Evaluation of Sagittal Root Positions and Bone Perforation in Anterior Teeth Using Cone Beam Computed Tomography: An Observational Study.

Cone beam computed tomography (CBCT) and virtual implant help clinicians assess implant positioning with nearby vital structures and plan implant surgical procedures. Thus, the current study aims to evaluate the anterior sagittal root position and assess labial bone perforations in CBCT images. This study was carried out using CBCT scans of 140 samples involving 1338 teeth. The Digital Imaging and Communications in Medicine (DICOM) files were imported into Carestream 3-dimensional imaging software for analysis. All measurements were made in the appropriate section slice of 200-µm thickness in a darkened room. A standardized orientation was established by 2 examiners. The sagittal root positions (SRPs) were assessed in maxillary and mandibular anterior teeth. Labial bone perforation (LBP) was assessed using tapered implants in the virtual implant software. Overall, Class I SRP was highest (81.48% and 38.49%, respectively) in both the sextants. The SRP for Class I was most prevalent in canine teeth in both arches (87.96% and 56.45%, respectively), followed by incisors in other types in the maxillary arch. In the mandibular arch, both incisors were in Class IV and I relationships. The overall LBP was 4.26% and was more likely in the mandibular arch (5.64%) than in the maxillary arch (2.8%). The mandibular central incisors showed the highest rate of perforation (8.5% to 11.93%). The SRP and LBP did not show a statistically significant difference between the right and left sides in both arches. The correlation coefficient between SRP and LBP showed a statistically significant result (P < .01). Class I SRP was the most prevalent in maxillary and mandibular arches. Significantly more perforations occurred with mandibular anterior teeth and in Class IV SRP types (approximately 10% to 30%), which suggests that implant placement requires careful presurgical planning and regenerative approaches or delayed implant placement may be considered.

Leidenfrost phenomenon during quenching in aqueous solutions: effect of evaporation-induced concentration gradients.

The minimum temperature limit for a sustained vapor film on a hot surface defines the well-known Leidenfrost temperature (LFT). LFT for pure fluids is typically a strong function of the surface tension. However, the effect of surface tension on LFT of aqueous additive solutions is confusing with many complicated trends. For example, despite an insignificant increase of ≈1 mN m-1 in surface tension, a substantial increase in LFT of ≈50 °C with aqueous salt and sugar solutions has been reported in comparison to pure water. Conversely, no appreciable change in LFT (within ±2 °C) is observed despite a substantial drop of up to ≈30 mN m-1 in surface tension upon varying the concentration of surfactant additives in aqueous solutions. Here, we perform simultaneous thermal, visual, and acoustic characterization of pool quenching experiments with aqueous solutions of salt, sugar, surfactant, and ionic liquids. We model the evaporation-induced increase in the concentration of the non-volatile additives at the liquid-vapor interface using Fick's second law of diffusion. We show that the localized concentration buildup of additives at the liquid-vapor interface dramatically alters the surface tension values in comparison to the typical equilibrium values estimated otherwise. We use these modified surface tension values to correlate the diverse set of experimental LFT data reported in our work and in the literature using a unified framework. We believe that these clarifications regarding the Leidenfrost mechanism will encourage the use of additives in various applications, specifically those where surface modification strategies may not be practically feasible.

Low energy chronic traumatic spondylolisthesis of the axis.

OBJECTIVE: The aim of this study is to present a unique case of a patient who presented to our Emergency Department with evidence of a chronic traumatic spondylolisthesis of the axis with severe displacement treated with anterior cervical discectomy and fusion (ACDF) of C2-C3 as well as and posterior cervical fusion (PCF) of C1-C3. METHODS: One patient with an untreated traumatic spondylolisthesis of the axis with Levine type II injury pattern and 1.2 cm of anterior subluxation underwent ACDF C2-C3 and PCF C1-C3. RESULTS: The patient recovered well, radiographs demonstrated reduction of the anterior subluxation, and the patient reported a neck disability index (NDI) score of 20 at 6-month follow-up with full neurologic function intact. The patient was then lost to follow-up. CONCLUSION: In this report, we present an alcoholic patient with a history of many falls who presented with a Levine type II traumatic spondylolisthesis of the axis with signs of chronicity seen on magnetic resonance imaging (MRI). We were able to partially reduce the anterior displacement with traction, but needed both anterior and posterior cervical approaches to achieve adequate reduction and stabilization of the injury.

Incidence of Neuraxial Abnormalities Is Approximately 8% Among Patients With Adolescent Idiopathic Scoliosis: A Meta-analysis.

BACKGROUND: Several studies have sought to address the role of routine preoperative MRI in patients with adolescent idiopathic scoliosis (AIS) undergoing deformity correction. Despite similar results regarding the prevalence of neuraxial anomalies detected on MRI, published conclusions conflict and give opposing recommendations. Lack of consensus has led to important variations in use of MRI before spinal surgery for patients with AIS. QUESTIONS/PURPOSES: This systematic review and meta-analysis of studies about patients with AIS evaluated (1) the overall proportion of neuraxial abnormalities; (2) the patient factors and curve characteristics that may be associated with abnormalities; and (3) the proportion of patients who underwent neurosurgical intervention before scoliosis surgery and the kinds of neuraxial lesions that were identified. METHODS: We performed a search of four electronic databases (PubMed, EMBASE, CINAHL Plus, and SCOPUS) utilizing search terms related to routine MRI and AIS, yielding 206 articles. Studies included had at least 20 participants, patients with ages 11 to 21 years, and a Methodological Index for Non-Randomized Studies (MINORS) study quality score of 8 and 16 points for noncomparative and comparative studies, respectively. Non-English manuscripts, animal studies, and those that did not include patients with AIS solely were excluded. Eighteen articles with 4746 patients were included for analysis of the overall proportion of neuraxial abnormalities, 12 articles with 3028 patients for analysis by sex, eight articles with 1603 patients for right main thoracic curve, eight articles with 665 patients for a left main thoracic curve, and 13 articles with 3063 patients and 230 (7.5%) abnormalities for number of neurosurgical interventions before scoliosis correction. The mean MINORS score for studies included was 14 (range, 10-20). Each study was analyzed for the proportion of patients identified with neuraxial abnormalities and associations with specific demographics. We determined the proportion of patients who underwent surgical interventions before scoliosis surgery as well as the types of neuraxial lesions identified. The articles were assessed for heterogeneity and publication bias. Because all groups were determined to be heterogeneous, a random-effects model was used for each group in this meta-analysis; with this analysis, an overlap of 95% confidence intervals suggests no difference at the p < 0.05 level, but this analytic approach does not provide p values. RESULTS: The pooled proportion of neuraxial abnormalities detected on MRI was 8% (95% confidence interval [CI], 6%-12%). With the numbers available, we found no difference in the proportion of male and female patients with neuraxial abnormalities (18% [95% CI, 11%-29%] versus 9% [95% CI, 6%-12%], respectively). Likewise, there was no difference in the proportion of pooled neuraxial abnormalities in right and left curves (9% [95% CI, 6%-14%] versus 15% [95% CI, 5%-35%], respectively). In the subset of abnormalities analyzed for number of neurosurgical interventions before scoliosis correction, the pooled proportion showed that 33% (95% CI, 24%-43%) underwent neurosurgical intervention before deformity correction. The most common abnormalities of the 367 found on MRI were syringomyelia in 127 patients (35%), Arnold-Chiari Type 1 malformation with syrinx in 103 patients (28%), and isolated Arnold-Chiari Type 1 malformation in 91 patients (25%). CONCLUSIONS: The proportion of patients with AIS who have neuraxial abnormalities is high (8%) and a large number undergo surgical intervention before scoliosis reconstruction. We did not find any particular demographic variables that indicated an increased risk of abnormality. Clinicians should consider advanced imaging before surgical intervention in the treatment of a patient with an idiopathic diagnosis. Preventable variables need to be identified by future studies to establish a better working treatment protocol for these patients. LEVEL OF EVIDENCE: Level III, diagnostic study.

Delay in Diagnosis of Vertebral Osteomyelitis Affects the Utility of Cultures.

INTRODUCTION: Obtaining blood or tissue cultures prior to administration of antibiotics has been the standard of care in the treatment of osteomyelitis of the spine. A delay in diagnosis of vertebral osteomyelitis is the primary culprit for the inaccuracy of blood cultures and biopsies. The purpose of this study was to evaluate the outcomes of spinal osteomyelitis in patients where the infecting organism was identified through cultures in contrast to cases where the cultures continued to be negative. MATERIALS AND METHODS: We retrospectively reviewed the database of spinal osteomyelitis cases presented at a high-volume institution from 2001-2011. This resulted in 91 patients (51 men and 40 women) who had a mean age of 59 years with a mean follow-up of four years. Delay in diagnosis was defined as greater than 2.5 months from first ER visit for non-specific back pain to diagnosis of osteomyelitis without antibiotic treatment in the interim. Nineteen patients had a delay in diagnosis (DD) and 72 were diagnosed early (ED). Outcomes evaluated include clearance of infection, clinical outcomes measured by Oswestry disability index scores (ODIs), and the efficacy of blood cultures and biopsies. RESULTS: The ED group had a higher odds ratio of osteomyelitis clearance compared to the delay in diagnosis group and this trended toward significance [p=0.08]. The mean improvements in ODIs were significantly greater in the ED group compared to the DD group. Positive blood cultures were more positive when drawn within one month compared to after one month [p=.001]. Percutaneous biopsy cultures were more positive when drawn within 2.5 months compared to after 2.5 months [p=.025]. Open biopsy cultures were more positive when drawn within 4.5 months compared to after that [p<0.001]. DISCUSSION: We found that delayed diagnosis may negatively affect the treatment outcome as evidenced by the greater improvements in ODI scores among those diagnosed early. Although we were unable to show a difference in clearance between early and delayed diagnosis, it is quite possible that larger cohorts may have shown this given the trend toward significance. CONCLUSION: Hence, an early diagnosis has improved vertebral osteomyelitis clearance and clinical outcomes, and blood cultures and biopsies may have a low yield if delayed.

When Do You Drain Epidural Abscesses of the Spine?

BACKGROUND: How the relative volume of an epidural abscess on MRI affects outcomes with antibiotics alone has limited literature. The purpose of this study was to identify which infected epidural collections will reabsorb with antibiotics alone. Specifically, what is the critical size and enhancement on contrast MRIs to require a drainage procedure? MATERIALS AND METHODS: A retrospective review of all spinal osteomyelitis patients from 2001-2012 was performed. Inclusion criteria included appropriate initial imaging, lab results, no drainage procedures of collections, and no treatment prior to admission at an outside institution. Large size epidural abscess was defined as abscesses with a volume greater than 1400 mm3. Clearance and mortality rates were evaluated. RESULTS: The cohort consisted of 128 patients including 76 men and 52 women who had a mean age of 62 years (range, 21 to 90 years) and had a mean follow-up of 38 months (range, 24 to 72 months). Patients with a large epidural abscess had a greater clearance rate of the infection and decreased mortality rate when treated with surgery or drainage compared to patients treated with antibiotics alone [clearance: p=0.048; mortality: p=0.048]. Those small epidural abscesses had similar clearance and mortality rates when treated with surgery or drainage compared to antibiotics alone [clearance: p=0.75; mortality: p=0.13]. Patients with non-enhancing epidural abscesses had similar clearance rates-but increased mortality rates-when treated with antibiotics alone compared to surgery or drainage [clearance: p>0.9; mortality: p=0.03]. Those with enhancing epidural collections had similar clearance and mortality rates when treated with antibiotics alone compared to surgery or drainage [clearance: p=0.08, mortality: p=0.10]. CONCLUSION: Large epidural infected collections require surgery or a percutaneous drainage procedure. Clearance rates are higher and mortality rates are lower compared to non-operative management in these instances. Neurologically intact patients with a small epidural collection can be treated with antibiotics alone with good expected outcomes.

Dataset for boiling acoustic emissions: A tool for data driven boiling regime prediction.

Boiling is used for the thermal management of high-energy-density devices and systems. However, sudden thermal runaway at boiling crisis often results in catastrophic failures. Machine learning is a promising tool for in-situ monitoring of boiling-based systems for preemptive control of boiling crisis. A carefully acquired and well-labeled dataset is a primary requirement for utilizing any data-driven learning framework to extract valuable descriptors. Here, we present a comprehensive dataset of boiling acoustics presented in our recent work [1]. We collect the audio files through meticulously controlled near-saturated pool boiling experiments under steady-state conditions. To this end, we connect a high-sensitivity hydrophone to a pre-amplifier and a data acquisition unit for accurate and reliable acquisition of acoustic signals. We organize the audio files into four categories as per the respective boiling regimes: background or natural convection (BKG, 2-5W/cm2), nucleate boiling (NB, 8-140W/cm2), excluding those at higher heat flux values preceding the onset of boiling crisis or the critical heat flux (Pre-CHF, ≈145W/cm2), and transition boiling (TB, uncontrolled). Each audio file label provides explicit information about the heat flux value and the experimental conditions. This dataset, consisting of 2056 files for BKG, 13367 files for NB, 399 files for Pre-CHF, and 460 files for TB, serves as the foundation for training and evaluating a deep learning strategy to predict boiling regimes. The dataset also includes acoustic emission data from transient pool boiling experiments conducted with varying heating strategies, heater surface, and boiling fluid modifications, creating a valuable dataset for developing robust data-driven models to predict boiling regimes. We also provide the associated MATLAB® codes used to process and classify these audio files.

Should patient eligibility criteria for cervical disc arthroplasty (CDA) be expanded? A retrospective cohort analysis of relatively contraindicated patients undergoing CDA.

BACKGROUND CONTEXT: Cervical disc arthroplasty (CDA) is a safe and effective alternative to anterior cervical discectomy and fusion (ACDF) in the treatment of various degenerative pathologies with advantages of motion preservation and lower rates of adjacent segment degeneration (ASD). Absolute contraindications for CDA have been well outlined in order to prevent adverse outcomes in patients. However, in cases of patients with relative contraindications (kyphotic deformity, prior cervical surgery, etc.), there remains controversy. There is minimal literature evaluating long-term outcomes in this patient population. PURPOSE: To compare long-term clinical and functional outcomes of CDA in typical patients versus those with relative contraindications. DESIGN: Retrospective cohort review. PATIENT SAMPLE: Eighty-nine patients were included in the study: 55 (no contraindications) in Group 1 and 34 (relatively contraindicated) in Group 2 and 26 (preoperative segmental kyphosis) in Group 3. OUTCOME MEASURES: (1) Patient demographics; (2) perioperative data; (3) rates of complications and revisions; (5) visual analogue scale (VAS), and neck disability index (NDI) scores. METHODS: Patients were placed in the relatively contraindicated cohort if they possessed at least one of the following: (1) segmental kyphosis of 5° to 10°, (2) significant loss of disc height (between 50% and 75% of initial measurements or 1.5-3mm), (3) bridging osteophytes, and (4) prior cervical spine surgery based on preoperative cervical radiographs. The other cohort included patients without any relative contraindication who underwent CDA over the same time frame. Additionally, a subgroup analysis was used to compare those without any contraindications to those with only preoperative segmental kyphosis. Patients were included in this study if they met the following criteria: over 18 years of age, minimum follow-up of 24 months, and availability of complete medical records. Patient demographics, levels operated on, and perioperative outcomes were assessed between the two groups. Revision and complication rates were recorded. Functional outcomes scores were compared using VAS and NDI scores at 6-months, 12-months and final follow-up. RESULTS: Mean follow-up was 40.8 months in Group 1 and 38.3 months in Group 2 (p=.569). Complication rates were 21.8% in Group 1 and 26.4% in Group 2 (p=.615). Complication rates in a comparison between Groups 1 and 3 were statistically insignificant (p=.383). The most common complication was transient approach-related postoperative dysphagia (Group 1: 20% vs Group 2: 23.5%, p=.693). No significant differences were observed in the rates of transient dysphonia (Group 1: 0.0% vs Group 2: 2.9%, p=.201), adjacent segment degeneration (ASD) (Group 1: 1.8% vs Group 2: 0.0%, p=.429), infection (Group 1: 1.8% vs Group 2: 2.9%, p=.712), heterotopic ossification (Group 1: 49.1% vs Group 2: 50.0%, p=.934) or spontaneous fusion (Group 1: 1.8% vs Group 2: 2.9%, p=.728). No revision surgeries were observed in either cohort. All three groups demonstrated significant improvements in their VAS and NDI scores compared with preoperative measurements (p<.001), but no significant differences were found in the degree of improvement between groups at any point in time. CONCLUSIONS: Our study found no significant differences in clinical and functional outcomes between patients undergoing 1- and 2-level CDA with relative contraindications versus typical patients. These findings suggest that patient eligibility criteria for CDA may warrant expansion. However, future prospective studies over a longer period of follow-up are necessary to corroborate our results.

Comparing outcomes between anterior cervical disc replacement (ACDR) and minimally invasive posterior cervical foraminotomy (MI-PCF) in the treatment of cervical radiculopathy.

BACKGROUND CONTEXT: Anterior cervical disc replacement (ACDR) and minimally invasive posterior cervical foraminotomy (MI-PCF) have emerged as two increasingly popular alternatives to anterior cervical discectomy and fusion (ACDF) for the management of cervical radiculopathy. Both techniques provide advantages of segmental motion preservation and lower rates of adjacent segment degeneration (ASD) compared to ACDF. PURPOSE: The purpose of this study was to analyze the clinical and functional outcomes of patients undergoing ACDR or MI-PCF for the treatment of unilateral cervical radiculopathy. STUDY DESIGN/SETTING: Retrospective Cohort Review. PATIENT SAMPLE: A total of 152 patients were included (86 ACDR and 66 MI-PCF). OUTCOME MEASURES: (1) Patient demographics; (2) perioperative data; (3) rates of complications and revisions; (5) visual analogue scale (VAS) and Neck Disability Index (NDI) scores. METHODS: A retrospective cohort review was performed to identify all patients at a single institution between 2012-2020 who underwent 1- or 2- level ACDR or MI-PCF from C3-C7 with a minimum follow-up of 24 months. Patient demographics, perioperative data, postoperative complications, and revisions were analyzed. Patient reported outcome measures including VAS and NDI scores were compared. RESULTS: The ACDR group had a significantly greater mean operative time (99.8 minutes vs 79.2 minutes, p<.001), but comparable estimated blood loss and length of stay following surgical intervention (p=.899). The overall complication rate was significantly greater in the ACDR group than the MI-PCF group (24.4% vs 6.2%; p=.003) but was largely driven by approach-related dysphagia in 20.9% of ACDR patients. The MI-PCF group had significantly greater revision rates (13.6% vs 1.2%; p=.002) with an average time to revision of 20.7 months in the MI-PCF group compared to 40.3 months in the ACDR group. The ACDR cohort had significantly greater improvements in NDI scores at the final follow-up (25.0 vs 21.3, p<.001). CONCLUSION: Our results suggest that ACDR offer clinically relevant advantages over MI-PCF in terms of long-term revision rates despite an increased approach-related risk of transient postoperative dysphagia. Additionally, patients in the ACDR cohort achieved greater mean improvements in NDI scores but these results may have limited clinical significance due to inability to reach minimally clinically important difference (MCID) thresholds.

Are Patients With Segmental Cervical Kyphosis Appropriate Candidates for Cervical Disc Arthroplasty (CDA)? A Clinical and Radiographic Analysis Compared to Anterior Cervical Discectomy and Fusion (ACDF).

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To compare the clinical and radiographic outcomes of Anterior Cervical Discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) in patients with preoperative segmental kyphosis. METHODS: Patients with segmental cervical kyphosis at the operative levels undergoing 1- or 2-level ACDF or CDA from 2017 to 2020 with 2 years of follow were identified. Patient demographics, perioperative data, complication rates, radiographic findings and reported outcomes were analyzed. RESULTS: A total of 48 patients met inclusion criteria and were included in our study (ACDF: n = 24, CDA: n = 24). Patient demographic data between the 2 cohorts was similar expect for proportion of males (ACDF: 62.5% vs CDA: 33.3%, P = .043). There was no statistical significance in the change of segmental lordosis (ACDF: +8.09° vs CDA: +5.88°, P = .075) between the preoperative and final postoperative period. Additionally, the change in cervical lordosis was similar between groups (ACDF:+ 9.86° vs CDA: +7.60°, P = .226). VAS scores were similar between the 2 groups at every follow-up interval. NDI scores were significantly different at the 6-month, 12 month and the final follow-up. Mean improvements between preoperative and final postoperative periods were statistically superior in the CDA cohort compared to the ACDF cohort (ACDF: 22.8 vs CDA: 24.1, P = .0375). CONCLUSION: CDA was superior to ACDF in regards to NDI scores following index procedure in patients with preoperative segmental cervical kyphosis. Those in the CDA cohort had similar complication rates, revision rates and radiographic outcomes as those who underwent ACDF.

The Impact of Patient Characteristics on Outcomes of Surgically Managed Vertebral Osteomyelitis in the United States: Insights from a National Database Study.

This study was conducted to assess the patient characteristics, types of treatment, and outcomes of patients who are surgically treated for vertebral osteomyelitis (VO) in the United States. VO can be treated with or without surgical intervention. Surgically treated cases of VO are associated with significant morbidity and mortality, and incur major healthcare costs. There are few studies assessing the characteristics and outcomes of patients with VO who are treated surgically, as well as the overall impact of surgically managed VO on the healthcare system of the United States. Utilizing the Nationwide Inpatient Sample (NIS) database, 44,401 patients were identified who underwent surgical treatment for VO over a fifteen year period. Severity of comorbidity burden was calculated using the Deyo Index (DI). Surgical approach and comorbidities were analyzed in regard to their impact on complications, mortality rate, LOS, and hospitalization charges. The incidence of surgical intervention for patients who had VO increased from 0.6 to 1.1 per U.S. persons over the study period. Surgically treated patients had a mean age of 56 years, were 75.8% white, were 54.5% male, 37.9% carried Medicare insurance, and they had a mean DI of 0.88. Anterior/posterior approach (OR: 3.53), thoracolumbar fusion (OR: 2.69), thoracolumbar fusion (OR: 19.94), and anterior/posterior approach (OR: 64.73) were the surgical factors that most significantly predicted any complication, mortality, increased LOS, and increased hospital charges, respectively (P < 0.001). The mean inflation-adjusted total hospital cost increased from $20,355 to $39,991 per patient over the study period. VO has been steadily increasing in the United States. Incidence and inflation-adjusted costs nearly doubled. Anterior/posterior approach and thoracolumbar fusion most significantly predicted negative outcomes. VO is associated with lengthy and expensive hospital stays resulting in a significant burden to patients and the healthcare system.

Safety and Efficacy of Outpatient Anterior Cervical Disk Replacement (ACDR) in an Ambulatory Surgery Center Versus Hospital Setting: A 2-year Retrospective Analysis.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: To compare clinical outcomes of outpatient anterior cervical disk replacements (ACDR) performed in free-standing private ambulatory surgery centers versus tertiary hospital centers. SUMMARY OF BACKGROUND DATA: ACDR is an increasingly popular technique for treating various degenerative pathologies of the cervical spine. There has been an increase in the utilization of ambulatory surgery centers (ASCs) for outpatient cervical procedures due to economic and convenience benefits; however, a paucity of literature exists in evaluating long-term safety and efficacy of ACDRs performed in ASCs versus outpatient hospital centers. METHODS: A retrospective cohort review of all patients undergoing 1- or 2-level ACDRs at 2 outpatient ASCs and 4 tertiary care medical centers from 2012 to 2020, with a minimum follow-up of 24 months, was performed. Approval by each patient's insurance and patient preference determined distribution into an ASC or non-ASC. Demographics, perioperative data, length of follow-up, complications, and revision rates were analyzed. Functional outcomes were assessed using VAS and NDI at follow-up visits. RESULTS: One hundred seventeen patients were included (65 non-ASC and 52 ASC). There were no significant differences in demographics or length of follow-up between the cohorts. ASC patients had significantly lower operative times (ASC: 89.5 minutes vs. non-ASC: 110.5 minutes, P<0.001) and mean blood loss (ASC: 17.5 mL vs. non-ASC: 25.3 mL, P<0.001). No significant differences were observed in rates of dysphagia (ASC: 21.2% vs. non-ASC: 15.6%, P<0.001), infection (ASC: 0.0% vs. non-ASC: 1.6%, P=0.202), ASD (ASC: 1.9% vs. non-ASC: 1.6%, P=0.202), or revision (ASC: 1.9% vs. non-ASC: 0.0%, P=0.262). Both groups demonstrated significant improvements in VAS and NDI scores (P<0.001), but no significant differences in the degree of improvement were observed. CONCLUSIONS: Our 2-year results demonstrate that ACDRs performed in ASCs may offer the advantages of reduced operative time and blood loss without an increased risk of postoperative complications.

The 5-factor modified frailty index (mFI-5) predicts adverse outcomes after elective anterior cervical discectomy and fusion (ACDF).

Background: Anterior cervical discectomy and fusion (ACDF) is a reliable procedure commonly performed in older patients with degenerative diseases of the cervical spine. Over 130,000 procedures are performed every year with an annual increase of 5%, and overall morbidity rates can reach as high as 19.3%, indicating a need for surgeons to gauge their patients' risk for adverse outcomes. Frailty is an age-associated decline in functioning of multiple organ systems and has been shown to predict adverse outcomes following various spine procedures. There have been several proposed frailty indices of various factors including the 11-factor modified frailty index (mFI-11), which has been shown to be an effective tool for predicting complications in patients undergoing ACDF. However, there is a paucity of literature assessing the utility of the 5-factor modified frailty index (mFI-5) as a risk stratification tool for patients undergoing ACDF. The purpose of this study was to analyze the predictive capability of the mFI-5 score for 30-day postoperative adverse events following elective ACDF. Methods: A retrospective review was performed using the National Surgical Quality Improvement Program (NSQIP) database from 2010 through 2019. Patients older than 50 years of age who underwent elective ACDF were identified using Current Procedural Terminology ([CPT] codes 22554, 22551, 22552, and 63075). Exclusion criteria removed patients under the age of 51, as well as those with fractures, sepsis, disseminated cancer, a prior operation in the last 30 days, ascites, wound infection, or an emergency surgery. Patients were grouped using mFI scores of 1, 2, and 3+. Univariate analysis, using chi-squared and one-way analysis of variance (ANOVA) tests, was conducted to compare demographics, comorbidities, and postoperative complications across the varying cohorts based on mFI-5 scores. Multivariate logistic regression, including patient demographics and preoperative comorbidities as covariates, was performed to evaluate if mFI-5 scores were independent predictors of 30-day postoperative adverse events. Covariates including race, BMI, sex, ASA, and comorbidities were included in regression models. Results: The 45,991 patients were identified and allocated in cohorts based on mFI-5 score. Rates for superficial surgical site infection (SSI), organ/deep space SSI, pneumonia, progressive renal insufficiency, acute renal failure (ARF), urinary tract infection (UTI), stroke/cardiovascular accident (CVA), cardiac arrest requiring cardiopulmonary resuscitation (CPR), myocardial infarction, bleeding requiring transfusions, deep vein thrombosis/thrombophlebitis, sepsis, septic shock, readmissions, reoperation, and mortality incrementally increased with mFI-5 scores from 0 to 3+. Multivariate regression analysis revealed that mFI-5 scores 1 to 3+ increased the odds, in a stepwise manner, of total complications, cardiac arrest requiring CPR, pneumonia and mortality. MFI-5 scores of 2 and 3+ were independent predictors of readmission (2: OR=1.5, p<.001; 3+: OR=2.0, p<.001) and myocardial infarction (2: OR=3.4, p=.001; 3+: OR=6.9, p<.001). A score of 3+ increased the odds of ARF (OR=9.7, p=.022), septic shock (OR=3.6, p=.036), UTI (OR=2.1, p=.007), bleeding requiring transfusions (OR=2.1, p=.016), and reoperations (OR=1.7, p=.004). Conclusion: mFI-5 score is a quick and viable option for surgeons to use as an assessment tool to stratify high risk patients undergoing elective ACDF, as increasing mFI-5 scores showed significantly higher rates of all adverse outcomes accounted for in this study, except for deep incisional SSI, wound disruption, and PE. Additionally, moderate to severe mFI-5 scores of 2 or 3+ were independent predictors for 30-day postoperative ARF, UTI, MI, bleeding requiring transfusions, septic shock, reoperation, and readmissions following elective ACDF surgery in adults over 50 years old.

Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF): A Video Technique Guide.

Background: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been established as an excellent alternative to the traditional open approach for the treatment of degenerative conditions of the lumbar spine1-3. Description: The procedure is performed with the patient under general anesthesia and on a radiolucent table in order to allow for intraoperative fluoroscopy. The procedure is performed through small incisions made over the vertebral levels of interest, typically utilizing either a fixed or expandable type of tubular dilator, which is eventually seated against the facet joint complex4. A laminectomy and/or facetectomy is performed in order to expose the disc space, and the ipsilateral neural elements are visualized5. The end plates are prepared, and an interbody device is placed after the disc is removed. Pedicle screws and rods are then placed for posterior fixation. Alternatives: Nonoperative alternatives include physical therapy and corticosteroid injections. Other operative techniques include open TLIF or other types of lumbar fusion approaches, such as posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion, lateral or extreme lateral interbody fusion, or oblique lumbar interbody fusion. Rationale: Open TLIF was developed in order to obtain a more lateral approach to the lumbar disc space than was previously possible with PLIF. The goal of this was to minimize the amount of thecal-sac and nerve-root retraction required during PLIF4. Additionally, as the number of patients who required revision after PLIF increased, the need arose for an approach to the lumbar spine that circumvented the posterior midline scarring from previous PLIF surgical sites6. MI-TLIF was introduced to reduce the approach-related paraspinal muscle damage of open TLIF5. Indications for MI-TLIF include most degenerative pathology of the lumbar spine, including disc herniation, low-grade spondylolisthesis, and spinal and foraminal stenosis7. However, MI-TLIF allows for less robust correction of deformity than other minimally invasive approaches; therefore, MI-TLIF may not be as effective in cases of substantial spinal deformity or high-grade spondylolisthesis8. Expected Outcomes: MI-TLIF results in significantly less blood loss, postoperative pain, and hospital length of stay compared with open TLIF1-3. Although some studies have suggested increased operative time for MI-TLIF9,10, meta-analyses have shown comparable operative times between the 2 techniques1-3. It is thought that the discrepancy in reported operative times is the result of a learning curve and that, once that is overcome, the difference in operative time between the 2 techniques becomes minimal11,12. One disadvantage of MI-TLIF that has remained constant in the literature is its increased intraoperative fluoroscopy time compared with open TLIF3,13. The complication rate has largely been found to be equivalent between open and MI-TLIF1-3 or slightly lower with MI-TLIF14, especially in the hands of an experienced surgeon15. Finally, the fusion rate and improvement in patient outcome scores have also been found to be largely equivalent1-3. Important Tips: We suggest placing the ipsilateral pedicle screw after the interbody cage has been inserted.Fully visualize the Kambin triangle16 prior to performing the facetectomy. Protect the exiting and traversing nerve roots by placing small cottonoids around them and retracting delicately.Bone removed during facetectomy can be utilized as autograft for the interbody cage.Avoid removing pedicle bone during decompression.If central stenosis is present, the neural decompression should be extended medial to the epidural fat so that the dura mater can be visualized all of the way to the contralateral pedicle.Perform an adequate end plate preparation prior to interbody insertion while being mindful to avoid injuring the end plate, to minimize the risk of future cage subsidence.Confirm correct placement of the interbody device on intraoperative fluoroscopy.If bone morphogenic protein is utilized, be careful not to pack too much posteriorly as this may cause nerve irritation. Acronyms and Abbreviations: TLIF = transforaminal lumbar interbody fusionMI-TLIF = minimally invasive TLIFPLIF = posterior lumbar interbody fusionALIF = anterior lumbar interbody fusionLLIF = lateral lumbar interbody fusionXLIF = extreme lateral interbody fusionOLIF = oblique lumbar interbody fusionDLIF = direct lateral interbody fusionMRI = magnetic resonance imagingA/P = anteroposteriorEMG = electromyographicBMP = bone morphogenic proteinXR = x-ray (radiograph)OTC = over the counterDVT = deep vein thrombosisPE = pulmonary embolismMI = myocardial infarctionMIS = minimally invasive surgeryOR = operating roomLOS = length of stayVAS = visual analog scaleODI = Oswestry Disability IndexM-H = Mantel-HaenszelRR = risk ratioCI = confidence intervalNSAIDs = nonsteroidal anti-inflammatory drugs.

The 5-Factor Modified Frailty Index is Associated With Increased Risk of Reoperations and Adjacent Level Disease Following Single-Level Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the predictive capability between the 5-factor modified frailty index (mFI-5) scores and adverse clinical and radiographic outcomes following single-level transforaminal lumbar interbody fusion (TLIF). METHODS: All patients over the age of 50 undergoing single-level open or minimally invasive TLIF from 2012 to 2021 with a minimum follow-up of 1 year were identified. Deformity, trauma, emergency, and tumor cases were excluded as were patients undergoing revision surgeries. An mFI-5 score was computed for each patient using a set of five factors which included hypertension requiring medication, chronic obstructive pulmonary disease, diabetes mellitus, congestive heart failure, and partially or fully dependent functional status. Univariate and multivariate logistic regression analysis were performed to evaluate the impact of mFI-5 scores on readmissions, reoperations, and postoperative complications. RESULTS: 156 patients were included and grouped according to their level of frailty: no-frailty (mFI = 0, n = 67), mild frailty (mFI = 1, n = 59), and severe frailty (mFI = 2+, n = 30). Multivariate analysis found high levels of frailty (mFI = 2+) to be independent predictors of reoperation (OR: 16.9, CI: 2.7 - 106.9, P = .003) and related readmissions (OR = 16.5, CI: 2.6 - 102.7, P = .003) as compared to the no-frailty group. An mFI-5 score of 2+ was also predictive of any complication (OR = 4.5, CI: 1.4 - 14.3, P = .01) and adjacent segment disease (ASD) (OR = 12.5, CI: 1.2 - 134.0, P = .037). CONCLUSION: High levels of frailty were predictive of related readmissions, reoperations, any complications, and ASD in older adult patients undergoing single-level TLIF.

Comparing clinical and radiological outcomes between single-level OLIF and XLIF: A systematic review and meta-analysis.

Background Context: Oblique lumbar interbody fusion (OLIF) and extreme lateral interbody fusion (XLIF) are 2 popular minimally invasive spinal fusion techniques with unique approach-related complication profiles. Accordingly, patient-specific anatomical factors, such as vascular anatomy or iliac crest height, greatly influence which technique to use. Previous studies comparing these approaches do not account for the inability of XLIF to access the L5-S1 disc space and therefore do not exclude this level in their analysis. The purpose of this study was to compare radiological and clinical outcomes of these techniques in the L1-L5 region. Methods: A query of 3 electronic databases (PubMed, CINAHL plus, and SCOPUS) was performed, without time restriction, to identify studies that evaluated outcomes of single-level OLIF and/or XLIF between L1 and L5. Based on heterogeneity, a random effects meta-analysis was performed to evaluate the pooled estimation of each variable between the groups. An overlap of 95% confidence intervals suggests no statistically significant difference at the p<.05 level. Results: A total of 1,010 patients (408 OLIF, 602 XLIF) were included from 24 published studies. Improvements in disc height (OLIF: 4.2 mm; XLIF: 5.3 mm), lumbar segmental (OLIF: 2.3°; XLIF: 3.1°), and lumbar lordotic angles (OLIF: 5.3°; XLIF: 3.3°) showed no significant difference. The rate of neuropraxia was significantly greater in the XLIF group at 21.2% versus 10.9% in the OLIF group (p<.05). However, the rate of vascular injury was higher in the OLIF cohort at 3.2% (95% CI:1.7-6.0) as compared to 0.0 (95% CI: 0.0-1.4) in the XLIF cohort. Improvements in VAS-b (OLIF: 5.6; XLIF: 4.5) and ODI (OLIF: 37.9; XLIF: 25.6) scores were not significantly different between the 2 groups. Conclusions: This meta-analysis demonstrates similar clinical and radiological outcomes between single-level OLIF and XLIF from L1 to L5. XLIF had significantly higher rates of neuropraxia, whereas OLIF had greater rates of vascular injury.

The 5-factor modified Frailty Index (mFI-5) predicts adverse outcomes after elective Anterior Lumbar Interbody Fusion (ALIF).

Background: The 5-factor modified frailty index (mFI-5) has been shown to be a concise and effective tool for predicting adverse events following various spine procedures. However, there have been no studies assessing its utility in patients undergoing anterior lumbar interbody fusion (ALIF). Therefore, the aim of this study was to analyze the predictive capabilities of the mFI-5 for 30-day postoperative adverse events following elective ALIF. Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried from 2010 through 2019 to identify patients who underwent elective ALIF using Current Procedural Terminology (CPT) codes in patients over the age of 50. The mFI-5 score was calculated using variables for hypertension, congestive heart failure, comorbid diabetes, chronic obstructive pulmonary disease, and partially or fully dependent functional status which were each assigned 1 point. Univariate analysis and multivariate logistic regression models were utilized to identify the associations between mFI-5 scores, and 30-day rates of overall complications, readmissions, reoperations, and mortality. Results: 11,711 patients were included (mFI-5=0: 4,026 patients, mFI-5=1: 5,392, mFI-5=2: 2,102, mFI-5=3+: 187. Multivariate logistic regression revealed that mFI-5 scores of 1 (OR: 2.2, CI: 1.2-4.2, p=0.02), 2 (OR: 3.6, CI: 1.8-7.3, p<0.001), and 3+ (OR: 7.0, CI: 2.5-19.3, p<0.001) versus a score of 0 were significant predictors of pneumonia. An mFI-5 score of 2 (OR: 1.3; CI: 1.01-1.6, p=0.04), and 3+ (OR: 1.9; CI: 1.1-3.1; p=0.01) were both independent predictors of related readmissions. An mFI score of 3+ was an independent predictor of any complication (OR: 1.5, CI: 1.01-2.2, p=0.004), UTI (OR: 2.4, CI: 1.1-5.2, p=0.02), and unplanned intubation (OR: 4.5, CI: 1.3-16.1, p=0.02). Conclusions: The mFI-5 is an independent predictor for 30-day postoperative complications, readmissions, UTI, pneumonia, and unplanned intubations following elective ALIF surgery in adults over the age of 50.

Numerical Analysis of Temperature Distribution Profiles of Breast Tissues with Cyst and Tumor of Different sizes and Locations.

Breast cancer causes more deaths among all types of cancers. Efforts have been put to study the change in temperature distribution profile of the breast in presence of an abnormality. By applying Pennes's bio-heat equation, a 2D finite element model is developed for the heat transfer mechanism. Surface temperature gradients due to the presence of abnormalities at various depths and sizes are analyzed. The results show that the presence of a cyst decreases the temperature whereas the occurrence of tumor increases the temperature inside the breast. It is observed that abnormal tissue having a radius less than 1.5cm and depth greater than 5cm, has a negligible effect on the surface temperature profile. The highest change in surface temperature is observed when a cyst or tumor is larger and present near the skin. The simulation results help in the better interpretation of the thermal images and calibration of infrared camera. This study could be helpful in the early diagnosis of breast cancer.