Prevalence and Risk Factors of Degenerative Spondylolisthesis and Retrolisthesis in the Thoracolumbar and Lumbar Spine - An EOS Study Using Updated Radiographic Parameters.

STUDY DESIGN: Single centre, cross-sectional study. OBJECTIVES: The objective is to report the prevalence of spondylolisthesis and retrolisthesis, analyse both conditions in terms of the affected levels and severity, as well as identify their risk factors. METHODS: A review of clinical data and radiographic images of consecutive spine patients seen in outpatient clinics over a 1-month period is performed. Images are obtained using the EOS® technology under standardised protocol, and radiographic measurements were performed by 2 independent, blinded spine surgeons. The prevalence of both conditions were shown and categorised based on the spinal level involvement and severity. Associated risk factors were identified. RESULTS: A total of 256 subjects (46.1% males) with 2304 discs from T9/10 to L5/S1 were studied. Their mean age was 52.2(± 18.7) years. The overall prevalence of spondylolisthesis and retrolisthesis was 25.9% and 17.1% respectively. Spondylolisthesis occurs frequently at L4/5(16.3%), and retrolisthesis at L3/4(6.8%). Majority of the patients with spondylolisthesis had a Grade I slip (84.3%), while those with retrolisthesis had a Grade I slip. The presence of spondylolisthesis was found associated with increased age (P < .001), female gender (OR: 2.310; P = .005), predominantly sitting occupations (OR:2.421; P = .008), higher American Society of Anaesthesiology grades (P = .001), and lower limb radiculopathy (OR: 2.175; P = .007). Patients with spondylolisthesis had larger Pelvic Incidence (P < .001), Pelvic Tilt (P < .001) and Knee alignment angle (P = .011), but smaller Thoracolumbar junctional angle (P = .008), Spinocoxa angle (P = .007). Retrolisthesis was associated with a larger Thoracolumbar junctional angle (P =.039). CONCLUSION: This is the first study that details the prevalence of spondylolisthesis and retrolisthesis simultaneously, using the EOS technology and updated sagittal radiographic parameters. It allows better understanding of both conditions, their mutual relationship, and associated clinical and radiographic risk factors.

Fulcrum to Generate Maximum Extension of the Spine and Hip-Proposing A New Strategy using EOS Imaging for Patient-specific Assessment of Degenerated Lumbar Spines.

STUDY DESIGN: A retrospective, radiographic comparative study conducted in a single academic institution. OBJECTIVE: This study aims to compare fulcrum extension with conventional extension imaging to determine maximum "hip lordosis" (HL), an important novel patient-specific parameter in spinal realignment surgery, as well as understand the extension capabilities of the lower lumbar spine, which together, are key contributors to whole-body balancing. SUMMARY OF BACKGROUND DATA: Recent literature recognizes the hip as an important contributor to whole-body lordosis beyond a compensator for spinal imbalance. METHODS: Patients >45 years' old with mechanical low back pain due to degenerative spinal conditions were included and grouped based on the imaging performed-fulcrum or conventional extension. All imaging was performed using EOS under standardized instructions and visual aids. Radiographic parameters include global lumbar angle (GLA), inflexion-S1 (Inf-S1) angle, segmental lumbar angles, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), femoral alignment angle (FAA), HL and spinocoxa angle (SCA). Unpaired t test was used to compare between radiographic parameters. RESULTS: One hundred patients (40 males and 60 females, mean age 63.0 years) underwent either fulcrum or conventional extension EOS® imaging. Both groups had comparable baseline radiographic parameters. Fulcrum extension gave a larger mean GLA (-60.7° vs. -48.5°, P = 0.001), Inf-S1 angle (-58.8° vs. -48.8°, P = 0.003), SCA (-36.5° vs. -24.8°, P < 0.001), L4/5 and L5/S1 lordosis (-20.7° vs. -17.7°, P = 0.041, and -22.3° vs. -17.1°, P = 0.018, respectively), compared to conventional extension. PI, SS, PT, FAA, and HL were similar between both extension postures. CONCLUSION: Fulcrum extension, compared to conventional extension, is better at generating lordosis in the lower lumbar spine, thus improving preoperative assessment of stiffness or instability of the lumbar spine. Both extension methods were equally effective at determining the patient-specific maximum HL to assess the flexibility and compensation occurring at the hip, potentially guiding surgical management of patients with degenerative spines.Level of Evidence: 3.

Sagittal Radiographic Parameters of the Spine in Three Physiological Postures Characterized Using a Slot Scanner and Their Potential Implications on Spinal Weight-Bearing Properties.

STUDY DESIGN: Prospective radiographic comparative study. PURPOSE: To compare and understand the load-bearing properties of each functional spinal unit (FSU) using three commonly assumed, physiological, spinal postures, namely, the flexed (slump sitting), erect (standing) and extended (backward bending) postures. OVERVIEW OF LITERATURE: Sagittal spinal alignment is posture-dependent and influences the load-bearing properties of the spine. The routine placement of intervertebral cages "as anterior as possible" to correct deformity may compromise the load-bearing capabilities of the spine, leading to complications. METHODS: We recruited young patients with nonspecific low back pain for <3 months, who were otherwise healthy. Each patient had EOS images taken in the flexed, erect and extended positions, in random order, as well as magnetic resonance imaging to assess for disk degeneration. Angular and disk height measurements were performed and compared in all three postures using paired t-tests. Changes in disk height relative to the erect posture were caclulated to determine the alignment-specific load-bearing area of each FSU. RESULTS: Eighty-three patients (415 lumbar intervertebral disks) were studied. Significant alignment changes were found between all three postures at L1/2, and only between erect and flexion at the other FSUs. Disk height measurements showed that the neutral axis of the spine, marked by zones where disk heights did not change, varied between postures and was level specific. The load-bearing areas were also found to be more anterior in flexion and more posterior in extension, with the erect spine resembling the extended spine to a greater extent. CONCLUSIONS: Load-bearing areas of the lumbar spine are sagittal alignment-specific and level-specific. This may imply that, depending on the surgical realignment strategy, attention should be paid not just to placing an intervertebral cage "as anterior as possible" for generating lordosis, but also on optimizing load-bearing in the lumbar spine.

Addressing Coronavirus Disease 2019 in Spine Surgery: A Rapid National Consensus Using the Delphi Method via Teleconference.

The magnitude and potential duration of the current coronavirus disease 2019 (COVID-19) pandemic is something that most doctors currently in practice have yet to experience. While considerable information regarding COVID-19 is being published every day, it is challenging to filter out the most relevant or appropriate information for our individual practice. The Spine Society of Singapore convened via a teleconference on April 24, 2020 to collaborate on a national level and share collective wisdom in order to tackle the ongoing crisis. In the teleconference, 13 spine surgeons from across various hospitals in Singapore constituted the panel of experts. The following topics were discussed: repurposing of surgeons, continuity of spine services, introduction of telemedicine, triaging of spinal surgeries, preoperative testing, new challenges in performing spine surgery, and preparing for the post-pandemic era. While some issues required only the sharing of best practices, the Delphi panel method was adopted to form a consensus on others. Existing spine specific triage guidelines were debated and a locally accepted set of guidelines was established. Although preoperative testing is currently not performed routinely, the panel voted in favor of its implementation because they concluded that it is vital to protect themselves, their colleagues, and their patients. Solutions to operating room specific concerns were also discussed. This article reflects the opinions and insights shared during this meeting and reviews the evidence relevant to the issues that were raised. The rapid consensus reached during the teleconference has enabled us to be concerted, and thus stronger, in our national efforts to provide the best standard of care via our spine services in these challenging times. We believe that this article will provide some guidance for addressing COVID-19 in spine surgery and encourage other national/regional societies to conduct similar discussions that would help their navigation of this pandemic.

Anatomic techniques for cervical pedicle screw placement.

Instrumentation of the cervical spine with cervical pedicle screws (CPS) is beneficial in patients with various types of spinal pathology. Despite posing greater technical challenges, CPS instrumentation confers better fixation outcomes when compared to lateral mass screws. While developments in technology have augmented the accuracy of CPS insertion, mastery in freehand CPS insertion allows the aforementioned technologies to reach their full potential in improving patient outcomes. The aim of this article is to discuss freehand CPS insertion techniques as established in the current literature while sharing our experience in this context. A comprehensive literature search was performed using the following electronic databases: PubMed, Medline, and EMBASE. Full-text articles focusing on clinical studies with description of freehand techniques were included. Articles which were on cadaveric studies, drill jig, navigation or robotic technology were excluded. Thirteen primary references comprising 1,480 patients were included in this review. Majority of studies reported utilizing the cranial margin of lamina for C2 level as a landmark for entry point, as well as lateral to centre of the articular mass, and just medial to the lateral border of the superior articular process for C3-7 levels. Method of tracking and facilitation of trajectory was reported in multiple studies, with use of instruments ranging from curved pedicle probes to high-speed burrs. Limited studies reported specific trajectories of CPS insertion. Most studies noted testing pedicle wall integrity at various checkpoints, with pedicle screw repositioning or conversion to lateral screw mass following detection of perforation or screw malpositioning. Success in CPS insertion rests on meticulous preoperative planning to identify the ideal screw entry point and trajectory. Patient-specific drill jigs, navigation and robotic technologies, while beneficial to progress in the field of cervical spine surgery and patient outcomes, should serve primarily to augment good expertise in freehand CPS insertion technique.

Characterization of Sagittal Spine Alignment With Reference to the Gravity Line and Vertebral Slopes: An Analysis of Different Roussouly Curves.

MINI: Spinal sagittal realignment necessitates a reference posture, and thus far this has only been defined for an "averaged" curve via horizontal offsets from the gravity line (GL). This prospective study of 169 healthy subjects demonstrates normative sagittal spatial orientation of each vertebra, for all Roussouly curve types, using vertebral slopes and horizontal offsets from the GL. STUDY DESIGN: Prospective study. OBJECTIVE: To map the healthy standing alignment of the adult spine, grouped according to Roussouly curve types, using both horizontal offset distance from the gravity line (GL), as well as vertebral slope measurements. SUMMARY OF BACKGROUND DATA: Spinal sagittal realignment requires a reference posture, and this has been defined in the literature via horizontal offsets from the GL. While useful, this does not provide information on the orientation of each vertebral segment, or distinguish between the various physiological curve types. METHODS: A total of 169 consecutive young adult subjects with healthy spines were recruited over a year. (EOS Imaging, Paris, France) whole body radiographs were performed. Radiographic measurements collected included sagittal vertical axis (SVA), T1-slope, global cervical angle (GCA), global thoracic angle (GTA), global lumbar angle (GLA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), apical and inflection vertebrae. Outcome measures comprised slope measurements, and distance offsets relative to the GL for individual vertebrae from T3 to S1. RESULTS: GLA, PI, PT, SS, apex of lordosis, and inflection vertebra were significantly different across groups, while SVA, T1-slope, GCA, GTA, and apex of kyphosis were not. Mean PI to LL discrepancy for Type I to IV groups were 8.0°, 2.3°, 4.8°, and 3.0°, respectively. Between groups, T3, T7 to T12, and L2 to S1 slopes and T9 to L3 offset distances from GL were significantly different, while the distance of the hip center from the GL was not. GLA was significantly different between curve types except between Type 1 and 2 curves, while the inflection vertebrae were not significantly different between Type 1 and 2 curves, as well as Type 3 and 4 curves. CONCLUSION: This study demonstrates normative sagittal spatial orientation of each vertebra in healthy adults, for each Roussouly type. Comparison across groups suggests the possibility of further refining the sagittal curve patterns described by Roussouly. LEVEL OF EVIDENCE: 3.

Prospective study. To map the healthy standing alignment of the adult spine, grouped according to Roussouly curve types, using both horizontal offset distance from the gravity line (GL), as well as vertebral slope measurements. Spinal sagittal realignment requires a reference posture, and this has been defined in the literature via horizontal offsets from the GL. While useful, this does not provide information on the orientation of each vertebral segment, or distinguish between the various physiological curve types. A total of 169 consecutive young adult subjects with healthy spines were recruited over a year. (EOS Imaging, Paris, France) whole body radiographs were performed. Radiographic measurements collected included sagittal vertical axis (SVA), T1-slope, global cervical angle (GCA), global thoracic angle (GTA), global lumbar angle (GLA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), apical and inflection vertebrae. Outcome measures comprised slope measurements, and distance offsets relative to the GL for individual vertebrae from T3 to S1. GLA, PI, PT, SS, apex of lordosis, and inflection vertebra were significantly different across groups, while SVA, T1-slope, GCA, GTA, and apex of kyphosis were not. Mean PI to LL discrepancy for Type I to IV groups were 8.0°, 2.3°, 4.8°, and 3.0°, respectively. Between groups, T3, T7 to T12, and L2 to S1 slopes and T9 to L3 offset distances from GL were significantly different, while the distance of the hip center from the GL was not. GLA was significantly different between curve types except between Type 1 and 2 curves, while the inflection vertebrae were not significantly different between Type 1 and 2 curves, as well as Type 3 and 4 curves. This study demonstrates normative sagittal spatial orientation of each vertebra in healthy adults, for each Roussouly type. Comparison across groups suggests the possibility of further refining the sagittal curve patterns described by Roussouly. Level of Evidence: 3.

Comparison of whole body sagittal alignment during directed vs natural, relaxed standing postures in young, healthy adults.

BACKGROUND CONTEXT: Imaging for adult spinal deformity is conventionally performed in a directed manner to assess the most upright standing posture one can assume. However, this method does not reflect an individual's natural, relaxed posture, which is the posture a patient likely reverts to postoperatively, and also the posture likely to explain spinal pathologies. PURPOSE: To identify radiographic differences between directed and natural, relaxed standing postures in young healthy subjects. STUDY DESIGN: A randomized, prospective, radiographic study. PATIENT SAMPLE: Sixty healthy 21-year-old subjects (48 male, 12 female). OUTCOME MEASURES: Radiographic parameters including sagittal vertical axis (SVA), C2 SVA, C2-7 SVA global cervical angle, T1-slope, global thoracic angle (GTA), thoracolumbar angle (TLA), global lumbar angle (GLA), sacral slope, pelvic tilt (PT), pelvic incidence, femoral alignment angle (FAA), and knee alignment angle (KAA). METHODS: The EOS whole body radiographs of patients in directed and natural, relaxed standing postures were obtained, with subsequent comparison of radiographic parameters. Differences in Roussouly curve types, sagittal curve apices, and end vertebrae were also evaluated. Univariate analyses using Wilcoxon sign-rank, paired t tests, and paired chi-square tests were performed. RESULTS: Compared with directed standing, natural, relaxed standing results in a more kyphotic spinal profile marked by a significantly less lordotic GLA, larger GTA, TLA, and T1-slope. The PT+FAA demonstrated true hip movement during sagittal balancing. Lower thoracic and lumbar apices, lower thoracolumbar end vertebrae, and lower Roussouly curve types were observed during natural, relaxed standing. CONCLUSIONS: Our study found significant differences in sagittal radiographic parameters between directed standing and the natural, relaxed standing posture, with the latter demonstrating a more kyphotic spinal profile in terms of magnitude and span, as well as complementary changes in cervical and spinopelvic alignment. The natural, relaxed standing posture, a marker for energy conservation principles in standing, may infer value in less aggressive lordotic restoration, as well as concentration of lordosis in the lower lumbar spine.

The Influence of Histologic Subtype in Predicting Survival of Lung Cancer Patients With Spinal Metastases.

STUDY DESIGN: Retrospective analysis. SUMMARY OF BACKGROUND DATA: Recent advancements in systemic treatment of lung cancer have significantly improved the survival of patients with certain histolopathologic and molecular subtypes. Existing prognostic scores do not account for this and patients with lung cancer spinal metastases are grouped together as poor prognostic candidates, and consequently, some may be inappropriately denied palliative spine surgery. OBJECTIVE: The objective of the study was to study whether the expected survival in patients with lung cancer spinal metastases is affected by histolopathologic and molecular subtypes in the context of modern systemic therapy. MATERIALS AND METHODS: We retrospectively reviewed all patients with histologically confirmed lung cancer treated for spinal metastases at our institution between 2001 and 2012. Patients' demographics, histopathologic details, treatment modalities, and survival data were collected. The primary outcome was survival from time of spinal metastases diagnosis. The Cox regression analysis was used to evaluate the influence of tumor histology, molecular profile and treatment modality on survival. The Kaplan-Meier survival analysis was conducted to compare lung cancer subtypes, as well as various treatment regimens. RESULTS: Out of 180 patients, 51 underwent surgery for spinal metastases. Female sex (P=0.019), absence of palsy (P=0.023), good Karnofsky performance scores (P<0.001), and non-small cell lung cancer (NSCLC) (P=0.002) were favorable prognostic factors. Patients who received systemic therapy, including tyrosine kinase inhibitors, platinum doublet chemotherapy, or both showed increased survival (P<0.01). The median survival time was 2.40 months [95% confidence interval (CI), 2.13-2.68] in the small cell lung cancer cohort, with no patients surviving past a year; 5.10 months (95% CI, 3.78-6.41) in the NSCLC cohort, with 25.9% 1-year survival; and 13.3 months (95% CI, 2.26-24.40) in adenocarcinoma patients who received both tyrosine kinase inhibitors and platinum doublet therapy, with 50.0% 1-year survival. CONCLUSIONS: NSCLC, systemic therapy, female sex, absence of palsy and good Karnofsky performance scores are all independent favorable prognostic factors for patients with lung cancer spinal metastases. These should be routinely considered during prognostication.

Using spinopelvic parameters to estimate residual lumbar lordosis assuming previous lumbosacral fusion-a study of normative values.

BACKGROUND CONTEXT: Pelvic incidence (PI)=pelvic tilt (PT)+sacral slope (SS) is an established trigonometric equation which can be expanded from studying the fixed pelvis with the spine to a fixed spinopelvic complex with the remnant spine, in scenarios of spinopelvic fusion or ankylosis. For a fixed spinopelvic complex, we propose the equation termed: lumbar incidence (LI)=lumbar tilt (LT)+lumbar slope (LS). PURPOSE: This study aimed to establish reference values for LI, LT, and LS at each lumbar vertebral level, and to show how LI can be used to determine residual lumbar lordosis (rLL). STUDY DESIGN: This is a cross-sectional study of prospectively collected data, conducted at a single academic tertiary health-care center. PATIENT SAMPLE: The study included 53 healthy patients aged 19-35 with first episode mechanical low back pain for a period of <3 months. Patients with previous spinal intervention, those with known or suspected spinal pathologies, and those who were pregnant, were excluded. OUTCOME MEASURES: Radiological measurements of LI, LT, LS, and rLL. METHODS: All patients had full-body lateral standing radiographs obtained via a slot scanner. Basic global and regional radiographic parameters, spinopelvic parameters, and the aforementioned new parameters were measured. LI was correlated with rLL at each level by plotting LI against rLL on scatter plots and drawing lines-of-best-fit through the datapoints. RESULTS: The mean value of L5I was 22.82°, L4I was 6.52°, L3I was -0.92°, L2I was -5.56°, and L1I was -5.95°. LI turns negative at L3, LS turns negative at the L3/L4 apex, and LT remains positive throughout the lumbar spine. We found that the relationship of LI with its corresponding rLL follows a parabolic trend. Thus, rLL can be determined from the linear equations of the tangents to the parabolic lumbar spine. We propose the LI-rLL method for determining rLL as the LI recalibrates via spinopelvic compensation post instrumentation, and thus the predicted rLL will be based on this new equilibrium, promoting restoration of harmonized lordosis. The rLL-to-LI ratio is a simplified, but less accurate, method of deriving rLL from LI. CONCLUSIONS: This study demonstrates the extended use of PI=PT+SS proposed as LI=LT+LS. These new spinopelvic reference values help us better understand the position of each vertebra relative to the hip. In situations when lumbar vertebrae are fused or ankylosed to the sacrum to form a single spinopelvic complex, LI can be used to determine rLL, to preserve spinal harmony within the limits of compensated body balance.

Concomitant meniscal injury in anterior cruciate ligament reconstruction does not lead to poorer short-term post-operative outcomes.

PURPOSE: The main objective was to compare post-operative outcomes in patients undergoing anterior cruciate ligament (ACL) reconstruction both with and without concomitant meniscus injury at a mean follow-up of 3.5 years. The secondary objective was to study the effect of different meniscal injury sites and treatment modalities on post-operative outcomes (PROS). METHODS: This is a retrospective analysis of a prospectively maintained database of patients undergoing ACL reconstruction at our tertiary institution between 2009 and 2012. Age, sex, graft type, graft fixation modality, location of meniscal tear and treatment (meniscal repair or meniscectomy) were recorded in the database. PROS used included the Tegner activity scale and the Lysholm score. RESULTS: There were no significant differences between patients with or without meniscal injury in terms of age, BMI or preoperative PROS. There was no significant difference in the post-operative outcome scores between patients with or without meniscal injury at a mean follow-up of 3.5 years. Regardless of the location of meniscal injury, the post-operative scores improved as compared to preoperative scores. CONCLUSION: Concomitant meniscal injury in cases of ACL reconstruction is not associated with poorer short-term post-operative PROS (mean follow-up time: 3.5 years). These findings may influence management decisions and help in preoperative counselling. LEVEL OF EVIDENCE: IV.

The utility of magnetic resonance imaging in addition to computed tomography scans in the evaluation of cervical spine injuries: a study of obtunded blunt trauma patients.

PURPOSE: Evidence guiding the use of CT and MRI scans in blunt trauma patients who are obtunded remains controversial. This study aims to determine and predict if computed tomography (CT) scans alone can be performed without risking oversight of substantial injuries found on follow-up magnetic resonance imaging (MRI). METHODS: This is a retrospective cohort study of 63 blunt trauma patients with a Glasgow Coma Scale of < 8. Data were collated from electronic medical records and included patient demographics, premorbid mobility, mechanism of injury, suspected level of injury and neurological examination findings. Patients were urgently evaluated using CT scans, followed by non-contrast MRI scans within 48 h of admission. The accuracy of CT scan was evaluated using MRI as a reference. Adjusted multivariable analysis was also performed to identify predictors for findings detected on MRI but not on CT. RESULTS: The mean age of patients was 42.3 years and 90.5% were males. CT scans had a high specificity of 100% and sensitivity of 87.2%. Predictors of MRI abnormalities include females, patients with relatively milder mechanisms of injury, patients with suspected thoracic spine injury, and CT scan findings of facet dislocation and intracranial haemorrhage. There was no predictor for spinal cord oedema. CONCLUSIONS: MRI should be performed in the presence of the aforementioned predictive factors and in the presence of neurological deficits. Otherwise, patients can be treated medically without the fear of missing a substantial cervical injury.

Radiologically defining horizontal gaze using EOS imaging-a prospective study of healthy subjects and a retrospective audit.

BACKGROUND CONTEXT: As sagittal alignment of the cervical spine is important for maintaining horizontal gaze, it is important to determine the former for surgical correction. However, horizontal gaze remains poorly-defined from a radiological point of view. PURPOSE: The objective of this study was to establish radiological criteria to define horizontal gaze. STUDY DESIGN/SETTING: This study was conducted at a tertiary health-care institution over a 1-month period. PATIENT SAMPLE: A prospective cohort of healthy patients was used to determine the best radiological criteria for defining horizontal gaze. A retrospective cohort of patients without rigid spinal deformities was used to audit the incidence of horizontal gaze. OUTCOME MEASURES: Two categories of radiological parameters for determining horizontal gaze were tested: (1) the vertical offset distances of key identifiable structures from the horizontal gaze axis and (2) imaginary lines convergent with the horizontal gaze axis. MATERIALS AND METHODS: Sixty-seven healthy subjects underwent whole-body EOS radiographs taken in a directed standing posture. Horizontal gaze was radiologically defined using each parameter, as represented by their means, 95% confidence intervals (CIs), and associated 2 standard deviations (SDs). Subsequently, applying the radiological criteria, we conducted a retrospective audit of such radiographs (before the implementation of a strict radioimaging standardization). RESULTS: The mean age of our prospective cohort was 46.8 years, whereas that of our retrospective cohort was 37.2 years. Gender was evenly distributed across both cohorts. The four parameters with the lowest 95% CI and 2 SD were the distance offsets of the midpoint of the hard palate (A) and the base of the sella turcica (B), the horizontal convergents formed by the tangential line to the hard palate (C), and the line joining the center of the orbital orifice with the internal occipital protuberance (D). In the prospective cohort, good sensitivity (>98%) was attained when two or more parameters were used. Audit using Criterion B+D yielded compliance rates of 76.7%, a figure much closer to that of A+B+C+D (74.8%). From a practical viewpoint, Criterion B+D were most suitable for clinical use and could be simplified to the "3-6-12 rule" as a form of cursory assessment. Verbal instructions in the absence of stringent postural checks only ensured that ~75% of subjects achieved horizontal gaze. CONCLUSIONS: Fulfillment of Criterion B+D is sufficient to evaluate for horizontal gaze. Further criteria can be added to increase sensitivity. Verbal instructions alone yield high rates of inaccuracy when attempting to image patients in horizontal gaze. Apart from improving methods for obtaining radiographs, a radiological definition of horizontal gaze should be routinely applied for better evaluation of sagittal spinal alignment.

Evaluation of Prognostic Factors and Proposed Changes to the Modified Tokuhashi Score in Patients With Spinal Metastases From Breast Cancer.

STUDY DESIGN: A retrospective study of all patients with histologically confirmed breast cancer spinal metastases presenting to a single institution between May 2001 and April 2012. OBJECTIVES: The aim of this study was to investigate whether the 2014mT is more accurate than the 2005mT. SUMMARY OF BACKGROUND DATA: The commonly used 2005 modified Tokuhashi score (2005mT) has become more inaccurate as oncologists move toward treating tumors according to their molecular and genomic profile, rather than their tissue-of-origin. In attempts to improve the accuracy of the 2005mT, a revised score (2014mT) was published, suggesting that hormone receptor negative and triple-negative breast cancer patients be given a modified Tokuhashi histological score of 3 rather than 5. METHODS: Demographic characteristics, tumor receptor status, clinical findings in relation to the primary tumor and its metastases, and actual survival time were collated. The 2005mT was compared with the 2014mT. Univariate and multivariate Cox regression analyses were used to evaluate the influence of each parameter on survival, and receiver operating characteristic curves were used to determine predictive values of each score version. RESULTS: Of the 185 patients included, 32 underwent operative treatment, while 153 were managed nonoperatively for their spinal metastases. The overall cohort had a median survival time of 24 months following the diagnosis of spinal metastases, with a 6-month survival rate of 90%. Hormone, HER2 and triple-negative receptor statuses were significant predictors of poorer survival upon multivariate analysis (P = 0.004, P = 0.007, P < 0.001, and P < 0.001, respectively). Age, the original Tokuhashi score components, previous breast surgery for cancer, previous radiotherapy to the breast, previous radiotherapy to the spine, previous chemotherapy, and previous immunotherapy were not significant. At 6 months, the 2005mT AUROC was 0.62, while that of the 2014mT was 0.64 (P = 0.5394). CONCLUSION: Tumor histological subtype is crucial when prognosticating the survival of patients with breast cancer spinal metastases. Although the 2014mT was marginally more accurate than the 2005mT, its predictive ability remains poor. LEVEL OF EVIDENCE: 3.

Outcomes of Short Fusion versus Long Fusion for Adult Degenerative Scoliosis: A Systematic Review and Meta-analysis.

The objective of this study was to evaluate differences in clinical and radiographic outcomes between short (<3 levels) and long (≥3 levels) fusions in the setting of degenerative lumbar scoliosis. A literature search was performed from six electronic databases. The key terms of "degenerative scoliosis" OR "lumbar scoliosis" AND "fusion" were combined and used as MeSH subheadings. From relevant studies identified, demographic data, complication rates, Oswestry Disability Index (ODI), and radiographic parameters were extracted and the data was pooled and analyzed. Long fusion was associated with comparable overall complication rates to short fusion (17% vs 14%, P = 0.20). There was a significant difference in the incidence of pulmonary complications when comparing short versus long fusion (0.42% vs 2.70%; P = 0.02). No significant difference was found in terms of motor, sensory complications, infections, construct-related or cardiac complications, pseudoarthrosis, dural tears, cerebrospinal fluid (CSF) leak, or urinary retention. A longer fusion was associated with a greater reduction in coronal Cobb angle and increases in lumbar lordosis, but both findings failed to achieve statistical significance. The ODI was comparable across both cohorts. If shorter fusion lengths are clinically indicated, they should be used instead of longer fusion lengths to reduce perioperative time, costs, and some other complications. However, there are no statistically significant differences in terms of radiographically measurable restoration associated with a short or long fusion.

Anterior lumbar discectomy and fusion for acute cauda equina syndrome caused by recurrent disc prolapse: report of 3 cases.

There is a lack of information and consensus regarding the optimal treatment for recurrent disc herniation previously treated by posterior discectomy, and no reports have described an anterior approach for recurrent disc herniation causing cauda equina syndrome (CES). Revision posterior decompression, irrespective of the presence of CES, has been reported to be associated with significantly higher rates of dural tears, hematomas, and iatrogenic nerve root damage. The authors describe treatment and outcomes in 3 consecutive cases of patients who underwent anterior lumbar discectomy and fusion (ALDF) for CES caused by recurrent disc herniations that had been previously treated with posterior discectomy. All 3 patients were operated on within 12 hours of presentation and were treated with an anterior retroperitoneal lumbar approach. Follow-up ranged from 12 to 24 months. Complete retrieval of herniated disc material was achieved without encountering significant epidural scar tissue in all 3 cases. No perioperative infection or neurological injury occurred, and all 3 patients had neurological recovery with restoration of bladder and bowel function and improvement in back and leg pain. ALDF is one option to treat CES caused by recurrent lumbar disc prolapse previously treated with posterior discectomy. The main advantage is that it avoids dissection around epidural scar tissue, but the procedure is associated with other risks and further evaluation of its safety in larger series is required.

Bone bridge formation across the neuroforamen 14 years after instrumented fusion for isthmic spondylolisthesis-a case report.

This case report describes the first case of a bone bridge formation across the left L5/S1 neuroforamen after instrumented posterolateral fusion for L5/S1 isthmic spondylolisthesis. Our patient was a 70-year-old lady who had grade 2, L5/S1 isthmic spondylolisthesis and bilateral S1 nerve root compression. She suffered from mechanical low back pain and neurogenic claudication, with radicular pain over both S1 dermatomes. She underwent in-situ, instrumented, posterolateral fusion and was asymptomatic for more than 13 years before developing progressive onset of left radicular pain over the L5 dermatome. Imaging revealed a bisected left L5/S1 neuroforamen secondary to a bone bridge formation resulting in stenosis. The pars defect in this case may have had sufficient osteogenic and osteoinductive factors to heal following spinal stabilization. Although in-situ posterolateral fusion is an accepted surgical treatment for isthmic spondylolisthesis, surgeons should consider reduction of the spondylolisthesis and excision of the pars defects to avoid this possible long-term complication.

Distal junctional failure secondary to L5 vertebral fracture-a report of two rare cases.

Distal junctional failure (DJF) with fracture at the last instrumented vertebra is a rare occurrence. In this case report, we present two patients with L5 vertebral fracture post-instrumented fusion of the lumbar spine. The first patient is a 78-year-old female who had multi-level degenerative disc disease, spinal stenosis and degenerative scoliosis involving levels T12 to L5. She underwent instrumented posterolateral fusion (PLF) from T12 to L5, and transforaminal lumbar interbody fusion (TLIF) at L2/3 and L4/5. Six months after her operation, she presented with a fracture of the L5 vertebral body necessitating revision of the L5 pedicle screws, with additional TLIF of L5/S1. The second patient is a 71-year-old female who underwent decompression and TLIF of L3/4 and L4/5 for degenerative spondylolisthesis. Six months after the surgery, she developed a fracture of the L5 vertebral body with loosening of the L5 screws. The patient declined revision surgery despite being symptomatic. DJF remains poorly understood as its rare incidence precludes sufficiently powered studies within a single institution. This report aims to contribute to the currently scarce literature on DJF.

Prevalence and Predictors of Pressure Injuries From Spine Surgery in the Prone Position: Do Body Morphological Changes During Deformity Correction Increase the Risks?

MINI: Pressure injuries are prevalent in patients undergoing spine surgery while prone. Multiple risk factors exist and should be addressed. We found that patients undergoing spinal deformity correction surgery are at unique risk (odds ratio 3.31, P = 0.010) due to body morphological changes occurring secondary to intraoperative changes in spinal alignment. STUDY DESIGN: Review of data and prospective study. OBJECTIVE: To investigate the prevalence and predictive factors of pressure injuries in spine surgery performed in the prone position, and to determine whether morphological changes and truncal shifts occurring during deformity correction predispose to this complication. SUMMARY OF BACKGROUND DATA: Spine surgery performed in the prone position presents the risk of developing pressure injuries. This risk is potentially increased in deformity correction, because it tends to involve more extensive procedures, with associated longer operating times. METHODS: Cases of pressure injuries after spine surgery in the prone position were reviewed to ascertain prevalence and determine risk factors. Data including patient factors (age, sex, height, weight, body mass index, American Society of Anesthesiologists grade, comorbidities, Braden scale, neurological status, spinal pathology) and surgical factors (approach, procedure type, number of screws, operated levels, operative time) were collected. Independent risk factors were identified via multivariate analysis. A subsequent prospective analysis of all patients undergoing spinal deformity correction was conducted by performing intraoperative measurements of body morphological changes and shifts in truncal positions. Statistical correlation was performed to determine whether positional shifts cause pressure injuries. RESULTS: The prevalence of pressure injuries was 23.0%. Previous skin problems (P = 0.034), myelopathy (P = 0.013), operative time >300 minutes (P = 0.005), and more than four operated levels (P = 0.006) were independent predictors of pressure injuries. Being a spinal deformity patient was also an independent risk factor for developing pressure injuries (odds ratio 3.31, P = 0.010). Significant changes in body measurements during deformity correction were predictive of pressure injuries. CONCLUSION: Pressure injuries are prevalent in patients undergoing spine surgery while prone. Future studies should investigate strategies to prevent this complication based on the multiple risk factors identified in the present study. Patients undergoing spinal deformity correction surgery are particularly at risk due to intraoperative body morphological changes. Improved padding methods should be trialed in future studies. LEVEL OF EVIDENCE: 3.

How are patients influenced when counseled for minimally invasive lumbar spine surgeries? A stepwise model assessing pivotal information for decision-making.

BACKGROUND CONTEXT: Although minimally invasive surgery (MIS)-transforaminal lumbar interbody fusion (TLIF) has many evidence-based short-term benefits over open TLIF, both procedures have similar long-term outcomes. Patients' preference for MIS over open TLIF may be confounded by a lack of understanding of what each approach entails. PURPOSE: The study aimed to identify the various factors influencing patients' choice between MIS and open TLIF. STUDY DESIGN/SETTING: This is a cross-sectional study conducted at a tertiary health-care institution. PATIENT SAMPLE: Patients, for whom TLIF procedures were indicated, were recruited over a 3-month period from specialist outpatient clinics. OUTCOME MEASURE: The outcome measure was patients' choice of surgical approach (MIS or open). METHODS: All patients were subjected to a stepwise interviewing process and were asked to select between open and MIS approaches at each step. Further subgroup analysis stratifying subjects based on stages of decision-making was performed to identify key predictors of selection changes. No sources of funding were required for this study and there are no conflicts of interests. RESULTS: Fifty-four patients with a mean age of 55.8 years participated in the study. Thirteen (24.1%) consistently selected a single approach, whereas 31 (57.4%) changed their selection more than once during the interviewing process. Overall, 12 patients (22.2%) had a final decision different from their initial choice, and 15 patients (27.8%) were unable to decide. A large proportion of patients (65.0%) initially favored the open approach's midline incision. This proportion dropped to 16.7% (p<.001) upon mention of the term MIS. The proportion of patients favoring MIS dropped significantly following discussion on the pros and cons (p=.002) of each approach, as well as conversion or revision surgery (p=.017). Radiation and cosmesis were identified as the two most important factors influencing patients' final decisions. CONCLUSIONS: The longer midline incision of the open approach is cosmetically more appealing to patients than the paramedian stab wounds of MIS. The advantages of the MIS approach may not be as valued by patients as they are by surgeons. Given the equivalent long-term outcomes of both approaches, it is crucial that patients are adequately informed during preoperative counseling to achieve the best consensus decision.