Posterior Laminectomy Research Articles

SPIN-02 AN INTRAMEDULLARY MYXOPAPILLARY EPENDYMOMA: A RARE OCCURANCE IN THE CERVICO-THORACIC SPINE

Abstract BACKGROUND Spinal myxopapillary ependymomas are a rare variant of spinal ependymoma that are considered to occur exclusively in the conus medullaris and filum terminale. They account for about 13% of all spinal ependymomas and have a slight male predominance. Case presentation: We report a case of 38-year-old male, Muganda, that presented at the Neurosurgery department Mulago National Referral Hospital with progressive paresthesia and paraparesis, of the upper limbs and chronic neck pain for 2years. MRI showed an isointense lesion on TIWI extending from C4 to T2 levels and exhibited heterogenous enhancement on gadolinium administration. The lesion was hyperintense on T2WI with a syrinx above the tumor. A radiological diagnosis of an intramedullary neoplastic process was made with differentials of Ependymoma, Schwanomma, and Astrocytoma. The patient underwent posterior laminectomy, and the tumor was completely excised. He is currently under follow up by the Neurosurgery team. CONCLUSION This case underscores the rarity of intramedullary myxopapillary ependymomas highlighting diagnostic challenges and the critical role of tailored surgical interventions in managing rare spinal neoplasms.

Anterior decompression and posterior total laminectomy with fusion for ossification of the cervical posterior longitudinal ligament.

Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre. Included in this retrospective cohort study were 48 patients (12 females; mean age 55.79 years (SD 8.94)) who were diagnosed with cervical OPLL, received treatment in our centre, and were followed up for 10.22 to 15.25 years. Of them, 24 patients (six females; mean age 52.88 years (SD 8.79)) received ADF, and the other 24 patients (five females; mean age 56.25 years (SD 9.44)) received PLF. Clinical data including age, sex, and the OPLL canal-occupying ratio were analyzed and compared. The primary outcome was Japanese Orthopaedic Association (JOA) score, and the secondary outcome was visual analogue scale neck pain. Compared with the baseline, neurological function improved significantly after surgery in all patients of both groups (p < 0.001). The JOA recovery rate in the ADF group was significantly higher than that in the PLF group (p < 0.001). There was no significant difference in postoperative cervical pain between the two groups (p = 0.387). The operating time was longer and intraoperative blood loss was greater in the PLF group than the ADF group. More complications were observed in the ADF group than in the PLF group, although the difference was not statistically significant. Long-term neurological function improved significantly after surgery in both groups, with the improvement more pronounced in the ADF group. There was no significant difference in postoperative neck pain between the two groups. The operating time was shorter and intraoperative blood loss was lower in the ADF group; however, the incidence of perioperative complications was higher.

Reasons and strategies of reoperation after oblique lateral interbody fusion

To summarize the reasons and management strategies of reoperation after oblique lateral interbody fusion (OLIF), and put forward preventive measures. From October 2015 to December 2019, 23 patients who underwent reoperation after OLIF in four spine surgery centers were retrospectively analyzed. There were 9 males and 14 females with an average age of (61.89±8.80) years old ranging from 44 to 81 years old. The index diagnosis was degenerative lumbar intervertebral dics diseases in 3 cases, discogenic low back pain in 1 case, degenerative lumbar spondylolisthesis in 6 cases, lumbar spinal stenosis in 9 cases and degenerative lumbar spinal kyphoscoliosis in 4 cases. Sixteen patients were primarily treated with Stand-alone OLIF procedures and 7 cases were primarily treated with OLIF combined with posterior pedicle screw fixation. There were 17 cases of single fusion segment, 2 of 2 fusion segments, 4 of 3 fusion segments. All the cases underwent reoperation within 3 months after the initial surgery. The strategies of reoperation included supplementary posterior pedicle screw instrumentation in 16 cases;posterior laminectomy, cage adjustment and neurolysis in 2 cases, arthroplasty and neurolysis under endoscope in 1 case, posterior laminectomy and neurolysis in 1 case, pedicle screw adjustment in 1 case, exploration and decompression under percutaneous endoscopic in 1 case, interbody fusion cage and pedicle screw revision in 1 case. Visual analogue scale (VAS) and Oswestry disability index (ODI) index were used to evaluate and compare the recovery of low back pain and lumbar function before reoperation and at the last follow-up. During the follow-up process, the phenomenon of fusion cage settlement or re-displacement, as well as the condition of intervertebral fusion, were observed. The changes in intervertebral space height before the first operation, after the first operation, before the second operation, 3 to 5 days after the second operation, 6 months after the second operation, and at the latest follow-up were measured and compared. There was no skin necrosis and infection. All patients were followed up from 12 to 48 months with an average of (28.1±7.3) months. Nerve root injury symptoms were relieved within 3 to 6 months. No cage transverse shifting and no dislodgement, loosening or breakage of the instrumentation was observed in any patient during the follow-up period. Though the intervertebral disc height was obviously increased at the first postoperative, there was a rapid loss in the early stage, and still partially lost after reoperation. The VAS for back pain recovered from (6.20±1.69) points preoperatively to (1.60±0.71) points postoperatively(P<0.05). The ODI recovered from (40.60±7.01)% preoperatively to (9.14±2.66)% postoperatively(P<0.05). There is a risk of reoperation due to failure after OLIF surgery. The reasons for reoperation include preoperative bone loss or osteoporosis the initial surgery was performed by Stand-alone, intraoperative endplate injury, significant subsidence of the fusion cage after surgery, postoperative fusion cage displacement, nerve damage, etc. As long as it is discovered in a timely manner and handled properly, further surgery after OLIF surgery can achieve better clinical results, but prevention still needs to be strengthened.

Robotic thoracic surgery for neurogenic tumors.

Thoracic neurogenic tumors usually present as benign nerve sheath tumors that can be resected via transthoracic or posterior approaches, depending on the anatomical location. Robot-assisted thoracic surgery (RATS) is increasingly being used for the transthoracic approach, but evidence is very limited. The authors initiated the current study to evaluate the efficacy and safety of RATS for thoracic neurogenic tumors. This retrospective study is based on a prospectively created database that includes all RATS surgeries between 2018 and 2023. All patients with histologically confirmed neurogenic tumors were included in the study. The patients' medical and surgical records as well as radiological and pathological findings were analyzed. During a 5-year period, 27 patients underwent robotic resection of neurogenic tumors at a high-volume thoracic surgery center. Two patients had previously undergone posterior laminectomy for resection of the intraspinal components. The pathologies included schwannomas (18, 64%), ganglioneuromas (8, 29%), 1 paraganglioma, and 1 neurofibroma occurring close to a schwannoma unilaterally in the same patient. The median tumor size was 4.7 cm (range 0.9-11.4 cm). The median operating time was 69 minutes (range 27-169 minutes), and the median postoperative stay was 3 days (range 1-19 days). There was one conversion due to adhesions after a previous surgery. No major bleeding occurred. There was no perioperative mortality. Morbidity included a lymphatic fistula (n = 1), pneumonia (n = 1), prolonged air leak (n = 1), and 4 cases of postoperative pain persisting for more than 4 weeks. Neurological complications were mostly observed in patients with tumors located at the thoracic apex: 2 cases of Horner's syndrome, 2 cases with compensatory hyperhidrosis, 1 patient with paresis of the recurrent laryngeal nerve, and a T1 lesion resulting in a minor motor deficit of the small hand muscles (Medical Research Council grade 4) and hypoesthesia of the respective dermatome. RATS for thoracic neurogenic tumors is feasible and safe. Tumors at the thoracic apex are at high risk of neurological deficit and should be approached with care. Close interdisciplinary collaboration between neurosurgeons and thoracic surgeons is necessary for optimal patient selection and a good postoperative outcome.

MANAGEMENT OF DISC HERNIATION AT THE LUMBAR REGION THAT IS COMPLICATED WITH SPINAL STENOSIS USING SMALL INCISION FENESTRATION

Objectives: The objective of the current study was to compare the alternative approach of smaller incision fenestration in managing lumbar disc herniation with spinal stenosis to previous conventional laminectomy procedures. Patients and methods: The current case-control study included a total of 290 patients who were represented by two groups. Those patients were complaining of herniation of the lumbar disc with a complication of stenosis of the lumbar segments. Patients in the study group were treated by a small incision fenestration approach, whereas patients in the control group were treated by posterior laminectomy and decompression. Those patients were selected retrospectively from the pool of patients visiting the orthopedic units of Adiwaniyah Teaching Hospital, Adiwaniyah province, Iraq. Results: Mean hospital stay of patients in the study group was lower in a significant way in comparison with that of patients in the control group, 6.03 ±2.08 days versus 8.07 ±3.13 days, separately (p&lt; 0.001). Added to that, mean operative loss was significantly lower in a group of intervention in comparison with the control group, 52.12 ±5.17 ml versus 65.48 ±5.08 ml, respectively (p&lt; 0.001). Added to that, mean operative time was lower in a significant way in the group of intervention in comparison with patients in the group of control, 62.62 ±3.09 minutes versus 87.09 ±3.47 minutes, respectively (p&lt; 0.001). The mean“visual analogue score (VAS)” was significantly lower in the study group in comparison with the control group, 3.09 ±1.15 versus 6.08 ±2.17, respectively (p&lt;0.001). A comparison of the mean “Japanese orthopedic association (JOA) score” for nerve function between the study group and the control group is shown in Figure 2. The mean “Japanese orthopedic association (JOA) score” was higher in a significant manner in the group of an intervention study in comparison with the control group, 27.15 ±3.07 versus 20.18 ±4.81, respectively (p&lt; 0.001). Conclusion: Small incision fenestration techniques are associated with significantly less hospital stay, less duration of operation, less blood loss, less visual pain score and better nerve function in comparison with conventional laminectomy procedure. Keywords: smaller incision fenestration, lumbar disc herniation, spinal stenosis

Delayed neurological dysfunction following posterior laminectomy with lateral mass screw fixation: A case report and review of literature

BACKGROUND While most complications of cervical surgery are reversible, some, such as symptomatic postoperative spinal epidural hematoma (SEH), which generally occurs within 24 h, are associated with increased morbidity and mortality. Delayed neurological dysfunction is diagnosed in cases when symptoms present &gt; 3 d postoperatively. Owing to its rarity, the risk factors for delayed neurological dysfunction are unclear. Consequently, this condition can result in irreversible neurological deficits and serious consequences. In this paper, we present a case of postoperative SEH that developed three days after hematoma evacuation. CASE SUMMARY A 68-year-old man with an American Spinal Injury Association (ASIA) grade C injury was admitted to our hospital with neck pain and tetraplegia following a fall. The C3-C7 posterior laminectomy and the lateral mass screw fixation surgery were performed on the tenth day. Postoperatively, the patient showed no changes in muscle strength or ASIA grade. The patient experienced neck pain and subcutaneous swelling on the third day postoperatively, his muscle strength decreased, and his ASIA score was grade A. Magnetic resonance imaging showed hypointense signals on T1 weighted image (T1WI) and T2WI located behind the epidural space, with spinal cord compression. Emergency surgical intervention for the hematoma was performed 12 h after onset. Although hypoproteinemia and pleural effusion did not improve in the perioperative period, the patient recovered to ASIA grade C on day 30 after surgery, and was transferred to a functional rehabilitation exercise unit. CONCLUSION This case shows that amelioration of low blood albumin and pleural effusion is an important aspect of the perioperative management of cervical surgery. Surgery to relieve the pressure on the spinal cord should be performed as soon as possible to decrease neurological disabilities.

Additional cement augmentation reduces cage subsidence and improves clinical outcomes in oblique lumbar interbody fusion combined with anterolateral screw fixation: A retrospective cohort study

PURPOSE: Although OLIF has been well established as a successful surgical treatment for lumbar spondylosis, cage subsidence is one of the troublesome complications. Avoiding risk factors and improving surgical techniques are generally passive ways for cage subsidence prevention. To our knowledge, there has been no active way reported to decrease cage subsidence following OLIF. METHODS: From 2018 to 2021, 63 patients were enrolled and divided into two groups, OLIF group (37 patients) and OLIF with cement augmentation (OLIF-C) group (26 patients). The patients’ characteristics, age, sex, BMI, lesion level, days of hospitalization, visual analogue scale (VAS), surgical data and radiological parameters were recorded and compared. RESULTS: The demographic and surgical data showed no statistical significance between OLIF and OLIF-C groups. OLIF-C group had better pain relief in postoperative 3 months (p = 0.015) and at the last follow-up (p = 0.030), less rate of cage subsidence (p <0.001) with better disc height restoration, segmental lordotic angle maintenance and interbody fusion rate. CONCLUSIONS: Additional cement augmentation for OLIF could minimize the rate of postoperative cage subsidence and the whole procedure was completed through the anterolateral approach without posterior laminectomy and instrumentation, avoiding the damage of posterior back muscle and facet joints.

Transdural Ventral Sling Technique for Calcified Thoracic Disk Herniations

BackgroundSurgery for thoracic disc herniations remains an ongoing challenge, with a variety of surgical approaches, all with their own inherent risks. Discectomy via a posterior laminectomy was historically the treatment of choice; however, it was deemed very high risk with elevated rates of neurologic injury. The posterior transdural approach is an alternative surgical option for soft and calcified thoracic disc herniations. ObjectiveTo present a surgical technique to remove a calcified thoracic disc herniation without entry into the thoracic cavity. MethodsA 56-year-old female presented with many years of numbness/tingling in her hands and difficulty with fine motor tasks but developed progressive weakness and loss of balance in her legs. Imaging revealed a prominent focal central calcified disc herniation at the T5-T6 level causing severe effacement and distortion of the spinal cord. A posterior transdural approach for direct visualization of a large, calcified disc herniation was performed to remove the calcified disc herniation without the need for extensive surgical exposure or entry into the thoracic cavity. A ventral sling of the dura was created to allow rotation of the spinal cord while removing the calcified disc. Preoperative and postoperative radiographic assessments were conducted to evaluate the effectiveness of the approach. ConclusionsThe transdural approach is less invasive in nature, minimizes surgical exposure, patient morbidity, and provides better intraoperative control of the spinal cord. This constitutes an effective alternative surgical approach to both soft and calcified central thoracic disc herniations.

The clinical efficacy of laminectomy fusion fixation and posterior single open-door laminoplasty in the treatment of multilevel cervical ossification of the posterior longitudinal ligament (OPLL): a retrospective study

BackgroundTo compared the clinical efficacy of two surgical methods, posterior laminectomy fusion fixation, and posterior single open-door laminoplasty, in treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL).MethodsThe study retrospectively included 102 patients treated between December 2016 and December 2020. The patients were included into an observation group (56 cases) treated with total laminectomy and lateral screw fixation, and a control group (46 cases) treated with single open-door laminoplasty.ResultsAfter 24 months, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores and Visual Analogue Scale (VAS) scores, indicating better clinical symptoms and functional recovery. There was no significant difference in preoperative JOA and VAS scores between the two groups (P > 0.05). At 24 months after surgery, there was no significant difference in JOA and VAS scores between the two groups (P > 0.05). However, the observation group had a significantly higher cervical curvature index (CCI) and lower range of motion (ROM) of the cervical spine compared to the control group (P < 0.05). The CCI in control group was lower than before surgery, while the CCI in observation group was higher than before surgery, and CCI in the control group was considerably lower than that in the observation group (P < 0.05). The complication rate was lower in the control group, with fewer cases of axial symptoms, fifth cervical nerve root palsy, and overall complications. The overall complication rate was 25.0% (14/56) in the observation group and 10.8% (5/46) in the control group (P < 0.05).ConclusionsBoth posterior laminectomy fusion fixation and posterior single open-door laminoplasty yield positive outcomes in improving clinical neurological function, cervical curvature, range of motion of the cervical spine, and cervical sagittal balance. Although open-door laminoplasty is less effective than total laminectomy in maintaining CCI and sagittal balance, it excels in preserving cervical range of motion, less surgical trauma and complications. Thus, open-door laminoplasty may be a suitable first-choice treatment for multi-segmental cervical OPLL, especially for patients with lordotic cervical spine physiological curvature.

Anterior controllable antedisplacement and fusion as revision surgery for the treatment of OPLL after anterior and posterior decompression: A case report

Background: In cases of cervical ossification of the posterior longitudinal ligament (OPLL), when initial anterior or posterior decompression fails to yield satisfactory results, the alternative approach is often chosen for revision surgery. Nevertheless, there is a lack of reported information regarding the treatment and prognosis of patients with complex OPLL who have undergone both anterior and posterior decompression but experienced relapse. Case presentation: A 79-year-old male patient presented with numbness, weakness, and muscle atrophy in the right upper extremity, along with weakness in the right lower extremity. Initial assessment on admission revealed a Japanese Orthopaedic Association (JOA) score of 7. The patient previously underwent anterior cervical discectomy and fusion (ACDF) 25 years ago for spinal stenosis, followed by posterior laminectomy as revision surgery. After experiencing recurrent symptoms following a fall one year ago, the patient underwent a second revision surgery using the anterior controllable antedisplacement and fusion (ACAF) technique which led to symptom improvement, and resulted in a postoperative JOA score of 14 at 3 months of follow-up. Conclusions: Treatment of OPLL patients with symptom recurrence after traditional anterior and posterior decompression is challenging. ACAF offers a viable solution for managing this complex case.

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.

Factors Influencing Surgical Decision-Making in the Posterior Laminectomy With Fixation for Degenerative Cervical Myelopathy (POLYFIX-DCM) Trial: Survey Study.

Degenerative cervical myelopathy (DCM) is estimated to affect 2% of the adult population. DCM occurs when degenerative processes cause compression and injure the spinal cord. Surgery to remove the stress caused by the compression of the spinal cord is the mainstay of treatment, with a range of techniques in use. Although various factors are described to inform the selection of these techniques, there needs to be more consensus and limited comparative evidence. The main objective of this survey was to explore the variation of practice and decision-making, with a focus on laminectomy versus laminectomy and fusion in posterior surgery of the cervical spine. We present the results of a survey conducted among the principal investigators (PIs) of the National Institute for Health and Care Research (NIHR) randomized controlled trial on posterior laminectomy with fixation for degenerative cervical myelopathy (POLYFIX-DCM). A series of 7 cases were shared with 24 PIs using SurveyMonkey. Each case consisted of a midsagittal T2-weighted magnetic resonance imaging and lateral cervical x-rays in flexion and extension. Surgeons were asked if their preferred approach was anterior or posterior. If posterior, they were asked whether they preferred to instrument and whether they had the equipoise to randomize in the NIHR POLYFIX-DCM trial. Variability in decision-making was then explored using factors reported to inform decision-making, such as alignment, location of compression, number of levels operated, presence of mobile spondylolisthesis, and patient age. The majority of PIs (16/30, 53%) completed the survey. Overall, PIs favored a posterior approach (12/16, 75%) with instrumentation (75/112, average 66%) and would randomize (67/112, average 62%) most cases. Factors reported to inform decision-making poorly explained variability in responses in both univariate testing and with a multivariate model (R2=0.1). Only surgeon experience of more than 5 years and orthopedic specialty training background were significant predictors, both associated with an anterior approach (odds ratio [OR] 1.255; P=.02 and OR 1.344; P=.007, respectively) and fusion for posterior procedures (OR 0.628; P<.001 and OR 1.344; P<.001, respectively). Surgeon experience also significantly affected the openness to randomize, with those with more than 5 years of experience less likely to randomize (OR -0.68; P<.001). In this representative sample of spine surgeons participating in the POLYFIX-DCM trial as investigators, there is no consensus on surgical strategy, including the role of instrumented fusion following posterior decompression. Overall, this study supports the view that there appears to be a clinical equipoise, and conceptually, a randomized controlled trial appears feasible, which sets the scene for the NIHR POLYFIX-DCM trial.

Uniportal Thoracic Endoscopic Unilateral Laminotomy with Bilateral Decompression of Thoracic Ossification of Ligamentum Flavum: A Systematic Review of Current Literature

Thoracic ossification of ligamentum flavum (TOLF) is a rare disease that often results in worsening neurologic sequelae if left untreated. Although the gold standard treatment for TOLF is open posterior laminectomy, it is often accompanied by high rates of complications and perioperative morbidity. There have been studies looking into feasibility of endoscopic posterior decompression for TOLF, citing potential for lower perioperative morbidity and achieving similar functional outcomes to its open laminectomy counterparts. We provide an up-to-date systematic review of clinical outcomes after endoscopic posterior decompression for TOLF from the latest assemblage of evidence. A systematic review of the technique was conducted from May 2000 to May 2023. Articles were selected based on PRISMA guidelines. Eligibility of studies was independently by 2 reviewers, with disagreements resolved by a third author. Nineteen primary references comprising 337 patients with TOLF who underwent endoscopic posterior decompression were included in the systematic review. Mean follow-up time across all studies ranged from 8.9 to 65.3 months. Mean age ranged from 51.2 to 63 years, with mean intraoperative blood loss ranging from 15 to 62 mL. There is significant improvement in visual analog scale (VAS) score, VAS back, VAS leg, modified Japanese Orthopaedic Association score, and Oswestry Disability Index compared with preoperative recorded values across all studies, with low rates of complications reported. Endoscopic posterior spinal decompression is a safe and effective technique for treatment of TOLF, with a low rate of complications and improvement in pain and function.

Factors Affecting the Surgical Outcomes of Patients Treated With "de-tension" Surgical Strategy for Multilevel Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine: A Minimum 2-year Follow-Up Study of 83 Patients in a Single Center.

Retrospective cohort study. To describe the clinical characteristics and surgical outcomes of patients with multilevel-ossification of the posterior longitudinal ligament (mT-OPLL), and to identify risk factors for unfavorable outcomes. Patients who were diagnosed with mT-OPLL and underwent one-stage thoracic posterior laminectomy combined with selective OPLL resection, spinal cord de-tension, and fusion surgery between August 2012 and October 2020 were recruited. Patients' demographic-, surgical- and radiological-related parameters were collected and analyzed. Neurological status was evaluated with mJOA score, and recovery rate (RR) was calculated using the Hirabayashi formula. According to RR, patients were divided into a favorable outcome group (FOG, RR ≥50%) and an unfavorable outcome group (UOG, RR <50%). Univariate and multivariate analyses were used to compare the difference between the 2 groups and to identify risk factors for unfavorable outcomes. A total of 83 patients were included, with an average age of 50.6 ± 8.3 years. Cerebrospinal fluid leakage (60.2%) and transient neurological deterioration (9.6%) were the most common complications. The average mJOA score improved from preoperative 4.3 ± 2.2 to 9.0 ± 2.4 at the last follow-up, and the mean RR was 74.9 ± 26.3%. Disease duration, preoperative nonambulatory status, and the number of decompressed levels were identified as potential risk factors by Univariate analysis (all P < .05). Multivariate analysis showed that the preoperative disease duration and nonambulatory status were independent risk factors for unfavorable outcomes. Long disease duration and nonambulatory status before surgery were independent risk factors for unfavorable outcomes.

433 Trajectory-based Classification of Recovery Potential in Mild Degenerative Cervical Myelopathy: Analysis of a Prospective Multicentre Dataset of 1047 Patients

INTRODUCTION: Degenerative Cervical Myelopathy (DCM) is the leading cause of disability secondary to a spinal pathology in adults. There exists clinical equipoise between surgery and conservative management with monitoring for patients with mild DCM. METHODS: A harmonized dataset was developed from the AOSpine North America, AOSpine International datasets as well as the CSM-Protect trial (N:1047). DCM patients (mJOA ≥15) were selected from the harmonized dataset. Latent class trajectory modeling was applied to classify patients into distinct trajectories. The optimal number of trajectories were chosen based on i) least Bayesian Information Criterion; ii) posterior probability &gt;0.70; iii) odds of correct classification &gt;5; and concordance between the estimated and actual proportion of patients assigned to a class. Predictors of recovery trajectories were identified using descriptive statistics and logistic regression on baseline variables. RESULTS: Two distinct recovery trajectories were revealed from our analysis. Good recovery trajectory had patients that improved to near-maximal mJOA scores within 12 months. Functional decline trajectory was characterized by a decline in more than two mJOA points over 12 months. There were 33 patients (15.6%) that followed functional decline and 179 that showed good recovery (84.4%). Demographic factors associated with following a functional decline trajectory included older age, hypertension, and higher baseline Nurick score. Posterior laminectomy and fusion was associated with functional decline compared to anterior fixation. CONCLUSIONS: Mild DCM can be classified into one of two distinct subpopulations with different recovery trajectories. This study lends support to the heterogeneity of mild DCM and classifying the clinical course of mild DCM based on defined clinical phenotypes rather than baseline severity of myelopathy alone. We also discovered that anterior surgery is associated with better neurological recovery in the context of mild DCM patients.

Abstract Number ‐ 221: Lower Thoracic Spinal Dural Arteriovenous Fistula Presenting With Progressive Paraplegia: A Case Report

Introduction We present a 72‐year‐old male with osteoarthritis, lumbar stenosis, coronary artery disease with a 4‐vessel bypass graft in February 2020, hypertension, hyperlipidemia, and obesity who presented with subacute progressive lower extremity weakness. He began having lower back pain following his cardiac surgery in February 2020. He was evaluated by a rehabilitation doctor in September 2020 who diagnosed him with lumbar radiculopathy and treated him with one round of steroid injections that helped a bit. Six months later he returned for follow‐up with the aid of a wheelchair which he started using in the last two weeks due to progressive lower extremity weakness. He was sent to the ED for neurologic evaluation. He denied radicular pain, saddle anesthesia, and urinary or bowel incontinence. Methods On neurologic exam, he had 2/5 bilateral hip flexion strength, 4/5 bilateral distal lower extremity strength, intact sensation to all modalities, and diffuse bilateral hyporeflexia (1+) with flexor plantar responses. An MRI brain was unremarkable. An MRI cervical, thoracic and lumbar spine with contrast showed extensive confluent cord edema with enhancement from T9 to the conus medullaris. He was started on high‐dose IV methylprednisolone for concern of transverse myelitis. Serum metabolic, hematologic, autoimmune, and infectious workup were negative. Due to a lack of improvement, his spinal imaging was reviewed with neuroradiology who recognized previously unidentified posterior T2 flow voids in the subarachnoid space at T1. A spinal angiogram for suspicion of a spinal dural arteriovenous fistula (dAVF) was subsequently scheduled. Results Angiography confirmed a type I spinal dAVF which was treated with posterior laminectomy and surgical ligation. The patient’s lower extremity strength improved and he was discharged to acute rehab. At his 1‐month neurology follow‐up appointment, he was ambulating with minimal assistance from a cane with near full lower extremity strength. Conclusions With an initial presentation of subacute progressive lower extremity weakness and imaging findings concerning for longitudinally extensive transverse myelitis, our initial suspicion was highest for an underlying autoimmune or infectious disease. However, this case teaches us to not presume all transverse myelitis or enhancing spinal cord lesions must be from an inflammatory, neoplastic, or infectious condition. A wide differential for this presentation including spinal dAVF is necessary as this is one of the most commonly missed neurovascular diagnoses. T2 flow voids are highly suggestive of this condition, but a spinal angiogram is the gold standard for diagnosis.

Comparison of posterior muscle-preserving selective laminectomy and laminectomy with fusion for treating cervical spondylotic myelopathy: study protocol for a randomized controlled trial

BackgroundCervical spondylotic myelopathy (CSM) is the predominant cause of spinal cord dysfunction in the elderly. The patients are often frail and susceptible to complications. Posterior surgical techniques involving non-fusion are complicated by postlaminectomy kyphosis and instrumented fusion techniques by distal junction kyphosis, pseudarthrosis, or implant failure. The optimal surgical approach is still a matter of controversy.Since anterior and posterior fusion techniques have been compared without presenting any superiority, the objective of this study is to compare stand-alone laminectomy with laminectomy and fusion to determine which treatment has the lowest frequency of reoperations.MethodsThis is a multicenter randomized, controlled, parallel-group non-inferiority trial. A total of 300 adult patients are allocated in a ratio of 1:1. The primary endpoint is reoperation for any reason at 5 years of follow-up. Sample size and power calculation were performed by estimating the reoperation rate after laminectomy to 3.5% and after laminectomy with fusion to 7.4% based on the data from the Swedish spine registry (Swespine) on patients with CSM. Secondary outcomes are the patient-derived Japanese Orthopaedic Association (P-mJOA) score, Neck Disability Index (NDI), European Quality of Life Five Dimensions (EQ-5D), Numeric Rating Scale (NRS) for neck and arm pain, Hospital Anxiety and Depression Scale (HADS), development of kyphosis measured as the cervical sagittal vertical axis (cSVA), and death. Clinical and radiological follow-up is performed at 3, 12, 24, and 60 months after surgery. The main inclusion criterium is 1–4 levels of CSM in the subaxial spine, C3–C7. The REDcap software will be used for safe data management. Data will be analyzed according to the modified intention to treat (mITT) population, defined as randomized patients who are still alive without having emigrated or left the study after 2 and 5 years.DiscussionThis will be the first randomized controlled trial comparing two of the most common surgical treatments for CSM: the posterior muscle-preserving selective laminectomy and posterior laminectomy with instrumented fusion. The results of the myelopathy randomized controlled (MyRanC) study will provide surgical treatment recommendations for CSM. This may result in improvements in surgical treatment and clinical practice regarding CSM.Trial registrationClinicalTrials.govNCT04936074. Registered on 23 June 2021

Comparison Between Sagittal Balance Outcomes After Corpectomy, Laminectomy, and Fusion for Cervical Spondylotic Myelopathy: A Matched Cohort Study.

Cervical spondylotic myelopathy (CSM) can be successfully decompressed via either anterior cervical corpectomy and fusion (ACCF) or posterior laminectomy with fusion (LMF). However, few studies have compared the isolated effect of both techniques on cervical sagittal balance, a surrogate end point for clinical outcomes.We aimed to compare the sagittal balance radiological outcomes of ACCF against LMF. A case-matched controlled study of radiological cervical alignment parameters (C0-2, C2-3, index angles, T1 slope, and sagittal vertical axis (SVA)) in two groups of patients was performed by using pre- and postoperative neutral cervical X-rays.In total, 34 patients were enrolled (ACCF n = 17; LMF n = 17). The mean preoperative C2-7 angle was similar (11.58 ± 16.00° for ACCF; 13.36 ± 12.21° for LMF) in both cohorts. Both led to a loss of lordosis (-2.68 ± 13.8°, p = 0.43; -2.94 ± 11.5°, p = 0.31, respectively). At the C0-2, the two operations induced opposite variations (-0.9 ± 8.0°, p = 0.709 for ACCF; 3.5 ± 15.4°, p = 0.357 for LMF). ACCF led to a significant increase in SVA (7.1 ± 11.9 mm, p = 0.002). The C2-3 disk angle more pronouncedly increased with LMF.Both techniques show an equivalent kyphotic effect, with a greater disadvantage for ACCF. The negative impact on SVA changes is greater with ACCF. Both affect the C0-2 unit, with a tendency for kyphosis with ACCF and one for lordosis with LMF. When choosing the appropriate decompression and fusion technique, preoperative sagittal balance parameters should be included in the decision-making process.

Measurement of Deformity at the Craniovertebral Junction: Correlation of Triangular Area and Myelopathy.

Diseases of the craniovertebral junction (CVJ) are commonly associated with deformity, malalignment, and subsequent myelopathy. The misaligned CVJ might cause compression of neuronal tissues and subsequently clinical symptoms. The triangular area (TA), measured by magnetic resonance imaging/images (MRI/s), is a novel measurement for quantification of the severity of compression to the brain stem. This study aimed to assess the normal and pathological values of TA by a comparison of patients with CVJ disease to age- and sex-matched controls. Moreover, postoperative TAs were correlated with outcomes. Consecutive patients who underwent surgery for CVJ disease were included for comparison to an age- and sex-matched cohort of normal CVJ persons as controls. The demographics, perioperative information, and pre- and postoperative 2-year cervical MRIs were collected for analysis. Cervical TAs were measured and compared. A total of 201 patients, all of whom had pre- or postoperative MRI, were analyzed. The TA of the CVJ deformity group was larger than the healthy control group (1.62 ± 0.57 cm2 vs. 1.01 ± 0.18 cm2, p < 0.001). Moreover, patients who had combined anterior odontoidectomy and posterior laminectomy with fixation had the greatest reduction in the TA (1.18 ± 0.58 cm2). In CVJ deformity, the measurement of the cervical TA could indicate the severity of brain stem compression. After surgery, the TA had a varying degree of improvement, which could represent the efficacy of surgery.

The surgical strategy for multilevel massive ossification of the posterior longitudinal ligaments.

Creating enough decompression, favorable outcome, less complication, and maintain adequate lordosis and stability in the patients with cervical myelopathy due to multilevel massive ossification of the posterior longitudinal ligament (OPLL) still poses a challenge for surgeons. The aim of our study is to retrospectively evaluate our patients and try to seek a better surgical strategy. Between 2015 and 2019, 55 consecutive patients with multilevel massive OPLL underwent surgical treatment. Among these, 40 patients were treated with cervical laminectomy and then anterior decompression, fusion, and fixation (ADF), which was defined as group 1, and 15 patients were treated with cervical laminectomy and fixation simultaneously, which was defined as group 2. The patient's radiographic characteristics and postoperative outcomes were evaluated. Better postoperative cervical sagittal lordosis and less long-term axial pain was achieved in group 1 (p < 0.001), though the functional outcome had no significant difference. In the multivariable analysis, anterior fixation accounts for independent factors for better cervical sagittal alignment (p < 0.001). No complications directly associated with cervical laminectomy were observed. In patients with cervical multilevel massive OPLL, laminectomy at compression level and then ADF depended on the severity and range of compression, but corpectomy of not more than two vertebral bodies is suggested, except K-line (+) and long-segment massive OPLL majorly involving the C2 and posterior laminectomy above and below the OPLL-affected levels with posterior fixation simultaneously.