A Spinal MRI Image Segmentation Method Based on Improved Swin-UNet.

As the number of patients increases, physicians are dealing with more and more cases of degenerative spine pathologies on a daily basis. To reduce the workload of healthcare professionals, we propose a modified Swin-UNet network model. Firstly, the Swin Transformer Blocks are improved using a residual post-normalization and scaling cosine attention mechanism, which makes the training process of the model more stable and improves the accuracy. Secondly, we use the log-space continuous position biasing method instead of the bicubic interpolation position biasing method. This method solves the problem of performance loss caused by the large difference between the resolution of the pretraining image and the resolution of the spine image. Finally, we introduce a segmentation smooth module (SSM) at the decoder stage. The SSM effectively reduces redundancy, and enhances the segmentation edge processing to improve the model's segmentation accuracy. To validate the proposed method, we conducted experiments on a real dataset provided by hospitals. The average segmentation accuracy is no less than 95%. The experimental results demonstrate the superiority of the proposed method over the original model and other models of the same type in segmenting the spinous processes of the vertebrae and the posterior arch of the spine.

Cross-cultural adaptation, validation and establishment of the minimal clinically important change score of the European Portuguese core outcome measures index in patients with lumbar degenerative spine disease.

PURPOSE: The core outcome measures index (COMI) for the back is a questionnaire that evaluates five domains and has been translated into several languages and validated for different populations. We aimed to translate, cross-culturally adapt and validate it in European Portuguese for use in patients with degenerative lumbar disease. Additionally, we aimed to establish the minimal clinically important change score (MCIC). METHODS: The translation and cultural adaptation were done according to published guidelines. Patients awaiting surgery at a neurosurgical center completed the COMI, Oswestry Disability Index (ODI), EQ-5D questionnaires and a pain visual analog scale (VAS). To evaluate COMI's reproducibility, patients completed the questionnaire twice within two weeks, preoperatively, in addition to answering a transition question. The MCIC was determined by analysis of postoperative changes in total COMI score, using the anchor method, with a question ascertaining surgical outcome as perceived by the patient. RESULTS: The first set of questionnaires was answered by 108 patients and the second, by 98 patients. COMI's construct validity was confirmed by demonstrating the hypothesized correlation between each domain's score (Spearman Rho > 0.4) and the corresponding questionnaire score (ODI, EQ-5D and VAS) and through adequate correlation (Spearman > 0.6) between COMI's total score and ODI and EQ-5D total scores. Intraclass correlation coefficients between each domain and COMI's total score were > 0.8. The MCIC was calculated as 2.1. CONCLUSION: The cross-culturally adapted COMI questionnaire is a valid clinical assessment tool for European Portuguese-speaking patients with degenerative lumbar disease, with an MCIC of 2.1 points.

Changes in frailty among patients hospitalized for spine pathologies during the COVID-19 pandemic in Germany-a nationwide observational study.

PURPOSE: In spine care, frailty is associated with poor outcomes. The aim of this study was to describe changes in frailty in spine care during the coronavirus disease 2019 (COVID-19) pandemic and their relation to surgical management and outcomes. METHODS: Patients hospitalized for spine pathologies between January 1, 2019, and May 17, 2022, within a nationwide network of 76 hospitals in Germany were retrospectively included. Patient frailty, types of surgery, and in-hospital mortality rates were compared between pandemic and pre-pandemic periods. RESULTS: Of the 223,418 included patients with spine pathologies, 151,766 were admitted during the pandemic and 71,652 during corresponding pre-pandemic periods in 2019. During the pandemic, the proportion of high-frailty patients increased from a range of 5.1-6.1% to 6.5-8.8% (p < 0.01), while the proportion of low frailty patients decreased from a range of 70.5-71.4% to 65.5-70.1% (p < 0.01). In most phases of the pandemic, the Elixhauser comorbidity index (ECI) showed larger increases among high compared to low frailty patients (by 0.2-1.8 vs. 0.2-0.8 [p < 0.01]). Changes in rates of spine surgery were associated with frailty, most clearly in rates of spine fusion, showing consistent increases among low frailty patients (by 2.2-2.5%) versus decreases (by 0.3-0.8%) among high-frailty patients (p < 0.02). Changes in rates of in-hospital mortality were not associated with frailty. CONCLUSIONS: During the COVID-19 pandemic, the proportion of high-frailty patients increased among those hospitalized for spine pathologies in Germany. Low frailty was associated with a rise in rates of spine surgery and high frailty with comparably larger increases in rates of comorbidities.

[Effectiveness of spinal traction in degenerative spine diseases. (A literature review)]. / Effektivnost' primeneniya vytyazheniya pozvonochnika pri degenerativnykh zabolevaniyakh pozvonochnika. (Obzor literatury).

Back pain is one of the most urgent healthcare problems in many countries of the world. The high prevalence of the disease among persons of working age, the high disability indices and the high economic losses determine the relevance of this problem and its epidemiological and socio-economic significance. OBJECTIVE: To analyze sources of scientific and technical literature and study materials of meta-analyses, systematic reviews on the issues of evaluation of the spinal traction effectiveness (dry and underwater, horizontal and vertical) in the treatment of patients with degenerative spine diseases. MATERIAL AND METHODS: An analysis of 67 sources, including 54 periodical articles, 5 meta-analyses and 8 systematic reviews was conducted. The search depth was 20 years. RESULTS: The ability of the spinal traction method to influence on the pain intensity, functional state, general improvement or return to work in patients with degenerative spine diseases has been identified. There has been a statistically significant regression of lumbar and radicular pain under the influence of «dry¼ horizontal tractions of the spine (13389 patients with degenerative spine diseases received them), including in combination with physiotherapy (vibration, impulse currents, laser therapy), and there has been an improvement in the motor function of the spine, a decrease in the disability rate in patients with herniated disks. These results were also obvious in short-term observation (up to 3 months after intervention). Underwater traction (5533 patients received it) had a positive impact on pain syndrome at rest and during activity, increased the activity of patients. All registered effects were related to short-term effect for up to 3 months after the intervention. CONCLUSION: The evidence, based on the materials of meta-analyses and systematic reviews of medium and low quality, that «dry¼ and underwater spinal traction can be considered as a therapeutic tool for short-term (within 3 months) reducing pain and disability in patients with lumbar pain and lumbar radiculopathy, is presented.

Incidence of spine surgery in the South African private healthcare sector: ten-year trends within a large open medical scheme.

PURPOSE: Studies from developed countries suggest a dramatic increase in the utilization of spine surgery in recent decades, however less is known about spine surgery rates in the developing world. The aim of this study was to investigate ten-year trends in the incidence of spine surgery within South Africa's largest open medical scheme. METHODS: This retrospective review included adult inpatient spine surgeries funded by the scheme between 2008 and 2017. The incidence of spine surgery was investigated by age group-overall and for degenerative pathologies, fusion and instrumentation. Surgeons per 100,000 members were determined. Trends were evaluated by linear regression and by crude 10-year change in incidence. RESULTS: A total of 49,575 spine surgeries were included. The incidence of surgery for lumbar degenerative pathology showed a significant upward trend among 60-79 year olds but declined among 40-59 year olds. The incidence of lumbar fusion and lumbar instrumentation declined significantly among 40-59 year olds with little change among 60-79 year olds. The ratio of orthopaedic spinal surgeons decreased from 10.2 to 6.3 per 100,000 members whereas the ratio of neurosurgeons decreased from 7.6 to 6.5 per 100,000. CONCLUSION: Spine surgery in the South African private healthcare sector bears some similarity to developed countries in that it is dominated by elective procedures for degenerative pathology. However, the findings did not reflect the marked increases in the utilization of spine surgery reported elsewhere. It is hypothesized that this may be partly related to differences in the supply of spinal surgery.

[VITOM 3D exoscopic system compared to microsurgical technique in spinal surgery]. / Rezul'taty ispol'zovaniya 3D-ekzoskopii VITOM v sravnenii s mikrokhirurgicheskoi tekhnikoi v spinal'noi khirurgii.

3D exoscopy based on Video Telescope Operating Monitor (VITOM) technology provides good visualization quality and portability. There are few data on comparison of extracorporeal telescoping with microsurgical techniques in spinal surgery. OBJECTIVE: To compare the effectiveness of VITOM 3D exoscopy and microsurgical techniques in spinal surgery. MATERIAL AND METHODS: A prospective study included 80 patients (54 men and 26 women). Two groups were distinguished: group 1 (ES, n=40) - VITOM 3D exoscopy, group 2 (SM, n=40) - Pentero 900 surgical microscope. We analyzed surgery time, postoperative rehabilitation, hospital-stay and complications. ES and microsurgical technique were compared using the questionnaire by Takahashi S. and rapid upper limb assessment (RULA). RESULTS: Conventional microsurgical technique was characterized by less surgery time (p<0.05) and morbidity (p=0.02). Postoperative rehabilitation and hospital-stay were similar (p=0.26 and p=0.39, respectively). Image quality in ES was comparable to microsurgical technique in shallow accesses and manipulations perpendicular to skin incision. Availability of neurosurgical instruments at different depths of the wound channel was comparable in both groups. The limitation of ES was length of skin incision, depth of the wound and its visualization at certain angle. These features required expansion of surgical approach or conversion of intervention. In general, surgeons rated intraoperative posture comfort as comparable in both groups that was consistent with the RULA scale. CONCLUSION: VITOM 3D exoscopy is an alternative to traditional microscopy and more ergonomically beneficial in spinal surgery in case of manipulations perpendicular to skin incision and shallow wide accesses. There are several important limitations of this device including difficult manipulations in narrow deep wounds and visualization under certain angle.

Utility of machine learning algorithms in degenerative cervical and lumbar spine disease: a systematic review.

Machine learning is a rapidly evolving field that offers physicians an innovative and comprehensive mechanism to examine various aspects of patient data. Cervical and lumbar degenerative spine disorders are commonly age-related disease processes that can utilize machine learning to improve patient outcomes with careful patient selection and intervention. The aim of this study is to examine the current applications of machine learning in cervical and lumbar degenerative spine disease. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of PubMed, Embase, Medline, and Cochrane was conducted through May 31st, 2020, using the following terms: "artificial intelligence" OR "machine learning" AND "neurosurgery" AND "spine." Studies were included if original research on machine learning was utilized in patient care for degenerative spine disease, including radiographic machine learning applications. Studies focusing on robotic applications in neurosurgery, navigation, or stereotactic radiosurgery were excluded. The literature search identified 296 papers, with 35 articles meeting inclusion criteria. There were nine studies involving cervical degenerative spine disease and 26 studies on lumbar degenerative spine disease. The majority of studies for both cervical and lumbar spines utilized machine learning for the prediction of postoperative outcomes, with 5 (55.6%) and 15 (61.5%) studies, respectively. Machine learning applications focusing on degenerative lumbar spine greatly outnumber the current volume of cervical spine studies. The current research in lumbar spine also demonstrates more advanced clinical applications of radiographic, diagnostic, and predictive machine learning models.

Complications of injections in conservative treatment of degenerative spine disease: a prospective unicentric study.

BACKGROUND: Spinal injection has been an accepted part of conservative therapy for degenerative diseases. The drugs used can cause side effects and severe complications. The aim of this study was to determine the occurrence of general side effects (GSE) and complications when performing consecutive different types of spinal injections and to evaluate pain reduction. METHODS: Prospective data evaluation of patients with degenerative spine disease at hospital admission, discharge, and six and 12 weeks after discharge. All patients received a specific injection protocol depending on their symptoms and radiological findings. The injections performed were dorsal sacroiliac joint injections, perineural injections, epidural interlaminar and epidural periradicular injections, and facet joint injections. Potential complications were categorized and recorded as GSE and complications. In addition, the Numerical Analog Scale (NAS) for pain, the Oswestry Disability Index (ODI) were evaluated. RESULTS: Forty-eight patients were enrolled. There were 282 spinal injections performed. A total of 131 common treatment-related events were recorded. Depending on the type of injection, transient pain at the injection site (32.4-73.5%), radiating pain (9.4-34.7%), and nerve root irritation (2-18.4%) were the most common. One complication with postpuncture syndrome occurred with epidural-interlaminar injection. No persistent neurologic deficits occurred. The highest rate of GSE was observed with periradicular injections (relative frequency (RF) = 0.8), followed by epidural-interlaminar injections (RF = 0.65), least frequently with FJ injections (RF = 0.32). From the time of admission to discharge, NAS scores were significantly decreased and ODI score significantly improved at discharge (p < 0.001), but relapse occurred at the 12-week follow-up. CONCLUSIONS: Various consecutive spinal injections for conservative treatment of degenerative spine diseases are safe and lead to a decrease in pain and improvement in quality of life. GSE are common, but not persistent. Although complications are rare, they can have serious consequences for the patient.

Paraspinal muscle degeneration and lower bone mineral density as predictors of proximal junctional kyphosis in elderly patients with degenerative spinal diseases: a propensity score matched case-control analysis.

STUDY DESIGN: Retrospective case-control study. OBJECTIVES: Proximal junctional kyphosis (PJK) is a postoperative complication involving the proximal segments which is commonly seen in patients with degenerative spine diseases (DSD). The purpose of the present study was to identify predictive factors for postoperative PJK in elderly patients with DSD. METHODS: We reviewed elderly patients with DSD who underwent thoracolumbar fusion involving no less than 3 levels. Patients who developed PJK were propensity score-matched with patients with DSD who received the same procedure but did not develop PJK. Demographic characteristics, sagittal vertical axis (SVA), computed tomography (CT) value (Hounsfield unit), and paraspinal muscle parameters were compared between PJK and non-PJK groups. RESULTS: Eighty-three PJK and non-PJK patients were selected by propensity score matching for age, sex, history of smoking, body mass index, number of fused segments, and upper instrumented vertebra (UIV) location. SVA showed no significant difference between the two groups. In PJK group, fatty infiltration (FI) in erector spinae and multifidus was significantly greater, while the relative cross-sectional area (rCSA) of erector spinae was significantly smaller than that in non-PJK group. CT value was significantly lower in PJK group. Lower erector spinae rCSA and CT value of the UIV, higher erector spinae FI and multifidus FI were identified as predictors of postoperative PJK. CONCLUSIONS: PJK is a common complication in older patients with DSD. Paraspinal muscle degeneration and low bone mineral density of the UIV are predictors of PJK. Protective measures targeting paraspinal muscles and the UIV may help prevent postoperative PJK.

Spinal pathology and outcome post-THA: does segment of arthrodesis matter?

INTRODUCTION: The presence of lumbar spine arthrodesis (SA) is associated with abnormal spinopelvic characteristics and inferior outcome post total hip arthroplasty (THA). However, whether patients with upper segment SA are also at increased risk of complications is unknown. This study aims to (1) determine if upper segment SA is associated with inferior THA outcomes; (2) assess spino-pelvic characteristics; and (3) test whether static or dynamic spinopelvic characteristics correlate with outcome post-THA. MATERIALS AND METHODS: In this retrospective, case-matched, cohort study from a tertiary referral centre, 40 patients (59 hips) that had undergone both THA and any level of spinal arthrodesis (49 THA-Lumb and 10 THA-Cerv) were compared with 41 patients (59 hips) who had THA-only without known spinal pathology. Spino-pelvic characteristics [including severity of Degenerative-Disc-Disease (DDD); spinal balance and stiffness] and outcome, including patient reported outcome measures (PROMs), at minimum of 1-year post-THA were assessed. RESULTS: THA-Lumb and THA-Cerv groups had greater number of complications and inferior hip and spinal PROMs compared to THA-Only (p < 0.001). Similar spinopelvic characteristics were seen between the THA-Cerv and THA-Lumb, which were significantly different to the THA-only group. The presence of DDD and unbalanced or stiff spine was associated with increased dislocation and inferior PROMs in the whole cohort. CONCLUSIONS: THA in the presence of SA, regardless of level, is associated with inferior outcomes and an increased risk for dislocation. The presence of a SA is associated with increased risk of adverse spinopelvic characteristics. Such characteristics were strongly associated with increased dislocation-risk and inferior PROMs. It is likely that these adverse characteristics are the most important adverse predictor, rather than segment of SA per se.

Revision by S2-alar-iliac instrumentation reduces caudal screw loosening while improving sacroiliac joint pain-a group comparison study.

Lumbosacral instrumentation continues to be challenging due to complex biomechanical force distributions and poor sacral bone quality. Various techniques have therefore been established. The aim of this study was to investigate the outcome of patients treated with S2-alar-iliac (S2AI), S2-alar (S2A), and iliac (I) instrumentation as the most caudal level. Sixty patients underwent one of the 3 techniques between January 2012 and June 2017 (S2AI 18 patients, S2A 20 patients, I 22 patients). Mean age was 70.4 ± 8.5 years. Screw loosening (SL) and sacroiliac joint (SIJ) pain were evaluated during the course at 3-month and maximum follow-up (FU). All patients completed 3-month FU, the mean FU period was 2.5 ± 1.5 years (p = 0.38), and a median of 5 segments was operated on (p = 0.26), respectively. Bone mineral density (BMD), derived opportunistically from computed tomography (CT), did not significantly differ between the groups (p = 0.66), but cages were more frequently implanted in patients of the S2A group (p = 0.04). SL of sacral or iliac screws was more common in patients of the S2A and I groups compared with the S2AI group (S2AI 16.7%, S2A 55.0%, I 27.3% of patients; p = 0.03). SIJ pain was more often improved in the S2AI group not only after 3 months but also at maximum FU (S2AI 61.1%, S2A 25.0%, I 22.7% of patients showing improvement; p = 0.02). Even in shorter or mid-length lumbar or thoracolumbar constructs, S2AI might be considered superior to S2A and I instrumentation due to showing lower incidences of caudal SL and SIJ pain.

Predictive model of global tilt (GT) determined by individual thoracic kyphosis, lumbar lordosis and pelvic incidence in the human degenerative spine.

PURPOSE: Previous studies only investigated the simple linear relationships of global tilt (GT) with thoracic kyphosis (TK), lumbar lordosis (LL) and pelvic incidence (PI). This study aimed to establish multiple linear regressions of GT based on individual TK, LL and PI in patients with degenerative spines. METHODS: Four hundred sixty-nine adult patients aged older than 35 years with various degenerative spinal diseases were enrolled in this two-centre study between January 2017 and December 2020. Full-spine X-rays were performed for all the subjects in a standing position. The following regional and global parameters were measured in the sagittal plane: TK, LL, PI, pelvic tilt (PT), sagittal vertical axis (SVA) and GT. The correlations of the GT, PT and SVA with the TK, LL and PI were analysed, and then multiple linear regressions were constructed. RESULTS: GT was statistically correlated with TK, LL and PI. Additionally, TK, LL and PI were significant predictors for the GT, PT and SVA models. The relevant predictive formulae were as follows: GT = -9.60 + 1.09*PI + 0.89*LL + 0.42*TK (R2 = 0.935), PT = -4.49 + 0.81*PI + 0.56*LL + 0.24*TK (R2 = 0.792) and SVA = -25.68 + 2.98*LL + 2.37*PI + 1.67*TK (R2 = 0.416). CONCLUSION: The specific sagittal spinopelvic morphology, evaluated by GT parameters, should be determined by individual TK, LL and PI values in the degenerative spine. Surgeons can utilize such predictive models to better understand the degenerative evolution of sagittal alignment and recognize the relationships between regional parameters and global sagittal alignment to customize a precise correction strategy.

The prevalence of depression in degenerative spine disease patients: A systematic review and meta-analysis.

PURPOSE: To estimate the prevalence of depression in degenerative spine disease (DSD) patients. METHODS: The PubMed, EMBASE, and PsycINFO were systematically searched, the relevant studies that reported the depression prevalence of in DSD patients were identified. Data were extracted independently by 2 reviewers. Subgroup analysis and sensitivity analysis were also performed. RESULTS: 24 articles met the inclusion criteria and were selected for the current study. The pooled prevalence estimate of depression in DSD patients before operative treatment was 30.8% [95% CI 24.0-38.5%]. Nine articles reported the prevalence rate in DSD patients after operative treatment, and the pooled prevalence estimate was 27.0% [95% CI 19.9-35.4%]. There were significant differences for prevalence estimates before operative treatment in types of disorders (Q = 4.56, P = 0.10), spine surgery history (Q = 5.55, P = 0.02), representativeness of sample (Q = 11.00, P = 0.00), and validity of assessment method (Q = 3.32, P = 0.07). The prevalence estimates in patients with lumbar spine stenosis, lumbar disc herniation and cervical spondylotic myelopathy were 24.0%, 40.9% and 37.3%, respectively. Studies that included patients with a history of spine surgery yielded a more extreme prevalence estimate than studies excluding those (36.9% vs 24.3%). For results of patients after operative treatment, significant differences for prevalence estimates were showed in different degrees of pain (Q = 4.72, P = 0.03), screening instruments (Q = 4.83, P = 0.09), and representativeness of sample (Q = 15.70, P = 0.00). CONCLUSION: The systematic review indicated increased prevalence of depression in DSD patients. In consideration of the relationship between depression and poor surgical outcome, we should pay more attention to identifying strategies for preventing and treating depression in DSD patients.

Development of a model to predict the probability of incurring a complication during spine surgery.

PURPOSE: Predictive models in spine surgery are of use in shared decision-making. This study sought to develop multivariable models to predict the probability of general and surgical perioperative complications of spinal surgery for lumbar degenerative diseases. METHODS: Data came from EUROSPINE's Spine Tango Registry (1.2012-12.2017). Separate prediction models were built for surgical and general complications. Potential predictors included age, gender, previous spine surgery, additional pathology, BMI, smoking status, morbidity, prophylaxis, technology used, and the modified Mirza invasiveness index score. Complete case multiple logistic regression was used. Discrimination was assessed using area under the receiver operating characteristic curve (AUC) with 95% confidence intervals (CI). Plots were used to assess the calibration of the models. RESULTS: Overall, 23'714/68'111 patients (54.6%) were available for complete case analysis: 763 (3.2%) had a general complication, with ASA score being strongly predictive (ASA-2 OR 1.6, 95% CI 1.20-2.12; ASA-3 OR 2.98, 95% CI 2.19-4.07; ASA-4 OR 5.62, 95% CI 3.04-10.41), while 2534 (10.7%) had a surgical complication, with previous surgery at the same level being an important predictor (OR 1.9, 95%CI 1.71-2.12). Respectively, model AUCs were 0.74 (95% CI, 0.72-0.76) and 0.64 (95% CI, 0.62-0.65), and calibration was good up to predicted probabilities of 0.30 and 0.25, respectively. CONCLUSION: We developed two models to predict complications associated with spinal surgery. Surgical complications were predicted with less discriminative ability than general complications. Reoperation at the same level was strongly predictive of surgical complications and a higher ASA score, of general complications. A web-based prediction tool was developed at https://sst.webauthor.com/go/fx/run.cfm?fx=SSTCalculator .

Morbidity and mortality following degenerative spine surgery in a prospective cohort of 1687 consecutive surgical procedures.

STUDY DESIGN: Prospective, observational cohort study. OBJECTIVE: To determine the true incidence of adverse events (AEs) in European adults undergoing surgery for degenerative spine diseases. The majority of surgeries performed for degenerative spinal diseases are elective, and the need for adequate estimation of risk-benefit of the intended surgery is imperative. A cumbersome obstacle for adequate estimation of surgery-related risks is that the true incidence of complications or adverse events (AEs) remains unclear. METHODS: All adult patients (≥ 18 years) undergoing spine surgery at a single center from February 1, 2016, to January 31, 2017, were prospectively and consecutively included. Morbidity and mortality were determined using the Spine AdVerse Events Severity (SAVES) system. Additionally, the correlation between the AEs and length of stay (LOS) and mortality was assessed. RESULTS: A total of 1687 procedures were performed in the study period, and all were included for analysis. Of these, 1399 (83%) were lumbar procedures and 288 (17%) were cervical. The overall incidence of AEs was 47.4%, with a minor AE incidence of 43.2% and a major of 14.5%. Female sex (OR 1.5 [95% CI 1.2-1.9), p < 0.001) and age > 65 years (OR 1.5 [95% CI 1.1-1.7], p = 0.012) were significantly associated with increased odds of having an AE. CONCLUSION: Based on prospectively registered AEs in this single-center study, we validated the use of the SAVES system in a European population undergoing spine surgery due to degenerative spine disease. We found a higher incidence of AEs than previously reported in retrospective studies. The major AEs registered occurred significantly more often perioperatively and in patients > 65 years.

Modifications in lumbar facet joint are associated with spondylolisthesis in the degenerative spine diseases: a comparative analysis.

BACKGROUND: Magnetic resonance imaging (MRI) is important in the assessment of degenerative spine disease. However, its role is limited in the identification of spinal instability; therefore, weight-bearing and dynamic studies like X-rays are required. The supine position eliminates the gravitational pull, corrects the vertebral slippage, and opens the facet joints leading to the collection of the synovial fluid into the joint space, which is detected on the MRI and can serve as a marker for instability. We aim to compare the facet fluid, facet hypertrophy, facet angle, and disc degenerative changes among the patients presenting with degenerative spondylolisthesis (DS) and those without. METHODS: We performed a retrospective review for all the patients treated at our institution from January 2015 to December 2016. Facet Fluid Index (FFI) (ratio of facet fluid width and facet joint width) was calculated to assess the joint fluid. The percentage of spondylolisthesis was measured on X-rays. Each radiological parameter was compared between the two groups, i.e., patients with DS and patients without DS. A p value < 0.05 was considered significant. RESULTS: In total, 61 patients, 28 with DS and 33 without DS, were enrolled. Baseline characteristics were similar in the two groups (p > 0.05). The average values of FFI, facet fluid width, and the difference between the superior and inferior facet were significantly higher in the group with instability (p < 0.05). Multivariate analysis demonstrated a 4.44 (95% confidence interval [CI] 2.03-5.365) times increase in the odds of instability with a unit increase in FFI, p < 0.0001. CONCLUSIONS: We report a positive linear correlation between the facet joint effusion and facet hypertrophy on MRI and the percentage of vertebral translation on X-ray. Prospective studies will determine if these markers can play a role in predicting spinal instability.

How I do it? Uniportal full endoscopic pseudoarthrosis release of left L5/S1 Bertolotti's syndrome under intraoperative computer tomographic guidance in an ambulatory setting.

BACKGROUND: There is limited literature on technique full endoscopic pseudoarthrosis release of Bertolotti syndrome. METHODS: Uniportal full endoscopic pseudoarthrosis release technique applies for patients presenting with symptomatic Bertolotti's syndrome. Full-thickness endoscopic drilling is carried out from most ventrolateral margin of pseudoarthrosis articulating with the highest part of sacral ala (PH) point to dorsal medioinferior margin of pseudoarthrosis adjacent to superior articular process (MS) point. Complete pseudoarthrosis release was confirmed with an intraoperative 3D imaging system. CONCLUSION: The uniportal full endoscopic pseudoarthrosis release is a good alternative to open surgery to release pseudoarthrosis in L5/S1 Bertolotti's syndrome in an ambulatory setting.

Acute bilateral foot drop with or without cauda equina syndrome-a case series.

INTRODUCTION: Isolated acute bilateral foot drop due to degenerative spine disease is an extremely rare neurosurgical presentation, whilst the literature is rich with accounts of chronic bilateral foot drop occurring as a sequela of systemic illnesses. We present, to our knowledge, the largest case series of acute bilateral foot drop, with trauma and relevant systemic illness excluded. METHODS: Data from three different centres had been collected at the time of historic treatment, and records were subsequently reviewed retrospectively, documenting the clinical presentation, radiological level of compression, timing of surgery, and degree of neurological recovery. RESULTS: Seven patients are presented. The mean age at presentation was 52.1 years (range 41-66). All patients but one were male. All had a painful radiculopathic presentation. Relevant discopathy was observed from L2/3 to L5/S1, the commonest level being L3/4. Five were treated within 24 h of presentation, and two within 48 h. Three had concomitant cauda equina syndrome; of these, the first two made a full motor recovery, one by 6 weeks follow-up and the second on the same-day post-op evaluation. Overall, five out of seven cases had full resolution of their ankle dorsiflexion pareses. One patient with 1/5 power has not improved. Another with 1/5 weakness improved to normal on the one side and to 3/5 on the other. CONCLUSION: When bilateral foot drop occurs acutely, we encourage the consideration of degenerative spinal disease. Relevant discopathy was observed from L2/3 to L5/S1; aberrant innervation may be at play. Cauda equina syndrome is not necessarily associated with acute bilateral foot drop. The prognosis seems to be pretty good with respect to recovery of the foot drop, especially if partial at presentation and if treated within 48 h.

The Effect of a Degenerative Spine and Adverse Pelvic Mobility on Prosthetic Impingement in Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: Despite the placement of acetabular components in the traditional "safe-zone", dislocations and all parts of the instability spectrum, including impingement, continue to be an issue. Recent research has established the importance of a degenerative spine and adverse pelvic mobility on functional acetabular orientation. The purpose of this study is to quantify the clinical consequences of a degenerative spine and adverse pelvic mobility on prosthetic impingement in patients undergoing total hip arthroplasty. METHODS: Between January 2018 and December 2019, a series of 1592 patients undergoing total hip arthroplasty had functional lateral radiographs and a computed tomography scan taken. Two spinal parameters and 2 pelvic mobility parameters were investigated for their association with impingement. Each patient was evaluated for anterior and posterior impingement, at all orientations within a traditional supine safe zone and a patient-specific functional safe zone. RESULTS: Patients with limited lumbar flexion (stiff spine), higher pelvic incidence-lumbar lordosis mismatch (sagittal imbalance), and more anterior pelvic mobility from stand to flexed-seated, exhibit increased anterior impingement. Patients with larger posterior pelvic mobility from supine-to-stand exhibited increased posterior impingement. Impingement was reduced 3-fold when the target cup orientation was tailored to a patient's functional safe zone rather than a generic target. Six percent of patients showed unavoidable impingement even with an optimized functional cup orientation. CONCLUSION: Our results support growing evidence that patients with a degenerative spine and adverse pelvic mobility are likely to have unfavorable functional cup orientations, resulting in prosthetic impingement. Preoperative functional radiographic screening is recommended to assess the likelihood of a patient experiencing impingement due to their unique spinopelvic mobility.

Estimation of bone mineral density with hounsfield unit measurement.

OBJECTIVE: Although dual-energy x-ray absorptiometry (DXA) remains the gold standard for the measurement of bone mineral density (BMD), degenerative spine and spinal instrumentation yields inaccurate results, warranting the need for optional methods. METHODS: Surgical options depend on the BMD of the patients, and to accommodate this need, we compared Hounsfield unit (HU) measurements obtained from computed tomography (CT) scans with the T-scores obtained from DXA scans to inquire whether HU measurements can screen for BMD. In this study, we also evaluated the relationship between body mass index and spontaneous fractures. RESULTS: Based on the findings described in this study, we provide evidence that HU measurements obtained from CT scans can predict BMD. CONCLUSIONS: This, therefore, allows HU measurements to be used as an effective diagnostic method in lieu of DXA scans when deciding on appropriate management of therapy for patients with spinal instrumentation or degenerative spines.