Spinal Canal Occupation Research Articles

Posterior Thoracic Antidisplacement and Fusion Surgery for a Special Type of Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine: Indications and Preliminary Clinical Results of 2-Year Follow-Up

To describe a novel technique, posterior thoracic antidisplacement and fusion (PTAF), for a special type of ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL), and to evaluate its safety and efficacy. From July to December 2020, 5 consecutive patients with beak-type T-OPLL located at the thoracic vertebral body level underwent PTAF surgery. Their demographic data, radiological parameters, perioperative complications, and surgery-related findings were recorded and analyzed. The surgical outcomes were assessed using a modified Japanese Orthopedic Association scale, and the recovery rate was calculated using the Hirabayashi's method. All patients were followed up for at least two years. The mean thickness of OPLL was 9.4±1.0mm, and the OPLL spinal canal occupying ratio was 67.7%±8.5%. Postoperatively, the mean antidisplacement distance of OPLL was 8.1±1.8mm, and the average shortened distance of the spinal column was 6.0±1.13mm. The mean operation time and blood loss were 158.2±26.3minutes and 460±89.4mL, respectively. Perioperative complications were cerebrospinal fluid leakage and instrument failure, 2 cases each. The mean modified Japanese Orthopedic Association score was increased from 3.6±2.9 before surgery to 9.4±3.0 at the last follow-up, and the average recovery rate was 84.2±30.5%. The preliminary clinical outcomes indicate that PTAF is a safe and effective method for the treatment of beak-type T-OPLL, which has its apex located at the vertebral body level and has a high spinal canal occupation ratio.

Timing of Resection of Spinal Meningiomas and Its Influence on Quality of Life and Treatment.

The main treatment modality for spinal meningiomas (SM) is gross total resection (GTR). However, the optimal timing of surgery, especially in cases with absent or mild neurological symptoms, remains unclear. The aim of this study is to assess the impact of early-stage resection on neurological outcome, quality of life (QoL), and quality of care. The primary objective is a favorable neurological outcome (McCormick scale 1). We retrospectively analyzed data from patients who underwent operations for SM between 2011 and 2021. Patients with mild neurological symptoms preoperatively (McCormick scale 1 and 2) were compared to those with more severe neurological symptoms (McCormick scale 3-5). Disabilities and QoL were assessed according to validated questionnaires (SF-36, ODI, NDI). Age, spinal cord edema, thoracic localization, and spinal canal occupancy ratio were associated with more severe neurological symptoms (all p < 0.05). Patients presenting with mild symptoms were associated with favorable neurological outcomes (OR: 14.778 (95%CI 3.918-55.746, p < 0.001)), which is associated with shorter hospitalization, better QoL, and fewer disabilities (p < 0.05). Quality of care was comparable in both cohorts. Early surgical intervention for SM, before the development of severe neurological deficits, should be considered as it is associated with a favorable neurological outcome and quality of life.

Potential thresholds of critically increased cardiac-related spinal cord motion in degenerative cervical myelopathy.

New diagnostic techniques are a substantial research focus in degenerative cervical myelopathy (DCM). This cross-sectional study determined the significance of cardiac-related spinal cord motion and the extent of spinal stenosis as indicators of mechanical strain on the cord. Eighty-four DCM patients underwent MRI/clinical assessments and were classified as MRI+ [T2-weighted (T2w) hyperintense lesion in MRI] or MRI- (no T2w-hyperintense lesion). Cord motion (displacement assessed by phase-contrast MRI) and spinal stenosis [adapted spinal canal occupation ratio (aSCOR)] were related to neurological (sensory/motor) and neurophysiological readouts [contact heat evoked potentials (CHEPs)] by receiver operating characteristic (ROC) analysis. MRI+ patients (N = 31; 36.9%) were more impaired compared to MRI- patients (N = 53; 63.1%) based on the modified Japanese Orthopedic Association (mJOA) subscores for upper {MRI+ [median (Interquartile range)]: 4 (4-5); MRI-: 5 (5-5); p < 0.01} and lower extremity [MRI+: 6 (6-7); MRI-: 7 (6-7); p = 0.03] motor dysfunction and the monofilament score [MRI+: 21 (18-23); MRI-: 24 (22-24); p < 0.01]. Both patient groups showed similar extent of cord motion and stenosis. Only in the MRI- group displacement identified patients with pathologic assessments [trunk/lower extremity pin prick score (T/LEPP): AUC = 0.67, p = 0.03; CHEPs: AUC = 0.73, p = 0.01]. Cord motion thresholds: T/LEPP: 1.67 mm (sensitivity 84.6%, specificity 52.5%); CHEPs: 1.96 mm (sensitivity 83.3%, specificity 65.6%). The aSCOR failed to show any relation to the clinical assessments. These findings affirm cord motion measurements as a promising additional biomarker to improve the clinical workup and to enable timely surgical treatment particularly in MRI- DCM patients. www.clinicaltrials.gov, NCT02170155.

A rare case of intervertebral disc calcification combined with ossification of the posterior longitudinal ligament in a child: a case report and literature review

BackgroundIntervertebral disc calcification (IDC) combined with calcification in children has been sporadically reported, while ossification of the posterior longitudinal ligament (OPLL) in the cervical spine in pediatric patients is exceedingly rare. The aim of this study is to investigate the potential prognosis and outcomes associated with this condition.Case presentationWe present an unusual case involving a 10-year-old Chinese child diagnosed with calcified cervical disc herniation and ossification of the posterior longitudinal ligament. Conservative treatment measures were implemented, and at the 1-month and 6-month follow-up, the patient's pain exhibited significant improvement. Subsequent cervical MRI and CT scans revealed the complete disappearance of OPLL and substantial absorption of the calcified disc. During the three-month follow-up, CT demonstrated slight residual disc calcification, however, the patient remained asymptomatic with no discernible limitation in cervical motion.ConclusionsWe conducted a comprehensive review of several cases presenting with the same diagnosis. It is noteworthy that IDC combined with OPLL in children constitutes a rare clinical entity. Despite imaging indications of potential spinal canal occupation, the majority of such cases demonstrate complete absorption following conservative treatment, with OPLL exhibiting a faster absorption rate than calcified discs.

Analysis of risk factors for axial symptoms after posterior cervical open-door laminoplasty

BackgroundLaminoplasty (LP), a procedure commonly used to treat cervical spondylotic myelopathy (CSM), often results in the development of axial symptoms (AS) postoperatively. This study aims to analyze the risk factors associated with the occurrence of AS after LP.MethodsWe collected and evaluated clinical data from 264 patients with CSM who underwent LP treatment at our institution from January 2018 to January 2022 through a single-center retrospective study. Of the patients, 153 were male and 111 were female, with an average age of 58.1 ± 6.7 years. All patients underwent C3-7 posterior laminoplasty. Based on the occurrence of postoperative axial symptoms, the patients were divided into an AS group and a non-AS group. General information, including age, gender, disease duration, Japanese Orthopaedic Association (JOA) score, postoperation early function training, and collar-wearing time, was recorded and compared between the two groups. Surgical-related data, such as operative segments, surgical time, intraoperative blood loss, intraoperative facet joint destruction, and destruction of the C7 spinous process muscle insertion, were also compared. Imaging data, including preoperative cervical curvature, cervical range of motion, preoperative encroachment rate of the anterior spinal canal, and angle of laminar opening, were collected. Univariate and multivariate logistic regression analyses were used to identify risk factors for the development of AS after LP, and receiver operator characteristic (ROC) curves were utilized to explore the optimal preoperative parameters.ResultsAll 264 patients successfully underwent surgery and were followed up for an average of 19.5 ± 6.8 months. At the 6-month follow-up, 117 patients were diagnosed with AS, resulting in an incidence rate of 40.2%. The multivariate logistic regression analysis identified that preoperative encroachment rate of anterior spinal canal (Pre-op ERASC), intraoperative facet joints destruction (Intra-op FJD), intraoperative open-door angle (Intra-op OA), destroy the C7 spinous process muscle insertion (Destroy C7 SPMI), postoperative loss of cervical curvature (Post-op LCC), and postoperative loss of cervical range of motion (Post-op LCROM) were independent risk factors for AS. Conversely, preoperative cervical curvature (Pre-op CC) and postoperation early function training (Post-op EFT) were protective factors against AS. According to the ROC curve, the cutoff values for preoperative anterior spinal canal occupation rate and preoperative cervical curvature were 28.5% and 16.5°, respectively. When the preoperative anterior spinal canal occupation rate was greater than 28.5% or the preoperative cervical curvature was less than 16.5°, AS was more likely to occur after surgery.ConclusionHigh preoperative anterior spinal canal occupation rate, facet joint damage during surgery, C7 spinous process muscle stop point damage, larger angle of laminar opening, and greater postoperative cervical curvature loss and cervical range of motion loss are associated with an increased risk of developing AS after cervical laminoplasty. Conversely, a larger preoperative cervical curvature and early postoperative functional exercises can help reduce the occurrence of AS.

The Quality of Life of the Patients with Thoracic Ossification of the Ligamentum Flavum after Surgery Using EQ-5D-5L.

There is a lack of studies on the quality of life (QoL) after posterior laminectomy in patients with thoracic ossification of the ligamentum flavum (TOLF), and risk factors associated with poor prognosis remain controversial. Therefore, the present study was conducted to illustrate the QoL for TOLF patients after surgery and determine its relationship with their demographic, surgery-related, clinical characteristics and imaging data. One hundred and eighteen patients diagnosed with thoracic myelopathy because of TOLF were enrolled in this retrospective study. They all underwent posterior decompressive laminectomy from August 2010 to January 2022. The QoL was evaluated based on the EQ-5D-5L. Collecting gender, age, number of operations, compressed segments, Frankel grade, complications, body mass index (BMI), symptoms and duration, modified Japanese Orthopaedic Association (mJOA) score (preoperative), follow-up time and type of ossification, increased signal on Sagittal T2-weighted Images (ISST2I), occupancy rate and analyzing by Mann-Whitney U-test, Kruskal-Wallis test, the χ2 -test, and logistic regression tests. Average follow-up 70.8 months (18-149), the mean age was 59.74 ± 9.81 years and the mean score for the QoL based on the EQ-5D-5 L and visual analogue scale (VAS) score were 0.71 ± 0.28 and 78.88 ± 10.21 at the final follow-up. Moderate and severe problems were found in the pain/discomfort in 22.0% of the patients. These mobility and usual activities numbers were slightly higher (24.6% and 30.4%, respectively). The mean scores for QoL and VAS were significantly higher in patients with mild and moderate neurological impairment, normal BMI, <60 years of age, no dural tears, symptom relief at hospital discharge, unilateral and bilateral ossification on axial CT scan, ≤ 50% spinal canal occupancy on CT and MRI, and none or fuzzy on ISST2I. QoL after posterior laminectomy in TOLF patients is generally satisfactory compared to preoperative levels. Preoperative mJOA score, Age, comorbid diabetes, the major symptom is activity limitation, BMI, ISST2I, Intraoperative dural tears and spinal canal occupancy rate correlate significantly with the corresponding dimensions and are predictive. Age, spinal canal occupancy rate, ISST2I, preoperative mJOA score, BMI are significantly associated with and have predictive value for overall postoperative QoL.

Predictors of Neurological Worsening after Resection of Spinal Meningiomas.

Due to the slow-growing nature of spinal meningiomas, they are mostly asymptomatic for a long time, and become symptomatic after the compression of the spinal cord or nerve roots. The aim of this study was to identify predictors for a poor clinical outcome after the surgical resection of spinal meningiomas and thereby to allow a preoperative identification of high-risk spinal meningiomas. Data acquisition was conducted as a single-center retrospective analysis. From 1 January 2004 to 31 December 2019, 121 patients who underwent surgical resection of a spinal meningioma were reviewed. Clinical and radiological data (such as tumor size, location, occupation ratio of the spinal canal, and the degree of spinal cord compression) were assessed. The functional clinical findings of the patients were recorded using the Karnofsky Performance Score, modified McCormick scale, and Frankel scale preoperatively, at discharge, and 3-6 months after surgery. The mean patient age was 66 ± 13 years. A total of 104 (86%) patients were female and 17 (14%) were male. The thoracic spine (68%) was the most common location, followed by the cervical (29%) and lumbar (3%) spine. Preoperatively, 11.7% of patients were categorized as McCormick 1, 35.8% as 2, 39.2% as 3, 11.7% as 4, and 1.7% as 5. The neurological function of the patients with a functional deficit prior to surgery improved in 46% of the patients, remained unchanged in 52%, and worsened in 2% at discharge. At early follow-up, the proportions were 54%, 28%, and 5%, respectively. Preoperative Frankel scale was a significant predictor of a postoperative deterioration. Patients with Frankel score A to C preoperatively had a 9.2 times higher chance of clinical deterioration postoperatively (OR = 9.16). We found that the Frankel scale weakly correlated with the degree of spinal cord compression. In this study, other radiological parameters, such as the degree of cord compression and spinal canal occupation ratio, did not show a significant effect on the outcome. Surgery of intraspinal meningiomas can be considered safe. Neurological function improves in a large proportion of patients after surgery. However, a relevant preoperative deficit according to the Frankel scale (grade A-C) was a significant predictor of a postoperative neurological deterioration.

Surgical timing prevails as the main factor over morphologic characteristics in the reduction by ligamentotaxis of thoracolumbar burst fractures

Backgroundthoracolumbar burst fractures are associated with spinal canal occupation. The indirect decompression of the spinal canal and reduction of the fragment can be achieved with the distraction of the middle column and ligamentotaxis. Nevertheless, the factors that influence the effectiveness of this procedure and its temporality are controversial.MethodsThe aim of this observational, cross-sectional study was to evaluate the effectiveness of indirect reduction by ligamentotaxis in thoracolumbar burst fractures according to the fracture’s radiologic characteristics and the procedure’s temporality. Patients diagnosed with a thoracolumbar burst fracture between 2010 and 2021 were submitted to indirect reduction by distraction and ligamentotaxis. A retrospective analysis of radiologic characteristics and temporality of the procedure was performed with an independent sample t-test or Pearson’s correlation coefficient, as required.ResultsA total of 58 patients were included in the analysis. Postoperatively, ligamentotaxis significantly improved all radiologic parameters (canal occupation, endplates distance, and vertebra height). Still, none of the radiological characteristics of the fracture (width, height, position, sagittal angle) were associated with the postoperative change in canal occupation. The endplates distance and the temporality of ligamentotaxis significantly predicted the reduction of the fracture.ConclusionFragment reduction effectiveness is more significant when performed as early as possible and adequate distraction is achieved using the internal fixator system. The radiologic characteristics of the fractured fragment do not determine its reduction capacity.

Clinical effect of limited posterior decompression and 13-mm titanium mesh implantation onsevere thoracolumbar burst fractures: A case series.

Posterior incision with 270° spinal canal decompression and reconstruction surgery is a treatment option for thoracolumbar burst fractures (TLBF), but the large diameter titanium mesh placement is difficult. This study evaluated the characteristics and clinical effects of limited posterior decompression and 13-mm titanium mesh implantation to treat TLBF. 13-mm titanium meshes could be used to fix thoracolumbar burst fractures. This case series included patients who underwent limited posterior decompression and 13-mm titanium mesh implantation at China Medical University Shaoxing Hospital (01/2015-12/2019). The Cobb angle, injury vertebral anterior edge height loss percentage, and spinal canal occupancy rate were analyzed. The degree of spinal cord injury was evaluated according to the ASIA grade. Fifteen patients were included (eight males and seven females). The patients were 32.2 ± 4.6 years of age. The American Association of Spinal Injury improved after surgery (A/B/C/D/E: from 2/6/5/2/0 to 0/0/2/8/5, P < 0.001). The Cobb angle decreased after surgery (from 20.1 ± 4.8° to 7.1 ± 1.4°, P < 0.001) but increased to 8.2 ± 0.9° at 1 year (P = 0.003). The percentage of loss of the anterior edge height of the injured vertebrae decreased after surgery (from 40.9% ± 6.1% to 7.5% ± 1.8%, P < 0.001) and decreased at 1 year (7.0% ± 1.5%, P = 0.044). The spinal canal occupancy rate decreased after surgery (from 64.8% ± 7.8% to 20.1% ± 4.2%, P < 0.001) but did not decrease further at 1 year (19.4% ± 3.4%, P = 0.166). Spinal canal limited posterior decompression, and 13-mm titanium mesh implantation in the treatment of TLBF can achieve one-stage spinal canal decompression and three-column reconstruction. The curative effect was satisfying. Level IV; case series.

The Relationship between the Area of Lumbar Disc Herniation, Spinal Canal Occupancy, and Clinical Findings: Comparison of L4-5 and L5-S Levels

The Relationship between the Area of Lumbar Disc Herniation, Spinal Canal Occupancy, and Clinical Findings: Comparison of L4-5 and L5-S Levels

Risk factors associated with post-operative neurological deterioration in patients with thoracic disc disorders with myelopathy.

Post-operative neurological deterioration (ND) is a severe complication. However, limited literature exists on the ND in thoracic disc disorders with myelopathy (TDM). This study describes the risk factors of neurological deterioration in TDM with instrumentation and fusion. A single-centre review of TDM with instrumentation and fusion during 2006-2019 was performed. Post-operative neurological deterioration was defined as the deterioration of pre-existing neurological function or the appearance of new neurological symptoms. Patients were then grouped into two groups depending on neurological deterioration (ND group) or not (non-ND group). Demographics, radiographic parameters, and surgical characteristics were compared between the two groups. A total of 257 cases were included, and neurological deterioration occurred in 16 (6.23%) cases. Multivariate analysis revealed spinal canal occupancy ratio > 75%, U-shaped compressed spinal cord in axial MRI, calcified herniated disc, anterior approach, and intra-operative blood loss > 1500 mL were associated with ND. Ten patients (62.5%) had complete neurological recovery within six months, and four patients (25%) had progressive neurological function improvement and equal or better than pre-operation within nine months. The rate of neurological deterioration is 6.23%, and a higher spinal canal occupancy ratio, U-shaped compressed spinal cord, calcified herniated disc, anterior approach, and massive intra-operative blood loss were associated with neurological deterioration. Long-term outcomes of neurological deterioration are favourable, and 62.5% of patients experienced complete neurological recovery within six months. Patients with TMD who undergo surgery should be properly informed of the potential risks of neurological deterioration, despite its usually transient nature in most patients.

Predictive Risk Factors of Poor Preliminary Postoperative Outcome for Thoracic Ossification of the Ligamentum Flavum.

ObjectiveThe aim of the present study was to ascertain the independent risk factors of poor preliminary outcome and to reveal the value of these factors in predicting the postoperative prognosis.MethodsA total of 165 patients diagnosed with thoracic myelopathy because of thoracic ossification of the ligamentum flavum (TOLF) were enrolled in this retrospective study. All of them underwent posterior decompressive laminectomy surgery in our hospital from May 2016 to June 2019. The postoperative improvement of symptoms was evaluated using the modified Japanese Orthopaedic Association (mJOA) scoring system. Clinical data, such as age, sex, body mass index (BMI), duration of symptoms, history of hypertension and diabetes, tobacco use, history of drinking, symptoms of incontinence, number of compressed segments, and preoperative mJOA score, were respectively recorded. Radiologic features data included sagittal maximum spinal cord compression (MSCC), axial spinal canal occupation ratio (SCOR), grades and extension of increased signal on sagittal T2‐weighted images (ISST2I), types of increased signal on axial T2‐weighted images (ISAT2I), and the classification of ossification on axial CT scan and sagittal MRI. The t‐test, the χ2‐test, Fisher's exact test, binary logistic regression analyses, receiver operating characteristic (ROC) curves, and subgroup analyses were used to evaluate the effects of individual risk predictors on surgical outcomes.ResultsA total of 76 men and 89 women were enrolled in this study. The mean age of all patients was 58.53 years. After comparison between two groups, we found some risk factors that may be associated with postoperative outcomes, such as age, preoperative mJOA score, BMI, history of hypertension, MSCC, SCOR, grade and extension of ISST2I, type of ISAT2I, axial type of ossification, and sagittal type of ossification (P < 0.05, respectively). Binary logistic regression analysis revealed that older age (odds ratio [OR] = 1.062, 95% confidence interval [CI] = 1.006–1.121, P = 0.030), number of compressed segments (OR = 1.916, 95% CI = 1.250–2.937, P = 0.003), bilateral and bridged types of ossification (OR = 4 314, 95% CI = 1.454–8.657, P = 0.019; OR = 6.630, 95% CI = 2.580–17.530, P = 0.004), and grade 1 and 2 ISST2I (OR = 8.986, 95% CI =3.056–20.294, P < 0.001; OR = 7.552, 95% CI = 3.529–16.004, P < 0.001) were independent risk factors for a poor preliminary postoperative outcome. ROC curve analysis showed that the grade of ISST2I had an excellent discriminative power (area under the curve [AUC] = 0.817). In addition, risk factors have different values for predicting the clinical outcome in each subgroup.ConclusionAge, duration of symptoms, number of compressed segments, SCOR, grade, and extension of ISST2I and classification of ossification were associated with the preliminary prognosis, and the intramedullary increased signal on sagittal T2‐weighted MRI was highly predictive of poor postoperative outcome.

Chemonucleolysis with Chondroitin Sulfate ABC Endolyase for Treating Lumbar Disc Herniation: Exploration of Prognostic Factors for Good or Poor Clinical Outcomes.

Background and Objectives: Chondroitin sulfate ABC endolyase (condoliase) was launched as a new drug for chemonucleolysis in 2018. Few studies assessed its clinical outcomes, and many important factors remain unclear. This study aimed to clarify the preoperative conditions in which condoliase could be highly effective. Materials and Methods: Of 47 patients who received condoliase, 34 were enrolled in this study. The mean age of the patients was 33 years. The average duration since the onset of disease was 8.6 months. We evaluated patients’ low back and leg pain using a numerical rating scale (NRS) score at two time points (before therapy and 3 months after therapy). We divided the patients into two groups (good group (G): NRS score improvement ≥ 50%, poor group (P): NRS score improvement < 50%). The parameters evaluated were age, disease duration, body mass index (BMI), and positive or negative straight leg raising test results. In addition, the loss of disc height and preoperative radiological findings were evaluated. Results: In terms of low back and leg pain, the G group included 9/34 (26.5%) and 21/34 (61.8%) patients, respectively. Patients’ age (low back pain G/P, 21/36.5 years) was significantly lower in the G group for low back pain (p = 0.001). High-intensity change in the protruded nucleus pulposus (NP) and spinal canal occupancy by the NP ≥ 40% were significantly high in those with leg pain in the G groups (14/21, p = 0.04; and 13/21, p = 0.03, respectively). Conclusions: The efficacy of improvement in leg pain was significantly correlated with high-intensity change and size of the protruded NP. Condoliase was not significantly effective for low back pain but could have an effect on younger patients.

Modified percutaneous Kyphoplasty technique in the treatment of osteoporotic thoracolumbar burst fractures: could it reduce the odds of cement leakage?

BackgroundOsteoporotic thoracolumbar burst fracture (OTLBF) is common in seniors. Due to the fracture of the posterior vertebra and spinal canal occupancy, the risk of cement leakage and spine injury is high in OTLBF patients, thus the application of vertebroplasty and kyphoplasty is limited in these patients. This study aims to investigate the efficacy and safety of the modified percutaneous kyphoplasty (MPKP) in the treatment of OTLBF.MethodsClinical data of the OTLBF patients treated with MPKP and the osteoporotic thoracolumbar compression fracture (OTLCF) patients undergone PKP from January 2014 to June 2016 were collected. The key procedure of the MPKP was to fill the bone cavity with gel-foam by the first balloon inflation and to press the gel-foam by a second balloon inflation. Pain intensity, Oswestry disability index (ODI), and bone cement leakage of the patients in the two groups were analyzed.ResultsIn the burst fracture group, the overall spinal canal occupancy was relatively low, and the maximum occupancy was 1/3 of the sagittal diameter of the spinal canal. The surgical duration was longer in the burst fracture group (39.0 ± 5.0 min with 95% CI: 37.7, 40.3) than in the compression fracture group (31.7 ± 4.3 min with 95% CI: 31.1, 32.3), and the difference between the two groups was statistically significant (Z = -8.668 and P = 0.000). Both the Oswestry disability index (ODI) and the visual analog scales (VAS) were apparently improved, but there was no significant difference between the two groups. Cement leakage occurred in 13 out of the 53 cases (24.5%) in the burst fracture group and 35 out of the 193 cases (18.1%) in the compression fracture group, and there was no significant difference between the two groups (Z = − 1.038 and P = 0.299). Neither group had consequential symptoms, such as spinal cord lesion, pain, and numbness of the peripheral nerve.ConclusionSimilar to the efficacy of PKP in the treatment of OTLCF, MPKP efficiently reduced the cement leakage rate and improved the safety of the surgery, although it prolonged the surgical duration and introduced more surgical steps.

Comparative Analysis of the Therapeutic Efficiency and Radiographic Measurement Between the Transforaminal Approach and Interlaminar Approach in Percutaneous Endoscopic Discectomy.

To investigate and compare the therapeutic efficiency and radiographic measurement between the transforaminal approach and interlaminar approach in percutaneous endoscopic discectomy. From January 2017 to January 2018, 86 patients suffering from single lumbar disc herniation were included in this retrospective analysis and divided into the percutaneous endoscopic transforaminal discectomy (PETD) group and percutaneous endoscopic interlaminar discectomy (PEID) group according to different surgical approaches. Data on age, gender, course of the disease, smoking status, and body mass index (BMI) were also obtained. Moreover, lumbar spine X-ray (anterior? posterior, lateral, and excessive flexion and extension), CT scan, and MRI were performed preoperatively for all patients. Another MRI of the lumbar spine was performed within the week after the operation. Clinical efficacy was calculated to assess the clinical effect of the therapy using the visual analogue scale (VAS) and Oswestry Disability Index (ODI) at 1 day before surgery, 3 months after surgery, 1 year after surgery, and the last follow-up visit. All patients were followed up for above two year. 44 and 42 cases were enrolled, respectively, in the PETD and PEID groups. 62 males and 24 females were included in this study. The mean ages of the PETD and PEID groups were 34.58 ± 6.70 and 33.72 ± 7.12 years, respectively (p=0.763). The symptoms showed evident improvement after surgery, but there were no significant differences regarding VAS scores, ODI scores, spinal canal occupation rate and lumbar lordosis except disc height and pfirrmann grade between the two groups (p > 0.05). The revision surgery rates of the PETD and PEID groups at the last follow-up time were 2.3% and 4.8%, respectively (p=0.612). One patient in the PETD group underwent PEID revision surgery because of residual disk herniation. Re-operation were performed on 2 patients in the PEID group due to recurrencee. Approaches of the PEID and PETD are pivotal to address lumbar disc herniation (LDH) disease. Selection of surgery approach depends on anatomical structure, physiological characteristic and operative skill of the surgeon.

Surgical treatment of thoracic disc herniation: an overview.

Surgical treatment of thoracic disc herniation (TDH) is technically demanding due to its proximity to the spinal cord. Literature review. Symptomatic TDH is a rare condition predominantly localized between T8 and L1. Surgical indications include intractable back or radicular pain, neurological deficits, and myelopathy signs. Giant calcified TDH (> 40% spinal canal occupation) are frequently associated with myelopathy, intradural extension, and post-operative complications. Careful pre-operative planning helps reduce the risk of complications. Pre-operative CT and MRI identify the hernia's location and size, calcifications, and intradural extension. The approach must provide adequate dural sac visualization with minimal manipulation of the cord. Non-anterior approaches are favoured if they provide at least equal exposure than anterior approach owing to higher risk of pulmonary morbidity associated with anterior approach. A transthoracic approach is recommended for central calcified herniated discs. A posterolateral approach is often suitable for non-calcified lateralized TDH. Thoracoscopic approaches are less invasive but have a substantial learning curve. Retropleural mini-thoracotomy is an acceptable alternative. Pre-operative identification of the pathological level is confirmed by intra-operative level check. Intra-operative cord monitoring is preferable but warrant further studies. Magnification and adequate lightening of the surgical field are paramount (microscope, thoracoscopy). Intra-operative CT scan with navigation is becoming increasingly popular since it provides real-time control on the decompression. Indications of fusion consist of pre-operative back pain, Scheuermann's disease, multilevel resection, wide vertebral body resection (> 50%), and herniation at thoracolumbar junction. Neurological deterioration, dural tear, and subarachnoid-pleural fistula are the most severe complications. Further improvements are still warranted in thoracic spine surgery despite the advent of minimally invasive techniques. Intra-operative CT scan will probably enhance the safety of the TDH surgery.

Radiographic Features and Correlation Analysis of Location of Ossification in Patients with Cervical Ossification of the Posterior Longitudinal Ligament Combined with Ossification of the Nuchal Ligament

To investigate the incidence, distribution characteristics, and radiographic features of the ossification of the posterior longitudinal ligament (OPLL) combined with ossification of the nuchal ligament (ONL) and to analyze the correlation between the location of ONL and degree of ossification in patients with cervical OPLL. From January 2010 to December 2016, the clinical data of 217 patients with cervical OPLL were reviewed retrospectively. Type and location of OPLL and ONL were determined on computed tomography images and lateral radiograph films. For patients with the local type of ONL, the segment with the largest spinal canal occupation ratio (COR) of OPLL was determined on cross-sectional computed tomography slices. The correlation between the location of ONL and segment with the largest COR of OPLL was evaluated. Of the 217 patients with cervical OPLL, 118 patients (54.4%) had OPLL combined with ONL (92 male and 26 female patients). The incidence of ONL was almost 1.4 times greater in males than in female patients (P= 0.03). C5-C6 (49.5%) was the segment at which ONL occurred most. Of 60 patients with the local type of ONL, 34 patients' ONL was located at the segment with largest COR of OPLL. The matching ratio was the largest (77.8%) when the type of OPLL was locally circumscribed (P= 0.003). The incidence of ONL was 54.4% in patients with cervical OPLL, and male patients were affected more than female patients. ONL occurred most in segment C5-C6. The location of local-type ONL commonly corresponded to the segment with the largest COR of OPLL when type of OPLL was circumscribed.

Evaluation of Measuring Methods of Spinal Canal Occupation Rate in Thoracic Ossification of Ligamentum Flavum.

The degree of hypertrophy of thoracic ossification of ligamentum flavum (TOLF) is related to the severity of the myelopathy. There is no uniform measuring method to calculate the spinal canal occupation ratio (COR) of TOLF simply and effectively. The study was to determine an appropriate measuring method to calculate the COR of TOLF. A total of 37 computed tomography cross-sectional imaging scans (bone window) from 22 patients were analyzed retrospectively in this study. The ventral side of the lamina or superior facet was selected as bottom in Method 1, and a line perpendicular to the anteroposterior diameter and on the dorsal side of the spinal canal was selected as bottom in Method 2. The maximum thickness of the bilateral ossified mass to the bottom is d1 and d2. The maximum distance from the anterior wall of the spinal canal to the bottom is d. COR of Method 1 or 2 was (d1+ d2)/2d× 100%. Standard COR values calculated by software served as controls. The standard COR values were <50% in 10 images, 51%-60% in 9 images, 61%-70% in 10 images, and >71% in 8 images. There was no significant difference between COR1 and COR in every range. There were significant differences between COR2 and COR in the ≤50%, 51%-60%, and 61%-70% groups but they were not statistically significant in the >70% group. Method 1 is a convenient and practical method to measure the COR of ossification in patients with TOLF.

Anterior Transthoracic Surgery with Motor Evoked Potential Monitoring for High-Risk Thoracic Disc Herniations: Technique and Results.

To present our experience with anterior transthoracic surgery for high-risk thoracic disc herniations (TDHs) using motor evoked potential monitoring (MEPm). We estimated surgical risk based on clinical and radiologic characteristics, including anteroposterior (AP) spinal canal occupation (SCO), AP spinal cord compression (SCC), residual AP spinal cord diameter (RSCD), and intramedullary signal changes (ISC). We analyzed Anand, ASIA, and Nurick scores, anesthesiologic, neurophysiological, and surgical reports. We considered >50% MEP signal deterioration significant. Out of 435 anterior transthoracic procedures, 77 concerned high-risk TDH(s): 69 single-level, 8 multilevel, 61 with clinical myelopathy, 6 with merely ISC. Mean SCO and SCC were 55.4% and 54.0% for single-level, 31.8% and 33.9% for multilevel cases. ISC were present in 64% of single-level and 50% of multilevel cases, calcifications in 87% of single-level and 84% of multilevel TDHs. We initially performed 23 mini-transthoracic approaches (mini-TTAs) and 24 thoracoscopic microdiscectomies (TMDs), more recently 29 TMDs (23 giant TDHs) and 1 transaxillary mini-TTA. Overall, 72 patients had reliable MEP signals. Isolated lower extremity MEP signal deteriorations (n=21) correlated with maximal TDH AP diameter, SCO, SCC, and ISC. ASIA and Nurick scores improved in 45% and 66% respectively. One patient became paraplegic. MEP signal deterioration had 100% sensitivity, 75% specificity, and 19% positive predictive value during and 44% at the end of surgery. Maximal TDH AP diameter, SCO, SCC, (sub)total calcification, and ISC correlate with lower extremity MEP signal deterioration. In experienced hands, TMD with MEPm support is a safe, efficient procedure for high-risk TDHs.

MRI observation of lumbar disc herniation of PELD therapy after surgery

Objective To investigate the curative effect PELD discectomy in the treatment of lumbar disc herniation by MRI examination. Methods 98 cases with lumbar disc herniation from November 2013 to March 2016 were treated, they were given PELD removal of herniated nucleus pulposus, preoperative and postoperative 3 days and 3 months, MRI examination was conducted, compared the canal occupancy rates and spinal stenosis.The clinical curative effect was observed. Results MRI results showed that the canal occupancy rates and spinal stenosis between preoperation and postoperative 3 days and 3 months had significant differences (t=40.368, 42.242, 31.955, 34.117, all P<0.001). MRI showed that the spinal canal and spinal stenosis occupancy rates had significant differences between three months after surgery and three days after surgery (t=47.619, 41.946, all P<0.001). Conclusion MRI images confirmed that the PELD discectomy in the treatment of lumbar disc herniation has obvious advantages, the technology can be removed completely protruding lumbar nucleus pulposus, relieve pressure on the nerve root and dural sac. Key words: Arthroscopy; Lumbar vertebrae; Intervertebral disk displacement; Magnetic resonance imaging