[Construction and stability analysis of finite element model for spinal canal reconstruction with miniplates fixation].

OBJECTIVE: To establish the finite element model of spinal canal reconstruction and internal fixation,analysis influence of spinal canal reconstruction and internal fixation on spinal stability,and verify the effectiveness and reliability of spinal canal reconstruction and internal fixation in spinal canal surgery. METHODS: A 30-year-old male healthy volunteer with a height of 172 cm and weight of 75 kg was selected and his lumbar CT data were collected to establish a finite element model of normal lumbar L3-L5,and the results were compared with in vitro solid results and published finite element analysis results to verify the validity of the model. They were divided into normal group,laminectomy group and spinal canal reconstruction group according to different treatment methods. Under the same boundary fixation and physiological load conditions,six kinds of activities were performed,including forward bending,backward extension,left bending,right bending,left rotation and right rotation,and the changes of range of motion (ROM) of L3-L4,L4-L5 segments and overall maximum ROM of L3-L5 were analyzed under the six conditions. RESULTS: The ROM displacement range of each segment of the constructed L3-L5 finite element model was consistent with the in vitro solid results and previous literature data,which confirms the validity of the model. In L3-L4,ROM of spinal canal reconstruction group was slightly increased than that of normal group during posterior extension(>5% difference),and ROM of other conditions was similar to that of normal group(<5% difference). ROM in laminectomy group was significantly increase than that in normal group and spinal canal reconstruction group under the condition of flexion,extension,left and right rotation. In L4-L5,ROM in spinal canal reconstruction group was similar to that in normal group(<5% difference),while ROM in laminectomy group was significantly higher than that in normal group and spinal canal reconstruction group(>5% difference). In the overall maximum ROM of L3-L5,spinal canal reconstruction group was only slightly higher than normal group under the condition of posterior extension(>5% difference),while laminectomy was significantly higher than normal group and spinal canal reconstruction group under the condition of anterior flexion,posterior extension,left and right rotation(>5% difference). The changes of each segment ROM and overall ROM of L3-L5 showed laminectomy group>spinal canal reconstruction group>normal group. CONCLUSION: Laminectomy could seriously affect biomechanical stability of the spine,but application of spinal canal reconstruction and internal fixation could effectively reduce ROM displacement of the responsible segment of spine and maintain its biomechanical stability.

Thoracic Vertebral Canal Stenosis and Vertebral Instability in a Young Minuet Cat.

This report describes a unique case of thoracic vertebral canal stenosis and vertebral instability in a 1 yr old Minuet cat. The cat presented with a history of chronic progressive nonambulatory paraparesis. Myelography with neutral and stress positions revealed dynamic compression at T1-4. Computed tomography and MRI revealed multiple sites of vertebral endplate osteolysis, adjacent bone sclerosis, intervertebral disk space narrowing, and spondylotic bridging within the cervical and cranial thoracic vertebral bodies and pedicles, particularly at C6-T4. The cat underwent a right-sided T1-4 hemilaminectomy and C7-T4 vertebral stabilization using positively threaded profile pins and polymethylmethacrylate. The cat fully recovered without any complication. The case highlights the potential for young cats, especially those with a chondrodysplastic condition, to develop vertebral canal stenosis and vertebral instability. The surgical treatment described herein resulted in an excellent outcome.

Analysis of spinal canal diameter in the placement of thoracic spinal cord stimulator paddle leads.

BACKGROUND: Neurologic deficit is known as a rare complication of thoracic spinal cord stimulator (SCS) paddle lead implantation, but many believe its incidence after SCS paddle lead placement is under-reported. It is possible that imaging characteristics may be used to help predict safe paddle lead placement. OBJECTIVE: This imaging study was undertaken to determine the minimum canal diameter required for safe paddle lead placement. METHODS: Patients who underwent thoracic laminotomy for new SCS paddle lead placement from January 2018 to March 2023 were identified retrospectively. Preoperative thoracic canal diameter was measured in the sagittal plane perpendicular to the disc space from T5/6 to T11/12. These thoracic levels were chosen because they span the most common levels targeted for SCS placement. Patients with and without new neurologic deficits were compared using a Mann-Whitney U-test. RESULTS: Of 185 patients initially identified, 180 had thoracic imaging available for review. One (0.5%) and 2 (1.1%) of 185 patients complained of permanent and transient neurologic deficit after thoracic SCS placement, respectively. Patients with neurologic deficits had average canal diameters of <11 mm. The average canal diameter of patients with and without neurologic deficits was 10.2 mm (range 6.1-12.9 mm) and 13.0 mm (range 5.9-20.2), respectively (p < 0.0001). CONCLUSION: Postoperative neurologic deficit is an uncommon complication after thoracic laminotomy for SCS paddle lead placement. The authors recommend ensuring a starting thoracic canal diameter of at least 12 mm to accommodate a SCS paddle lead measuring 2 mm thick to ensure a final diameter of >10 mm. If canal diameter is <12 mm, aggressive undercutting of the lamina, a second laminotomy, or placement of smaller SCS wire leads should be considered.

Effect of L5 spinal canal type on pedicle screw placement based on CT imaging: a retrospective clinical study.

PURPOSE: The objective of this study was to investigate the optimal entry point and pedicle camber angle for L5 pedicle screws of different canal types. METHODS: CT imaging data were processed by Mimics for simulated pedicle screw placement, and PD (Pedicle diameter), PCA (Pedicle camber angle), LD (Longitudinal distance), TD (Transverse distance), and PBG (Pedicle screw breach grade) were measured. Then they were divided into the Round group and Trefoil group according to the type of spinal canal. When comparing PD, PCA, LD, TD, and PBG, the two sides of the pedicle were compared separately, so they were first divided into the round-type pedicle group and the trefoil-type pedicle group. RESULTS: In the round-type pedicle group (n = 134) and the trefoil-type pedicle group (n = 264), there was no significant difference in PD and LD, but there was a significant difference in PCA between the two groups (t = - 4.072, P < 0.05). A statistically significant difference in the distance of the Magerl point relative to the optimal entry point (t = - 3.792, P < 0.05), and the distance of the Magerl point relative to the optimal entry point was greater in the trefoil-type pedicle group than in the round-type pedicle group. CONCLUSION: The optimal entry point for L5 is more outward than the Magerl point, and the Trefoil spinal canal L5 is more outwardly oriented than the Round spinal canal L5, with a greater angle of abduction during pedicle screw placement.

An innovative approach to assess spinal canal expansion following French-door cervical laminoplasty by intraoperative ultrasonography.

OBJECTIVE: To investigate the feasibility and effectiveness of applying intraoperative ultrasound (IOUS) to evaluate spinal canal expansion in patients undergoing French-door cervical laminoplasty (FDCL). MATERIALS AND METHODS: Twenty-five patients who underwent FDCL for multilevel degenerative cervical myelopathy were prospectively recruited. Formulae describing the relationship between laminoplasty opening angle (LOA) and laminoplasty opening size, the increase in sagittal canal diameter and the spinal canal area were deduced with trigonometric functions. The LOA was measured with IOUS imaging during surgery, and other spinal canal parameters were assessed. Actual spinal canal enlargement was verified on postoperative CT images. Linear correlation analysis and Bland‒Altman analysis were used to evaluate correlation and agreement between the intraoperative and postoperative measurements. RESULTS: The LOA at C5 measured with IOUS was 27.54 ± 3.12°, and it was 27.23 ± 3.02° on postoperative CT imaging. Linear correlation analysis revealed a significant correlation between IOUS and postoperative CT measurements (r = 0.88; p < 0.01). Bland-Altman plots showed good agreement between these two methods, with a mean difference of 0.30°. For other spinal canal expansion parameter measurements, correlation analysis showed a moderate to a high degree of correlation (p < 0.01), and Bland-Altman analysis indicated good agreement. CONCLUSION: In conclusion, during the French-door cervical laminoplasty procedure, application of IOUS can accurately evaluate spinal canal expansion. This innovative method may be helpful in improving surgical accuracy by enabling the operator to measure and determine canal enlargement during surgery, leading to ideal clinical outcomes and fewer postoperative complications. CLINICAL RELEVANCE STATEMENT: The use of intraoperative ultrasonography to assess spinal canal expansion following French-door cervical laminoplasty may improve outcomes for patients undergoing this procedure by providing more accurate measurements of spinal canal expansion. KEY POINTS: • Spinal canal expansion after French-door cervical laminoplasty substantially influences operative prognosis; insufficient or excessive lamina opening may result in unexpected outcomes. • Prediction of spinal canal expansion during surgery was previously impracticable, but based on this study, intraoperative ultrasonography offers an innovative approach and strongly agrees with postoperative CT measurement. • Since this is the first research to offer real-time canal expansion guidance for cervical laminoplasty, it may improve the accuracy of the operation and produce ideal clinical outcomes with fewer postoperative complications.

Is there a risk of further displacement of the fractured fragment into the spinal canal in osteoporotic vertebral burst fractures after unilateral PKP? A prospective study.

BACKGROUND CONTEXT: The optimal treatment for osteoporotic vertebral burst fracture (OVBF) without neurological symptoms is still a matter of debate. PURPOSE: To evaluate the safety and efficacy of percutaneous kyphoplasty (PKP) for OVBF. STUDY DESIGN: The study is a prospective study and is registered in the China Clinical Trials Registry with the registration number ChiCTR-OOC-17013227. PATIENT SAMPLE: The study involved 119 patients with 137 fractured vertebrae who underwent unilateral PKP for OVBF. OUTCOME MEASURES: The measurements were carried out independently by two physicians and measured with picture archiving and communication system (PACS) and ImageJ software (National Institutes of Health, Bethesda, MD, USA). METHODS: The change in the spinal canal area and posterior wall protrusions (PWP) were measured before and after surgery via three-dimensional computed tomographic imaging (CT). Preoperative, postoperative, and final follow-up standing X-rays were used to measure the height of the anterior wall (HAW), height of the posterior wall (HPW), and local kyphotic angle (LKA). Additionally, visual analogue scale (VAS) and the Oswestry Disability Index (ODI) were also determined. RESULTS: Among the 137 vertebrae assessed, 79 exhibited an increased postoperative canal area, while 57 showed a decrease, with mean values of 8.28±6.871 mm² and -9.04±5.991 mm², respectively. Notably, no significant change in postoperative canal area was identified on the entire dataset (p>.01). There was a significant decrease between median preoperative (3.9 [IQ1-IQ3=3.3-4.8] mm) and postoperative (3.7 [IQ1-IQ3=3.0-4.4] mm) PWP (p<.01). Preoperative and postoperative HAW measurements were 19.4±6.1 mm and 23.2±5.2 mm, respectively (p<.01). However, at the final follow-up, the HAW was lower than the postoperative value. The HPW was also significantly improved after surgery (p<.01), but at the final follow-up, it was significantly decreased compared with the postoperative measurement. Following surgery, KA was significantly corrected (p<.01); however, at the final follow-up, relapse was detected (average KA: 18.4±10.3°). At the final follow-up, both VAS and ODI were significantly improved compared with the preoperative period (p<.01). As for complications, 50 patients experienced cement leakage, and 16 patients experienced vertebral refracture. All patients did not develop neurological symptoms during the follow-up. CONCLUSIONS: OVBF without neurological deficits showed significant improvement in symptoms during the postoperative period after PKP. There was no notable alteration in the spinal canal area, but a significant decrease in PWP was observed. Consequently, we posit that PKP stands as a secure and efficacious surgical intervention for treating OVBF cases devoid of neurological symptoms.

Morphometric study of cervical spinal canal and transverse foramen diameter using computed tomography: Sex difference and relationship to age in Turkish population.

Accurate and detailed spinal canal diameter transverse foraminal morphometry measurements are essential for understanding spinal column-related diseases and surgical planning, especially for transpedicular screw fixation. This is especially because lateral cervical radiographs do not provide accurate measurements. This retrospective study was conducted to measure the dimensions of the transverse foramen sagittal and transverse diameter (TFD), spinal canal diameter, the distance of the spinal canal from the transverse foramina at the C1 to C7 cervical level, and the anteroposterior and TFDs in the Turkish population. A total of 150 patients who underwent cervical spine computed tomographic imaging with a 1:1 gender ratio were enrolled in the study. The sagittal and TFDs of the spinal canal, the distance of the spinal canal from the transverse foramen, and anteroposterior and TFDs in both right and left sides for all cervical levels C1 to C7. Foramina transversal diameters were measured using imaging tools of the imaging software in the radiology unit. The mean age of the study group was 47.99 ±â€…18.65 (range, 18-80) years. The majority of the distances of the spinal canal from the transverse foramen and antero-posterior (AP) & transverse (T) diameters for cervical vertebrae were significantly higher in male patients (P < .05). However, between age groups, a few measurements were found significantly different. Some of the distances of the spinal canal from the transverse foramen were significantly higher on the right side whereas all AP & T diameters were significantly higher on the left side in both male and female patients (P < .05). Almost all measurements were significantly higher on the left side for younger patients (<65 years) whereas only AP & T diameters were significantly higher on the left side for older patients (>65 years) (P < .05). Computed tomographic imaging is better than conventional radiographs for the preoperative evaluation of the cervical spine and for a better understanding of cervical spine morphometry. Care must be taken during transpedicular screw fixation, especially in female subjects, more so at the C2, C4, and C6 levels due to decreased distance of the spinal canal from the transverse foramina.

Replantation of lamina spinous process ligament complex and miniature titanium plate shaping internal fixation in the treatment of tumors in the spinal canal.

OBJECTIVE: Purpose This study aims to explore the clinical efficacy of laminospinous process ligament complex reimplantation combined with mini-titanium plate fixation in the treatment of thoracolumbar intraspinal tumors. METHODS: A retrospective analysis was performed on 43 cases of intraspinal tumors treated with thoracolumbar intraspinal tumor resection from August 2018 to March 2021, and 27 cases underwent laminospinous process ligament complex reimplantation combined with micro titanium plate shaping. Fixation (laminar replantation group), and 16 patients underwent laminectomy combined with pedicle screw internal fixation (laminectomy group). The operation time, blood loss, drainage tube removal time, cerebrospinal fluid leakage, spinal instability, and the incidence of secondary spinal stenosis were compared between the two groups. The pain VAS score, ODI score, and modified Macnab at the last follow-up were compared between the two groups. And the laminar fusion rate of the laminoplasty group was measured. RESULTS: Both groups successfully completed the surgery and obtained complete follow-up. The incidence of cerebrospinal fluid leakage and secondary spinal canal stenosis in the laminectomy group was lower than that in the laminectomy group, and the difference was statistically significant (P < 0.05). There was no statistically significant difference in the incidence of spinal instability between the two groups (P > 0.05). The operation time and intraoperative blood loss in the laminectomy group were less than those in the laminectomy group, and the drainage tube removal time was earlier than that in the laminectomy group. The difference was statistically significant (P < 0.05). At the final follow-up, there was no statistically significant difference in the pain VAS score, ODI score, and modified Macnab between the two groups (P > 0.05), but they were all significantly improved compared with preoperative ones. Fusion evaluation was conducted on the laminoplasty group. Two years after surgery, the fusion rate was 97.56% (40/41). CONCLUSIONS: The application of laminospinous process ligament complex reimplantation combined with mini titanium plate fixation during thoracolumbar intraspinal tumor resection can effectively reconstruct the spinal canal and posterior column structure, reduce the incidence of cerebrospinal fluid leakage and secondary spinal stenosis. The laminar fusion rate is high.

[Unilateral interlaminar approach 270° circular spinal canal decompression under the iLESSYS Delta for the treatment of lumbar spinal stenosis in the elderly].

OBJECTIVE: To investigate the clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the Interlaminar Endoscopic Surgical System(iLESSYS) Delta for the treatment of lumbar spinal stenosis (LSS) in the elderly. METHODS: Total of 29 patients with LSS treated with the iLESSYS Delta from December 2018 to January 2021 were retrospectively analyzed, including 12 males and 17 females with an average age of (71.52±10.82) years old ranging from 63 to 83 years old. All patients had definite intermittent claudication, mainly neurogenic symptoms of both lower limbs. All patients had single-level spinal stenosis, including L3,4 5 cases, L4,5 21 cases, and L5S1 3 cases. Visual analogue scale (VAS), Oswestry Disability Index (ODI) and modified Macnab assessment criteria were used to evaluate pain, low back pain dysfunction index and clinical efficacy, respectively. RESULTS: All 29 cases were successfully completed. The operation time was (73.45±5.89) min, the intraoperative blood loss was (9.93±0.83) ml, the hospital stay was (4.03±0.41) days, and the follow-up was more than 12 months. The VAS scores of low back pain before surgery and 1 day, 1 month, 3 months, 1 year after surgery were 2.31±0.88, 1.45±0.62, 1.21±0.61, 1.10±0.55, 1.03±0.49;VAS of leg pain were 6.48±0.49 0.56, 1.97±0.61, 1.31±0.59, 1.17±0.59, 1.10±0.55;ODI scores were 38.41±2.74, 18.14±1.17, 5.17±0.53, 5.07±0.45, 4.90±0.48;low back and leg pain VAS score and ODI score have statistically significant differences between preoperative and postoperative follow-up time points (P<0.05). The MacNab efficacy evaluation at 1-year follow-up:excellent in 22 cases, good in 5 cases and fair in 2 cases. CONCLUSION: The clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the iLESSYS Delta for the treatment of lumbar spinal stenosis in the elderly is satisfactory, with the advantages of less trauma and less bleeding, large microscopic operation space, sufficient decompression, and ideal post-operative recovery, and at the same time, it can minimize the damage to the stable structure of the lumbar spine, which is an ideal surgical method for the treatment of elderly lumbar spinal stenosis.

Unilateral laminotomy with bilateral spinal canal decompression: systematic review of outcomes and complications.

BACKGROUND: Unilateral laminotomy with bilateral spinal canal decompression has gained popularity recently. AIM: To systematically review the literature of unilateral laminotomy with bilateral spinal canal decompression for lumbar spinal stenosis (LSS) aiming to assess outcomes and complications of the different techniques described in literature. METHODS: On August 7, 2022, Pubmed and EMBASE were searched by 2 reviewers independently, and all the relevant studies published up to date were considered based on predetermined inclusion and exclusion criteria. The subject headings "unilateral laminotomy", "bilateral decompression" and their related key terms were used. The Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement was used to screen the articles. RESULTS: A total of seven studies including 371 patients were included. The mean age of the patients was 69.0 years (range: 55-83 years). The follow up duration ranged from 1 to 3 years. Rate of postoperative pain and functional improvement was favorable based on VAS, JOA, JOABPEQ, RMDW, ODI and SF-36, for example improved from a range of 4.2-7.5 preoperatively on the VAS score to a range of 1.4-3.0 postoperatively at the final follow up. Insufficient decompression was noted in 3% of the reported cases. The overall complication rate was reported at 18-20%, with dural tear at 3.6-9% and hematoma at 0-4%. CONCLUSION: Unilateral laminotomy with bilateral decompression has favorable short- and mid-term pain and functional outcomes with low recurrence and complication rates. This, however, needs to be further confirmed in larger, long-term follow-up, prospective, comparative studies between open, and minimally invasive techniques.

Efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery.

PURPOSE: The purpose of the study was to evaluate the efficacy of OLIF combined with pedicle screw internal fixation in the treatment of lumbar spinal stenosis by assessing the changes in spinal canal before and after surgery. METHODS: In this retrospective study, we included sixteen patients who underwent a combination of single-segment OLIF and pedicle screw internal fixation for the treatment of lumbar spinal stenosis at the Affiliated Hospital of Jiangxi University of Chinese Medicine between February 2018 and August 2022. The patients' pre- and post-operative data were compared. Intraoperative bleeding, duration of surgery, visual analogue score (VAS), Oswestry Disability Index (ODI), disc height (DH), cross-sectional area of vertebral canal (CSAVC), cross-sectional area of dural sac (CSADS), cross-sectional area of intervertebral foramen (CSAIF), spinal canal volume (SCV), spinal canal volume expansion rate, lumbar lordosis, and sagittal vertical axis were observed and recorded. The efficacy of OLIF combined with pedicle screw internal fixation for lumbar spinal stenosis on spinal canal changes before and after surgery was summarized. RESULTS: The results showed that OLIF combined with pedicle screw internal fixation effectively restored disc height and increased the cross-sectional area of the spinal canal. It also had an indirect decompression effect. The intraoperative bleeding and duration of surgery were within acceptable ranges. The VAS and ODI scores significantly improved after surgery, indicating a reduction in pain and improvement in functional disability. The CSAVC, CSADS, CSAIF, SCV, and spinal canal volume expansion rate were all increased postoperatively. Additionally, there was improvement in lumbar lordosis and sagittal vertical axis. We conducted a follow-up of all patients at 1 year after the surgery. The results revealed that the parameter values at 1 year post-surgery showed varying degrees of decrease or increase compared to the immediate postoperative values. However, these values remained statistically significant when compared to the preoperative parameter values (P < 0.05). CONCLUSIONS: OLIF combined with pedicle screw internal fixation effectively restores disc height and increases the cross-sectional area of the vertebral canal in patients with LSS, reflecting the indirect decompression effect. Measuring parameters such as DH, CSAVC, CSADS, CSAIF, SCV, and SCV expansion rate before and after surgery provides valuable information for evaluating the efficacy and functional recovery of the lumbar spine in LSS patients treated with OLIF surgery.

Comparison of the Degree of Expanded Spinal Canal Area between the Hinge-Side Area and the Open-Side Area in Cervical Open-Door Laminoplasty.

Background: There have been reports on the significant canal cross-sectional area (CSA) expansion difference between pre- and post-operation, but no comparison of CSA expansion between the hinge-side area (Area H) and the open-side area (Area O) has been reported. This study aimed to measure the spinal CSA expansion between Area H and Area O retrospectively after open-door laminoplasty using new titanium spacers and evaluated this common decompression procedure's effectiveness. Materials and Methods: This study included 27 patients diagnosed with cervical spondylotic radiculopathy or myelopathy, ossification of the posterior longitudinal ligament, and developmental canal stenosis from February 2021 to October 2022. The CSA difference between pre- and post-cervical laminoplasty (C4-C6 levels) was measured with cervical transverse computed tomography scan images. The CSA difference in Area H and Area O between pre- and post-laminoplasty was similarly calculated. Results: The spinal canal areas of each segment after open-door laminoplasty were significantly enlarged (P < 0.05). Area O was also significantly enlarged compared to that of Area H (P < 0.05). Conclusion: Area O was more enlarged than Area H, and both sides were statistically enlarged after open-door laminoplasty.

Effect of the preoperative assessment of the anteroposterior diameters of the spinal canal and dural area on the efficacy of oblique lumbar interbody fusion in patients with lumbar spinal stenosis.

OBJECTIVE: The purpose of this study was to quantify the degree of lumbar spinal stenosis by assessing the anterior and posterior vertebral canal diameter and dural area, determine the sensitivity of the anterior and posterior spinal canal diameter, dural area and dural occupying rate in predicting the postoperative efficacy of oblique lumbar interbody fusion (OLIF) for patients with single-stage lumbar spinal stenosis, and identify the corresponding indicators suggesting that OLIF surgery should not be performed. METHODS: In a retrospective analysis of patients who had previously undergone OLIF surgery in our hospital, we included a total of 104 patients with lumbar spinal stenosis who had previously undergone single-stage surgery in our hospital. Three independent observers were employed to measure the anterior and posterior diameter of the spinal canal (AD, mm), dural area (CSA, mm2), the spinal canal area (SCA, mm2), and the ratio of the dural area to the spinal canal area (DM, %) at the disc level with the most severe stenosis on MRI. According to the values of AD and CSA in preoperative MRI, patients were divided into three groups: A, B, and C (Group A: AD > 12 and 100 < CSA ≤ 130, group B: Except A and C, group C: AD ≤ 10 and CSA ≤ 75). Preoperative and postoperative clinical outcome scores (Japanese Orthopaedic Association [JOA] score, VAS score, modified Macnab standard) of 104 patients were statistically. RESULTS: There were significant differences in the preoperative and postoperative clinical correlation scores among the mild, moderate and severe lumbar spinal stenosis groups. The improvement rate of the post treatment JOA score, the difference between the preoperative and postoperative VAS score, and the modified Macnab standard were compared pairwise. There was no statistical significance in the improvement rate of the post treatment JOA score, the difference between the preoperative and postoperative VAS score, and the modified Macnab standard between Group A and Group B (P = 0.125, P = 0.620, P = 0.803). There were statistically significant differences between Group A and Group C and between Group B and Group C in the improvement rate of the JOA score, the difference in the pre- and postoperative VAS score, and the modified Macnab standard. The anterior and posterior vertebral canal diameter and dural area are sensitive predictors of the postoperative efficacy of OLIF surgery for single-stage lumbar spinal stenosis. Moreover, when the anterior and posterior vertebral canal diameter was less than 6.545 mm and the dural area was less than 34.43 mm2, the postoperative effect of OLIF surgery was poor. CONCLUSIONS: All the patients with mild, moderate, and severe lumbar spinal stenosis achieved curative effects after OLIF surgery. Patients with mild and moderate lumbar spinal stenosis had better curative effects, and there was no significant difference between them, while patients with severe lumbar spinal stenosis had poor curative effects. Both the anteroposterior diameter of the spinal canal and the dural area of the spinal canal were sensitive in predicting the curative effect of OLIF surgery for single-stage lumbar spinal stenosis. When the anterior and posterior vertebral canal diameter was less than 6.545 mm and the dural area was less than 34.43 mm2, the postoperative effect of OLIF surgery was poor.

Lipoblastomatosis Extended into the Lumbar Spinal Canal in a Child: A Case Report.

INTRODUCTION: Lipoblastoma and lipoblastomatosis are rare benign mesenchymal adipose tumors that originate from embryonic white adipocytes and occur most commonly in infancy and early childhood. Lipoblastomas occur in the extremities and trunk, including the retroperitoneum and peritoneal cavity. Therefore, infiltration into the spinal canal has rarely been reported. CASE PRESENTATION: A 4-year-old girl presented to our clinic because of difficulty sitting on the floor with her legs straight. She also complained of enuresis and constipation for the past 6 months with persistent headaches and back pain evoked by body anteflexion. A magnetic resonance imaging revealed a massive lesion of the psoas major muscle, retroperitoneal, and subcutaneous spaces, extending into the spinal epidural space between L2 and S1. The patient underwent surgery which resulted in gross total removal of the tumor from the spinal canal. The mass was yellowish, soft, lobulated, fatty, and easily removed from the surrounding structures. Pathology confirmed the diagnosis of lipoblastoma. The postoperative course was uneventful, and the patient was discharged without any signs of neurological deficit. CONCLUSION: We herein discuss a rare case of lipoblastoma extending into the spinal canal, resulting in neurological symptoms. Although this tumor is benign with no potential for metastasis, it is prone to local recurrence. Therefore, close postoperative observation should be performed.

Balancing ability of patients with lumbar spinal canal stenosis.

PURPOSE: To determine the relationship between postural sway and the severity of lumbar spinal canal stenosis as well as the effect on postoperative improvement. METHODS: Stabilometry was performed before and 6 months after surgery in 52 patients (29 men and 23 women; mean age, 74.1 ± 7.8 years) who underwent decompression surgery for lumbar spinal canal stenosis. The environmental area (EA; the area surrounding the circumference of the stabilogram) and locus length per EA (L/EA) were evaluated. The patients were divided into moderate (n = 22) and severe (n = 30) groups according to the severity of canal stenosis. Patient characteristics and parameters were compared between the groups before and after surgery, including the visual analog scale (VAS) score for leg pain, Oswestry Disability Index (ODI), EA, and L/EA. In addition, factors affecting EA and L/EA were evaluated using multiple regression analysis. RESULTS: Age (p = 0.031), preoperative EA (p < 0.001), preoperative L/EA (p = 0.032), and sagittal vertical axis (p = 0.033) were significantly different between groups. The VAS score and ODI significantly improved postoperatively in both groups (p < 0.001). The EA significantly improved postoperatively only in the severe group (p < 0.001), whereas the L/EA did not significantly improve in either group. Multiple regression analysis showed that only the severity of canal stenosis was significantly associated with preoperative EA (p = 0.030), whereas age (p = 0.040) and severity of canal stenosis (p = 0.030) were significantly associated with preoperative L/EA. Diabetes was significantly associated with postoperative EA (p = 0.046) and L/EA (p = 0.030). CONCLUSION: The severity of canal stenosis affected abnormal postural sway, which improved after decompression surgery.

An unusual case of pediatric cervical myelopathy due to congenital spinal canal stenosis.

Cervical myelopathy is a condition that is rarely reported in pediatric patients who have movement or neuromuscular disorders. We, herein, present a rare case of cervical myelopathy observed in a 14-year-old patient, who was previously a healthy boy treated with cervical laminoplasty, which was caused by cervical spinal canal stenosis based on multiple level disc herniation. The patient presented to the clinic with spastic and ataxic gait with previous diagnostic challenges. Magnetic resonance imaging showed cervical degenerative changes mainly marked at the C3-C4 and C4-C5 levels, along with canal narrowing and a central high signal cord abnormality on T2-weighted images. A C3-C4 open-door laminoplasty surgery technique was performed. The neurological symptoms and signs improved dramatically following surgery. Subsequently, cervical computed tomography and magnetic resonance imaging showed good decompression of the cervical spinal cord during the 5 years of follow-up with the preservation of the range of movement. We concluded that though it is pretty rare, cervical myelopathy should be considered in diagnosing adolescent patients with gait and balance disorders.

10-year Longitudinal MRI Study of Intervertebral Disk Degeneration in Patients With Lumbar Spinal Canal Stenosis After Posterior Lumbar Decompression Surgery.

STUDY DESIGN: A prospective longitudinal magnetic resonance imaging (MRI) study. OBJECTIVE: The objective of this study was to describe the progression of intervertebral disk (IVD) degeneration in patients who underwent posterior decompression surgery for lumbar spinal canal stenosis (LSS). SUMMARY OF BACKGROUND DATA: IVD degeneration contributes to the pathogenesis of LSS; however, the long-term consequences of degenerative changes after decompression surgery remain unknown. MATERIALS AND METHODS: Of 258 consecutive patients who underwent posterior lumbar decompression surgery for LSS, 62 who underwent MRI at their 10-year follow-up were included; 17 age-matched asymptomatic volunteers were analyzed as controls. Three MRI findings representing IVD degeneration were graded on their severity: decrease in signal intensity, posterior disk protrusion (PDP), and disk space narrowing (DSN). Clinical outcome was assessed using the low back pain (LBP) score from the Japanese Orthopaedic Association scoring system. We examined the association between the progression of degenerative changes on MRI and LBP/associated factors using logistic regression adjusting for age at baseline and sex. RESULTS: The severity of IVD degeneration tended to be higher in patients with LSS than asymptomatic volunteers at both baseline and follow-up. IVD degeneration progressed in all patients during the 10-year follow-up period. Progression of decrease in signal intensity and PDP was observed at L1/2 in 73% and at L2/3 in 34%, respectively (the highest frequencies in the lumbar spine). Progression of DSN was highest at L4/5 in 42%. The rates of PDP and DSN progression during the 10-year follow-up period tended to be greater in patients with LSS than in asymptomatic volunteers. No significant difference in the proportion of LBP deterioration was evident for individuals with and without MRI findings of progression. CONCLUSIONS: Our study reveals a natural history of the long-term postoperative course of IVD degeneration after posterior decompression surgery for LSS. Compared with healthy controls, patients with LSS seemed to be predisposed to IVD degeneration. Lumbar decompression surgery may promote the progression of DSN; however, progression of IVD degeneration after lumbar decompression surgery was not associated with worsening LBP scores.