Risk Factors for Sacroiliac Joint Fusion after Instrumented Spinal Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To identify risk factors for sacroiliac (SI) joint fusion after instrumented spinal fusion. METHODS: Patients were identified from the PearlDiver BiscayneBay database. Patients who underwent 1 level (CPT: 22840), 3-6 vertebral segment (22842), and 7+ vertebral segment spinal fusions (22843 and 22844) were identified. Patients were separated based on whether they received an SI joint fusion (27280 and 27279) after their spinal fusion. A univariate analysis and multivariate logistic regression was performed to evaluate the associations between patient factors and incidence of SI joint fusion. RESULTS: 549,625 patients who underwent posterior spinal fusions were identified, 6068 of whom underwent subsequent SI joint fusion (1.1%). Factors associated with future SI joint fusion included female gender, patients with obesity, fibromyalgia, diabetes, tobacco use, increased construct length, and prior SI joint injection. Prior SI joint injection had the highest odds ratio (OR: 8.70; 95% CI: 8.25-9.16; P < 0.001), followed by 7+ vertebral segment (OR: 2.17; 95% CI: 2.03-2.33; P < 0.001) and 3-6 vertebral segment fusion (OR: 1.49; 95% CI: 1.42-1.57; P < 0.001). CONCLUSIONS: The highest predictor of requiring subsequent SI joint fusion is a prior SI joint injection. We also found that longer fusion constructs are associated with increased risk for future SI joint fusion.

Elective Versus Nonelective Spinal Fusions: Surgical and Financial Outcomes in a Bundled Payment Reimbursement Model.

BACKGROUND AND OBJECTIVES: Bundled payment for care improvement advanced (BPCIA) is a voluntary alternative payment model administered by the Centers for Medicare and Medicaid Services using value-based care to reduce costs by incentivizing care coordination and improved quality. We aimed to identify drivers of negative financial performance in BPCIA among patients undergoing spinal fusion surgery. METHODS: This is a single-institution retrospective review of patients enrolled in BPCIA undergoing spinal fusion with DRGs 453, 454, 455, 459, and 460 from 2018 to 2022. Univariate and multivariable logistic regression analyses were used to identify factors associated with negative financial performance and compare nonelective vs elective surgeries. RESULTS: We identified 172 cases, of which 24% (n = 41) had negative financial performance and 9% (n = 16) were nonelective cases. Nonelective surgery (P < .001, odds ratios 19.81), greater levels instrumented (P < .001), and no anterior procedure (P = .001) were associated with negative financial performance. Surgical outcomes associated with negative financial performance and factors more common in nonelective cases respectively included higher hospital length of stay (P < .001, P = .005), nonhome discharge (P < .001, P < .001), 90-day hospital readmission (P < .001, P < .001), 90-day additional nonspine surgery (P = .01, P < .001), and less days at home of the 90 days (P < .001, P = .01). Nonelective surgeries had higher total spend (P = .01), readmission spend (P = .03), skilled nursing facility spend (P = .02), durable medical equipment spend (P = .003), and professional billing spend (P = .04) despite similar target pricing (P = .60), all of which resulted in greater financial loss compared with elective surgeries (P = .001). CONCLUSION: Nonelective spinal surgery is an independent preoperative predictor of negative financial performance in BPCIA. Nonelective spinal surgeries are more likely than elective surgeries to have higher length of stay, nonhome discharge, 90-day hospital readmission, 90-day additional nonspine surgeries, and less time spent at home during the bundled period, all of which contribute to higher health care utilization. The Centers for Medicare and Medicaid Services should consider incorporating nonelective spine surgery into risk-adjustment models.

Enoxaparin and Early Postoperative Tibial Nailing: Increased Nonunion Revision Rates.

OBJECTIVES: To determine the association between postoperative enoxaparin use and the risk of requiring surgery for nonunion in patients treated with intramedullary nailing for midshaft fractures of the tibia. DESIGN: Retrospective cohort analysis. SETTING: Data were sourced from the PearlDiver national database. PATIENT SELECTION CRITERIA: Patients were identified through the PearlDiver database by using Current Procedural Terminology and International Classification of Diseases (ICD-10) codes. Included patients had undergone intramedullary nailing for midshaft fractures of the tibia between 2015 and 2020 and subsequently underwent revision surgery due to nonunion. OUTCOME MEASURES AND COMPARISONS: The primary outcome measured in this study was the rate of nonunion following intramedullary nailing for the different types of tibial shaft fractures (closed, Type I/II open, Type III open). For each fracture subtype, the study compared nonunion rates between those who received enoxaparin in the postoperative period and those who did not receive enoxaparin at any time during the first 6 weeks postoperatively. Factors such as the timing and duration of enoxaparin therapy and demographic variables were also considered. RESULTS: The study included 16,986 patients, average age was 49.2 years (SD 17.3); 43.1% were female. Five hundred four patients required revision surgery for nonunion (3.4%). Among patients who did not receive enoxaparin, the nonunion rates were 1.6%, 3.9%, and 6.9% for closed, Type I/II open, and Type III open fractures, respectively. For patients who received enoxaparin within the first 2 weeks, the nonunion rates were 2.6%, 4.7%, and 7.9% for closed (RR = 1.67, P < 0.0001), Type I/II open (RR = 1.21, P < 0.0001), and Type III open (RR = 1.17, P = 0.355) fractures, respectively. Logistic regression confirmed enoxaparin was independently associated with nonunion (odds ratios [OR] = 1.75, P = 0.0013 for closed fractures; OR = 1.51, P = 0.034 for Type I/II open fractures). Tobacco use was also a contributing factor (OR = 2.43, P < 0.0001 for closed fractures; OR = 2.00, P < 0.0001 for Type I/II open fractures; OR = 2.04, P = 0.0008 for Type III open fractures). CONCLUSIONS: The postoperative use of enoxaparin was associated with an elevated risk of nonunion in patients treated with intramedullary nailing for fractures of the tibial shaft. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Strategic stabilization of arousal boosts sustained attention.

Arousal and motivation interact to profoundly influence behavior. For example, experience tells us that we have some capacity to control our arousal when appropriately motivated, such as staying awake while driving a motor vehicle. However, little is known about how arousal and motivation jointly influence decision computations, including if and how animals, such as rodents, adapt their arousal state to their needs. Here, we developed and show results from an auditory, feature-based, sustained-attention task with intermittently shifting task utility. We use pupil size to estimate arousal across a wide range of states and apply tailored signal-detection theoretic, hazard function, and accumulation-to-bound modeling approaches in a large cohort of mice. We find that pupil-linked arousal and task utility both have major impacts on multiple aspects of task performance. Although substantial arousal fluctuations persist across utility conditions, mice partially stabilize their arousal near an intermediate and optimal level when task utility is high. Behavioral analyses show that multiple elements of behavior improve during high task utility and that arousal influences some, but not all, of them. Specifically, arousal influences the likelihood and timescale of sensory evidence accumulation but not the quantity of evidence accumulated per time step while attending. In sum, the results establish specific decision-computational signatures of arousal, motivation, and their interaction in attention. So doing, we provide an experimental and analysis framework for studying arousal self-regulation in neurotypical brains and in diseases such as attention-deficit/hyperactivity disorder.

The Multiplicative Effects of Individual Risk Factors in the Development of Osteonecrosis of the Femoral Head.

BACKGROUND: While individual risk factors, including chronic corticosteroid use, alcohol abuse, and smoking, are implicated in osteonecrosis of the femoral head (ONFH), the degree to which multiple risk factors increase risk is unknown. This study aimed to: (1) identify the demographic characteristics of patients who have ONFH; (2) quantify the effects of individual risk factors on ONFH development; (3) quantify the effects of combined risk factors on ONFH development; and (4) determine the prognostic implications of combined risk factors on ONFH development. METHODS: This was a retrospective cohort study. A national insurance database was used to study a population of 2,612,383 adult patients who had a 10-year follow-up period. There were 10,233 patients identified who had a diagnosis of ONFH. We identified patients who had chronic corticosteroid use, tobacco use, and/or alcohol abuse and assessed the risk of developing ONFH over a 10-year period. Patients who had individual and multiple risk factors were grouped for comparison, and Chi-square analyses were performed. RESULTS: Higher proportions of patients who had each individual risk factor developed ONFH compared to proportions of patients who did not have risk factors. Patients who had combined risk factors were at greater risk of developing ONFH compared to patients who had no risk factors and those who had single risk factors. Combined risk factors demonstrated multiplicative effects on the development of ONFH: tobacco-alcohol risk ratio (RR) 5.25, corticosteroid-alcohol RR 10.20, tobacco-corticosteroid RR 8.69, and corticosteroid-tobacco-alcohol RR 12.54. Patients who had combined risk factors developed ONFH at younger ages than those who had single risk factors. Kaplan-Meier curve analyses demonstrated worse 10-year hip survival in the setting of combined risk factors. CONCLUSIONS: Combined risk factors have a multiplicative effect on the risk of developing of atraumatic ONFH. Orthopaedic surgeons may care for at-risk individuals through modulation of risk factors. LEVEL OF EVIDENCE: Retrospective Cohort Study, Level III.

Age-Related Changes in Temporal Binding Involving Auditory and Vestibular Inputs.

Maintaining balance involves the combination of sensory signals from the visual, vestibular, proprioceptive, and auditory systems. However, physical and biological constraints ensure that these signals are perceived slightly asynchronously. The brain only recognizes them as simultaneous when they occur within a period of time called the temporal binding window (TBW). Aging can prolong the TBW, leading to temporal uncertainty during multisensory integration. This effect might contribute to imbalance in the elderly but has not been examined with respect to vestibular inputs. Here, we compared the vestibular-related TBW in 13 younger and 12 older subjects undergoing 0.5 Hz sinusoidal rotations about the earth-vertical axis. An alternating dichotic auditory stimulus was presented at the same frequency but with the phase varied to determine the temporal range over which the two stimuli were perceived as simultaneous at least 75% of the time, defined as the TBW. The mean TBW among younger subjects was 286 ms (SEM ± 56 ms) and among older subjects was 560 ms (SEM ± 52 ms). TBW was related to vestibular sensitivity among younger but not older subjects, suggesting that a prolonged TBW could be a mechanism for imbalance in the elderly person independent of changes in peripheral vestibular function.

Standardised Measurements for Monitoring and Comparing Multiphoton Microscope Systems.

The goal of this protocol is to enable better characterisation of multiphoton microscopy hardware across a large user base. The scope of this protocol is purposefully limited to focus on hardware, touching on software and data analysis routines only where relevant. The intended audiences are scientists using and building multiphoton microscopes in their laboratories. The goal is that any scientist, not only those with optical expertise, can test whether their multiphoton microscope is performing well and producing consistent data over the lifetime of their system.

Maximally mixing active nematics.

Active nematics are an important new paradigm in soft condensed matter systems. They consist of rodlike components with an internal driving force pushing them out of equilibrium. The resulting fluid motion exhibits chaotic advection, in which a small patch of fluid is stretched exponentially in length. Using simulation, this paper shows that this system can exhibit stable periodic motion when confined to a sufficiently small square with periodic boundary conditions. Moreover, employing tools from braid theory, we show that this motion is maximally mixing, in that it optimizes the (dimensionless) "topological entropy"-the exponential stretching rate of a material line advected by the fluid. That is, this periodic motion of the defects, counterintuitively, produces more chaotic mixing than chaotic motion of the defects. We also explore the stability of the periodic state. Importantly, we show how to stabilize this orbit into a larger periodic tiling, a critical necessity for it to be seen in future experiments.

Age-Based Incidence of Dens Fracture Has Unimodal Distribution Rather Than Commonly Claimed Bimodal Distribution.

Background: Type-II dens fractures have long been described in the literature as occurring in a bimodal distribution, peaking in young adulthood as well as in older adulthood; however, the origin of this claim is unclear. The primary goal of this study was to examine the incidence of type-II dens fractures and assess for bimodality. Methods: This is a retrospective cross-sectional review of the National Trauma Data Bank (NTDB) records on traumatic type-II dens fractures between October 2015 and December 2016. Rates were obtained from the NTDB, and the incidence per 100,000 was ascertained by utilizing U.S. Census data from 2016. Subgroupings by gender and Black or White race were also examined. Results: Dens fractures occur unimodally, peaking around 89 years of age overall, skewed left by high rates in older White adults. The Black subgroup demonstrated trimodality, with the fracture incidence peaking at 25, 62, and 82 years of age. Rates among Black and White patients were similar until age 65, after which dens fractures occurred disproportionately in White patients. Fractures prior to age 75 occurred predominantly in men. Conclusions: The evidence derived in this study challenges the common belief that type-II dens fractures occur bimodally across the entire population. However, there remains utility in considering younger and older patients as distinct groups for the purposes of management.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database.

INTRODUCTION: Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation. METHOD: Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests. RESULTS: Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014). CONCLUSION: Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

The Cousa objective: a long-working distance air objective for multiphoton imaging in vivo.

Multiphoton microscopy can resolve fluorescent structures and dynamics deep in scattering tissue and has transformed neural imaging, but applying this technique in vivo can be limited by the mechanical and optical constraints of conventional objectives. Short working distance objectives can collide with compact surgical windows or other instrumentation and preclude imaging. Here we present an ultra-long working distance (20 mm) air objective called the Cousa objective. It is optimized for performance across multiphoton imaging wavelengths, offers a more than 4 mm2 field of view with submicrometer lateral resolution and is compatible with commonly used multiphoton imaging systems. A novel mechanical design, wider than typical microscope objectives, enabled this combination of specifications. We share the full optical prescription, and report performance including in vivo two-photon and three-photon imaging in an array of species and preparations, including nonhuman primates. The Cousa objective can enable a range of experiments in neuroscience and beyond.

Impact of State Laws on Dispensing Opioid Prescriptions Following Posterior Lumbar Interbody Fusion Procedures: A Retrospective Large National Database Study.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: This study aimed to examine the effect of state legislation on prescribing behavior after a commonly performed spinal procedure, posterior lumbar interbody fusion (PLIF). METHODS: Two cohorts of patients from the Pearl Diver Database were created based on patients who underwent PLIF surgery in 2014-15 and 2018-19. We compared opioid prescription rates and morphine-milli-equivalent (MME) between states with and without prescription legislation. RESULTS: We analyzed 50 958 PLIF patients from 2014-15 and 46 751 patients from 2018-19. Among them, 38 states passed opioid prescription laws in 2016-2017, while 12 states did not. The percentage of patients receiving opioid prescriptions within 365 days post-surgery remained similar in both time periods (49% in 2014-15 and 48% in 2018-2019). This trend was consistent across states with and without prescription legislation (50% vs 48% in 2014-2015, and similar in 2018-19). Opioid prescription quantity significantly decreased in all states between 2014-15 and 2018-19. In states with legislation, average MME dropped from 9198 ± 21 002 to 4932 ± 13 213 (46.4% decrease), and in states without legislation, it decreased from 9175 ± 21 032 to 4994 ± 11 687 (45.6% decrease). However, these differences were not statistically significant (P = .7985). CONCLUSION: From 2014 to 2018, there was a significant decrease in the number of opioids prescribed after PLIF. However, this decrease occurred irrespective of state legislation on prescribing practices being passed. We believe the reduction in opioids prescribed was due to increased awareness surrounding the dangers of opioids among physicians.

Deep-brain optical recording of neural dynamics during behavior.

In vivo fluorescence recording techniques have produced landmark discoveries in neuroscience, providing insight into how single cell and circuit-level computations mediate sensory processing and generate complex behaviors. While much attention has been given to recording from cortical brain regions, deep-brain fluorescence recording is more complex because it requires additional measures to gain optical access to harder to reach brain nuclei. Here we discuss detailed considerations and tradeoffs regarding deep-brain fluorescence recording techniques and provide a comprehensive guide for all major steps involved, from project planning to data analysis. The goal is to impart guidance for new and experienced investigators seeking to use in vivo deep fluorescence optical recordings in awake, behaving rodent models.

Community Water Fluoridation and Rate of Pediatric Fractures.

BACKGROUND: The effect of community water fluoridation on bone fragility and fracture has been inconclusive in the literature. The null hypothesis of this study was that no association was observed between water fluoride level and risk of fracture in children. METHODS: Community fluoridation data were obtained from the Centers for Disease Control and Prevention while data on fracture rates were obtained from the PearlDiver database. The rate of fracture type for each state was then compared with state-level fluoridation data using Pearson correlation coefficients and Wilcoxon rank-sum tests. RESULTS: Positive correlations were found between the percentage of state water fluoridation and fracture rates for both bone forearm fracture (BBFFx) and femur fracture. Fluoride levels had positive correlations with fracture rates for all fracture types. Increased fracture rates were found between states in the highest quartiles of percentage of state water fluoridation and fluoride water levels for supracondylar humerus fracture and BBFFx. CONCLUSIONS: A higher level of water fluoridation was associated with higher rates of supracondylar humerus fracture and BBFFx in children aged 4 to 10 years. These findings do not imply causality, but they suggest that additional investigation into the effect of fluoride on pediatric bone health may be indicated.

Is Timing of Total Hip Arthroplasty and Lumbar Spine Fusion Associated With Risk of Hip Dislocation?

Background: In patients with concomitant hip and lumbar spine disease, the question of which surgery-total hip arthroplasty (THA) or lumbar spine fusion (LSF)-to address first has not been adequately answered. We aimed to evaluate the risk of dislocation after THA in patients with LSF first or after THA. Methods: Retrospective review utilizing the PearlDiver database querying Current Procedural Terminology codes for LSF in the year prior (LSF first) or in the year after primary or revision THA (THA first). International Classification of Disease codes identified postoperative hip dislocation as our primary outcome variable. Demographic data collected included age, sex, and obesity. Dislocation rates were described as a proportion of the cohort and compared with chi-square tests. Results: We identified 280,857 primary THA and 42,314 revision THA cases from 2012-2019. Of these, 2090 underwent primary THA and LSF, and 283 underwent revision THA and LSF within a year of each procedure. No differences in age, sex, or obesity between groups were noted. No difference in rate of all-time dislocation for primary THA was noted for the LSF first 51/1429 (3.6%) compared to the THA first 30/661 (4.0%) groups (P = .34), or for revision THA with LSF first 48/204 (23.5%) compared to THA first 27/117 (23.1%) groups (P = 1.0). Conclusions: There was no difference in the risk of dislocation after primary or revision THA if LSF occurred prior to or after the THA. These findings can help surgeons as they counsel patients with concomitant lumbar spine and hip degeneration.

Objective discrimination of bimodal speech using frequency following responses.

Bimodal hearing, in which a contralateral hearing aid is combined with a cochlear implant (CI), provides greater speech recognition benefits than using a CI alone. Factors predicting individual bimodal patient success are not fully understood. Previous studies have shown that bimodal benefits may be driven by a patient's ability to extract fundamental frequency (f0) and/or temporal fine structure cues (e.g., F1). Both of these features may be represented in frequency following responses (FFR) to bimodal speech. Thus, the goals of this study were to: 1) parametrically examine neural encoding of f0 and F1 in simulated bimodal speech conditions; 2) examine objective discrimination of FFRs to bimodal speech conditions using machine learning; 3) explore whether FFRs are predictive of perceptual bimodal benefit. Three vowels (/ε/, /i/, and /ʊ/) with identical f0 were manipulated by a vocoder (right ear) and low-pass filters (left ear) to create five bimodal simulations for evoking FFRs: Vocoder-only, Vocoder +125 Hz, Vocoder +250 Hz, Vocoder +500 Hz, and Vocoder +750 Hz. Perceptual performance on the BKB-SIN test was also measured using the same five configurations. Results suggested that neural representation of f0 and F1 FFR components were enhanced with increasing acoustic bandwidth in the simulated "non-implanted" ear. As spectral differences between vowels emerged in the FFRs with increased acoustic bandwidth, FFRs were more accurately classified and discriminated using a machine learning algorithm. Enhancement of f0 and F1 neural encoding with increasing bandwidth were collectively predictive of perceptual bimodal benefit on a speech-in-noise task. Given these results, FFR may be a useful tool to objectively assess individual variability in bimodal hearing.

Fibromyalgia Increases Post-operative Healthcare Utilization Following total Hip Arthroplasty.

BACKGROUND: Preoperative factors can complicate the postoperative course and increase health care utilization following total hip arthroplasty (THA). Fibromyalgia is not generally recognized as a modifiable risk factor prior to THA. The aim of this investigation was to assess the effect of fibromyalgia on postoperative health care utilization following THA. METHODS: Patients who underwent primary THA from 2018 to 2019 were identified from a large national database using Current Procedural Terminology and International Classification of Diseases, tenth revision (International Classification of Diseases-10) codes. Patient demographics, age, sex, and preoperative opioid use were collected. Analysis compared patients who did and did not have fibromyalgia for postoperative health care utilization metrics; lengths of stay (LOS), 90-day postoperative opioid usages, dislocations, and emergency room visits. Independent t-tests were used to compare LOS and rates of ongoing opioid use. Logistic regression analyses with adjusted odds ratios evaluated the risk of dislocation and emergency room visit after adjusting for demographic characteristics and comorbidities. RESULTS: Compared to those who did not have fibromyalgia, patients who had fibromyalgia experienced longer LOS (P < .0001), increased odds of opioid use 90 days postoperatively (P < .0001) as well as increased odds of hip dislocation (P < .0001) and presentation to the emergency room (P < .0001). Patients who had fibromyalgia were also more likely to be "frequent flyers" with ≥5 emergency room visits after THA (P < .0001). CONCLUSIONS: Fibromyalgia can complicate postoperative care following THA with increased LOS, higher rates of opioid use, and increased odds of dislocation and emergency room visits. As focus shifts to preoperative optimization and risk stratification, more attention should be placed on fibromyalgia prior to THA.

Evaluation of corn-fermented protein as a dietary ingredient in extruded dog and cat diets.

Most pet foods utilize traditional ingredients like corn, wheat, and soy. These ingredients and other grains, such as distillers dried grains (DDG), have been used by the pet food industry. Corn-fermented protein (CFP) is a nutrient-dense enhancement on DDG but has not been evaluated in pet food. Therefore, it was the objective of this study to determine the effect of CFP in the production of extruded pet diets, and to determine the effect on nutrient utilization (digestibility) and stool consistency in dogs, and palatability in dogs and cats. Experimental diets with treatment protein sources (corn gluten meal [CGM], soybean meal [SBM], and CFP) were produced in triplicate using a single-screw extruder. Processing parameters and kibble samples were collected at timed intervals during diet production. Kibbles were evaluated for physical dimension and texture. No differences (P > 0.05) were observed in any physical dimension or texture parameters evaluated, with exception of radial expansion, which was lower (P < 0.05) for CFP kibble compared to others. The CFP kibble required a smaller (P < 0.05) mass restriction valve opening, to keep similar bulk density among dietary treatments. However, there was no difference (P > 0.05) in specific mechanical energy among treatments during diet production. Twelve beagles were fed the experimental diets in a 3 × 3 replicated Latin Square design in which four dogs were randomly assigned to each of three treatments for each period. Diets were formulated to be isonitrogenous and were supplemented with titanium dioxide to serve as an external marker in order to estimate apparent total tract digestibility. Dogs were housed individually and fed twice daily, and water was available ad libitum. Feces were collected after feedings. The diet produced with CGM was more digestible (P < 0.05) than CFP and SBM for dry matter, organic matter, crude protein, crude fat, and gross energy. Further, the CFP diet was also less (P < 0.05) digestible than the SBM diet for dry matter and organic matter. Dogs fed the diet containing CFP had higher (P < 0.05) fecal mass than those fed SBM and CGM. The CFP diet also resulted in a higher fecal score (P < 0.05) than those fed diets with the CGM diet, but similar (P > 0.05) to the SBM diet. For palatability assessment, dogs had a preference (P < 0.05) for CGM over SBM or CFP, but cats showed a preference (P < 0.05) for SBM and CFP over CGM. Results indicate that CFP is acceptable for use in dog and cat diets. Further research should be conducted to evaluate the use of these ingredients at lower inclusion levels.

It is the Opioids Not the Spine Surgeon; Dislocation After Total Hip Arthroplasty is Associated With Opioid Use in Patients Who Have Prior Lumbar Spine Fusion.

BACKGROUND: Patients who have prior lumbar spine fusion (LSF) have an increased risk for dislocation after total hip arthroplasty (THA). These patients also have elevated rates of opioid use. We aimed to evaluate the associated risk of dislocation after THA in patients who have prior LSF comparing those who have opioid use to those who do not. METHODS: This was a retrospective review using a large national database of 246,617 primary and 34,083 revision THA cases from 2012 to 2019. There were 1,903 primary THA and 288 revision THA cases identified with LSF prior to THA. Postoperative hip dislocation was our primary outcome variable and patients were stratified to use or nonuse of opioid at THA. Demographic data including age, sex, and obesity were collected. Multivariate analyses evaluated association of opioid use and dislocation after adjusting for demographics. RESULTS: There was increased odds of dislocation for opioid use at THA for both primary (adjusted Odds Ratio [aOR] = 2.29, 95% Confidence Interval [CI] 1.46 to 3.57, P < .0003) and revision THA (aOR = 1.92, 95% CI 1.62 to 3.08, P < .0003), in patients who have prior LSF. Prior LSF without opioid use was associated with increased odds of dislocation (aOR = 1.38, 95% CI 1.01 to 1.88, P = .04), but this was lower than the associated risk of opioid use without LSF (aOR 1.72, 95% CI 1.63 to 1.81, P < .001). CONCLUSION: Increased odds of dislocation were noted with opioid use at time of THA in patients who have prior LSF. Associated risk of dislocation was higher for opioid use than prior LSF. This suggests that dislocation risk is multifactorial and we should look to strategies to reduce opioid use prior to THA.

Surgery on the Day of Admission Decreases Postoperative Complication Rates for Patients With Central Cord Syndrome: An Analysis of National Surgical Quality Improvement (NSQIP) Data From 2010 to 2020.

STUDY DESIGN: Retrospective review. OBJECTIVE: This study was undertaken to determine what constitutes "early optimal timing" of surgical management of central cord syndrome (CCS) with respect to a reduction of medical complications. SUMMARY OF BACKGROUND DATA: Data varies on the optimal time for surgical treatment of CCS with some studies favoring early intervention and others advocating that surgery can or should be delayed for 2-6 weeks. METHODS: This IRB-approved study was a retrospective cross-sectional review of surgical management outcomes for patients diagnosed with CCS using the National Surgical Quality Improvement Program database, which consists of anonymized medical record data from the year 2010 to 2020. Patient data included age, sex, American Society of Anesthesiologists score, current procedural terminology codes, length of stay, and postoperative complications. Patients were grouped into admission-day surgery, next-day surgery, and late-surgery groups. RESULTS: A total of 738 patients who underwent surgery to treat CCS were identified in the National Surgical Quality Improvement Program database from 2010 to 2020 and included in this study. Admission-day surgery compared with next-day surgery was associated with a decreased postoperative complication rate after multivariate analysis (odds ratio: 0.52; 95% CI: 0.28-0.97; P =0.0387) as well as shorter length of stay ( P <0.0001). Complication rates between the next-day-surgery cohort and late-surgery cohort did not differ after multivariate analysis (odds ratio: 1.02; 95% CI: 0.63-1.65; P =0.9451), but the length of stay was shorter for next-day surgery ( P <0.0001). Two-year rolling averages for the admission-day-surgery rate and next-day-surgery rate show a compound annual growth rate of 2.52% and 4.10%, respectively. CONCLUSIONS: In patients admitted for surgical treatment of CCS, those who receive admission-day surgery have significantly reduced 30-day complication rates as well as shorter length of stays. Therefore, we advocate that "early surgery" should be defined as surgery on the day of admission and should occur in as timely a manner as possible. Prior studies, which define "early surgery" as within 24 hours might, unfortunately, fall short of reaching the optimal threshold for the reduction of 30-day medical complications associated with the treatment of patients with CCS.