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Abstract Background Air pollution harms health across the life course. Children are at particular risk of adverse effects during development, which may impact on health in later life. Interventions that improve air quality are urgently needed both to improve public health now, and prevent longer-term increased vulnerability to chronic disease. Low Emission Zones are a public health policy intervention aimed at reducing traffic-derived contributions to urban air pollution, but evidence that they deliver health benefits is lacking. We describe a natural experiment study (CHILL: Children’s Health in London and Luton) to evaluate the impacts of the introduction of London’s Ultra Low Emission Zone (ULEZ) on children’s health. Methods CHILL is a prospective two-arm parallel longitudinal cohort study recruiting children at age 6–9 years from primary schools in Central London (the focus of the first phase of the ULEZ) and Luton (a comparator site), with the primary outcome being the impact of changes in annual air pollutant exposures (nitrogen oxides [NOx], nitrogen dioxide [NO2], particulate matter with a diameter of less than 2.5micrograms [PM2.5], and less than 10 micrograms [PM10]) across the two sites on lung function growth, measured as post-bronchodilator forced expiratory volume in one second (FEV1) over five years. Secondary outcomes include physical activity, cognitive development, mental health, quality of life, health inequalities, and a range of respiratory and health economic data. Discussion CHILL’s prospective parallel cohort design will enable robust conclusions to be drawn on the effectiveness of the ULEZ at improving air quality and delivering improvements in children’s respiratory health. With increasing proportions of the world’s population now living in large urban areas exceeding World Health Organisation air pollution limit guidelines, our study findings will have important implications for the design and implementation of Low Emission and Clean Air Zones in the UK, and worldwide. ClinicalTrials.gov NCT04695093 (05/01/2021).

Flame retardants are chemical substances that are intended to mitigate fire safety risks posed by a range of goods including furniture, electronics, and building insulation. There are growing concerns about their effectiveness in ensuring fire safety and the potential harms they pose to human health and the environment. In response to these concerns, on 13 June 2022, a roundtable of experts was convened by the UKRI Six Clean Air Strategic Priorities Fund programme 7. The meeting produced a Consensus Statement that summarises the issues around the use of flame retardants, laying out a series of policy recommendations that should lead to more effective fire safety measures and reduce the human and environmental health risks posed by these potentially toxic chemicals.

Abstract The relationship between exposure to household air pollution (HAP) from solid fuel use and cognition remains poorly understood. Among 401 older adults in peri-urban northern China enrolled in the INTERMAP-China Prospective Study, we estimated the associations between exposure to HAP and z-standardized domain-specific and overall cognitive scores from the Montreal Cognitive Assessment. Interquartile range increases in exposures to fine particulate matter (53.2-µg/m3) and black carbon (0.9-µg/m3) were linearly associated with lower overall cognition [− 0.13 (95% confidence interval: − 0.22, − 0.04) and − 0.10 (− 0.19, − 0.01), respectively]. Using solid fuel indoors and greater intensity of its use were also associated with lower overall cognition (range of point estimates: − 0.13 to − 0.03), though confidence intervals included zero. Among individual cognitive domains, attention had the largest associations with most exposure measures. Our findings indicate that exposure to HAP may be a dose-dependent risk factor for cognitive impairment. As exposure to HAP remains pervasive in China and worldwide, reducing exposure through the promotion of less-polluting stoves and fuels may be a population-wide intervention strategy to lessen the burden of cognitive impairment.

Severe episodic air pollution blankets entire cities and regions and have a profound impact on humans and their activities. We compiled daily fine particle (PM2.5) data from 100 cities in five continents, investigated the trends of number, frequency, and duration of pollution episodes, and compared these with the baseline trend in air pollution. We showed that the factors contributing to these events are complex; however, long-term measures to abate emissions from all anthropogenic sources at all times is also the most efficient way to reduce the occurrence of severe air pollution events. In the short term, accurate forecasting systems of such events based on the meteorological conditions favouring their occurrence, together with effective emergency mitigation of anthropogenic sources, may lessen their magnitude and/or duration. However, there is no clear way of preventing events caused by natural sources affected by climate change, such as wildfires and desert dust outbreaks.

Exposure to air pollution is a leading health risk factor. The variance components and contributions of indoor versus outdoor source determinants of personal exposure to air pollution are poorly understood, especially in settings of household solid fuel use. We conducted a panel study with up to 4 days of repeated measures of integrated gravimetric personal exposure to PM2.5 and black carbon in 787 men and women (ages 40–79) living in peri-urban villages in northern (Beijing and Shanxi) and southern (Guangxi) China. We simultaneously measured outdoor PM2.5 and collected questionnaire data on sociodemographic characteristics and indoor pollution sources including tobacco smoking and solid fuel stove use. We obtained over 2000 days of personal exposure monitoring which showed higher exposures in the heating season (geometric mean (GM): 108 versus 65 μg/m3 in the non-heating season for PM2.5) and among northern participants (GM: 90 versus 59 μg/m3 in southern China in the non-heating season for PM2.5). We used mixed-effects models to estimate within- and between-participant variance components and to assess the determinants of exposures. Within-participant variance in exposure dominated the total variability (68–95%). Outdoor PM2.5 was the dominant variable for explaining within-participant variance in exposure to PM2.5 (16%). Household fuel use (PM2.5: 8%; black carbon: 10%) and smoking status (PM2.5: 27%; black carbon: 5%) explained the most between-participant variance. Indoor sources (solid fuel stoves, tobacco smoking) were associated with 13–30% higher exposures to air pollution and each 10 μg/m3 increase in outdoor PM2.5 was associated with 6–8% higher exposure. Our findings indicate that repeated measurements of daily exposure are likely needed to capture longer-term exposures in settings of household solid fuel use, even within a single season, and that reducing air pollution from both outdoor and indoor sources is likely needed to achieve measurable reductions in exposures to air pollution.

Introduction Air and noise pollution are emerging environmental health hazards in African cities, with potentially complex spatial and temporal patterns. Limited local data are a barrier to the formulation and evaluation of policies to reduce air and noise pollution.Methods and analysis We designed a year-long measurement campaign to characterise air and noise pollution and their sources at high-resolution within the Greater Accra Metropolitan Area (GAMA), Ghana. Our design uses a combination of fixed (year-long, n=10) and rotating (week-long, n =~130) sites, selected to represent a range of land uses and source influences (eg, background, road traffic, commercial, industrial and residential areas, and various neighbourhood socioeconomic classes). We will collect data on fine particulate matter (PM2.5), nitrogen oxides (NOx), weather variables, sound (noise level and audio) along with street-level time-lapse images. We deploy low-cost, low-power, lightweight monitoring devices that are robust, socially unobtrusive, and able to function in Sub-Saharan African (SSA) climate. We will use state-of-the-art methods, including spatial statistics, deep/machine learning, and processed-based emissions modelling, to capture highly resolved temporal and spatial variations in pollution levels across the GAMA and to identify their potential sources. This protocol can serve as a prototype for other SSA cities.Ethics and dissemination This environmental study was deemed exempt from full ethics review at Imperial College London and the University of Massachusetts Amherst; it was approved by the University of Ghana Ethics Committee (ECH 149/18-19). This protocol is designed to be implementable in SSA cities to map environmental pollution to inform urban planning decisions to reduce health harming exposures to air and noise pollution. It will be disseminated through local stakeholder engagement (public and private sectors), peer-reviewed publications, contribution to policy documents, media, and conference presentations.

Sub-Saharan Africa (SSA) is rapidly urbanizing, and ambient air pollution has emerged as a major environmental health concern in growing cities. Yet, effective air quality management is hindered by limited data. We deployed robust, low-cost and low-power devices in a large-scale measurement campaign and characterized within-city variations in fine particulate matter (PM _2.5 ) and black carbon (BC) pollution in Accra, Ghana. Between April 2019 and June 2020, we measured weekly gravimetric (filter-based) and minute-by-minute PM _2.5 concentrations at 146 unique locations, comprising of 10 fixed (∼1 year) and 136 rotating (7 day) sites covering a range of land-use and source influences. Filters were weighed for mass, and light absorbance (10 ^−5 m ^−1 ) of the filters was used as proxy for BC concentration. Year-long data at four fixed sites that were monitored in a previous study (2006–2007) were compared to assess changes in PM _2.5 concentrations. The mean annual PM _2.5 across the fixed sites ranged from 26 μ g m ^−3 at a peri-urban site to 43 μ g m ^−3 at a commercial, business, and industrial (CBI) site. CBI areas had the highest PM _2.5 levels (mean: 37 μ g m ^−3 ), followed by high-density residential neighborhoods (mean: 36 μ g m ^−3 ), while peri-urban areas recorded the lowest (mean: 26 μ g m ^−3 ). Both PM _2.5 and BC levels were highest during the dry dusty Harmattan period (mean PM _2.5 : 89 μ g m ^−3 ) compared to non-Harmattan season (mean PM _2.5 : 23 μ g m ^−3 ). PM _2.5 at all sites peaked at dawn and dusk, coinciding with morning and evening heavy traffic. We found about a 50% reduction (71 vs 37 μ g m ^−3 ) in mean annual PM _2.5 concentrations when compared to measurements in 2006–2007 in Accra. Ambient PM _2.5 concentrations in Accra may have plateaued at levels lower than those seen in large Asian megacities. However, levels are still 2- to 4-fold higher than the WHO guideline. Effective and equitable policies are needed to reduce pollution levels and protect public health.

The increasing penetration of electric vehicles over the coming decades, taken together with the high cost to upgrade local distribution networks and consumer demand for home charging, suggest that managing congestion on low voltage networks will be a crucial component of the electric vehicle revolution and the move away from fossil fuels in transportation. Here, we model the max-flow and proportional fairness protocols for the control of congestion caused by a fleet of vehicles charging on two real-world distribution networks. We show that the system undergoes a continuous phase transition to a congested state as a function of the rate of vehicles plugging to the network to charge. We focus on the order parameter and its fluctuations close to the phase transition, and show that the critical point depends on the choice of congestion protocol. Finally, we analyse the inequality in the charging times as the vehicle arrival rate increases, and show that charging times are considerably more equitable in proportional fairness than in max-flow.

Worldwide, foods are scored with composition indices. However, processing scores are now emerging. The objective of this study was to study the interconnectedness of the degree of processing and composition for 28,747 industrially packaged foods (71.6% of ultra-processed foods, UPFs) representative of retail assortments. The Nutri-score and Traffic Light Labelling System (TLLS) were used to assess the composition, and the Siga index was used to assess the degree of processing. On average, the more nutritionally favourable Nutri-score and TLLS groups exhibited 56.5 and 50.0% UPFs, respectively. Among markers of ultra-processing non-additives mostly included added fat/sugar/fibre/vitamin, animal and/or plant protein isolates, and taste exhausters, while additives mostly included sweeteners and taste exhausters, suggesting that markers of ultra-processing (MUP) are added to foods to improve composition scores. In conclusion, both types of scores are not complementary as such but obey to a fundamental hierarchy: processing first, then composition if necessary. [ABSTRACT FROM AUTHOR]

In France, around 70% of conventional industrial foods are ultra-processed, with no data for organic foods. The objectives of this study were to evaluate the percentage of ultra-processed foods (UPFs) in industrially packaged organic (n = 8554) and conventional (n = 45,791) foods, and to describe their marker of ultra-processing (MUP) profiles. The percentage of UPFs and MUP profiles were determined with the Siga methodology. UPF percentages were 53% in organic foods and 74% in conventional foods, and there was 8% more organic UPFs in conventional stores than in organic stores. The more additive MUPs are used, the greater the quantity of nonadditive MUPs. Conventional UPFs contained twice as many total MUPs as organic UPFs. Main MUPs in organic UPFs were refined oils, extracts and natural aromas, native starches, glucose syrup, lecithins and citric acid. Organic foods are, therefore, overall less ultra-processed although still containing high levels of nonadditive MUPs. [ABSTRACT FROM AUTHOR]

Introduction. The lateral lumbar interbody fusion (LLIF) surgical approach has potential advantages over other approaches but is associated with some unique neurologic risks due to the proximity of the lumbosacral plexus. The present study analyzed complications following LLIF surgical approach using a novel single flat-blade retractor system. Methods. A retrospective data collection of patients receiving LLIF using a novel single flat-blade retractor system at two institutions in the US. Inclusion criteria were all patients receiving an LLIF procedure with the RAVINE® Lateral Access System (K2M, Inc., Leesburg, VA, USA). There was no restriction on preoperative diagnosis or number of levels treated. Approach-related neurologic complications were collected and analyzed postoperatively through a minimum of one year. Results. Analysis included 253 patients with one to four treated lateral levels. Immediate postoperative neurologic complications were present in 11.1% (28/253) of patients. At one-year follow-up the approach-related neurologic complications resolved in all except 5 patients (2.0%). Conclusion. We observed an 11.1% neurologic complication rate in LLIF procedures. There was resolution of symptoms for most patients by 12-month follow-up, with only 2% of patients with residual symptoms. This supports the hypothesis that the vast majority of approach-related neurologic symptoms are transient. [ABSTRACT FROM AUTHOR]

The telecommunications industry is going through a technological revolution, involving a transition from multiple voice and data networks to integrated service networks using packet switching technologies. The paper describes a new framework (the IPCP framework) for capacity planning and costing in an IP network environment. Capacity planning is carried out in four stages, the first of which is based on the concept of effective bandwidth, with the other three addressing the needs of different classes of traffic (Real time, interactive data and streaming, and delay-tolerant services). The framework enables network operators to reduce costs by optimising their capacity requirements and, with the aid of the IP costing module, to determine the costs of the various services that use integrated IP networks, each of which may have a different set of service quality requirements. Illustrative results show that capacity requirements and costs per Mbit vary significantly by service type, a finding with far-reaching implications for business planning and pricing. The approach has been extended to support the design of the new pricing models that will be required in an IP environment and to provide a basis for decisions on traffic management and product portfolio optimisation. The paper also describes the policy implications of the migration to multi-service, packet-based networks, and emphasises the need for regulators, as well as operators, to gain an understanding of the new economics of service provision. [ABSTRACT FROM AUTHOR]

According to animal and human epidemiologic studies, exposure to outdoor light at night (LAN) may cause circadian disruption, which may disturb sleep quality and lead to incident type 2 diabetes mellitus (T2DM). We followed 283,374 persons from 2006 through 2020. Outdoor LAN exposure was estimated using satellite data for individual address with 500 m2 scale buffer during follow-up. Incidence of T2DM was confirmed by hospital inpatient records. We identified potential confounders by a directed acyclic graph, including demographic, genetic, individual and regional level socioeconomic status, and environmental risk factors, and calculated hazard ratios (HRs) and 95% confidence intervals (CIs) through time-varying Cox proportional hazard model. Furthermore, we examined the association of outdoor LAN with a defined health sleep scores and moderation of genetic predisposition and shift work on the relationship of outdoor LAN and incident T2DM. We identified 7,775 incident T2DM cases over 3,027,505 person-years. Higher outdoor LAN exposures were significantly associated with higher risk of T2DM. The estimated HR for incident T2DM with an interquartile range (IQR: 11.22 nW/cm2/sr) increase in outdoor LAN was 1.05 (95%CI: 1.01, 1.09) in the fully adjusted model. Participants who lived in the highest quarter of outdoor LAN area were more likely to develop T2DM (HR: 1.14,95%CI: 1.02, 1.27). Besides, those who were exposed to higher levels of outdoor LAN had poorer sleep quality. No moderation role of PRS on outdoor LAN-induced T2DM observed both on the multiplicated and additive scale. The hazards of outdoor LAN were observed in those who never owned a night shift work. Although further work is required to clarify potential mechanisms, our findings indicate that exposure to residential outdoor LAN may contribute to T2DM risk and low sleep quality. [Display omitted] • Exposure to Outdoor light at night (LAN) was associated with increased risk of T2DM. • No evidence indicated that genetic predisposition modified on the association between outdoor LAN and T2DM. • Exposure to Outdoor LAN was linked to reduced sleep quality. • Shift work might modify the association of outdoor LAN and sleep quality. [ABSTRACT FROM AUTHOR]

BACKGROUND CONTEXT Adjacent segment pathology (ASP) continues to be a concern for surgeons and patients following cervical spine surgery. Most reports to date have focused on either reoperation at the index level or reoperation at any level. There is little debate that radiographic ASP (rASP) favors cervical disc arthroplasty (CDA), but few studies have explored clinical ASP (cASP). PURPOSE To evaluate cASP in patients treated with CDA or ACDF. STUDY DESIGN/SETTING Post-hoc analyses were performed on data that was collected through 7years in a prospective, randomized, controlled clinical trial comparing CDA to ACDF with allograft and anterior plate at one or two contiguous levels. PATIENT SAMPLE The patient population consisted of 575 randomized patients: 164 one-level CDA and 81 one-level ACDF; 225 two-level CDA and 105 two-level ACDF. OUTCOME MEASURES Adjacent level surgeries through 7years. METHODS Kaplan-Meier survival curves for adjacent level surgery were compared using the log-rank test. Cox regression was used to assess the impact of treatment on the relative risk of adjacent level surgery. RESULTS Follow-up rates through 7years were 74.6%. The proportion of patients undergoing an adjacent level surgery was 14.8% for 1-level ACDF, 4.3% for 1-level CDA, 12.4% for 2-level ACDF, and 4.9% for two-level CDA. Kaplan–Meier survival estimates of the probability of adjacent level surgery heavily favored CDA over ACDF (p<.0001). The estimated rate of adjacent level surgery per 100 persons per year was 2.5 for ACDF and 0.7 for CDA (p<.0001). In the Cox model, treatment was a significant baseline predictor adjacent level surgery, with a patient treated with ACDF being 3.9times more likely to undergo adjacent level surgery than one treated with CDA (P=.0001). CONCLUSIONS The adjacent level surgery rates of ACDF patients are over three times higher than CDA at one-level and 2.5times for two-level through 7-years follow-up. In this patient population the survival estimates strongly favor CDA, with estimated rates of adjacent level surgery per 100 patients three times higher for ACDF (p<.0001). Baseline predictors, using the Cox model, further confirm that ACDF patients are more likely to undergo adjacent level surgery (p=.0001). This is the first analysis with compelling evidence that cASP is a significant factor in cervical spine surgery, favoring CDA over ACDF in the long-term. [ABSTRACT FROM AUTHOR]

Competing Interests: Intérêts concurrents :: Aucun déclaré.

Competing Interests: Competing interests:: None declared.

Background: Patient selection for cervical disc arthroplasty (CDA) in the United States remains a topic of debate among surgeons. Many surgeons base US patient selection for CDA implantation on the Food and Drug Administration (FDA) indications/contraindications. While off-label use does occur, the frequency and extent of off-label use in the US remains largely unknown. Outside the United States, patient selection is notably less stringent; however such data also remain largely unpublished or presented/published with a low level of evidence. Here, we will review the current approved US on-label patient selection criteria for CDA and discuss the rationale and supporting evidence to expand these criteria in the United States., Methods: A PubMed literature search was completed using the keywords "cervical disc arthroplasty" and "cervical disc replacement." The articles were evaluated by the authors for patient selection criteria., Conclusions: The current published data do not conclusively prove that the patients excluded from CDA by strict adherence to FDA indications would benefit from CDA surgery over anterior cervical discectomy and fusion. As surgeons, it is a difficult decision regarding when to expand indications to include off-label use of CDA. In our practice, generally CDA patient selection agrees with the FDA indications and contraindications, as there is a lack of level 1 evidence to confirm effectiveness of CDA outside of the current FDA indications. We will likely need more well-constructed studies to include prospective and controlled trials that specifically evaluate the "off-label" applications before US surgeons are convinced to expand indications and insurance companies agree to reimburse., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2020 ISASS.)

Background: Adjacent segment pathology (ASP) remains a concern following treatment with cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF). Radiographic ASP (RASP) is ASP identified on imaging, which may or may not include clinical symptoms. The risk factors for development of RASP and its clinical effects remain controversial. In part 1 of a 2-part publication we evaluate the incidence and predictors of RASP as well as determine whether any association exists between RASP and patient-reported outcomes (PROs)., Methods: Data were prospectively collected during a US Food and Drug Administration randomized, multicenter, investigational device exemption trial comparing CDA (Mobi-C; Zimmer Biomet, Westminster, CO) with ACDF. Multiple post hoc analyses were conducted on RASP as it related to demographics and patient outcomes. Kaplan-Meier estimates of time to Kellgren-Lawrence (K-L) grade 3/4 were calculated separately for all groups. Multivariate Cox proportional hazard models were used analyze whether RASP was associated with patient preoperative demographic characteristics and preoperative and postoperative radiographic characteristics. The association of RASP with PROs was analyzed using generalized estimating equations and matched, retrospective cohort analysis., Results: The incidence of grade 3/4 RASP was lower for patients treated with CDA when initial treatment was at 1 level (27% vs 47%, P < .0001) and at 2 levels (14% vs 49%, P < .0001). Kaplan-Meier estimates indicated significantly lower probability of grade 3/4 RASP over time for patients receiving CDA ( P < .001). Treatment with ACDF, treatment of 1 level, higher age, body mass index, higher preoperative physical components score, and a lower Cobb angle were associated with elevated risk of grade 3/4 RASP. CDA was shown to be more effective than ACDF (64.4%; 95% CI = 50.9, 74.2; P < .0001) at preventing RASP., Conclusions: The incidence and risk of RASP is decreased when patients are treated with CDA compared with ACDF. Although the mechanism of CDA that generates this protective effect is not understood, PROs remain unaffected through 7 years despite changes in RASP., Competing Interests: Disclosures and COI: Pierce Nunley receives royalties from K2M, Zimmer Biomet, Camber Spine, and Integrity Spine; is on the speakers bureau for K2M, Zimmer Biomet, Spineology, and Camber Spine; and is a paid consultant for K2M, Zimmer Biomet, Spineology, Vertiflex, Camber Spine, Integrity Spine, and Centinel Spine. He has stock or stock options in Paradigm, Spineology, and Camber Spine. Peter Campbell is a paid consultant for 4Web and Titan Spine. The other authors received no funding for this study and report no conflicts of interest., (©International Society for the Advancement of Spine Surgery 2020.)

Background: Adjacent segment pathology (ASP) following cervical disc arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF) is identified by imaging (RASP) or clinical symptoms (CASP). Clinical symptoms of CASP have been broadly defined, but subsequent adjacent-level surgeries are clear indicators of CASP. Current literature remains inconsistent in the incidence and potential predictors of CASP. Here, we will evaluate a robust data set for the incidence of CASP resulting in subsequent surgery, attempt to identify factors that might affect CASP, and analyze the association of CASP with patient-reported outcomes (PROS) and RASP., Methods: Data were prospectively collected during a US Food and Drug Administration randomized, multicenter, investigational device exemption trial comparing CDA (Mobi-C, Zimmer Biomet, Westminster, CO) with ACDF. CASP was defined as any adjacent-level subsequent surgical intervention. Post hoc analyses were conducted on the incidence, time to CASP diagnosis, and relationship of CASP with patient demographics. Longitudinal retrospective case-control analysis was used to assess the correlation of CASP to PROs and radiographic adjacent segment pathology (RASP)., Results: Kaplan-Meier estimates indicated significantly lower probability of CASP over time for 1-level ( P = .002) and 2-level ( P = .008) CDA patients. Treatment with ACDF and younger age were associated with higher CASP risk. CDA was more effective than ACDF (70.5%; 95% CI = 45.1, 84.2; P < .0001) at preventing CASP. Case-control analysis indicated increased probability of CASP for patients with grade 3/4 RASP, but the difference was not statistically significant. When we pooled CASP patients, the median grade of RASP at the visit prior to surgery was 1, with only 6 patients presenting with grade 3/4 RASP., Conclusions: Patients treated with CDA have a lower incidence of CASP than do patients treated with ACDF, although the mechanism remains unclear. CASP and RASP remain uncorrelated in this large data set, but other predictive variables such as treatment, age, and number of levels should be further investigated., Competing Interests: Disclosures and COI: Pierce Nunley receives royalties from K2M, Zimmer Biomet, Camber Spine, and Integrity Spine; is on the speakers bureau for K2M, Zimmer Biomet, Spineology, and Camber Spine; and is a paid consultant for K2M, Zimmer Biomet, Spineology, Vertiflex, Camber Spine, Integrity Spine, and Centinel Spine. He has stock or stock options in Paradigm, Spineology, and Camber Spine. Peter Campbell is a paid consultant for 4Web and Titan Spine. The other authors received no funding for this study and report no conflicts of interest., (©International Society for the Advancement of Spine Surgery 2020.)

Background: Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but the cause and effect of HO are not well understood. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for the development of HO have been hypothesized and reported in small-population, retrospective analyses, using univariate statistics., Methods: Posthoc, multiple-phase analysis of radiographic, clinical, and demographic data for CTDR as it relates to HO was performed. HO was radiographically graded for 164 one-level and 225 two-level CTDR patients using the McAfee and Mehren system. Analysis was performed to correlate HO grades to clinical outcomes and to evaluate potential risk factors for the development of HO using demographics and baseline clinical measures., Results: At 7 years, 1-level clinically relevant HO grades were 17.6% grade 3 and 11.1% grade 4. Two-level clinically relevant HO grades, evaluated using the highest patient grade, were 26.6% grade 3 and 10.8% grade 4. Interaction between HO and time revealed significance for neck disability index (NDI; P = .04) and Visual Analog Scale (VAS) neck pain ( P = .02). When analyzed at each time point NDI was significant at 48-84 months and VAS neck at 60 months. For predictors 2 analyses were run; odds ratios indicated follow-up visit, male sex, and preoperative VAS neck pain are related to HO development, whereas hazard ratios indicated male sex, obesity, endplate coverage, levels treated, and preoperative VAS neck pain., Conclusions: This is the largest study to report HO rates, and related outcomes and risk factors. To develop an accurate predictive model, further large-scale analyses need to be performed. Based on the results reported here, clinically relevant HO should be more accurately described as motion-restricting HO until a definitive link to outcomes has been established., Competing Interests: Disclosures and COI: P.D.N. receives royalties and is on the speaker's bureau for LDR Spine (now ZimmerBiomet); K.A.F. received institutional support from LDR Spine (now ZimmerBiomet); K.E.M. is a former employee of LDR Spine (now ZimmerBiomet); and M.B.S. received institutional support from LDR Spine (ZimmerBiomet).

Background: Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue., Methods: Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery., Results: One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study., Conclusion: Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population.