How Does Resorption Differ Among Single-Level and Multilevel Lumbar Disc Herniations? A Prospective Multi-Imaging and Clinical Phenotype Study.

STUDY DESIGN: Prospective, case series. OBJECTIVE: To identify and characterize any differences in specific patient factors, MRI findings, features of spontaneous disc resorption, and outcomes between patients with single-level and multilevel LDH. BACKGROUND: Lumbar disc herniation (LDH) is one of the most common spinal pathologies worldwide. Though many cases of LDH resolve by spontaneous resorption, the mechanism underlying this "self-healing" phenomenon remains poorly understood, particularly in the context of multilevel herniations. METHODS: A one-year prospective study was conducted of patients presenting with acute symptomatic LDH between 2017 and 2019. Baseline demographics, herniation characteristics, and MRI phenotypes were recorded before treatment, which consisted of gabapentin, acupuncture, and the avoidance of inflammatory-modulating medications. MRIs were performed approximately every three months after the initial evaluation to determine any differences between patients with single-level and multilevel LDH. RESULTS: Ninety patients were included, 17 demonstrated multilevel LDH. Body mass index was higher among patients with multilevel LDH ( P <0.001). Patients with multilevel LDH were more likely to exhibit L3/L4 inferior endplate defects ( P =0.001), L4/L5 superior endplate defects ( P =0.012), and L4/L5 inferior endplate defects ( P =0.020) on MRI. No other differences in MRI phenotypes ( e.g. Modic changes, osteophytes, etc .) existed between groups. Resorption rate and time to resolution did not differ between those with single-level and multilevel LDH. CONCLUSIONS: Resorption rates were similar between single-level and multilevel LDH at various time points throughout one prospective assessment, providing insights that disc healing may have unique programmed signatures. Compared with those with single-level LDH, patients with multilevel herniations were more likely to have a higher BMI, lesser initial axial and sagittal disc measurements, and endplate defects at specific lumbar levels. In addition, our findings support the use of conservative management in patients with LDH, regardless of the number of levels affected. LEVEL OF EVIDENCE: Level 3.

The Correlation Between Lymphocyte Nadir and Radiation Therapy for Soft Tissue Sarcoma: Defining Key Dosimetric Parameters and Outlining Clinical Significance.

Purpose: The objectives of this study were to identify key dosimetric parameters associated with postradiation therapy lymphopenia and uncover any effect on clinical outcomes. Methods and Materials: This was a retrospective review of 69 patients (between April 2010 and January 2023) who underwent radiation therapy (RT) as a part of curative intent for soft tissue sarcoma (STS) at a single academic institution. All patients with treatment plans available to review and measurable absolute lymphocyte count (ALC) nadir within a year after completion of RT were included. Results: Median follow-up was 22 months after the start of RT. A decrease in lymphocyte count was noted as early as during treatment and persisted at least 3 months after the completion of RT. On multivariable linear regression, the strongest correlations with ALC nadir were mean body dose, body V10 Gy, mean bone dose, bone V10 Gy, and bone V20 Gy. Five-year overall survival was 60% and 5-year disease-free survival was 44%. Advanced T-stage, chemotherapy use, use of intensity-modulated RT, lower ALC nadir, and the development of grade ≥2 lymphopenia at nadir were associated with worse overall survival and disease-free survival. Conclusions: Post-RT lymphopenia was associated with worse outcomes in STS. There were associations between higher body V10 Gy and bone V10 Gy and lower post-RT ALC nadir, despite the varying sites of STS presentation, which aligns with the well-known radiosensitivity of lymphocyte cell lines. These findings support efforts to reduce treatment-related hematopoietic toxicity as a way to improve oncologic outcomes. Additionally, this study supports the idea that the effect of radiation on lymphocyte progenitors in the bone marrow is more significant than that on circulating lymphocytes in treatments with limited involvement of the heart and lung.

Severity of Financial Toxicity for Patients Receiving Palliative Radiation Therapy.

Introduction: Financial toxicity has negative implications for patient well-being and health outcomes. There is a gap in understanding financial toxicity for patients undergoing palliative radiotherapy (RT). Methods: A review of patients treated with palliative RT was conducted from January 2021 to December 2022. The FACIT-COST (COST) was measured (higher scores implying better financial well-being). Financial toxicity was graded according to previously suggested cutoffs: Grade 0 (score ≥26), Grade 1 (14-25), Grade 2 (1-13), and Grade 3 (0). FACIT-TS-G was used for treatment satisfaction, and EORTC QLQ-C30 was assessed for global health status and functional scales. Results: 53 patients were identified. Median COST was 25 (range 0-44), 49% had Grade 0 financial toxicity, 32% Grade 1, 15% Grade 2, and 4% Grade 3. Overall, cancer caused financial hardship among 45%. Higher COST was weakly associated with higher global health status/Quality of Life (QoL), physical functioning, role functioning, and cognitive functioning; moderately associated with higher social functioning; and strongly associated with improved emotional functioning. Higher income or Medicare or private coverage (rather than Medicaid) was associated with less financial toxicity, whereas an underrepresented minority background or a non-English language preference was associated with greater financial toxicity. A multivariate model found that higher area income (HR .80, P = .007) and higher cognitive functioning (HR .96, P = .01) were significantly associated with financial toxicity. Conclusions: Financial toxicity was seen in approximately half of patients receiving palliative RT. The highest risk groups were those with lower income and lower cognitive functioning. This study supports the measurement of financial toxicity by clinicians.

The impact of novel inflammation-preserving treatment towards lumbar disc herniation resorption in symptomatic patients: a prospective, multi-imaging and clinical outcomes study.

PURPOSE: We performed a prospective one-year multi-imaging study to assess the clinical outcomes and rate of disc resorption in acute lumbar disc herniation (LDH) patients undergoing inflammation-preserving treatment (i.e. no NSAIDS, steroids). METHODS: All patients received gabapentin to relieve leg pain, 12 sessions of acupuncture. Repeat MRI was performed, every 3 months, after 12 sessions of treatment continued for those without 40% reduction in herniated disc sagittal area. Disc herniations sizes were measured on sagittal T2W MRI sequences, pre-treatment and at post-treatment intervals. Patients were stratified to fast, medium, slow, and prolonged recovery groups in relation to symptom resolution and disc resorption. RESULTS: Ninety patients (51% females; mean age: 48.6 years) were assessed. Mean size of disc herniation was 119.54 ± 54.34 mm2, and the mean VAS-Leg score was 6.12 ± 1.13 at initial presentation. A total of 19 patients (21.1%) improved at the time of the repeat MRI (i.e. within first 3 months post-treatment). 100% of all patient had LDH resorption within one year (mean: 4.4. months). There was no significant difference at baseline LDH between fast, medium, slow, and prolonged resorption groups. Initial LDH size was weakly associated with degree of leg pain at baseline and initial gabapentin levels. Surgery was avoided in all cases. CONCLUSION: This is the first study to note inflammation-preserving treatment, without conventional anti-inflammatory and steroid medications, as safe and effective for patients with an acute LDH. Rate of disc resorption (100%) was higher than comparative recent meta-analysis findings (66.7%) and no patient underwent surgery.

Prediction of lumbar disc herniation resorption in symptomatic patients: a prospective, multi-imaging and clinical phenotype study.

BACKGROUND CONTEXT: Symptomatic lumbar disc herniations (LDH) are very common. LDH resorption may occur by a "self-healing" process, however this phenomenon remains poorly understood. By most guidelines, if LDH remains symptomatic after 3 months and conservative management fails, surgical intervention may be an option. PURPOSE: The following prospective study aimed to identify determinants that may predict early versus late LDH resorption. STUDY DESIGN/SETTING: Prospective study with patients recruited at a single center. PATIENT SAMPLE: Ninety-three consecutive patients diagnosed with acute symptomatic LDH were included in this study (n=23 early resorption and n=67 late resorption groups) with a mean age of 48.7±11.9 years. OUTCOMES MEASURE: Baseline assessment of patient demographics (eg, smoking status, height, weight, etc.), herniation characteristics (eg, the initial level of herniation, the direction of herniation, prevalence of multiple herniations, etc.) and MRI phenotypes (eg, Modic changes, end plate abnormalities, disc degeneration, vertebral body dimensions, etc.) were collected for further analysis. Lumbar MRIs were performed approximately every 3 months for 1 year from time of enrollment to assess disc integrity. METHODS: All patients were managed similarly. LDH resorption was classified as early (<3 months) or late (>3 months). A prediction model of pretreatment factors was constructed. RESULTS: No significant differences were noted between groups at any time-point (p>.05). Patients in the early resorption group experienced greater percent reduction of disc herniation between MRI-0-MRI-1 (p=.043), reduction of herniation size for total study duration (p=.007), and percent resorption per day compared to the late resorption group (p<.001). Based on multivariate modeling, greater L4 posterior vertebral height (coeff:14.58), greater sacral slope (coeff:0.12), and greater herniated volume (coeff:0.013) at baseline were found to be most predictive of early resorption (p<.05). CONCLUSIONS: This is the first comprehensive imaging and clinical phenotypic prospective study, to our knowledge, that has identified distinct determinants for early LDH resorption. Early resorption can occur in 24.7% of LDH patients. We developed a prediction model for early resorption which demonstrated great overall performance according to pretreatment measures of herniation size, L4 posterior body height, and sacral slope. A risk profile is proposed which may aid clinical decision-making and managing patient expectations.

The Impact of COVID-19 Pandemic on Spine Surgeons Worldwide: A One Year Prospective Comparative Study.

STUDY DESIGN: Survey. OBJECTIVE: In March of 2020, an original study by Louie et al investigated the impact of COVID-19 on 902 spine surgeons internationally. Since then, due to varying government responses and public health initiatives to the pandemic, individual countries and regions of the world have been affected differently. Therefore, this follow-up study aimed to assess how the COVID-19 impact on spine surgeons has changed 1 year later. METHODS: A repeat, multi-dimensional, 90-item survey written in English was distributed to spine surgeons worldwide via email to the AO Spine membership who agreed to receive surveys. Questions were categorized into the following domains: demographics, COVID-19 observations, preparedness, personal impact, patient care, and future perceptions. RESULTS: Basic respondent demographics, such as gender, age, home demographics, medical comorbidities, practice type, and years since training completion, were similar to those of the original 2020 survey. Significant differences between groups included reasons for COVID testing, opinions of media coverage, hospital unemployment, likelihood to be performing elective surgery, percentage of cases cancelled, percentage of personal income, sick leave, personal time allocation, stress coping mechanisms, and the belief that future guidelines were needed (P<.05). CONCLUSION: Compared to baseline results collected at the beginning of the COVID-19 pandemic in 2020, significant differences in various domains related to COVID-19 perceptions, hospital preparedness, practice impact, personal impact, and future perceptions have developed. Follow-up assessment of spine surgeons has further indicated that telemedicine and virtual education are mainstays. Such findings may help to inform and manage expectations and responses to any future outbreaks.

Artificial intelligence in predicting early-onset adjacent segment degeneration following anterior cervical discectomy and fusion.

PURPOSE: Anterior cervical discectomy and fusion (ACDF) is a common surgical treatment for degenerative disease in the cervical spine. However, resultant biomechanical alterations may predispose to early-onset adjacent segment degeneration (EO-ASD), which may become symptomatic and require reoperation. This study aimed to develop and validate a machine learning (ML) model to predict EO-ASD following ACDF. METHODS: Retrospective review of prospectively collected data of patients undergoing ACDF at a quaternary referral medical center was performed. Patients > 18 years of age with > 6 months of follow-up and complete pre- and postoperative X-ray and MRI imaging were included. An ML-based algorithm was developed to predict EO-ASD based on preoperative demographic, clinical, and radiographic parameters, and model performance was evaluated according to discrimination and overall performance. RESULTS: In total, 366 ACDF patients were included (50.8% male, mean age 51.4 ± 11.1 years). Over 18.7 ± 20.9 months of follow-up, 97 (26.5%) patients developed EO-ASD. The model demonstrated good discrimination and overall performance according to precision (EO-ASD: 0.70, non-ASD: 0.88), recall (EO-ASD: 0.73, non-ASD: 0.87), accuracy (0.82), F1-score (0.79), Brier score (0.203), and AUC (0.794), with C4/C5 posterior disc bulge, C4/C5 anterior disc bulge, C6 posterior superior osteophyte, presence of osteophytes, and C6/C7 anterior disc bulge identified as the most important predictive features. CONCLUSIONS: Through an ML approach, the model identified risk factors and predicted development of EO-ASD following ACDF with good discrimination and overall performance. By addressing the shortcomings of traditional statistics, ML techniques can support discovery, clinical decision-making, and precision-based spine care.

Controversies in Lung Cancer: Heterogeneity in Treatment Recommendations for Stage III NSCLC According to Disease Burden and Oncogenic Driver Alterations.

INTRODUCTION: Therapeutic options for stage III non-small-cell lung cancer (NSCLC) consist of definitive chemoradiation, surgery combined with neoadjuvant/adjuvant chemotherapy, and trimodality therapy. More recently, biologically driven systemic therapy options, including immunotherapy and targeted therapy, have become increasingly available. METHODS: A customized, case-based survey was designed and distributed to members of the International Association for the Study of Lung Cancer (IASLC) to determine practice habits and preferences for NSCLC patients with stage III disease and N2 to N3 nodal involvement. RESULTS: Data were compiled from 87 respondents from 31 countries, including medical oncologists (49%), surgical oncologists (24%), and radiation oncologists (21%). Definitive chemoradiation was more likely to be recommended for stage IIIC (98.2%) or stage IIIB (75.8%) scenarios compared with stage IIIA (59.6%) without actionable driver alterations (P < .0001 and .0003, respectively); and chemoradiation was more likely for stage IIIB (57.7%) compared to stage IIIA (39.9%) with actionable EGFR/ALK alterations (P = .008). Surgery was more likely to be recommended in the presence of an actionable alteration (38.7% vs. 19%, P < .0001). Surgeons were more likely than medical oncologists to recommend surgical approaches in scenarios without actionable alterations (25.6% vs. 11.2%, P < .0001) or with actionable alterations (57.5% vs. 31.1%, P = .0001). DISCUSSION: The dominant recommended strategy for stage III NSCLC was chemoradiation, although respondents were more likely to recommend surgical approaches in the presence of actionable alterations. Despite the lack of reported clinical trial data, many IASLC lung cancer experts favored targeted therapy when actionable driver alterations were present.

Pediatric Back Pain: A Scoring System to Guide Use of Magnetic Resonance Imaging.

BACKGROUND: The prevalence of back pain in the pediatric population is increasing, and the workup of these patients presents a clinical challenge. Many cases are selflimited, but failure to diagnose a pathology that requires clinical intervention can carry severe repercussions. Magnetic resonance imaging (MRI) carries a high cost to the patient and health care system, and may even require procedural sedation in the pediatric population. The aim of this study was to develop a scoring system based on pediatric patient factors to help determine when an MRI will change clinical management. METHODS: This is a retrospective cohort analysis of consecutive pediatric patients who presented to clinic with a chief complaint of back pain between 2010 and 2018 at single orthopaedic surgery practice. Comprehensive demographic and presentation variables were collected. A predictive model of factors that influence whether MRI results in a change in management was then generated using cross-validation least absolute shrinkage and selection operator logistic regression analysis. RESULTS: A total of 729 patients were included, with a mean age of 15.1 years (range: 3 to 20 y). Of these, 344 (47.2%) had an MRI. A predictive model was generated, with nocturnal symptoms (5 points), neurological deficit (10 points), age (0.7 points per year), lumbar pain (2 points), sudden onset of pain (3.25 points), and leg pain (3.75 points) identified as significant predictors. A combined score of greater than 9.5 points for a given patient is highly suggestive that an MRI will result in a change in clinical management (specificity: 0.93; positive predictive value: 0.92). CONCLUSIONS: A predictive model was generated to help determine when ordering an MRI may result in a change in clinical management for workup of back pain in the pediatric population. The main factors included the presence of a neurological deficit, nocturnal symptoms, sudden onset, leg pain, lumbar pain, and age. Care providers can use these findings to better determine if and when an MRI might be appropriate. LEVEL OF EVIDENCE: Level III-diagnostic study.

Factors Affecting the Decision to Initiate Anticoagulation After Spine Surgery: Findings From the AOSpine Anticoagulation Global Initiative.

STUDY DESIGN: Cross-sectional, international survey. OBJECTIVES: To identify factors influencing pharmacologic anticoagulation initiation after spine surgery based on the AOSpine Anticoagulation Global Survey. METHODS: This survey was distributed to the international membership of AOSpine (n = 3805). A Likert-type scale described grade practice-specific factors on a scale from low (1) to high (5) importance, and patient-specific factors a scale from low (0) to high (3) importance. Analysis was performed to determine which factors were significant in the decision making surrounding the initiation of pharmacologic anticoagulation. RESULTS: A total of 316 spine surgeons from 64 countries completed the survey. In terms of practice-specific factors considered to initiate treatment, expert opinion was graded the highest (mean grade ± SD = 3.2 ± 1.3), followed by fellowship training (3.2 ± 1.3). Conversely, previous studies (2.7 ± 1.2) and unspecified guidelines were considered least important (2.6 ± 1.6). Patient body mass index (2.0 ± 1.0) and postoperative mobilization (2.3 ± 1.0) were deemed most important and graded highly overall. Those who rated estimated blood loss with greater importance in anticoagulation initiation decision making were more likely to administer thromboprophylaxis at later times (hazard ratio [HR] = 0.68-0.71), while those who rated drain output with greater importance were likely to administer thromboprophylaxis at earlier times (HR = 1.32-1.43). CONCLUSION: Among our global cohort of spine surgeons, certain patient factors (ie, patient mobilization and body mass index) and practice-specific factors (ie, expert opinion and fellowship training) were considered to be most important when considering anticoagulation start times.

Revision Strategies for Harrington Rod Instrumentation: Radiographic Outcomes and Complications.

STUDY DESIGN: Retrospective case series. OBJECTIVE: The purpose of this study is to evaluate the clinical and radiographic outcomes following revision surgery following Harrington rod instrumentation. METHODS: Patients who underwent revision surgery with a minimum of 1-year follow-up for flatback syndrome following Harrington rod instrumentation for adolescent idiopathic scoliosis were identified from a multicenter dataset. Baseline demographics and intraoperative information were obtained. Preoperative, initial postoperative, and most recent spinopelvic parameters were compared. Postoperative complications and reoperations were subsequently evaluated. RESULTS: A total of 41 patients met the inclusion criteria with an average follow-up of 27.7 months. Overall, 14 patients (34.1%) underwent a combined anterior-posterior fusion, and 27 (65.9%) underwent an osteotomy for correction. Preoperatively, the most common lower instrumented vertebra (LIV) was at L3 and L4 (61%), whereas 85% had a LIV to the pelvis after revision. The mean preoperative pelvic incidence-lumbar lordosis mismatch and C7 sagittal vertical axis were 23.7° and 89.6 mm. This was corrected to 8.1° and 28.9 mm and maintained to 9.04° and 34.4 mm at latest follow-up. Complications included deep wound infection (12.2%), durotomy (14.6%), implant related failures (14.6%), and temporary neurologic deficits (22.0%). Eight patients underwent further revision surgery at an average of 7.4 months after initial revision. CONCLUSIONS: There are multiple surgical techniques to address symptomatic flatback syndrome in patients with previous Harrington rod instrumentation for adolescent idiopathic scoliosis. At an average of 27.7 months follow-up, pelvic incidence-lumbar lordosis mismatch and C7 sagittal vertical axis can be successfully corrected and maintained. However, complication and reoperation rates remain high.

Spine Surgery and COVID-19: The Influence of Practice Type on Preparedness, Response, and Economic Impact.

STUDY DESIGN: Cross-sectional observational cohort study. OBJECTIVE: To investigate preparation, response, and economic impact of COVID-19 on private, public, academic, and privademic spine surgeons. METHODS: AO Spine COVID-19 and Spine Surgeon Global Impact Survey includes domains on surgeon demographics, location of practice, type of practice, COVID-19 perceptions, institutional preparedness and response, personal and practice impact, and future perceptions. The survey was distributed by AO Spine via email to members (n = 3805). Univariate and multivariate analyses were performed to identify differences between practice settings. RESULTS: A total of 902 surgeons completed the survey. In all, 45.4% of respondents worked in an academic setting, 22.9% in privademics, 16.1% in private practice, and 15.6% in public hospitals. Academic practice setting was independently associated with performing elective and emergent spine surgeries at the time of survey distribution. A majority of surgeons reported a >75% decrease in case volume. Private practice and privademic surgeons reported losing income at a higher rate compared with academic or public surgeons. Practice setting was associated with personal protective equipment availability and economic issues as a source of stress. CONCLUSIONS: The current study indicates that practice setting affected both preparedness and response to COVID-19. Surgeons in private and privademic practices reported increased worry about the economic implications of the current crisis compared with surgeons in academic and public hospitals. COVID-19 decreased overall clinical productivity, revenue, and income. Government response to the current pandemic and preparation for future pandemics needs to be adaptable to surgeons in all practice settings.

The Modic-endplate-complex phenotype in cervical spine patients: Association with symptoms and outcomes.

This study describes a novel, combined Modic changes (MC) and structural endplate abnormality phenotype of the cervical spine, which we have termed the Modic-Endplate-Complex (MEC), and its association with preoperative symptoms and outcomes in anterior cervical discectomy and fusion (ACDF) patients. This was a retrospective study of prospectively collected data at a single institution. Preoperative cervical magnetic resonance imagings were used to assess the presence of MC and endplate abnormalities. Patients were divided into four groups: MC-only, endplate abnormality-only, the MEC and controls. The MEC was defined as the presence of both a MC and endplate abnormality in the cervical spine. Phenotypes were further stratified by location and compared to controls. Associations with patient-reported outcome measures were assessed using regression controlling for baseline characteristics. A total of 628 patients were included, with 84 MC-only, 166 endplate abnormality-only, and 187 MEC patients. Both MC (p < 0.001) and endplate abnormalities (p < 0.001) were independently associated with one another. MC at the adjacent level (p = 0.018), endplate abnormalities (regardless of location) (p = 0.001), and the MEC within the fusion segment (p = 0.027) were all associated with higher Neck Disability Index scores. Both MC within the fusion segment (p = 0.008) and endplate abnormalities within the fusion segment (p = 0.017) associated with lower Veteran's Rand 12-item scores. MC and structural endplate abnormalities commonly manifest concomitantly in patients indicated for ACDF for degenerative pathology. Patients with the endplate pathology, including the MEC phenotype, reported significantly higher levels of postoperative disability following ACDF. These findings add valuable data to the prognostic assessment of degenerative cervical spine patients.

High-Intensity Zones on MRI of the Cervical Spine in Patients: Epidemiology and Association With Pain and Disability.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to address the prevalence, distribution, and clinical significance of cervical high-intensity zones (HIZs) on magnetic resonance imaging (MRI) with respect to pain and other patient-reported outcomes in the setting of patients that will undergo an anterior cervical discectomy and fusion (ACDF) procedure. METHODS: A retrospective cohort study of ACDF patients surgically treated at a single center from 2008 to 2015. Based on preoperative MRI, HIZ subtypes were identified as either traditional T2-hyperintense, T1-hypointense ("single-HIZs"), or combined T1- and T2-hyperintense ("dual-HIZs"), and their level-specific prevalence was assessed. Preoperative symptoms, patient-reported outcomes, and disc degeneration pathology were assessed in relation to HIZs and HIZ subtypes. RESULTS: Of 861 patients, 58 demonstrated evidence of HIZs in the cervical spine (6.7%). Single-HIZs and dual-HIZs comprised 63.8% and 36.2% of the overall HIZs, respectively. HIZs found outside of the planned fusion segment reported better preoperative Neck Disability Index (NDI; P = .049) and Visual Analogue Scale (VAS) Arm (P = .014) scores relative to patients without HIZs. Furthermore, patients with single-HIZs found inside the planned fusion segment had worse VAS Neck (P = .045) and VAS Arm (P = .010) scores. In general, dual-HIZ patients showed no significant differences across all clinical outcomes. CONCLUSIONS: This is the first study to evaluate the clinical significance of HIZs in the cervical spine, noting level-specific and clinical outcome-specific variations. Single-HIZs were associated with significantly more pain when located inside the fusion segment, while dual-HIZs showed no associations with patient-reported outcomes. The presence of single-HIZs may correlate with concurrent spinal pathologies and should be more closely evaluated.

Demographic, Surgical, and Radiographic Risk Factors for Symptomatic Adjacent Segment Disease After Lumbar Fusion: A Systematic Review and Meta-Analysis.

BACKGROUND: Although multiple studies have investigated risk factors for symptomatic adjacent segment disease (ASD) after lumbar fusion, their findings were diverse and inconsistent. This review aimed to summarize risk factors for ASD in order to guide the management of ASD and future research. METHODS: Six electronic databases were systematically searched from inception to December 2019. Two reviewers independently screened titles, abstracts, and full-text articles to identify studies investigating risk factors for ASD after lumbar fusion in humans. The methodological quality of the included studies and the strength of evidence regarding risk factors were evaluated. RESULTS: Sixteen studies involving 3,553 patients were included. Meta-analyses revealed that high body mass index, facet joint violation, anterior shift of the preoperative and postoperative lumbosacral sagittal plumb line, decreased preoperative and postoperative lumbar lordosis, preoperative adjacent disc degeneration, decreased preoperative adjacent disc height, increased postoperative lumbopelvic mismatch, postoperative pelvic incidence, and postoperative pelvic tilt were significantly related to ASD. CONCLUSIONS: This meta-analysis addressed the limitations of prior reviews and summarized evidence with regard to risk factors for ASD following lumbar fusion. Future prospective studies should investigate whether modification of these risk factors can reduce the ASD development. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Artificial intelligence predicts disk re-herniation following lumbar microdiscectomy: development of the "RAD" risk profile.

PURPOSE: Surgical treatment of herniated lumbar intervertebral disks is a common procedure worldwide. However, recurrent herniated nucleus pulposus (re-HNP) may develop, complicating outcomes and patient management. The purpose of this study was to utilize machine-learning (ML) analytics to predict lumbar re-HNP, whereby a personalized risk prediction can be developed as a clinical tool. METHODS: A retrospective, single center study was conducted of 2630 consecutive patients that underwent lumbar microdiscectomy (mean follow-up: 22-months). Various preoperative patient pain/disability/functional profiles, imaging parameters, and anthropomorphic/demographic metrics were noted. An Extreme Gradient Boost (XGBoost) classifier was implemented to develop a predictive model identifying patients at risk for re-HNP. The model was exported to a web application software for clinical utility. RESULTS: There were 1608 males and 1022 females, 114 of whom experienced re-HNP. Primary herniations were central (65.8%), paracentral (17.6%), and far lateral (17.1%). The XGBoost algorithm identified multiple re-HNP predictors and was incorporated into an open-access web application software, identifying patients at low or high risk for re-HNP. Preoperative VAS leg, disability, alignment parameters, elevated body mass index, symptom duration, and age were the strongest predictors. CONCLUSIONS: Our predictive modeling via an ML approach of our large-scale cohort is the first study, to our knowledge, that has identified significant risk factors for the development of re-HNP after initial lumbar decompression. We developed the re-herniation after decompression (RAD) profile index that has been translated into an online screening tool to identify low-high risk patients for re-HNP. Additional validation is needed for potential global implementation.

Reasons for revision following stand-alone anterior lumbar interbody fusion and lateral lumbar interbody fusion.

OBJECTIVE: Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) are alternative and less invasive techniques to stabilize the spine and indirectly decompress the neural elements compared with open posterior approaches. While reoperation rates have been described for open posterior lumbar surgery, there are sparse data on reoperation rates following these less invasive procedures without direct posterior decompression. This study aimed to evaluate the overall rate, cause, and timing of reoperation procedures following anterior or lateral lumbar interbody fusions without direct posterior decompression. METHODS: This was a retrospective cohort study of all consecutive patients indicated for an ALIF or LLIF for lumbar spine at a single academic institution. Patients who underwent concomitant posterior fusion or direct decompression surgeries were excluded. Rates, causes, and timing of reoperations were analyzed. Patients who underwent a revision decompression were matched with patients who did not require a reoperation, and preoperative imaging characteristics were analyzed to assess for risk factors for the reoperation. RESULTS: The study cohort consisted of 529 patients with an average follow-up of 2.37 years; 40.3% (213/529) and 67.3% (356/529) of patients had a minimum of 2 years and 1 year of follow-up, respectively. The total revision rate was 5.7% (30/529), with same-level revision in 3.8% (20/529) and adjacent-level revision in 1.9% (10/529) of patients. Same-level revision patients had significantly shorter time to revision (7.14 months) than adjacent-level revision patients (31.91 months) (p < 0.0001). Fifty percent of same-level revisions were for a posterior decompression. After further analysis of decompression revisions, an increased preoperative canal area was significantly associated with a lower risk of further decompression revision compared to the control group (p = 0.015; OR 0.977, 95% CI 0.959-0.995). CONCLUSIONS: There was a low reoperation rate after anterior or lateral lumbar interbody fusions without direct posterior decompression. The majority of same-level reoperations were due to a need for further decompression. Smaller preoperative canal diameters were associated with the need for revision decompression.

Duration of Symptoms Does Not Affect Clinical Outcome After Lumbar Arthrodesis.

STUDY DESIGN: Retrospective cohort study at a single institution. OBJECTIVE: To examine the effect of symptom duration on clinical outcomes after posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Nonoperative measures are generally exhausted before patients are indicated for surgical intervention, leaving patients with their symptomatology for varying lengths of time. It is unclear at what point in time surgical intervention may become less efficacious at alleviating preoperative symptoms. MATERIALS AND METHODS: Consecutive patients who underwent primary elective open posterior lumbar spinal fusion at a single academic institution were included. Patient and operative characteristics were compared between symptom duration groups (group 1: <12 mo of pain, group 2: ≥12 mo of pain). Preoperative and final postoperative visual analog scale back/leg pain, and Oswestry Disability Index, were collected. Preoperative, immediate postoperative, and final radiographs were assessed to measure lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and the PI-LL difference was calculated. RESULTS: In total, 167 patients were included in group 1, whereas 359 patients were included in group 2. Baseline demographics and operative characteristics were similar between the 2 groups. Both groups had similar changes in sagittal parameters and had no significant difference in rates of complication, reoperation, discharge to rehabilitation facility, or early adjacent segment degeneration. Both groups demonstrated similar improvement in clinical outcome measures. CONCLUSIONS: Despite differences in symptom duration, patients who had pain for ≥12 months demonstrated similar improvement after posterolateral lumbar arthrodesis than those who had pain for <12 months. Extended effort of conservative treatments or delay of operative intervention does not appear to negatively impact the eventual outcome of surgery. LEVEL OF EVIDENCE: Level III.

COVID-19 and the rise of virtual medicine in spine surgery: a worldwide study.

PURPOSE: The COVID-19 pandemic forced many surgeons to adopt "virtual medicine" practices, defined as telehealth services for patient care and online platforms for continuing medical education. The purpose of this study was to assess spine surgeon reliance on virtual medicine during the pandemic and to discuss the future of virtual medicine in spine surgery. METHODS: A comprehensive survey addressing demographic data and virtual medicine practices was distributed to spine surgeons worldwide between March 27, 2020, and April 4, 2020. RESULTS: 902 spine surgeons representing seven global regions responded. 35.6% of surgeons were identified as "high telehealth users," conducting more than half of clinic visits virtually. Predictors of high telehealth utilization included working in an academic practice (OR = 1.68, p = 0.0015) and practicing in Europe/North America (OR 3.42, p < 0.0001). 80.1% of all surgeons were interested in online education. Dedicating more than 25% of one's practice to teaching (OR = 1.89, p = 0.037) predicted increased interest in online education. 26.2% of respondents were identified as "virtual medicine surgeons," defined as surgeons with both high telehealth usage and increased interest in online education. Living in Europe/North America and practicing in an academic practice increased odds of being a virtual medicine surgeon by 2.28 (p = 0.002) and 1.15 (p = 0.0082), respectively. 93.8% of surgeons reported interest in a centralized platform facilitating surgeon-to-surgeon communication. CONCLUSION: COVID-19 has changed spine surgery by triggering rapid adoption of virtual medicine practices. The demonstrated global interest in virtual medicine suggests that it may become part of the "new normal" for surgeons in the post-pandemic era.