Sagittal Diameter Of Spinal Canal Research Articles

Normative MRI for Lumbar Spinal Canal and Vertebral Body Dimensions in a Jordanian Population Sample

Aim: To provide normal values for the lumbar spinal canal, lumbar vertebral body and dural sac dimensions and canal body ratio by MRI for a Jordanian population sample.
 Material and methods: Three well trained observers reviewed 218 lumbar MRI scans performed between 2019–2021 (1090 lumbar levels) and obtained from the central computerized medical archive of three main governmental hospitals in north, central and south Jordan. All MRIs with alignment abnormalities (scoliosis and kyphosis), canal compression, vertebral disease (including fractures) or technical artifacts were excluded. The following were measured from L1 to L5 levels: the midsagittal diameters of the spinal canal and vertebral body, axial anteroposterior (AP), and transverse diameter of the vertebral body, dural canal and dural canal area. Data on sex and age were also documented.
 Results: The studied MRI scans included 113 males (51.8%) and 105 females (48.2%). Age ranged between 23–86 years old (mean 52.23 ± 13.125). The mid sagittal mid vertebral AP diameter of the lumbar spine range was 2.8–3.1 cm. The mid sagittal spinal canal diameter range was 1.3–1.5 cm. Canal body ratio was 3.3–3.6. The AP, transverse dural sac diameter ranges were 1.2–1.4 cm and 1.5–1.9 cm, respectively. Finally, the dural sac area ranged from 331–362 mm2.
 Conclusion: The dimensions of the lumbar spinal canal, vertebral bodies, and vertebral canal ratio at all levels were documented for a Jordanian population sample. Dimensions varied according to sex and when compared with other ethnic groups (Asian and African). The findings suggest that canal stenosis criteria should take these differences into consideration.

Clinical significance and risk factors of redundant nerve root in patients with lumbar spinal stenosis

To investigate the clinical significance and screen the risk factors of redundant nerve roots(RNRs) in patients with lumbar spinal stenosis. The clinical data of 196 patients with lumbar spinal stenosis in the department of Spinal Surgery, Yijishan Hospital, Wannan Medical College from April 1, 2015 to November 30, 2020 were retrospectively analyzed. All patients were divided into RNRs positive group and RNRs negative group according to the presence of RNRs. The differences in general clinical data, imaging parameters, visual analogue scale(VAS), Oswestry disability index(ODI), and other indicators between the two groups were compared. The risk factors which are highly correlated with RNRs were screened by binary Logistic regression analysis. There were 59 cases in the RNRs positive group, with an occurrence rate of 29.95% (59/137), and 137 cases in the RNRs negative group. The incidence rate of RNRs in 196 patients with lumbar spinal stenosis was 30.10% (59/196). VAS and ODI scores of patients in the two groups were statistically significant (P<0.05), and clinical symptoms of patients in the RNRs positive group were more severe than those in the RNRs negative group. There were significant differences in age, number of stenosis segments, average area of lumbar dural sac, area of the narrowest segment and the narrowest segment(P<0.05). Binary logistic regression analysis showed that the number of stenosis segments, the average median sagittal diameter of spinal canal, and the average area of dural sac in lumbar intervertebral space were correlated with the generation of RNRs (P<0.05). The regression coefficient of the number of stenosis segments was -1.115, the regression coefficient of the median sagittal diameter of the spinal canal was -1.707, and the regression coefficient of the mean dural sac area of the lumbar intervertebral space was 7.556. The clinical symptoms of patients with lumbar spinal stenosis accompanied by RNRs are more severe than those without them. The number of narrow segments, median sagittal diameter of the spinal canal, and the area of the lumbar intervertebral dural sac are the high-risk factors for RNRs, with the area of the lumbar intervertebral dural sac has the highest correlation.

Initial clinical experiences of the muscle-preserving double door cervical laminoplasty with adjustable mini plates.

Shirashi's double door laminoplasty method was a popular decompression procedure for cervical myelopathy. In this paper, we introduced a modified double door laminoplasty based on Shirashi's method with preliminary results. This study retrospectively analyzed 22 patients who underwent modified double door laminoplasty. During procedure, a single segment of the unilateral lamina was separated from the cervical semispinalis muscle and the multifidus muscle space for the preparation of lamina groove. A self-developed mini titanium plate was used to fix the inner side of the spinous process to complete the fixation after open-door process. The VAS, JOA scores and QoL scale were recorded for pain assessment, neurological and functional recovery. The overall curvature and range of motion of C2-C7 were measured with x-ray images. Changes in sagittal diameter of spinal canal were measured by CT scans. MRI was used to measure the cross-sectional area of cervical paravertebral muscles. All 22 patients successfully recovered with this procedure. The mean operation time, blood loss and follow-up durations were 117 ± 25 min, 149 ± 32 ml and 16.1 ± 3.6 months respectively. The preoperative, 3-month postoperative and 12-month postoperative JOA scores were 9.35 ± 3.25, 13.74 ± 4.86 and 15.73 ± 5.19 respectively. with improvement rates of 57.4% and 83.4%. Mean VAS scores before, 3 months after and 12 months after surgery were 1.81 ± 0.79, 2.82 ± 1.56 and 2.18 ± 1.34 respectively. The C2-7 lordotic angle and overall range of motion shows no statistical difference preoperatively and 12 post-surgery. The average sagittal diameter of the cervical spinal canal was enlarged from 9.15 ± 1.55 mm to 14.25 ± 1.46 mm. The average area of cervical paravertebral volume measured preoperatively and 3 months post operation was 84% of pre-operative value respectively. This value was improved to 93% of the preoperative value at 12 months post-surgery. This paper introduced initial experience on a modified posterior cervical double-door laminoplasty that was based on Shirashi's method, featuring creating bilateral laminar grooves on both sides and fixing central gap with self-developed mini plates. This procedure prevented obvious axial symptoms and improved patients' quality of life, which provided a baseline for further research with larger cohorts.

Sexual Dimorphism in Cervical Spine – A Magnetic Resonance Imaging Study

Background: Morphometric measurements of the spinal cord provide important clues regarding neural and spinal injuries. They are also of forensic importance and can be used to determine sex of an individual. These parameters have been shown to vary across age groups and ethnicity. Currently, there is a paucity of data regarding these parameters in Maharashtra, India. Therefore, studies are required to provide reference values for spinal canal parameters for this population. Aims: To study the cervical spinal canal morphometric differences in males and females in the west Maharashtra population. Materials and Methods: A comparative, retrospective study was conducted on 70 subjects aged between 18 and 70 years (36 males, 34 females). The sagittal vertebral body diameter, the sagittal spinal canal diameter, and the sagittal spinal cord diameter were measured at the C3–C7 level by magnetic resonance imaging. The space available for the spinal cord and Torg's ratio were determined. Statistical Analysis Used: Mann–Whitney U-test and unpaired t-test were used to calculate significant difference at P &lt; 0.05. Results: Mean age of the patients was 48.53 ± 14.67 years. There was significant difference in the sagittal spinal canal diameter and spinal cord diameter (P = 0.000107 and P = 2.20e−16, respectively) from C3 to C7. In all the cases, the Torg's ratio of females (0.97–1.04) was higher than in males (0.89–0.95) and varied significantly (P &lt; 0.05). Conclusions: The study provides reference morphometric values for combined Torg's ratio and individually in males and females in the Kolhapur population.

An Assessment of the Effectiveness of Surgical Treatment Methods Used for Cervical Spondylosis.

To evaluate the preoperative and postoperative clinical and radiological findings of patients treated surgically for cervical spondylosis. The patients included in the study (n=32) were divided into three groups according to their preferred surgical approach. These surgical approaches are posterior cervical laminectomy, posterior cervical laminectomy plus fusion, and anterior approach. Then, pre-and postoperative modified Japanese Orthopaedic Association Myelopathy (mJOA) scores, Torg- Pavlov ratios measured on direct cervical radiography, and pre-and postoperative lordosis angles were recorded. The data obtained were evaluated statistically. The radiological examinations revealed that the average preoperative Torg-Pavlov ratio was < 1 in 29 patients. The average sagittal spinal canal diameter was 9 mm, and myelomalacia was detected in 25 patients. Postoperative mJOA scores in patients who underwent anterior corpectomy and fusion and posterior laminectomy were statistically significant (p < 0.05). The highest symptomatic recovery rate was found in patients with preoperative neck pain. This finding was not statistically significant (p > 0.05). Changes in the postoperative lordosis angles and recovery rates were also observed, depending on the preferred surgical approach. If there is no kyphotic deformity or straightening of the cervical lordosis, a posterior laminectomy can be performed to avoid the long-term complications caused by an anterior corpectomy. It should be kept in mind that multi-segment and wide laminectomies may cause instability problems.

Morphometric Measurements of Cervical Spine using Computed Tomography

The cervical spine antomy exhibits wide variations. For cervical spine pathologies which require surgical treatment, the prior knowledge of these anatomic variations would reduce the surgical complications. The aim of the study is to perform CT based measurements of cervical transverse foramen and spinal canal in indian population which would be useful in providing road map and guidance for surgical interventions of cervical spine. This is a retrospective study. A total of 73 patients (49 males, 24 females, age range: 18-75 years) indicated for CT cervical spine from June 2018 to June 2019 were included. The sagittal spinal canal Diameter (dSSC), sagittal (TFs) and transversr diameters (TFt) of transverse foramen, distance between transverse foramen and spinal canal (dTF-SC) were measured at C1-C7 levels. We found that significant difference in sagittal spinal canal diameters at all the levels of cervical spine (C1-C7) between males and females (p<0.01). Our study also found significant difference in sagittal (TFs) and transverse (TFs) diameters of transverse foramen at all cervical levels in males and females between right and left side (p<0.01). Significant difference were noted for distance between transverse foramen and spinal canal (dTF SC) at all the levels of cervical spine in males and females between right and left side (p<0.01). From our study we conclude that a thorough comprehension of cervical anatomy with CT- based measurements help in preoperative planning and reduce the complications in surgical interventions. Our study noticed significant reduction in distance between transverse foramen and spinal canal (dTF-SC) in both males and females on left side. Hence, care must be taken while performing surgical procedures of cervical spine on the left side in males and females at all cervical levels.

Early effectiveness of oblique lateral interbody fusion combined with pedicle screw fixation via small incision Wiltse approach for lumbar spondylolisthesis

To investigate the early effctiveness of oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation via small incision Wiltse approach for the treatment of lumbar spondylolisthesis. Between January 2016 and December 2016, 21 patients with lumbar spondylolisthesis were treated with OLIF and pedicle screw fixation via small incision Wiltse approach. There were 9 males and 12 females, aged 57-73 years, with an average age of 64.5 years. The disease duration was 24-60 months, with an average of 34.6 months. All cases were spondylolisthesis at L 4 (15 cases of degreeⅠ, 6 cases of degreeⅡ); 1 case had vertebral arch isthmus, and 20 cases had spinal stenosis. Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the effectiveness before operation and at last follow-up. Before operation and at 2 days after operation, anteroposterior and lateral X-ray films and CT were taken to measure the sagittal diameter and cross-sectional area of the spinal canal, and calculate the intervertebral height and degree of spondylolisthesis. At 6 months after operation, the intervertebral fusion was evaluated by CT. The operation time was 120-180 minutes, with an average of 155 minutes; the intraoperative blood loss was 100-340 mL, with an average of 225.5 mL. One patient had slight injury of lower endplate, 1 patient had numbness of thigh and weakness of hip flexion after operation, 1 patient had sympathetic nerve trunk injury. All the cases were followed up 12-18 months, with an average of 14.3 months. The symptoms of low back pain, leg pain, and numbness of lower limbs significantly relieved after operation, and there was no complication such as protrusion of fusion cage, screw breakage, and endplate collapse. At 2 days after operation, the intervertebral height, degree of spondylolisthesis, sagittal diameter of spinal canal, and cross-sectional area of spinal canal significantly improved compared with preoperative ones ( P<0.05). At 6 months after operation, CT showed that 1 patient had poor interbody fusion (grade Ⅲ), the other 20 patients had good interbody fusion (grade Ⅰ and Ⅱ), and the interbody fusion rate was 95.2%. At last follow-up, JOA score of lumbar spine significantly increased compared with that before operation ( t=24.980, P=0.000). OLIF combined with pedicle screw fixation via small incision Wiltse approach for the lumbar spondylolisthesis has minimally invasive features, such as less trauma, fewer complications, and higher intervertebral fusion rate. It is a safe and effective method.

Is the anterior spinal artery occluded in severe cervical compressive myelopathy?

Purpose: The goal of this study was to identify whether the anterior spinal artery (ASA) is occluded in severe cervical compressive myelopathy (CCM) according to computed tomography angiography (CTA); occlusion was defined as spinal canal sagittal diameter compression of more than 80%. Study design: A retrospective study. Setting: Xinqiao Hospital, Chongqing, China. Participants: The sample comprised 11 patients with spinal canal sagittal diameter compression of more than 80%. Interventions: The patient underwent CTA of the ASA after admission. Covisualization of the ASA and the artery of Adamkiewicz was used to identify the ASA. Outcome Measures: Spinal cord compression and decompression were determined with 1.5-Tesla magnetic resonance imaging. The neurologic status was evaluated according to the classification of the American Spinal Injury Association (ASIA). Results: No ASA occlusion was found in all 11 severe CCM patients who presented with chronic or acute onset. All patients demonstrated improved neurological status after the anterior cervical decompression and fusion procedure. Conclusion: ASA occlusion was not observed in CCM patients with spinal canal sagittal diameter compression of more than 80%.

Clinical implications morphometric study of the cervical spine on MRI

Degenerative changes, history of trauma or inflammation usually progressed to cervical spinal canal stenosis. This condition leads to cervical spondylosis neuropraxia and cervical spondylotic myelopathy (CSM). SAC (space available for the cord) value is important to understand the symptoms of spinal cord compression in cervical canal stenosis. The aim of our study is to establish cervical spinal canal morphometry in Western Maharashtra population observed by MRI of cervical region.70 subjects aged between 18-70 years. The sagittal vertebral body diameter, the sagittal spinal canal diameter and the sagittal spinal-cord diameter were measured at the C3 - C7 level. The SAC was determined. For each variable a two-way ANOVA was performed, sagittal canal diameter, sagittal spinal cord diameter and SAC were significant with p-value P&lt; 0.0001**. Mean vertebral body diameters observed were 1.49-1.51. Values of SAC observed were C3-1.5 cm, C4- 1.51cm, C5- 1.49cm, C6- 1.5cm, C7- 1.49cm. Average sagittal spinal canal diameter from C3-C7 was 14.1± 1.3 mm. The range of SAC was between 6.4-9.5mm, least at the C5 level. We conclude that subjects in our study do not have an increased risk of spinal cord compression.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P99. Laminoplasty and laminectomy hybrid decompression for the treatment of cervical spondylotic myelopathy with hypertrophic ligamentum flavum: a retrospective study

BACKGROUND CONTEXT Laminoplasty is widely used in patients with cervical spondylotic myelopathy (CSM); however, for CSM patients with hypertrophic ligamentum flavum (HLF), traditional laminoplasty does not include resection of a pathological ligamentum flavum. PURPOSE To report the outcomes of a posterior hybrid decompression protocol for the treatment of CSM)associated withHLF. STUDY DESIGN/SETTING This study retrospectively reviewed 116 CSM patients with HLF who underwent hybrid decompression with a minimum of 12 months of follow-up. The procedure consisted of reconstruction of the C4 and C6 laminae using CENTERPIECE plates with spinous process autografts, and resection of the C3, C5, and C7 laminae. Surgical outcomes were assessed using Japanese Orthopedic Association (JOA) score, recovery rate, cervical lordotic angle, cervical range of motion, spinal canal sagittal diameter, bone healing rates on both the hinge and open sides, dural sac expansion at the level of maximum compression, drift-back distance of the spinal cord, and postoperative neck pain assessed by visual analog scale. PATIENT SAMPLE During a consecutive 3-year period from February 2009 through April 2012, 283 patients underwent hybrid posteriordecompression in our hospital. The current study retrospectively reviewed 116 CSM patients with HLF who underwent thisprocedure. The researchers selected patients with CSM caused only by HLF (dorsal compression of the spinal cord owing to HLF) and patients with CSM caused by the combination of anterior disease plus HLF (dorsal compression of the spinal cord owing to HLF and anterior disease such as ossification of the posterior longitudinal ligament [OPLL], degenerative disk disease [DDD], and congenital pathologies). The inclusion criteria were: (1) a clear diagnosis made by history, physical examination, plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI); (2) complete pre- and postoperative imaging and clinical data records; (3) a minimum of 12 months’ postoperative follow-up. Exclusion criteria were: (1) CSM patients with multilevel anterior compression only; e.g., consecutive OPLL or DDD, bu without HLF; and (2) patients lost to follow-up. Of the 116 patients (89 men, 27 women [mean age 61.9 years], 55 also had segmental or localized OPLL, 41 also had cervical degenerative disk herniation (DDH), 11 also had developmental spinal canal stenosis (DSCS), and 9 had ossification of ligament flavum (OLF). Thirteen of 116 patients had single-level spinal canal stenosis, 29 had twolevel stenosis, 48 had three-level stenosis, and the remaining 26 patients had four- or five-level stenosis. OUTCOME MEASURES Results were analyzed using PASW Statistics for Windows, Version 18.0 (SPSS Inc., Chicago, IL, USA). Descriptive statisticswere used for demographics, and Student's t-test was used for continuous variables. Significance was set at P METHODS Not applicable. RESULTS No hardware failure or restenosis was noted. Postoperative JOA score improved significantly, with a mean recovery rate of 65.3±15.5%. Mean cervical lordotic angle had decreased 4.9° by 1 year after surgery (P CONCLUSIONS Hybrid laminectomy and autograft laminoplasty decompression using Centerpiece plates may facilitate bone healing and produce a comparatively satisfactory prognosis for CSM patients with HLF.

Variation of C1 spinolaminar line and prevalence of C1 stenosis in normal population.

The variation of C1 spinolaminar line in normal population is not fully understood. The relative position of C1 lamina to C3-C2 spinolaminar line is reported as good screening tool for determination of C1 canal stenosis. To determine the variation of C1 spinolaminar line and find the prevalence of C1 canal stenosis in normal population using C3-C2 spinolaminar test. Three hundred and fifteen lateral cervical radiographs from 315 volunteers without neurological symptoms were analyzed. The relative position of C1 spinolaminar line was determined by C3-C2 spinolaminar and considered positive if C1 lamina lay ventral to C3-C2 line. C1 space available for cord (SAC) was measured from posterior border of dens to the C1 lamina to determine the sagittal diameter. The mean sagittal spinal canal diameter of C1 was 22.2mm (13-26mm). Of 315, 14 (4.4%) had positive, 184 (58.4%) had neutral, and 117 (37.1%) had negative C1 spinolaminar line in relation to C3-C2 line. The mean SAC among positive group was 14.9mm compared to neutral and negative groups which were 22.2 and 23.3mm, respectively. 21.4% of positive group had SAC of less than 12mm. The 92.8% of positive C1 spinolaminar line was found in age≥60years. In a normal population, 4.4% has positive C1 spinolaminar line. The C1 stenosis is more prevalent in positive C1 spinolaminar line group.

Clinical and instrumental assessment of herniated discs after nucleoplasty: a preliminary study.

Background and Aim: The therapy for low back pain boasts different approaches; one of these is nucleoplasty. We wanted to assess the effectiveness of nucleoplasty both by clinical response both by MR imaging evaluation, including even extrusions larger than one third of the spinal canal. Methods: Fifty-seven patients were treated with nucleoplasty in our hospital, 11 of these patients accepted both clinical and MRI evaluation after six months from treatment. The clinical evaluation was performed with Visual Analogue Scale (VAS) of pain, scored before and after the procedure. MRI evaluation consisted of analysing some imaging parameters of disc protrusions before and after the treatment. Results: In 10 out of 11 (91%) patients, VAS was reduced and only 1 out of 11 (9%) had the same pain after procedure. The mean of decrease of VAS score was 64%. In our population 8/11 (72%) patients had a herniation larger than 1/3 of the sagittal diameter of spinal canal and 100% of them had an improvement with a mean VAS reduction value of 75%. With MRI evaluation, the mean percentage of expulsion before and after treatment was respectively 40% and 34%. The expulsion decreased in 7/13 discs, remained equal in 4/13, and increased in 2/13 discs. Among the 9 larger protrusions, 3 didn’t change, 6 reduced with a decrease mean value of 13%. Other MRI parameters didn’t change significantly. Conclusions: Our preliminary experience supports the success of coblation on pain relief, aiming to show progressively that this treatment is suitable even in case of great extrusions, which are generally treated only with surgical approach. It’s not clear the usefulness of MRI control yet, even if in most of cases we could have found a certain reduction of expulsion degree. (www.actabiomedica.it)

Anatomy research of cervical laminoplasty with preservation of the posterior ligament complex.

Objective: To evaluate the feasibility of cervical laminoplasty with preservation of the posterior ligament complex for enlarging the spinal canal. Methods: Six up-to-standard human corpse specimens were divided into two groups by simple randomization (start from C4 group, S4; start from C5 group, S5; 3 corpses in each group). Decompression operation of C3-C6 level was performed in a predetermined sequence by using the new procedure with preservation of the posterior ligament complex.The basic depth of spinal canal was measured with a depth gauge at fixed point after the right bone groove of single level was completed.The operation of the contralateral bone groove was continued, and then the spinal canal was measured again when the spinous process was pulled backward by using a tissue forceps until the ligament complex was just tight.Retreat value (RV) of vertebral lamina was obtained by calculating the difference between the two measurements.The earlier measured levels needed to be remeasured when the operation area increased by one level. Two independent sample and one-sample t test were used to analyze the measurement results. Results: RV of vertebral lamina was small after finishing the first level of the decompression operation [S4: (0.87±0.72) mm; S5: (1.83±0.29) mm], and the value reached its maximum after the completion of C3-C6 level.The overall average RVmaxs from C3 to C6 level were (2.37±0.52) mm, (4.27±0.78) mm, (3.73±0.93) mm and (2.16±0.77) mm, respectively.The overall average retreat rates (RR) were 17%±7%, 32%±9%, 29%±10% and 16%±6%, respectively. The overall average RVmax of C4 and C5 level reached or exceeded the decompression threshold value of 4 mm (t=0.839, -0.703, both P>0.05). The average RVmax of C4/C5 level was similar in the two groups (t=-1.204, 1.189, both P>0.05); however, the difference of average RVmax between C3 and C6 level was significant (t=-4.429, 4.196, both P<0.05). Conclusions: Cervical laminoplasty with preservation of the posterior ligament complex can enlarge the sagittal diameter of spinal canal and relieve the compression of spinal cord.In addition, RV of each level increases as the number of the operation level increases, and the ability of vertebral lamina to retreat is quite different from C3 to C6 level.The decompression effect in the middle of the operation area is better than that on the cranial and tail side.

MRI Study on Spinal Canal Morphometry: An Indian Study.

A large proportion of adults suffer from neck pain at some points of their life and show altered ranges of spinal canal morphometry in various studies. The differences in values are also seen due to genetic, hormonal and other factors too. Torg's ratio is a widely accepted measurement to eliminate such discrepancies. The measurement of Space Available for Cord (SAC) is also gaining importance as spinal stenosis is a contributor to neck pain. (1) To examine the cervical spinal canal and spinal cord morphometric determinants in symptomatic sub-Himalayan North Bengal population and to compare the obtained data with other populations; (2) To determine whether Torg's ratio vary with gender or not; (3) To determine SAC values in symptomatic individuals. Magnetic Resonance Imaging (MRI) based on midsagittal diameter of vertebral body, spinal canal, spinal cord and its Torg's ratio and SAC value of the lower cervical spine (C3-C7) from 71 symptomatic adults were recorded at the Radiology Department of North Bengal Medical College and Hospital, Bengal, India. Individuals with any evidence of trauma, infection, neoplasia or any congenital anomalies related to spinal canal and below 18 years of age were excluded from the study. The average diameter for vertebral body was significantly larger in males. The average diameter for spinal canal, spinal cord and values of Torg's ratio and SAC has no significant gender difference. But the mean value of Torg's ratio is greater in females is due to smaller vertebral body size in females. It is interpreted from our study that sagittal spinal canal diameter, Torg's ratio and SAC value did not show any significant gender difference. But sagittal vertebral body's diameter showed sexual dimorphism which influenced the mean value of Torg's ratio.

Cervical spinal canal stenosis first presenting after spinal cord injury due to minor trauma: An insight into the value of preventive decompression

Patients with pre-existing cervical spinal canal stenosis (CSCS) may have minimal or no symptoms. However, performing preventive decompression is controversial as the incidence of CSCS leading to severe cord injury is unknown. Hence, this study aims to revisit the threshold for surgery in "silent" CSCS by reviewing the neurologic outcomes of patients with undiagnosed CSCS who sustained a cervical spinal cord injury (CSCI). Two groups of subjects were recruited for analysis. Firstly, patients with trauma-induced CSCI without fracture or dislocation were included. Pre-existing CSCS was diagnosed by MRI measurements. The second group consisted of asymptomatic subjects recruited from the general population who also had MRIs performed. Canal sizes were compared between this control group and the patient group. Within the patient group, neurological assessments and outcomes by Frankel classification were performed in patients treated surgically or conservatively. 32 patients with CSCS were recruited. The mean spinal canal sagittal diameter (disc-level) of all CSCS cases was 5.3±1.4mm (1.3-8.2). In comparison, the diameter was 10.5±1.7mm (6.6-14.6) in the 47 asymptomatic individuals recruited from the general population. Decompression was performed in 17 patients and conservative treatment in 15. Mean follow-up was 19.3±17.0 months (6-84). At the final follow-up, 3 patients (9.3%) returned to their pre-injury Frankel grade, whereas 26 patients (83.3%) lost one or more neurological grade. Three patients (9.3%) died. Majority of patients with "silent" CSCS who sustained cervical cord injuries did not return to their pre-injury neurological status. All of these subjects have pre-existing canal stenosis hence the risk of cord injury. Given the poor neurological outcome of CSCS, a lower threshold for surgery could be indicated to avoid these disastrous injuries. However, before making any conclusive recommendation we must first identify the prevalence of "silent" CSCS in the general population and the risk of developing spinal cord injury with more prospective population-based studies.

Cervical Endoscopic Laminoplasty for Cervical Myelopathy.

Prospective clinical series. The aim of this study was to evaluate the safety, feasibility, and efficacy of a new minimally invasive laminoplasty technique for patients with cervical spondylotic myelopathy (CSM). Posterior decompression is one of the most common surgical interventions for CSM. Conservative posterior approaches require extensive release and extensive retraction of paraspinal muscles and/or treatment of bone (lamina), which leads to postoperative axial neck pain and a decrease in lordosis and range of motion (ROM). A total of 45 patients with CSM received cervical microendoscopic laminoplasty (CMEL). Surgery included endoscopy-assisted bilateral laminoplasty with spinous process-ligament complex and deep extensor muscle retroposition. Bilateral titanium mini-screws and plates were used for fixation. Effects and axial symptoms were evaluated according to the Japanese Orthopedic Association (JOA) scores for neurological condition and visual analog scales (VAS) for axial neck pain, respectively. Cervical curvature index (CCI) and ROM were evaluated by X-ray. Computerized tomography and magnetic resonance imaging scans evaluated laminar healing and spinal cord decompression. Follow-up ranged from 18 to 48 months (average 28 months). The duration of surgery averaged 119 minutes (range 62-147 min). Average blood loss was 360 mL (range 250-700 mL). Mean JOA scores improved from 8.0 ± 1.72 preoperatively to 13.29 ± 1.85 postoperatively. The effects were excellent in 13 cases, good in 25 cases, and fair in 7 cases. Axial symptoms were excellent in 16 cases, good in 18 cases, and fair in 11 cases. The VAS scores of axial pain significantly improved to 2.3 ± 2.0 at the final follow-up compared with 4.3 ± 2.1 preoperatively (P < 0.05). The CMEL procedure provided stable reconstruction of expanded laminar arches with no postoperative collapse or door-close. Sagittal spinal canal diameter increased by 1 to 3 mm. There were no differences in the pre- and postoperative CCI and ROM. The new CMEL provides stable reconstruction of an expanded laminar arch and causes less damage to the spinous process-ligament complex and the deep extensor muscles than conventional surgical approaches. The CMEL procedure can be used efficiently and safely to treat CSM. N/A.

Radiographic evaluation of indirect decompression of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion for degenerated lumbar spondylolisthesis.

Extreme lateral interbody fusion provides minimally invasive treatment of spinal deformity, but complications including nerve and psoas muscle injury have been noted. To avoid nerve injury, mini-open anterior retroperitoneal lumbar interbody fusion methods using an approach between the aorta and psoas, such as oblique lumbar interbody fusion (OLIF) have been applied. OLIF with percutaneous pedicle screws without posterior decompression can indirectly decompress the spinal canal in lumbar degenerated spondylolisthesis. In the current study, we examined the radiographic and clinical efficacy of OLIF for lumbar degenerated spondylolisthesis. We assessed 20 patients with lumbar degenerated spondylolisthesis who underwent OLIF and percutaneous pedicle screw fixation without posterior laminectomy. MR and CT images and clinical symptoms were evaluated before and 6months after surgery. Cross sections of the spinal canal were evaluated with MRI, and disk height, cross-sectional areas of intervertebral foramina, and degree of upper vertebral slip were evaluated with CT. Clinical symptoms including low back pain, leg pain, and lower extremity numbness were evaluated using a visual analog scale and the Oswestry Disability Index before and 6months after surgery. After surgery, significant increases in axial and sagittal spinal canal diameter (12 and 32%), spinal canal area (19%), disk height (61%), and intervertebral foramen areas (21% on the right side, 39% on the left), and significant decrease of upper vertebral slip (-9%) were found (P<0.05). Low back pain, leg pain, and lower extremity numbness were significantly reduced compared with before surgery (P<0.05). Significant improvements in disk height and spinal canal area were found after surgery. Bulging of disks was reduced through correction, and stretching the yellow ligament may have decompressed the spinal canal. Lumbar anterolateral fusion without laminectomy may be useful for lumbar spondylolisthesis with back and leg symptoms.

Treatment of thoracolumbar fracture by posterior reduction combined with H-shaped bone grafting and spinous process replantation for reconstruction of spinal structures

Objective To detect the clinical effect of posterior reduction combined with H-shaped bone grafting and spinous process replantation for reconstruction of spinal structures in treatment of thoracolumbar fracture.Methods Forty-three patients with thoracolumbar burst fracture treated surgically from February 2008 to June 2012 were reviewed retrospectively.There were 30 male and 13 female patients aged 23 to 55 years (mean,38 years).Fracture resulted from high falls in 21 patients,traffic accidents in 16 patients,and a crush by heavy objects in 6 patients.Denis system was used for classification of fracture and Frankel rating for assessing the degree of nerve damage and recovery.After posterior reduction combined with H-shaped bone grafting and spinous process replantation for all patients,visual analogue scale (VAS) was utilized to assess symptom improvement and Cobb' s angle and sagittal spinal canal diameter were measured to help assess the treatment outcome.Results Pain was apparently eased at a 24-month follow-up (range,12-46 months).Cobb' s angle improved from preoperative 43.56° to postoperative 8.23° (t =1.33,P ＜ 0.01).CT findings showed mean spinal canal stenosis rate was 56.3％ before surgery and that mean sagittal canal diameter of the injured spine was larger than that of adjacent segments at follow-up,with the mean ratio of 116.3％ (range,111.3％-120.3％).Rate of spinal canal stenosis was negative for all patients and posterior canal with bone grafts healed.Spinal cord injury improved at least one Frankel grade.Conclusion Posterior reduction combined with H-shaped bone grafting and spinous process replantation is worthy of clinical application,for the procedure can restore the fractured thoracolumbar spine and posterior canal structure,but also effectively avoid the iatrogenic spinal stenosis. Key words: Spinal fractures ; Thoracic vertebrae ; Lumbar vertebrae ; Spinal canal

Laminoplasty and laminectomy hybrid decompression for the treatment of cervical spondylotic myelopathy with hypertrophic ligamentum flavum: a retrospective study.

ObjectiveTo report the outcomes of a posterior hybrid decompression protocol for the treatment of cervical spondylotic myelopathy (CSM) associated with hypertrophic ligamentum flavum (HLF).BackgroundLaminoplasty is widely used in patients with CSM; however, for CSM patients with HLF, traditional laminoplasty does not include resection of a pathological ligamentum flavum.MethodsThis study retrospectively reviewed 116 CSM patients with HLF who underwent hybrid decompression with a minimum of 12 months of follow-up. The procedure consisted of reconstruction of the C4 and C6 laminae using CENTERPIECE plates with spinous process autografts, and resection of the C3, C5, and C7 laminae. Surgical outcomes were assessed using Japanese Orthopedic Association (JOA) score, recovery rate, cervical lordotic angle, cervical range of motion, spinal canal sagittal diameter, bone healing rates on both the hinge and open sides, dural sac expansion at the level of maximum compression, drift-back distance of the spinal cord, and postoperative neck pain assessed by visual analog scale.ResultsNo hardware failure or restenosis was noted. Postoperative JOA score improved significantly, with a mean recovery rate of 65.3±15.5%. Mean cervical lordotic angle had decreased 4.9 degrees by 1 year after surgery (P<0.05). Preservation of cervical range of motion was satisfactory postoperatively. Bone healing rates 6 months after surgery were 100% on the hinge side and 92.2% on the open side. Satisfactory decompression was demonstrated by a significantly increased sagittal canal diameter and cross-sectional area of the dural sac together with a significant drift-back distance of the spinal cord. The dural sac was also adequately expanded at the time of the final follow-up visit.ConclusionHybrid laminectomy and autograft laminoplasty decompression using Centerpiece plates may facilitate bone healing and produce a comparatively satisfactory prognosis for CSM patients with HLF.

CT angiography of anterior spinal artery in cervical spondylotic myelopathy.

To identify anterior spinal artery (ASA) infarct or occlusion by CT angiography (CTA) in patients with cervical spondylotic myelopathy (CSM). Fourteen patients with CSM were performed CTA of ASA after admission. T2-weighted hyperintensity of MR image was compared with image of CTA of ASA. All patients presented spinal canal sagittal diameter compression from 10 to 80% and different T2-weighted hyperintensity of MR images. No ASA infarct or occlusion was found in CSM patients. ASA infarct or occlusion is not commonly seen in CSM patients with spinal canal sagittal diameter compression less than 80%. Pathological changes about T2-weighted hyperintensity of MR image in CSM have no close correlation with ASA infarct.