Bilateral Facet Research Articles

Correlation Between Facet Tropism and Ossification of the Posterior Longitudinal Ligament in the Cervical Spine.

Retrospective cohort study. To explore the correlation between Facet Tropism (FT) and OPLL in cervical spine. One-hundred patients with OPLL of cervical spine and one-hundred normal participants without OPLL or cervical disc herniation were included in this study, the patients were matched to the normal participants respectively based on the same sex and similar age (±5). For patients, the cervical levels with and without OPLL were categorized into "OPLL group" and "patient control group," respectively. Bilateral facet joint angles at C2/3-C6/7 were measured on sagittal, coronal, and axial planes on CT. On every planes at the level of C2/3-C6/7,the mean difference between left and right facet angles and FT incidence in the most levels of the OPLL group were significantly greater than those in the control groups (P < 0.001). At the most cervical levels, there was no significant difference in mean difference of facet angles and FT incidence between the 2 control groups. On the axial plane, the incidence of FT in segmental type OPLL patients was significantly higher than that in continuous type OPLL patients (P = 0.036). On the coronal plane, the incidence of FT in segmental type OPLL was significantly higher than that in the other OPLL types (P < 0.001), and local type OPLL had a higher incidence of FT compared to mixed type OPLL (P = 0.016). On the sagittal plane, the incidence of FT in segmental type OPLL was higher than that in continuous type OPLL (P = 0.019) and mixed type OPLL (P = 0.036). There is a significant correlation between OPLL of cervical spine and FT. There are significant differences in the incidence of FT among different cervical OPLL types.

Tending to the Facial Surfaces of a Mathematical Biology Head-Scratcher: Why Does the Head of the Sea Turtle Natator depressus Resemble a Convex Zygomorphic Dodecahedron?

Two convex polyhedra that markedly resemble the head of the flatback sea turtle hatchling are identified. The first example is a zygomorphic tetragonal dodecahedron, while the other, an even better matching structure, is a related tetradecahedron, herein speculated to arise from this particular dodecahedron via known mechanisms gleaned from studies of the behavior of foams. A segmented, biomorphic, convex polyhedral model to address cephalic topology is thus presented stemming from solid geometry, anatomical observations, and a recently computed densest local packing arrangement of fifteen slightly oblate spheroids in which fourteen oblate spheroids surround a central such spheroid. This particular array of oblate spheroids shares salient structural features with the aforementioned dodecahedron. Successful testing of the model has been achieved by converting this array of fifteen oblate spheroids constructed with putty to the cephaloid dodecahedron in a process involving ventral elongation induced by stretching in the anterior direction along the anteroposterior axis (convergent extension). During convergent extension, the two left most anterolateral oblate spheroids that are in direct contact with the ventral spheroid of the array merge into a single lateral facet of the incipient dodecahedron, while the corresponding two right such oblate spheroids do the same. Thus, the fourteen outer oblate spheroids of the array give rise to the twelve facets of the finalized dodecahedron, while the central oblate spheroid remnant assumes an interior dodecahedral position. The hypothetical dodecahedron to tetradecahedron transformation entails the collapse of a tetravalent vertex (which is known to occur in foams as part of a T1 transition) followed by bilateral facet splitting. Remarkably, a model stipulating that convexity is to be retained in connection with this sequence of steps necessitates that the starting dodecahedral template undergoes modification to become a tetradecahedron in possession of precisely the highly ordered feature found at the top of the head of numerous specimens of the flatback sea turtle hatchling, namely, a fused medial pentagon-heptagon pair in the form of a pentagonal frontal scute and heptagonal frontoparietal scute. Such a possible new instance of geometric biomorphy, taken together with the correct anticipation of the cephalic pentagon-heptagon pair, might serve to instill further confidence in renewed efforts to shed light on morphogenesis with foam embryo models.

Radiographic Predictors of Lateral Translation in Patients With Residual Adolescent Idiopathic Scoliosis and Thoracolumbar/Lumbar Curves: A Focus on L3 Lateral Translation

BackgroundPatients with residual adolescent idiopathic scoliosis (AIS) and thoracolumbar/lumbar (TL/L) curves may present with progression after cessation of growth, with lateral translation as a major risk factor. Nonetheless, radiographic predictors and underlying mechanisms remain indefinite. This study aimed to determine these radiographic predictors and structural mechanisms in patients with residual AIS. MethodsRadiographic and clinical data were collected from 45 consecutive patients with preoperative residual AIS and TL/L Cobb angle >40° who subsequently underwent corrective surgery at our institution. Lateral translation was defined as intervertebral slippage ≥6 mm on computed tomography. Statistical analyses included Student’s t-test, Pearson’s correlation coefficients, receiver operating characteristic (ROC) curve analysis, and multivariate logistic regression analysis. ResultsOut of 45 patients, 3 were male, whereas 42 were female, with a mean age of 40.6±17.4 years. L3 slippage was observed in 21 patients, resulting in the categorization into the slippage and non-slippage cohorts. Multivariate logistic regression analysis revealed statistically significant disparities in the bilateral facet angles, facet joint opening, and facet joint vacuum phenomenon between the two cohorts. The ROC analysis determined a 20.5° cut-off value for predicting L3 slippage. In the non-slippage cohort, a strong correlation was particularly observed between L3 slippage and L2–L3 bridging. ConclusionFacet joint instability, L4 tilt ≥20.5°, and L3 cranial vertebral bridging are predictive radiographic factors for L3 lateral translation in patients with residual AIS. Thus, patients exhibiting these characteristics require consistent follow-up or early surgical intervention before lateral translation occurs.

Cervical facet joints injections of stem cells in treatment of neck pain after whiplash injury

Neck pain is a very common and often disabling conditions. Neck pain lifetime prevalence rates are 48.5% [1]. Pain originating from the complex of two bilateral Facet Joints (FJ) and one intervertebral disc often produces one of the most common conditions-mechanical neck pain [2].

Development, calibration and validation of impact-specific cervical spine models: A novel approach using hybrid multibody and finite-element methods

Background and Objective:Spinal cord injuries can have a severe impact on athletes’ or patients’ lives. High axial impact scenarios like tackling and scrummaging can cause hyperflexion and buckling of the cervical spine, which is often connected with bilateral facet dislocation. Typically, finite-element (FE) or musculoskeletal models are applied to investigate these scenarios, however, they have the drawbacks of high computational cost and lack of soft tissue information, respectively. Moreover, material properties of the involved tissues are commonly tested in quasi-static conditions, which do not accurately capture the mechanical behavior during impact scenarios. Thus, the aim of this study was to develop, calibrate and validate an approach for the creation of impact-specific hybrid, rigid body - finite-element spine models for high-dynamic axial impact scenarios. Methods:Five porcine cervical spine models were used to replicate in-vitro experiments to calibrate stiffness and damping parameters of the intervertebral joints by matching the kinematics of the in-vitro with the in-silico experiments. Afterwards, a five-fold cross-validation was conducted. Additionally, the von Mises stress of the lumped FE-discs was investigated during impact. Results:The results of the calibration and validation of our hybrid approach agree well with the in-vitro experiments. The stress maps of the lumped FE-discs showed that the highest stress of the most superior lumped disc was located anterior while the remaining lumped discs had their maximum in the posterior portion. Conclusion:Our hybrid method demonstrated the importance of impact-specific modeling. Overall, our hybrid modeling approach enhances the possibilities of identifying spine injury mechanisms by facilitating dynamic, impact-specific computational models.

Bipartition of the atlanto-occipital joint surfaces in a South African sample

BackgroundOne variation of the atlanto-occipital joint contains a groove or crest dividing the superior articulating facet of C1 and/or the corresponding occipital condyle. This study aimed to estimate the prevalence of bipartition of the facets associated with the atlanto-occipital joint and to determine the relationships between the corresponding joint surfaces, bilateral and unilateral facets as well as demographic factors in a South African sample. Materials and methodsData about shape and bipartition found on the superior articular facets of the atlas and the occipital condyles were collected from 109 skulls and atlases from the Pretoria Bone Collection, South Africa. Shape data was categorically classified according to existing criteria from literature. ResultsThe results revealed the occasional occurrence of a double facet at both the superior articular facet of the atlas (15.6 %), and the occipital condyle (7.34 %). Shape and facet number of the superior articulating facet and corresponding occipital condyle were significantly correlated. The prevalence of bipartition of neither the superior articular facets nor the occipital condyles were statistically significantly different between the left and right sides. Sex and age did not statistically significantly contribute to prevalence of bipartition in this population. However, population group statistically significantly contributed to prevalence of bipartition (p = 0.019), with the White South African sample having a much higher prevalence (88.24 % superior articulating facet, 100 % occipital condyle) of bipartition compared to the Black South African sample (11.76 % superior articular facet, 0 % occipital condyle). ConclusionAwareness of this joint variation and instances where it is more likely to occur may be valuable for neuro-vascular and orthopaedic surgeons when doing invasive treatments around the craniocervical junction, and chiropractors when assessing and treating patients.

Facet deflection and strain are dependent on axial compression and distraction in C5-C7 spinal segments under constrained flexion.

Facet fractures are frequently associated with clinically observed cervical facet dislocations (CFDs); however, to date there has only been one experimental study, using functional spinal units (FSUs), which has systematically produced CFD with concomitant facet fracture. The role of axial compression and distraction on the mechanical response of the cervical facets under intervertebral motions associated with CFD in FSUs has previously been shown. The same has not been demonstrated in multi-segment lower cervical spine specimens under flexion loading (postulated to be the local injury vector associated with CFD). This study investigated the mechanical response of the bilateral inferior C6 facets of thirteen C5-C7 specimens (67±13 yr, 6 male) during non-destructive constrained flexion, superimposed with each of five axial conditions: (1) 50 N compression (simulating weight of the head); (2-4) 300, 500, and 1000 N compression (simulating the spectrum of intervertebral compression resulting from neck muscle bracing prior to head-first impact and/or externally applied compressive forces); and, (5) 2 mm of C6/C7 distraction (simulating the intervertebral distraction present during inertial loading of the cervical spine by the weight of the head). Linear mixed-effects models (α = 0.05) assessed the effect of axial condition. Increasing amounts of intervertebral compression superimposed on flexion rotations, resulted in increased facet surface strains (range of estimated mean difference relative to Neutral: maximum principal = 77 to 110 με, minimum principal = 126 to 293 με, maximum shear = 203 to 375 με) and angular deflection of the bilateral inferior C6 facets relative to the C6 vertebral body (range of estimated mean difference relative to Neutral = 0.59° to 1.47°). These findings suggest increased facet engagement and higher load transfer through the facet joint, and potentially a higher likelihood of facet fracture under the compressed axial conditions.

Thoracic Fracture–Dislocation with Bilateral Locked Facet Joints: An Effective Reduction Technique

Thoracic Fracture–Dislocation with Bilateral Locked Facet Joints: An Effective Reduction Technique

Occlusion of vertebral artery and anterior spinal artery in cervical facet dislocation: a prospective study using computed tomography angiography.

A prospective study. To investigate the incidence of vertebral artery (VA) occlusion and whether anterior spinal artery (ASA) is occluded in cervical facet dislocation. University hospital, China. During a 2-year period, 21 conventional patients with cervical facet dislocation were prospectively enrolled. All patients received computed tomography angiography (CTA) to assess the patency of the VA, anterior radiculomedullary arteries (ARAs), and ASA at the time of injury. Clinical data were documented, including demographics, symptomatic vertebrobasilar ischemia, American Spinal Injury Association Impairment Scale (ASIA) grades, and ASA and VA radiological characteristics. VA unilateral occlusion occurred in 5 of 21 patients (24%), including 2 with unilateral facet dislocation and 3 with bilateral facet dislocation. No ASA occlusion was found in all 21 patients, including 5 with VA unilateral occlusion. No patients had symptomatic vertebrobasilar ischemia. VA occlusion occurs in approximately one-fourth of cervical facet dislocations, with infrequent symptomatic vertebrobasilar ischemia. ASA is not occluded following cervical facet dislocation, even with unilateral VA occlusion.

An Extended Neck Position is Likely to Produce Cervical Spine Injuries Through Buckling in Accidental Head-First Impacts During Rugby Tackling

Catastrophic cervical spine injuries in rugby often occur during tackling. The underlying mechanisms leading to these injuries remain unclear, with neck hyperflexion and buckling both proposed as the causative factor in the injury prevention literature. The aim of this study was to evaluate the effect of pre-impact head–neck posture on intervertebral neck loads and motions during a head-first rugby tackle. Using a validated, subject-specific musculoskeletal model of a rugby player, and computer simulations driven by in vivo and in vitro data, we examined the dynamic response of the cervical spine under such impact conditions. The simulations demonstrated that the initial head–neck sagittal-plane posture affected intervertebral loads and kinematics, with an extended neck resulting in buckling and supraphysiologic intervertebral shear and flexion loads and motions, typical of bilateral facet dislocation injuries. In contrast, an initially flexed neck increased axial compression forces and flexion angles without exceeding intervertebral physiological limits. These findings provide objective evidence that can inform injury prevention strategies or rugby law changes to improve the safety of the game of rugby.

Finite element analysis of the biomechanical effects of anterior and posterior cervical fusion surgery for bilateral cervical dislocation

Lower cervical spine injuries often manifest as lower cervical vertebral fractures and dislocations, as well as lower cervical facet joint dislocations. Especially in cases of bilateral facet joint dislocations, it is important to rapidly and effectively relieve spinal cord and nerve root compression to prevent secondary spinal cord injury, while also providing reliable and long-lasting stability to the injured segment after surgery. Combined anterior and posterior approaches have the advantages of both pure anterior or posterior approaches, but the actual situation is complex and variable, making systematic theoretical analysis crucial. This study, with bilateral facet joint dislocation of the C6 segment and cervical spinal cord injury as the research background, established a three-dimensional model of the cervical spine C3-C7 after implementing four types of anterior-posterior combined surgeries. The four surgical approaches consist of four combinations: anterior parallel or inclined screw placement combined with posterior Margel or Anderson method screw insertion. Through finite element method, a systematic comparative analysis of the theoretical effects of the four combined surgeries in treating bilateral facet joint dislocation of the cervical spine was conducted. The conclusion was that the variations in the four combined fixation methods have a certain impact on the biomechanical characteristics of the intervertebral disc nucleus. There is a clear mutual influence relationship among anterior and posterior fixation instruments. Based on the model used in this study, it is recommended to use a torque greater than 2.1 nm to tighten the locking nut of the posterior rod to ensure reliable internal fixation.

Predictors of failure after primary anterior cervical discectomy and fusion for subaxial traumatic spine injuries

IntroductionTraumatic subaxial fractures account for more than half of all cervical spine injuries. The optimal surgical approach is a matter of debate and may include anterior, posterior or a combined anteroposterior (360º) approach. Analyzing a cohort of patients initially treated with anterior cervical discectomy and fusion (ACDF) for traumatic subaxial injuries, the study aimed to identify predictors for treatment failure and the subsequent need for supplementary posterior fusion (PF).MethodsA retrospective, single center, consecutive cohort study of all adult patients undergoing primary ACDF for traumatic subaxial cervical spine fractures between 2006 and 2018 was undertaken and 341 patients were included. Baseline clinical and radiological data for all included patients were analyzed and 11 cases of supplementary posterior fixation were identified.ResultsPatients were operated at a median of 2.0 days from the trauma, undergoing 1-level (78%), 2-levels (16%) and ≥ 3-levels (6.2%) ACDF. A delayed supplementary PF was performed in 11 cases, due to ACDF failure. On univariable regression analysis, older age (p = 0.017), shorter stature (p = 0.031), posterior longitudinal ligament (PLL) injury (p = 0.004), injury to ligamentum flavum (p = 0.005), bilateral facet joint dislocation (p < 0.001) and traumatic cervical spondylolisthesis (p = 0.003) predicted ACDF failure. On the multivariable regression model, older age (p = 0.015), PLL injury (p = 0.048), and bilateral facet joint dislocation (p = 0.010) remained as independent predictors of ACDF failure.ConclusionsACDF is safe and effective for the treatment of subaxial cervical spine fractures. High age, bilateral facet joint dislocation and traumatic PLL disruption are independent predictors of failure. We suggest increased vigilance regarding these cases.

Fracture-dislocations of the subaxial cervical spine

Fracture-dislocations of the subaxial cervical spine are rare yet potentially devastating injuries often associated with high-energy trauma. These inherently unstable injuries frequently lead to neurologic compromise, necessitating urgent operative intervention. This review provides a comprehensive overview of subaxial cervical spine fracture-dislocations, addressing their epidemiology, anatomy, and classification systems. Classification schemes including Allen and Ferguson, Cervical Spine Injury Severity Score (CSISS), Subaxial Cervical Spine Injury Classification System (SLIC), and AO Spine Subaxial Cervical Spine Injury Classification System are discussed. Prompt recognition and management of these injuries is critical in optimizing long-term functional and neurologic outcomes. Rates of neurologic injury can exceed 50 %, with distractive flexion injuries and bilateral facet injuries often presenting with higher ASIA grades and lower neurologic recovery potential. Minimizing time to reduction is the most important factor in optimizing neurologic outcomes in these injury patterns. We discuss both closed and open reduction methods, timing considerations, technical pearls, and potential complications associated with each strategy. We also discuss the diagnosis and management of concurrent acute disk herniations, the role of advanced imaging, and the debated utility of pre-reduction MRI. Many subaxial cervical fracture-dislocations necessitate surgical intervention, which can be approached from an anterior, posterior, or combined approach. Although no standard surgical treatment algorithm exists, we discuss surgical options and situations where a preferred approach may exist. Selection of the approach depends on injury characteristics and surgeon preference, and there are no clearly defined surgical recommendations based on injury pattern.

Impact of bilateral facet joint violation on radiographic degeneration of superior adjacent segments and clinical outcomes.

Facet joint violation (FJV) is associated with postoperative low-back pain and is a confirmed risk factor for adjacent-segment degeneration, a long-term complication of lumbar fusion surgery. The authors' knowledge of its mechanisms comes from in vitro biomechanical research only; there is a lack of radiographic evidence of the effects of violation on the superior adjacent-segment facet joint, intervertebral disc, and other local radiographic parameters. Furthermore, any differences between unilateral and bilateral violation remain relatively unclear. The authors therefore aimed to explore the effects of nonviolation and unilateral and bilateral violation on radiographic degeneration of the facet joint and intervertebral disc at the fusion and superior adjacent segment. Patient-reported clinical outcomes were compared at the 2-year follow-up. The authors retrospectively analyzed data from 148 patients with lumbar degenerative diseases who underwent single-segment minimally invasive transforaminal lumbar interbody fusion between 2016 and 2020. FJV and facet joint degeneration were evaluated and graded using Shah's method and Pathria's standard, respectively. Radiographic parameters, including disc height and intervertebral Cobb angle at the fusion and superior adjacent segment, were measured. Clinical outcomes were evaluated using visual analog scale (VAS) and Japanese Orthopaedic Association scores. Preoperative data were comparable among the 3 groups (nonviolation, unilateral violation, and bilateral violation) (p > 0.05). Patient-reported clinical outcomes were followed up for at least 2 years (average duration 28.17 ± 6.17 months). At the last follow-up, facet joint degeneration grades were sequentially increased in the nonviolation, unilateral violation, and bilateral violation groups (p = 0.006). The unilateral (2.45 ± 2.17 mm) and bilateral (2.70 ± 1.94 mm) violation groups had more severe losses of disc height in the superior adjacent segment than did the nonviolation group (1.31 ± 2.01 mm). The VAS low-back pain and Japanese Orthopaedic Association scores in the bilateral (2.57 ± 1.44 and 19.83 ± 2.84, respectively) and unilateral (2.26 ± 0.79 and 20.43 ± 3.85, respectively) violation groups were significantly worse than in the nonviolation group (1.69 ± 1.12 and 21.80 ± 3.36, respectively) (p < 0.05). By contrast, there were no significant between-group differences in disc height, intervertebral Cobb angle in the fusion segment, or VAS leg pain scores (p > 0.05). FJV was associated with postoperative low-back pain and worse functional outcomes. It also aggravated facet joint and intervertebral disc changes in the superior adjacent segment, especially when bilateral violation occurred; this may be part of the mechanisms of adjacent-segment degeneration.

Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis.

Mixed-methods approach. Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

Contralateral approach using microscope and tubular retractor system for ipsilateral decompression of lumbar degenerative lateral recess stenosis associated with narrow spinal canal.

To summarize the clinical effect of a single-center retrospective analysis of the contralateral approach with a microscope and tubular retractor system for ipsilateral decompression in patients with lumbar lateral recess stenosis and a narrow spinal canal. A total of 25 patients who underwent ipsilateral decompression surgery via a contralateral approach with microscope and tubular retractor system, performed by one surgeon at a single center were retrospectively examined. The width of the lamina fenestration was compared with the preoperative distance from the root of the spinous process to the dorsal articular facet, the bilateral articular facet change in the suprapedicle notch section on CT scan, and with the changes in transverse and sagittal diameters of the canal area on MRI. Clinical efficacy was assessed using the Japanese Orthopedic Association (JOA), Visual Analog Scale (VAS), and Oswestry Disability Index (ODI) scores. In total, 25 patients were treated and the mean intraoperative time was 82.04 ± 12.48 min. There was no nerve injury, cerebrospinal fluid leakage, and infection complications. The postoperative CT revealed that the width of the contralateral laminar fenestration was less than the distance from the root of the spinous process to the dorsal articular facet. The residual widths of the ipsilateral articular facet and contralateral articular facet were greater than 2/3 of the preoperative articular facet width. The transverse and sagittal diameter of canal were significantly increased. The mean follow-up period was 12-16 months, and no recurrence or reoperation incidence were found at the last follow-up. When compared to pre-surgery, the ODI, VAS, and JOA scores were significantly improved after surgery (p < 0.05). Based on our single-center retrospective observation of 25 cases and combined with previous literature, the contralateral approach with a microscope and tubular retractor system for ipsilateral decompression in patients with lumbar lateral recess stenosis and a narrow spinal canal can reduce damage to the articular processes, and probably more conducive to the postoperative stability of the lumbar spine. This was a single center retrospective analysis with a small sample size and lacked randomized controlled trials (RCTs). However, larger-scale, multicenter RTCs are required for additional validation.

Association Between MRI Findings of Facet Arthropathy and Synovitis With Health-Related Outcome and Pain Scores Following Therapeutic Lumbar Facet Injections.

Low back pain is a common complaint among adults. The facet joint is a major source of lumbar pain, and therapeutic facet injections have gained popularity as a minimally invasive treatment option. In addition, magnetic resonance imaging (MRI) utilization for diagnosing low back pain has increased significantly over the past few decades. Facet synovitis is an entity characterized by edema and inflammatory changes affecting the facet joints, adjacent bone marrow, and surrounding soft tissues. Although its underlying etiology remains poorly understood, recent reports suggest a high incidence in patients with arthropathy and arthritis. It is essential to explore potential correlations between specific MRI findings and outcomes after lumbar facet injections. This investigation is particularly relevant for facet synovitis, given its inflammatory nature and the common use of anti-inflammatory agents in facet injections. We investigated associations between MRI evidence of facet arthropathy and/or synovitis and the degree of improvement in health-related outcome and pain scores after therapeutic facet injections. The review was conducted on patients who received bilateral therapeutic facet injections, excluding those with prior lumbar spinal surgery or transitional segments. Facet arthropathy and synovitis were assessed on MRI by two neuroradiologists, and postprocedure outcomes such as pain and function were compared using univariate and multivariate analyses based on MRI findings. Our retrospective review indicates that patients receiving facet injections experience greater mean reduction in daily activity and workability burden scores from back pain when facet synovitis is a known portion of their pathology. The authors pose that further study could help identify patient populations that are the best candidates for therapeutic intervention. This may ultimately improve delivery of care, cost efficacy, and patient satisfaction.

Supplementary posterior fusion in patients operated on employing TLIF may decrease the instrumentation failure rate.

It is supposed that additional posterior fusion may provide additional stability of the pedicle screw; however, the clinical impact of additional posterior fusion in patients treated with TLIF remains uncertain. The objective of this study is to assess the clinical efficacy of circumferential fusion in patients treated with TLIF. This is a single-center retrospective evaluation of consecutive 179 patients with degenerative lumbar stenosis and instability of spinal segments. Patients with axial pain and neurogenic claudication or radiculopathy associated with spinal stenosis were enrolled during the period from 2012 to 2018. Transforaminal lumbar interbody fusion (TLIF) with a single cage was used to treat patients. In 118 cases a supplementary posterior fusion was made. The duration of follow-up accounted for 24 months, logistic regression analysis was used to assess factors that influence the complication rate. The rate of pedicle screw loosening was growing with radiodensity getting decreased and was more frequent in patients with two level fusion. An increase in pedicle screw loosening rate correlated with anterior nonunion Tan 2 and 3 grade while both posterior complete and incomplete fusion resulted in a decline in the complication rate. Lumbosacral fusion, bilateral facet joints` resection and laminectomy turned out to be insignificant factors. The overall goodness of fit of the estimated general multivariate model was χ2 = 87.2230; P < 0.0001. To confirm clinical relevance of those findings, a univariate logistic regression was performed to assess the association between clinically significant pedicle screw instability and posterior fusion in patients operated on employing TLIF. The results of logistic regression analysis demonstrate that additional posterior fusion may decrease the rate of instrumentation failure that requires revision surgery in patients treated with TLIF [B0 = 1.314321; B1 = -3.218279; p = 0.0023; OR = 24.98507; 95% CI (3.209265; 194.5162), the overall goodness of fit of the estimated regression was χ2 = 22.29538, p = <0.0001]. Circumferential fusion in patients operated on employing TLIF is associated with a decline in the rate of pedicle screw loosening detected by CT imaging and clinically significant instrumentation failure.

Traumatic L5-S1 spondylolisthesis: A case report

Purpose: Here, we report the diagnosis and management of a patient with a traumatic lumbosacral spondylolisthesis, a rare clinical entity that is characterized by unilateral or bilateral facet dislocations causing displacement at the level of the fifth lumbar vertebra in relation to the sacrum. &#x0D; Case presentation: We report a case of a traumatic L5-S1 unilateral lumbosacral dislocation. Based on the preoperative CT and MRI findings, the patient sustained a right-side unilateral L5–S1 subluxation with an L5 right inferior articular process fracture, a torn anterior longitudinal ligament and posterior ligamentous complex, and L5-S1 disc protrusion. Decompression, reduction with L4, L5, S1 pedicular screw fixation, L5-S1 disc excision, and interbody cage insertion were performed. The patient had an uneventful recovery and returned to his previous activities 6 months after surgery.

SURG-27. 17-YEAR EXPERIENCE OF SURGICAL MANAGEMENT OF INTRADURAL EXTRAMEDULLARY (IDEM) TUMORS: CLINICAL OUTCOMES FROM A LOW- AND MIDDLE-INCOME COUNTRY

Abstract INTRODUCTION Surgical outcomes of intradural extramedullary (IDEM) tumors have been well-reported in the literature from high-income countries. However, limited contemporaneous data from low- and middle-income countries (LMICs) exists. This study sought to analyze the clinical outcomes of all IDEM tumor cases operated during a 17-year period at a resource-limited setting in an LMIC. METHODS The present work was conducted and reported in accordance with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. A retrospective cohort study was carried out to analyze all IDEM tumor cases, operated upon by a consultant neurosurgeon, during 2004-2021, at a resource-limited setting in Southern India. All patients underwent routine biochemical and radiological investigations, including contrast-enhanced MRI. Laminectomy and tumor resection under the microscope were done without using intraoperative neuro-monitoring. Nerve fibers running through the tumor were sacrificed. Bilateral facet joints were preserved to ensure integrity without spinal fusion. All cases received a dural closure with 5-0 Prolene, with postoperative MRI confirming complete resection. Patients received telephonic and/or in-person follow-up visits. RESULTS 50 patients with a mean age of 46.3 years (range 13-80) were included, with 31 males and 19 females. Their clinical presentation included radiculopathy (78%), radiculomyelopathy (12%), and radiculomyelopathy with bowel and bladder symptoms (10%). Histologically, schwannomas were the most common (52%), followed by neurofibromas (34%), meningiomas (12%), and ependymomas (2%). Two individuals were diagnosed with Neurofibromatosis Type 1. All meningiomas occurred in the thoracic region, with 83.3% of cases being in females. All patients had symptomatic relief postoperatively. No major adverse events occurred, including CSF leaks, permanent neurological deficits, or spinal instability. Recurrence occurred in two 'dumbbell' tumors (4%) at 5 and 7 years after primary excision during follow-up, managed with successful re-resection. CONCLUSION Microsurgical excision of IDEM tumors carries high safety and efficacy, including in resource-limited settings like LMICs.