Spinal Canal Volume Research Articles

Efficacy of PE-PLIF with a novel ULBD approach for lumbar degeneration diseases: a large-channel endoscopic retrospective study

PurposeThis study aims to assess the effectiveness of Percutaneous Endoscopic Posterior Lumbar Interbody Fusion (PE-PLIF) combined with a novel Unilateral Laminotomy for Bilateral Decompression (ULBD) approach using a large-channel endoscope in treating Lumbar Degenerative Diseases (LDD).MethodsThis retrospective analysis evaluates 41 LDD patients treated with PE-PLIF and ULBD from January 2021 to June 2023. A novel ULBD approach, called ‘Non-touch Over-Top’ technique, was utilized in this study. We compared preoperative and postoperative metrics such as demographic data, Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) score, surgical details, and radiographic changes.ResultsThe average follow-up duration was 14.41 ± 2.86 months. Notable improvements were observed postoperatively in VAS scores for back and leg pain (from 5.56 ± 0.20 and 6.95 ± 0.24 to 0.20 ± 0.06 and 0.12 ± 0.05), ODI (from 58.68 ± 0.80% to 8.10 ± 0.49%), and JOA scores (from 9.37 ± 0.37 to 25.07 ± 0.38). Radiographic measurements showed significant improvements in lumbar and segmental lordosis angles, disc height, and spinal canal area. A high fusion rate (97.56% at 6 months, 100% at 12 months) and a low cage subsidence rate (2.44%) were noted.ConclusionsPE-PLIF combined with the novel ULBD technique via a large-channel endoscope offers significant short-term benefits for LDD management. The procedure effectively expands spinal canal volume, decompresses nerve structures, improves lumbar alignment, and stabilizes the spine. Notably, it improves patients' quality of life and minimizes complications, highlighting its potential as a promising LDD treatment option.

The effectiveness of hesperidin on bisphenol A-induced spinal cord toxicity in a diabetic rat model

The potential health risks of bisphenol A (BS) and diabetes (DI) has sparked public concern due to be ubiquitous worldwide. The purpose of this study was to investigate the detrimental impact of BS (200 mg/kg) on the spinal cord tissue in a rat diabetic model. We also evaluated the antioxidant capacity of hesperidin (HS) (100 mg/kg) on spinal cord in BS-treated diabetic rat. Seventy male Wistar albino rats, weighing 180–230 g and 8 weeks old, were randomly chosen, and assigned into seven groups of 10 rats: Control (KON), BS, DI, BS + DI, HS + BS, HS + DI, HS + BS + DI. At the end of the 14-day experimental period, all samples were examined using stereological, biochemical, and histopathological techniques. Our biochemical findings revealed that the SOD level was significantly lower in the BS, DI, and BS + DI groups compared to the KON group (p < 0.05). Compared to the KON group, there was a significant decrease in the number of motor neurons and an increase in the mean volume of central canals in the BS, DI, and BS + DI groups (p < 0.05). In the HS + BC group than the BS group and in the HS + DI group than the DI group, SOD activity and the number of motor neurons were significantly higher; also, the mean volume of spinal central canal was significantly lower (p < 0.05). The novel findings gathered from the histopathological assessment supported our quantitative results. Our speculation was that the exposure to BS and DI was the main cause of neurological alteration in the spinal cord tissues. The administration of HS had the therapeutic potential to mitigate spinal cord abnormalities resulting from BS and DI. However, HS supplementation did not alleviate spinal cord complications in BS-treated diabetic rats.

Posterior Longitudinal Ligament Calcification with Myelopathy - A Case Report

Background:: Ossification of the posterior longitudinal ligament (OPLL) constitutes a significant etiology of cervical myelopathy. The most common clinical presentations are myelopathy and radiculopathy, which result from a decrease in the spinal canal's volume and the spinal cord's subsequent compression by the ossified posterior longitudinal ligament. This results in motor and sensory deficits, especially in the extremities. Case Presentation:: A 48-year-old male presented with a complaint of neck pain that radiated to both upper limbs and was associated with numbness, tingling, and paranesthesia. He also had a history of lower back pain that radiated to the right leg, which was also associated with numbness and limited mobility to his cervical spine. Lhermitte's sign was positive. Sensory deficit to pinprick and touch was noted in the right upper limb and lower limbs. Flexion deformities of the right hand and elbow extension fingers were noted. Neuroimaging of the cervical spine showed cervical canal stenosis, OPLL, and myelopathy. Surgical management included internal fixation using plates and transpedicular screws, lateral mass fixation, and laminectomy of the third to sixth cervical vertebrae (C3-C6). Conclusion:: OPLL should be considered an integral component of the differential diagnosis when evaluating a patient with neck pain and consequent motor and sensory deficits of the extremities. OPLL with mild and/or non-progressive symptoms can be addressed with non-operative measures. Assessing preoperative neuroimaging is crucial before surgery to determine the degree of spinal cord compression and the presence of OPLL in all patients with cervical myelopathy. Surgical treatment options for posterior longitudinal ligament calcification include laminectomy and fusion, anterior decompression including transpedicular and costo-transversectomy, laminoplasty, and circumferential decompression via staged posterior and anterior approaches. Determining the most effective surgical approach for managing OPLL is still controversial, and selecting the appropriate procedure should be based on the patient's clinical presentation and level of pathological involvement.

Comparative analysis of changes in spinal dimensions following different correction methods in adult spinal deformity surgery.

Background: Adult spinal deformity (ASD) surgery has gained popularity, with significant improvements in patient-reported outcomes. Posterior lumbar interbody fusion with multiple grade II osteotomies (PLIF + MOs) and lateral lumbar interbody fusion (LLIF) have been utilized to correct ASD; however, no studies have compared these methods with regard to the pre- and postoperative changes in length and volume of the spinal canal. This study aimed to investigate the 3-dimensional changes in the anterior vertical column length (AVCL), spinal canal length (SCL), and spinal canal volume (SCV) in patients with ASD after surgery, employing LLIF and PLIF + MOs. Methods: This retrospective study examined 44 patients with ASD who underwent surgery between 2010 and 2021 using two corrective surgical methods, LLIF and PLIF + MOs. Radiographic parameters and clinical outcomes were assessed, and three-dimensional models were created from computed tomography images to analyze changes in AVCL, SCL, and SCV. Results: We compared the effects of LLIF and PLIF + MOs on spinal canal dimensions during ASD surgery. LLIF demonstrated an increase in lumbar segment (L1-S1) AVCL and whole spine (T1-S1) SCL by 6.5 ± 8.0mm and 13.8 ± 7.6mm, respectively, compared with PLIF + MOs. However, PLIF + MOs exhibited a reduction in the lengths of the lumbar segment AVCL. Postoperative differences were significant for AVCL (L1-S1), SCL fusion level, and first-standing lumbar lordosis between the groups (p < 0.0001, 0.002, and 0.016, respectively). LLIF significantly increased the SCV at the fusion level and whole spine T1-S1 by 14.5% and 10.6%, respectively, outperforming PLIF + MOs. Despite changes in dimensions, the postoperative Oswestry disability index scores showed no significant difference between the two groups. Conclusions: Our study suggests that LLIF can increase spinal canal space, lumbar lordosis, and anterior column length in the lumbar spinal segment. Knowledge of these variations may be critical for enhancing surgical outcomes and preventing neurological complications.

Dosimetric Study of Total Marrow and Lymphoid Irradiation on a Ring Gantry-Based Medical Linac with a Two-Layer Multi-Leaf Collimator

In this study, we aimed to evaluate dosimetric quality of total marrow and lymphoid irradiation (TMLI) plans for a ring gantry-based medical Linac with a two-layer multi-leaf collimator. We retrospectively retrieved treatment planning CT images, structure sets, and plan dose for four adult patients, two male and two female, who previously received TMLI treatments on helical tomotherapy (HT) at our institution. TMLI plans were optimized for a ring gantry-based medical Linac with a two-layer multi-leaf collimator (Halcyon, Varian Medical Systems, Inc., Palo Alto, CA). A prescription dose of 12 Gy in 8 fractions was prescribed to the skeletal bones from the skull to mid-thigh, spleen, spinal canal, and lymphoid volume. Five or six isocenters were placed with equal spacing along the patient's longitudinal direction in each TMLI plan with two 6-MV flattening filter-free volumetric modulated arc therapy (VMAT) fields at each isocenter. Isocenter separation ranged from 15 cm to 16.5 cm. Each VMAT field has a field size of 28 cm to 28 cm with the collimator at 90° and a full gantry rotation. The nominal dose rate was 800 MU/minute, and the maximum gantry rotation speed was 24°/sec. Institutional dosimetric constraints were used for optimization including a mean lung dose limit of less than 8 Gy. All the plans were normalized so that 85% the primary planning target volume received the prescription dose. The average mean doses to the target volumes ranged from 12.2 to 12.6 Gy in the Halcyon TMLI plans, while they ranged from 12.1 to 12.5 Gy in the HT TMLI plans. Relative to the prescription dose, the average mean dose for normal organs ranged from 21.3% to 56.6% in the Halcyon TMLI plans, while it ranged from 10.1% to 68.4% in the clinical HT plans. The difference in the average mean dose to normal organs was less than 0.5 Gy except two organs between the Halcyon and HT TMLI plans. The average median dose for normal organs ranged from 18.2% to 48.8% relative to the prescription dose in the Halcyon TMLI plans. The mean lung dose (MLD) in the Halcyon TMLI plans met the institutional limit with an average dose of 6.75±0.42 Gy (range: 6.44 - 7.36 Gy), while the average MLD was 6.54±0.77 Gy (range: 6.24 - 7.22 Gy) in the HT plans (p-value = 0.71 in the paired t-test). The average total monitor unit in the Halcyon TMLI plans was 4,425±906 MU (range: 3,470 - 5,575 MU) with an average beam-on time of 5.1±1.3 minutes (range: 4.1 - 7.0 minutes), which excludes isocenter setup time, while the average beam-on time was 22.2±3.2 minutes (range: 19.6 - 26.1 minutes) with the HT plans. Halcyon TMLI plans met our institutional dosimetric constraints with adequate normal organ sparing and target dose coverage. The beam-on time with the Halcyon plans was significantly shorter than that with the HT plans, which could lead to shorter treatment time and increased patient comfort. This study showed the feasibility of TMLI treatments on the Halcyon machine. The same method could be used for total body irradiation on Halcyon.

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

PurposeThe 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.MethodsIn 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.ResultsThe 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).ConclusionsOLIF 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.

Treatment of Single Level Lumbar Spondylolisthesis with Lumbar Interbody Fusion via Oblique Lateral Approach (OLIF)

Objectives: To investigate the effect of lumbar interbody fusion via the oblique lateral approach (OLIF) in the treatment of single level lumbar spondylolisthesis. Methods: Retrospective analysis was made on 32 cases of single level lumbar spondylolisthesis treated by lumbar interbody fusion via the oblique lateral approach from July 2020 to July 2021. 14 males and 18 females; the age was (66.5 ± 11.5) years (55 - 82 years). 1) The operation time, intraoperative blood loss and complications were recorded; 2) the scores of visual analog scale. VAS and Oswestry disability index (ODI) of low back pain and lower limb pain were collected before operation and at the last follow-up; by observing the imaging data, the height of the intervertebral space, the anterior convex angle of the intervertebral space, the anterior convex angle of the lumbar spine, the sagittal diameter of the dural sac and the spondylolisthesis were measured. Results: All patients successfully completed the operation, the average operation time was (103.9 ± 21.1) min, the average intraoperative bleeding volume was (72.3 ± 16.4) ml. There was no vascular injury during the operation, no infection occurred in all surgical incisions, and Class I/A healing was achieved. The VAS scores of low back pain and leg pain before operation and at the last follow-up were lower than those before operation, and the difference was statistically significant (P the height of intervertebral foramen and the sagittal diameter of dural sac were greater than those before operation, with statistically significant differences (P than that before operation, with a statistically significant difference (P ureteral injury, retrograde ejaculation, intestinal and lumbar plexus injury. Conclusion: The early clinical effect of OLIF in the treatment of single level lumbar spondylolisthesis is significant. This surgical method is minimally invasive, safe and effective, which can significantly reduce the amount of intraoperative bleeding and reduce the risk of postoperative complications. Its main working principle is to make the annulus fibrosus, posterior longitudinal ligament and ligamentum flavum shrink and recover the height of the intervertebral space through decompression, loosening and stretching of the intervertebral space, so as to achieve the reduction of the slipped vertebral body, increase the height of the intervertebral foramen Enlarge the spinal canal volume and eliminate dynamic compression to play an indirect decompression role, improve the symptoms of low back and leg pain, and reconstruct the stability of the spine through interbody fusion.

Thoracic Spinal Stenosis: Surgical Approaches and Outcomes

Objective: Thoracic spinal stenosis (TSS) develops as a result of decreased spinal canal volume in the thoracic spine. The prevalence of TSS is low as when compared with cervical or lumbar spinal stenosis, and conservative treatment is not effective. The present study aimed to present all surgical methods employed and their outcomes in patients diagnosed with TSS in our clinic.Methods: In this study, the data of 14 patients including three patients with single-level, nine patients with two-level, one patient with three-level, and one patient with multilevel TSS and hypophosphatemic rickets who underwent surgery due to TSS, were retrospectively evaluated using the discharge summary, surgical reports, and preoperative and postoperative radiological images.Results: The age of the patients ranged from 53 to 68 years. Of the patients included in the study, one underwent hemilaminectomy, two underwent total laminectomy, six underwent laminoplasty, and five underwent total laminectomy with fusion and posterior instrumentation. A dramatic improvement was observed in the neurological deficits existing in the preoperative period in patients who were diagnosed in the early period and underwent surgery with adequate decompression before the development of severe neurological deficits and who continued postoperative rehabilitation added to the treatment.Conclusion: Patients with TSS have an insidious clinical course manifested by upper motor neuron symptoms. Although the prevalence of TSS is low, early diagnosis and treatment are important. The results of surgery are satisfactory when adequate decompression is achieved before the clinical condition worsens.

Clinical efficacy and therapeutic value of delayed surgery in patients with symptomatic old thoracolumbar fractures

BackgroundTo investigate the clinical efficacy and therapeutic value of posterior decompression reduction, bone grafting fusion, and internal fixation for treatment of symptomatic old thoracolumbar fractures.MethodRetrospective analysis was conducted for 14 patients (9 men, 5 women; average age 40.1 years) with old thoracolumbar fractures who underwent posterior operation. American Spinal Injury Association (ASIA) scores were used to evaluate neurologic function. Vertebral body height, Cobb angle in the sagittal plane, spinal canal volume ratio (%) and bone graft fusion were analyzed by radiography and computed tomography on different follow-up times.ResultsMean follow-up was 27.1 months (23–36 months). Of three patients with ASIA grade A, 2 had improved postoperative urination and defecation, although no classification change. Preoperative ASIA score for eight patients with incomplete injury was grade B; four patients recovered to grade C at final follow-up. Preoperative ASIA score was C in three patients, increased to D in two patients and returned to normal E in one patient. Preoperative results showed average injured vertebra height loss rate decreased from 50.4 to 8.9%; average Cobb angle on the sagittal plane recovered from 39.6 to 6.9°; and the average spinal canal volume ratio recovered from 33.8 to 5.9%. Bony fusion was achieved; local lumbago and leg pain were relieved to some extent. No patients exhibited loosening of the fracture treated by internal fixation, pseudoarthrosis, or other related serious complications.ConclusionTreatment of old thoracolumbar fractures by posterior decompression reduction, bone grafting fusion, and internal fixation can relieve spinal cord compression, improve neurologic function of some patients (ASIA grades B–C), effectively relieve pain, correct deformity, restore biomechanical stability, and significantly improve quality of life.

Bilateral osteoplastic decompression laminoplasty with simultaneous foraminotomy to treat multilevel cervical stenosis

Objective. To analyze surgical technique and possibilities of using bilateral laminoplasty technique with simultaneous foraminotomy for extended stenosis of the cervical spine.Material and Methods. The analysis included results of surgical treatment of 26 patients (18 males and 8 females, mean age 60.2 ± 1.3 years) operated on by the method of bilateral laminoplasty with simultaneous foraminotomy from January 2016 to April 2020. Pre- and postoperative clinical condition of patients was assessed, including using VAS, JOA and Nurick scales. An objective assessment of stenosis degree (linear dimensions, areas, volume of the stenotic spinal canal) was performed using standard measuring tools of the RadiAnt DICOM Viewer software. To assess the statistical significance of the obtained results, nonparametric Wilcoxon-T and Mann – Whitney-U tests were used. Differences were considered significant at p &lt; 0.05.Results. Upon admission to the hospital, all patients had specific neurological symptoms with varying degree of pain, myelopathic and radicular symptoms. According to neurovisualisation, the average number of involved in the process levels (stenotic) was 3.2 ± 0.1, (the average length of stenosis was 5.1 ± 0.2 cm). In the postoperative period, all patients showed positive dynamics in the form of a decrease in the severity of neurological disorders and pain (from 7.2 ± 0.1 to 5.07 ± 0.1 according to VAS, p &lt; 0.001). The manifestations of myelopathy decreased according to Nurick scale from 2.08 ± 0.71 to 1.84 ± 0.10 points (p &lt; 0.05). According to MRI data, the average area of the dural sac objectively increased from 1.25 ± 0.30 cm2 to 2.26 ± 0.27 cm2 (p &lt; 0.001), and the volume of spinal canal in the area of stenosis increased from 7.2 ± 0.2 cm3 to 13.4 ± 0.1 cm3 (p &lt; 0.001). Patients were mobilized on the 2nd day after surgery. The duration of inpatient treatment ranged from 4 to 17 days (on average, 7.1 ± 0.4 days). Intraoperative complications were not observed in the presented series. Mild postoperative complications were detected only in two out of 26 operated patients.Conclusion. Bilateral laminoplasty with simultaneous foraminotomy using titanium miniplates and osteoinductive material has a number of advantages and can be the surgery of choice in the treatment of patients with extended cervical stenosis complicated by myelopathy and radicular pain syndrome.

A novel three-dimensional volumetric method to measure indirect decompression after percutaneous cement discoplasty.

PurposePercutaneous cement discoplasty (PCD) is a minimally invasive surgical option to treat patients who suffer from the consequences of advanced disc degeneration. As the current two-dimensional methods can inappropriately measure the difference in the complex 3D anatomy of the spinal segment, our aim was to develop and apply a volumetric method to measure the geometrical change in the surgically treated segments.MethodsProspective clinical and radiological data of 10 patients who underwent single- or multilevel PCD was collected. Pre- and postoperative CT scan-based 3D reconstructions were performed. The injected PMMA (Polymethylmethacrylate) induced lifting of the cranial vertebra and the following volumetric change was measured by subtraction of the geometry of the spinal canal from a pre- and postoperatively predefined cylinder. The associations of the PMMA geometry and the volumetric change of the spinal canal with clinical outcome were determined.ResultsChange in the spinal canal volume (ΔV) due to the surgery proved to be significant (mean ΔV = 2266.5 ± 1172.2 mm3, n = 16; p = 0.0004). A significant, positive correlation was found between ΔV, the volume and the surface of the injected PMMA. A strong, significant association between pain intensity (low back and leg pain) and the magnitude of the volumetric increase of the spinal canal was shown (ρ = 0.772, p = 0.009 for LBP and ρ = 0.693, p = 0.026 for LP).ConclusionThe developed method is accurate, reproducible and applicable for the analysis of any other spinal surgical method. The volume and surface area of the injected PMMA have a predictive power on the extent of the indirect spinal canal decompression. The larger the ΔV the higher clinical benefit was achieved with the PCD procedure.The translational potential of this articleThe developed method has the potential to be integrated into clinical software’s to evaluate the efficacy of different surgical procedures based on indirect decompression effect such as PCD, anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), oblique lumbar interbody fusion (OLIF), extreme lateral interbody fusion (XLIF). The intraoperative use of the method will allow the surgeon to respond if the decompression does not reach the desired level.

Volumetric analysis of bilateral spinal canal decompression via hemilaminectomy versus laminoplasty in cervical spondylotic myelopathy

BackgroundCervical spondylotic myelopathy (CSM) is a degenerative process of the cervical spine requiring surgical decompression to prevent neurological deterioration. While both anterior and posterior approaches yield satisfactory results, posterior decompression is preferred in cases of the multilevel disease. In 2015, we described a muscle-sparing, novel technique of bilateral osteoligamentous decompression via hemilaminectomy (OLD) for CSM. In this study, we investigate whether this technique offers comparable volumetric results to laminoplasty in terms of spinal canal enlargement and whether this technique can yield significant clinical improvement.MethodsPatients undergoing OLD due to CSM were prospectively enrolled in this study and then matched to and compared with a historic cohort of patients with CSM treated by laminoplasty. An independent sample t test was performed to analyze whether the volumetric gain in the two separate groups was statistically significant. Patients in the OLD cohort were clinically evaluated with the mJOA score preoperatively and 3 months postoperatively. To assess clinical improvement, a paired sample t test was performed.ResultsA total of 38 patients were included in the analysis: 19 underwent OLD and 19 underwent laminoplasty. Both groups were well matched in terms of sex, age, preoperative spinal canal volume, and involved levels. Both surgical methods yielded statistically significant volumetric gain in the cervical spinal canal, but a trend towards a greater volume gain was seen in the OLD group. In the OLD group, a statistically significant clinical improvement was also demonstrated.ConclusionsOur study reveals that OLD can yield a comparable extent of decompression to laminoplasty in CSM while also delivering statistically significant clinical improvement.

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.

Double-door laminoplasty combined with C2 dome decompression for the treatment of cervical spinal stenosis

To investigate the clinical effect of double-door laminoplasty combined with C2 dome decompression in treatment of cervical spinal stenosis. The clinical data of 28 patients with cervical spinal stenosis who underwent double-door laminoplasty combined with C2 dome decompression from June 2016 to June 2018 were retrospectively analyzed, including 17 males and 11 females, aged 39 to 74 years with an average of (61.0±6.7) years. The clinical effects were evaluated by JOA score, axial symptoms, cervical spine activity, cervical spinal cord compression degree and so on. All patients were followed up for 6 to12 months with an average of 10.2 months. The JOA score in the final follow-up was significantly improved (P<0.05). The range of cervical activity before and after surgery was respectively (41.8±15.3) °, (36.3±18.2) °, and there was no significant difference (P>0.05). After operation, sagittal diameter at the narrowest level of C2-C3 spinal canal was (16.20±1.82) mm, which was significantly higher than (8.38±1.16) mm before operation (P<0.05). There were 4 cases with axial symptoms in 24 patients with the incidence rate of 14.29% (4/24). Double-door laminoplasty combined with C2 dome decompression can directly expand the volume of C2-C3 spinal canal, relieve the compression of spinal cord and nerve root, reduce the damage to the posterior cervical ligament complex as much as possible, maintain the stability of cervical spine sequence, reduce the occurrence of axial symptoms, and the operation is relatively simple, without the need of metal internal fixation.

Double-door laminoplasty combined with C2 dome decompression for the treatment of cervical spinal stenosis

To investigate the clinical effect of double-door laminoplasty combined with C2 dome decompression in treatment of cervical spinal stenosis. The clinical data of 28 patients with cervical spinal stenosis who underwent double-door laminoplasty combined with C2 dome decompression from June 2016 to June 2018 were retrospectively analyzed, including 17 males and 11 females, aged 39 to 74 years with an average of (61.0±6.7) years. The clinical effects were evaluated by JOA score, axial symptoms, cervical spine activity, cervical spinal cord compression degree and so on. All patients were followed up for 6 to12 months with an average of 10.2 months. The JOA score in the final follow-up was significantly improved (P<0.05). The range of cervical activity before and after surgery was respectively (41.8±15.3) °, (36.3±18.2) °, and there was no significant difference (P>0.05). After operation, sagittal diameter at the narrowest level of C2-C3 spinal canal was (16.20±1.82) mm, which was significantly higher than (8.38±1.16) mm before operation (P<0.05). There were 4 cases with axial symptoms in 24 patients with the incidence rate of 14.29% (4/24). Double-door laminoplasty combined with C2 dome decompression can directly expand the volume of C2-C3 spinal canal, relieve the compression of spinal cord and nerve root, reduce the damage to the posterior cervical ligament complex as much as possible, maintain the stability of cervical spine sequence, reduce the occurrence of axial symptoms, and the operation is relatively simple, without the need of metal internal fixation.

A Study of Critical Events That Lead to Spinal Cord Injury and the Importance of Rapid Reversal of Surgical Steps in Improving Neurological Outcomes: A Porcine Model.

Porcine model. To quantify critical vascular and mechanical events that occur before and during an evolving spinal cord injury. Spinal cord injuries are one of the most devastating complications in spine surgery. Intraoperative neuromonitoring changes can occur as a secondary event of spinal cord compression and decrease in spinal cord blood flow (SCBF). Laser Doppler flowmetry has been well validated for measuring blood flow. Seventeen pigs were studied, 14 of which completed the experiment. Multilevel, midthoracic laminectomies were performed. Laser Doppler flowmetry electrodes were placed on the dura to measure SCBF. Spinal cord injury was induced by incremental balloon inflation in the epidural space. The animals were separated into two groups. After motor-evoked potential (MEP) loss, group A underwent medical interventions and then balloon decompression approximately 20 minutes later. Group B underwent immediate balloon decompression followed by medical interventions. After interventions, wake-up test was performed and computed tomography scan measured thoracic spinal canal volume. Median SCBF changes were seen 15.8 (5.4-25.1) minutes before MEP loss. However, the 20% threshold interval was often reached before. At the 20% threshold, median pressure was 7 psi, balloon volume was 0.5 cm, and 50% of the spinal canal was compromised. In group A, no pigs moved and all had pathology indicating ischemia. In group B, 9 of 10 were found to be moving their hind legs with 7 indicating ischemia. Compression spinal cord injury is the end of a cascade involving increasing intracanal pressure, decreasing canal volume, and hypoperfusion. Rapid relief of compression leads to MEP return. SCBF monitoring can detect ischemia preinjury, giving surgeons an opportunity for early intervention. 4.

Surgical consideration for thoracolumbar burst fractures with spinal canal compromise without neurological deficit

SummaryBackgroundFor thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, is it necessary to perform additional laminectomy decompression after the currently accepted posterior pedicle-screw internal fixation?MethodsPatients were divided into two groups: decompression group (Group A) and nondecompression group (Group B). A retrospective analysis of the posterior vertebral body height of the fractured vertebral body, the ratio of the volume of the spinal canal, and the change of the Cobb angle, relative to the corresponding preoperative values, was conducted to analyse the reasons for choosing different surgical methods.ResultsCompared the intraoperative findings after fixation with the preoperative data, in Group A, the posterior vertebral body height of the fractured vertebral body was not significantly restored, the volume ratio of the spinal canal was not significantly improved, and the Cobb angle was not significantly reduced (p ​> ​0.05). In comparison, in Group B, the posterior vertebral body height of the fractured vertebral body was significantly restored, the volume ratio of spinal canal was significantly increased, and the Cobb angle was significantly reduced (p ​< ​0.001).ConclusionFor patients with thoracolumbar burst fractures with spinal canal compromise but no neurological deficit, if when the posterior intraoperative fixation is performed, the spinal canal fracture is partially recovered, the posterior vertebral body height of the injured vertebrae is significantly restored, the spinal canal volume ratio is significantly increased, and the large kyphosis is corrected, then the indirect decompression without the posterior laminectomy can be performed.The translational potential of this articleThis study contributes to offer treatment ​consideration for ​patients with thoracolumbar burst fracture without neurological symptoms.

140. Rapid reversal of surgical steps minimizes spinal cord injury in a porcine model

BACKGROUND CONTEXT Spinal cord injuries (SCI) are one of the most devastating in spine surgery. Intraop neuromonitoring changes can occur as a secondary characteristic of spinal cord compression and decrease in spinal cord blood flow (SCBF). Laser Doppler flowmetry has been well validated for measuring SCBF. PURPOSE To determine if critical, measurable changes occur before spinal cord injury occurs. STUDY DESIGN/SETTING Porcine model. PATIENT SAMPLE Seventeen pigs. OUTCOME MEASURES Spinal cord blood flow, MEP, MAP, neurological injury, spinal canal volume. METHODS After prone positioning and induction, multilevel laminectomies are performed in the midthoracic region. LDF electrodes were placed on the exposed dura in multiple areas to measure real-time SCBF. Spinal cord injury was induced by incremental balloon inflation in the epidural space. After MEP loss (SCI), interventions were carried out: raising the systolic BP, expanding the intravascular volume with colloids, and IV lidocaine. After interventions, wake up test is performed and CT scan was done to measure the thoracic spinal canal volume. Two groups based on intervention timing. Group A: medical interventions before balloon deflation; Group B: balloon deflated first. RESULTS Seventeenpigs were studied, 14 of which survived and completed the experiment. Recordable SCBF changes from baseline were seen 3–32 minutes before MEP loss. For this reason, we considered three minutes to be the critical time before SCI. However, the 20% threshold interval was often reached before the 3-minute mark. Three minutes before MEP loss, change in SCBF was −24.9% and balloon pressure was 9 psi. Balloon volume was 0.63 cc. The spinal canal compromise 3 minutes before MEP signals loss was 69.3%, while SCBF three minutes before MEP loss was 71. This was a 24.85% change from baseline SCBF. In Group A, no pigs moved. In Group B, 9/10 were found to be moving their hind legs. CONCLUSIONS Compression SCI is the end of a cascade involving increasing pressure, decreasing volume and hypoperfusion. Rapid relief of compression leads to MEP return and function. SCBF monitoring can detect ischemia preinjury, giving surgeons an opportunity for early intervention. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Treatment of benign tumors in thoracic spinal canal by modified replanting posterior ligament complex applying piezoelectric osteotomy

To investigate the feasibility and effectiveness of modified replanting posterior ligament complex (PLC) applying piezoelectric osteotomy in the treatment of primary benign tumors in thoracic spinal canal. The clinical data of 38 patients with primary benign tumors in thoracic spinal canal between March 2014 and March 2016 were retrospectively analyzed. There were 16 males and 22 females, aged from 21 to 72 years (mean, 47.1 years). The disease duration ranged from 6 to 57 months (mean, 32.6 months). Pathological examination showed 24 cases of schwannoma, 6 cases of meningioma, 4 cases of ependymoma, 2 cases of lipoma, and 2 cases of dermoid cyst. The lesions located in 18 cases of single segment, 15 cases of double segments, and 5 cases of three segments. The length of the tumors ranged from 0.7 to 6.5 cm. There were boundaries between the tumors and the spinal cord, cauda equina, and nerve roots. The preoperative Japanese Orthopaedic Association (JOA) score was 12.2±2.3 and the thoracic Cobb angle was (11.7±2.7)°. Modified PLC replantation and microsurgical resection were performed with piezoelectric osteotomy. Continuity of uniside supraspinal and interspinous ligaments were preserved during the operation. The PLC was exposed laterally. After removing the tumors under the microscope, the pedicled PLC was replanted in situ and fixed with bilateral micro-reconstruction titanium plate. X-ray film, CT, and MRI examinations were performed to observe spinal stability, spinal canal plasty, and tumor resection after operation. The effectiveness was evaluated by JOA score. The operation time was 56-142 minutes (mean, 77.1 minutes). The intraoperative blood loss was 110-370 mL (mean, 217.2 mL). The tumors were removed completely and the incisions healed well. Three cases complicated with cerebrospinal fluid leakage, and there was no complications such as spinal cord injury and infection. All the 38 patients were followed up 24-28 months (mean, 27.2 months). There was no internal fixation loosening, malposition, or other related complications. At last follow-up, X-ray films showed no sign of kyphosis and instability. CT showed no displacement of vertebral lamina and reduction of secondary spinal canal volume, and vertebral lamina healed well. MRI showed no recurrence of tumors. At last follow-up, the thoracic Cobb angle was (12.3±4.1)°, showing no significant difference when compared with preoperative value ( t=0.753, P=0.456). JOA score increased to 23.7±3.8, showing significant difference when compared with preoperative value ( t=15.960, P=0.000). Among them, 14 cases were excellent, 18 were good, 6 were fair, and the excellent and good rate was 84.2%. Modified replanting PLC applying piezoelectric osteotomy and micro-reconstruction with titanium plate for the primary benign tumors in thoracic spinal canal can reconstruct the anatomy of the spinal canal, enable patients to recover daily activities quickly. It is an effective and safe treatment.

Clinical and Radiological Outcomes of Anterior Approach Microscopic Surgery for the Pincer Mechanism in Cervical Spondylotic Myelopathy.

Objective We aimed to evaluate the efficacy of anterior approach microscopic surgery for patients with the pincer mechanism in cervical spondylotic myelopathy. Methods The clinical data of pincer cervical spondylotic myelopathy that received anterior cervical decompression and fusion in our hospital from Aug 2014 to Dec 2017 were analyzed retrospectively, including 12 males and 9 females, with an average age of 64.3 years (range 46-81 years). Occupying rate, anterior occupying rate, and posterior occupying rate were measured on pre- and postoperative mid-sagittal MRIs. Pre- and postoperative Japanese Orthopedic Association (JOA) scores, intervertebral space height, and C2 to C7 Cobb's angle were analyzed. Result Duration of follow-up was six months. The pre- and postoperative anterior occupying rate were averagely 38.6±8.5% and 12.9±5.5%, respectively, the posterior occupying rates were averagely 27.4±7.2% and 13.1±6.6%, respectively, and Cobb's angle changed from 15.3±8.0° to 22.7±7.9°. The intervertebral space height increased from 4.6±0.4mm to 6.5±0.4mm. JOA scores improved significantly by 59.4±34.0% at six months after surgery. Conclusion Decompression by anterior microscopic surgery can increase spinal canal volume directly, recover intervertebral space height, and resize Cobb's angle, but decrease the posterior compression by ligament Flava indirectly. Anterior decompression under the microscope may provide an alternative surgical option for partial patients with the pincer mechanism in cervical spondylotic myelopathy.