE EXTRAVERTEBRAL EXTENSION

Tumour excision and laminoplasty are commonly performed as surgical treatment of extra vertebral extension of cervical schwannoma. It is worth knowing that the conventional technique of multilevel laminectomy may hinder younger patients in the long-term. This article reports a 30-year old man with an intradural-extramedullary tumour which extended from C4 to T1 that underwent modified laminoplasty. This modified technique is preferable in maintaining the anteroposterior diameter of spinal canal as well as reducing the displacement of guttered laminae

Radiographic Cobb Angle: A Feature of Congenital Lumbar Spine Stenosis

Purpose: A low cost, reproducible radiographic method of diagnosing congenital lumbar spinal stenosis (CLSS) is lacking. We hypothesized that the Cobb angle for lumbar lordosis would be smaller in patients with CLSS, based on observations in our spine clinic patient population. Here, we compared lumbar lordosis Cobb angles with the radiographic ratio method in patients with normal spine imaging, degenerative spinal stenosis, and with CLSS. Materials and MethodsOrthopedic surgeons categorized patients with low back pain as “Normal,” “Degenerative spinal stenosis,” and “CLSS” based on clinical presentation and findings on lumbar magnetic resonance imaging. We included 30 patients from each cohort who had undergone lateral lumbar spine radiographs and lumbar magnetic resonance imaging. For each lateral radiograph, 2 measurement methods were used (1) 4-line lumbosacral Cobb angle between L2-S1 and (2) the ratio of the anteroposterior vertebral body diameter and spinal canal anteroposterior diameter at the L3 level. We performed logistic regression analyses of CLSS prediction by Cobb angle vs the ratio method in all three cohorts. Covariates included age, gender, and body mass index. ResultsThe radiographic Cobb angles were smaller in CLSS patients when compared to the degenerative disease and normal cohorts: a smaller radiographic Cobb angle showed higher odds ratio (OR) of predicting CLSS diagnosis compared to the radiographic ratio when compared with degenerative disease (OR = 0.28; 95% CI: 0.11-0.78, P = 0.01) and when compared with the normal cohort (OR = 0.46; 95% CI: 0.24-0.92, P = 0.03). Radiographic ratio measurements showed no difference between the three cohorts (P = 0.12). CLSS was associated with male gender (P = 0.04), younger age (P = 0.01), and higher body mass index (P = 0.01). ConclusionThe radiographic Cobb angle method for lumbar lordosis may be useful for raising the possibility of CLSS as the diagnosis.

Incidence of Inadvertent Dural Puncture During CT Fluoroscopy-Guided Interlaminar Epidural Corticosteroid Injections in the Cervical Spine: An Analysis of 974 Cases.

The objective of this study is to determine the rate of inadvertent dural puncture during CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injection. In addition, in a subanalysis, we aim to assess the rate of inadvertent dural puncture superior to C5-C6 occurring during interlaminar epidural corticosteroid injection using CT fluoroscopy guidance because such injections are not performed using conventional fluoroscopy. Images obtained from consecutive CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections conducted from November 2009 to November 2015 were reviewed. The following information was recorded: the presence of inadvertent dural puncture, the level of the cervical interlaminar space, approach laterality (left or right), anteroposterior spinal canal diameter, and the presence of a trainee. Two-tailed Fisher exact tests were used for assessment of categoric variables, and t tests were used for continuous variables. A total of 974 cervical interlaminar epidural corticosteroid injections were identified in 728 patients. Inadvertent dural punctures were identified in association with 1.4% (14/974) of these injections; all punctures were recognized during the procedure. Needle placements were performed at every cervical level (C1-C2 through C7-T1). The highest rate of dural puncture (2.8%) occurred at C5-C6. No dural punctures occurred superior to C5-C6 (16.6% of cases). The complication rate was 0.4%. Only greater anteroposterior spinal canal diameter was associated with increased dural puncture rates (p = 0.049). CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections were performed at all levels throughout the cervical spine. A very low complication rate and a minimal rate of inadvertent dural puncture were noted, similar to previously reported rates for conventional fluoroscopy-guided injections limited to the lower cervical spine only.

Individualized decompression strategy for lumbar spinal canal stenosis

Objective To discuss and evaluate the clinical outcome of the personal posterior decompression strategy for patients with lumbar spinal stenosis and underwent interbody fusion. Methods From October 2009 to March 2014 , there were 57 patients with 77 vertebraes, 34 male, 24 femal, age from 47-78 years, with the average of 65.4 years. All were treated by decompression and interbody fusion via posterior approach. 26 vertebra were underwent transforaminal intervertebral retracting decompression, 45 vertebras were underwent one side laminectomy and another side undermined laminectomy, 6 vertebras were underwent modified extensive lamina decompression. Patients were followed up 3 and 12months after operation and evaluated by Japanese Orthopaedic Association Score and Oswestry disability index, and anteroposterior diameter and cross-section area of spinal canal were measured by CT scan. Results All patients were followed up from 13-45 months with an average of 25.0 months. 57 cases felt better after surgery. JOA score was from (13.52±4.48) points before surgery to (22.50±2.38) points 3 months after surgery, and (24.62±5.62) points 12 months after surgery. Oswestry score was from (31.52±4.64) points before surgery to (16.55±4.48) points 3 months after surgery, and (11.84±3.85) points 12 months after surgery. Anteroposterior diameter and cross-section area of spinal canal were from (1.08±0.38) cm and (0.36±0.12) cm2 before surgery to (2.07±0.74) cm and (2.23±0.95) cm2 after surgery. In transforaminal intervertebral retracting decompression group, anteroposterior diameter of spinal canal increased from (1.10 ± 0.41) mm before surgery to (2.10±0.84) mm after surgery, and cross-section area of spinal canal was also increased from (0.38± 0.11) mm2 to (2.33±0.82) mm2 after surgery. All of anteroposterior diameter and cross-section area of spinal canal in undermined laminectomy group and modified extensive lamina decompression group increased. Conclusion Personal posterior decompression strategy can expand lumbar canal effectively, improve symptom and protect bone and soft tissue near the canal. Key words: Lumbar vertebrae; Spinal stenosis; Spinal fusion; Decompression, surgical

A clinically relevant MRI grading system for lumbar central canal stenosis

ObjectiveTo correlate lumbar spinal stenosis as graded on noncontrast magnetic resonance imaging (MRI) with clinical symptomatology. MethodsFive grades were developed for lumbar central canal stenosis based on compression of the dural sac and cauda equina. We studied concordance in 112 patients between the grading system and the anteroposterior diameter of spinal canal, dural sac cross-sectional area, Oswestry disability index, and the pain visual analogue scale (VAS). ResultIntra- and interobserver agreement was high. Although VAS was not significantly different between groups (P=.257), all other factors were significant (P≤.005). ConclusionThe MRI grading system reliably predicted the degree of stenosis and associated disability.