Changes in Attitudes towards Influenza and Pneumococcal Vaccination during the Subsiding COVID-19 Pandemic-Results of a Longitudinal Survey Study among Risk Groups in Germany between 2021 and 2023.

BACKGROUND: In many countries, an increase in influenza and pneumococcal vaccination rates was observed during the COVID-19 pandemic. We examined how attitude, risk perception and knowledge towards influenza and pneumococcal vaccines of at-risk patients developed when the COVID-19 pandemic subsided and if COVID-19 vaccination attitude (VA) was still associated with the attitudes towards the two other vaccines. METHODS: We used longitudinal data from two surveys conducted in Germany in 2021 and 2023 among persons with chronic diseases. We assessed VA, risk perception, vaccination knowledge and further psychological determinants of vaccine acceptance. Structural equation modelling using full information maximum likelihood was used to estimate multivariate regressions with planned missing data. RESULTS: Among 543 respondents, the influenza and pneumococcal vaccination rates remained relatively stable between 2021 and 2023. VA also remained unchanged at a moderately positive level, while COVID-19 VA decreased. A constantly positive association between COVID-19 VA and influenza as well as pneumococcal VA was found, independent from a general VA. The perceived danger of influenza increased between 2021 and 2023 and was among the strongest predictors of influenza VA. CONCLUSIONS: Also at the subsiding pandemic, COVID-19 VA was constantly associated with the influenza and pneumococcal VA. It seems sensible to take these aspects into account when designing future vaccination campaigns for at-risk patients. TRIAL REGISTRATION: DRKS00024561. Registered 9 March 2021.

Functional dependence following intensive care unit-treated sepsis: three-year follow-up results from the prospective Mid-German Sepsis Cohort (MSC).

Background: Surviving sepsis can lead to chronic physical, psychological and cognitive impairments, which affect millions of patients worldwide, including survivors after COVID-19 viral sepsis. We aimed to characterize the magnitude and trajectory of functional dependence and new impairments post-sepsis. Methods: We conducted a prospective cohort study including sepsis survivors who had been discharged from five German intensive care units (ICUs), until 36 months post-discharge. Primary outcome was functional dependence, defined as ≥1 impaired activity of daily living (ADL; 10-item ADL score <100), self-reported nursing care dependence or nursing care level. Secondary outcome was post-sepsis morbidity in the physical, psychological or cognitive domain. We used a multistate, competing risk model to address competing events in the course of dependence, and conducted multiple linear regression analyses to identify predictors associated with the ADL score. Findings: Of 3210 sepsis patients screened, 1968 survived the ICU treatment (61.3%). A total of 753 were included in the follow-up assessments of the Mid-German Sepsis cohort. Patients had a median age of 65 (Q1-Q3 56-74) years, 64.8% (488/753) were male and 76.1% (573/753) had a septic shock. Considering competing risk modelling, the probability of still being functional dependent was about 25%, while about 30% regained functional independence and 45% died within the three years post-sepsis. Patients reported a high burden of new and often overlapping impairments until three years post-sepsis. In the subgroup of three-year survivors (n = 330), new physical impairments affected 91.2% (n = 301) while new cognitive and psychological impairments were reported by 57.9% (n = 191) and 40.9% (n = 135), respectively. Patients with pre-existing functional limitations and higher age were at risk for low ADL scores three years after sepsis. Interpretation: Sepsis survivorship was associated with a broad range of new impairments and led to functional dependence in around one quarter of patients. Targeted measures are needed to mitigate the burden of this Post-Sepsis-Syndrome and increase the proportion of patients that achieve functional improvements. Funding: This work was supported by the Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC) at the Jena University Hospital funded by the German Ministry of Education and Research and by the Rudolf Presl GmbH & Co, Kreischa, Germany.

Improving prevention and early detection of sepsis among patient groups at risk: Introducing a model for a multimodal information campaign-The SepWiss study protocol.

BACKGROUND: Sepsis is a life-threatening organ dysfunction due to a dysregulated host response to infection. Annually, sepsis leads to approx. 90.000 deaths in Germany. Risk factors include amongst others older age (>60), innate or acquired dysfunction of the immune system, and underlying chronic diseases of the lung, heart, liver, or kidneys. The manifestation of sepsis is a medical emergency, and patient outcomes depend on timely diagnosis and immediate treatment. In addition, vaccinations e.g., against pneumococci or influenza virus, are a highly effective public health tool to prevent the most common underlying infections that may lead to sepsis. However, a lack of public awareness for the relevance of vaccination and detecting sepsis as an emergency underlines the need for public health interventions that address these issues. SepWiss aims to evaluate the effects of a multimodal information campaign designed to address this lack of awareness among the risk population in Germany. METHODS: SepWiss is an intervention at state level, consisting of a multimodal information campaign targeting risk groups in the German federal states of Berlin and Brandenburg (intervention region). Based on available evidence, various information formats were developed and implemented by outdoor advertising, social media, educational formats and through stakeholders' platforms, starting in August 2021. The control region comprises of the remaining 14 German federal states. We will analyze vaccination coverage (primary outcome), and sepsis knowledge, the ability to detect sepsis as an emergency, and attitude towards vaccination (secondary outcomes) amongst the risk population in a controlled before-after comparison. The implementation is accompanied by a mixed-method process evaluation. DISCUSSION: SepWiss is the first project of its kind to evaluate a complex multi-faceted evidence-based information campaign with regards to the topics of vaccination coverage, and the importance of sepsis detection and prevention for the most vulnerable populations in Germany. Results will be valuable for informing further nationwide campaigns. TRIAL REGISTRATION: German Registry for Clinical Trials: DRKS00024475. Registered February 24th, 2021.

Most patients with an increased risk for sepsis-related morbidity or death do not recognize sepsis as a medical emergency: results of a survey study using case vignettes.

BACKGROUND: Sepsis is a medical emergency with potentially life-threatening consequences. Patients play a crucial role in preventing and recognizing sepsis at an early stage. The understanding of risk groups' sepsis knowledge and their ability to use this knowledge to recognize sepsis as an emergency is incomplete. METHODS: We conducted a cross-sectional survey in Germany and included a sample of 740 persons stratified by age (< 60 years, ≥ 60 years), specific chronic diseases (e.g. diabetes, chronic diseases, cancer), and region (Berlin/Brandenburg vs. other federal states of Germany). Standardized questionnaires were administered by a market research institute through online, telephone, or face-to-face methods. We assessed sepsis knowledge through a series of questions and the ability to recognize sepsis as an emergency through five case vignettes. To identify predictors of sepsis knowledge and the ability to recognize sepsis as a medical emergency, we conducted multiple linear regressions. RESULTS: Of the 36 items on sepsis knowledge, participants answered less than 50 per cent correctly (mean 44.1%; standard deviation (SD) 20.1). Most patients knew that sepsis is a defensive host response to infection (75.9%), but only 30.8% knew that vaccination can prevent infections that lead to sepsis. Across the five vignettes, participants identified sepsis as an emergency in only 1.33 of all cases on average (SD = 1.27). Sepsis knowledge was higher among participants who were older, female, and more highly educated and who reported more extensive health information seeking behaviour. The ability to recognize sepsis as an emergency was higher among younger participants, participants without chronic diseases, and participants with higher health literacy, but it was not significantly associated with sepsis knowledge. CONCLUSIONS: Risk groups showed low levels of knowledge regarding the preventive importance of vaccination and a low ability to recognize sepsis as a medical emergency. Higher levels of sepsis knowledge alone were not sufficient to improve the ability to identify sepsis as a medical emergency. It is crucial to develop effective educational strategies-especially for persons with lower education levels and infrequent health information seeking behaviour-that not only transfer but also facilitate the choice of appropriate actions, such as seeking timely emergency care. TRIAL REGISTRATION: DRKS00024561. Registered 9 March 2021.

Sepsis survivors and caregivers perspectives on post-acute rehabilitation and aftercare in the first year after sepsis in Germany.

Background: Sepsis survivors often suffer from new morbidities. Current rehabilitation therapies are not tailored to their specific needs. The perspective of sepsis survivors and their caregivers on rehabilitation and aftercare is insufficiently understood. We aimed to assess how sepsis survivors in Germany rated the suitability, extent and satisfaction with rehabilitation therapies that they underwent in the year following the acute sepsis episode. Methods: Prospective mixed-methods, multicenter study among a cohort of adult ICU-treated sepsis survivors and their caregivers. Interviews were conducted 6 and 12 months after ICU discharge by telephone and comprised closed as well as open-ended questions. Primary outcomes were the utilization and patient satisfaction with inpatient and outpatient rehabilitation and post-sepsis aftercare in general. Open-ended questions were analyzed according to the principles of content analysis. Results: Foun hundred interviews were performed with 287 patients and/or relatives. At 6 months after sepsis, 85.0% of survivors had applied for and 70.0% had undergone rehabilitation. Among these, 97% received physical therapy, but only a minority reported therapies for specific ailments including pain, weaning from mechanical ventilation, cognitive deficits of fatigue. Survivors were moderately satisfied with the suitability, extent, and overall results of received therapies and perceived deficits in the timeliness, accessibility, and specificity of therapies as well as deficits in the structural support frameworks and patient education. Conclusion: From the perspective of survivors who undergo rehabilitation, therapies should already begin in hospital, be more appropriate for their specific ailments and include better patient and caregiver education. The general aftercare and structural support framework should be improved.

Psychometric properties of the Reintegration to Normal Living Index for sepsis survivors.

PURPOSE: Return to a normal state of living is a key patient-relevant outcome for sepsis survivors. The Reintegration to Normal Living Index (RNLI) assesses self-perceived participation in patients with chronic disease, but its psychometric properties have been analyzed neither for patients after sepsis nor in a German patient cohort. This study aims to analyze the psychometric properties of the German version of the RNLI in sepsis survivors. METHODS: In a prospective multicenter survey study, 287 sepsis survivors were interviewed 6 and 12 months after hospital discharge. Multiple-group categorical confirmatory factor analyses with three competing models were used to explore the factor structure of the RNLI. Concurrent validity was evaluated in relation to the EQ-5D-3L and the Barthel Index of Activities of Daily Living (ADL). RESULTS: Regarding structural validity, all models showed an acceptable model fit. Because of high correlation between the latent variables in the two-factor models (up to r = 0.969) and for reason of parsimony, we opted for the common factor model to analyze the concurrent validity. Our analyses showed moderate positive correlations between RNLI score and ADL score (r ≥ 0.630), EQ-5D-3L visual analogue scale (r ≥ 0.656) and EQ-5D-3L utility score (r ≥ 0.548). The reliability assessed by McDonald's Omega was 0.94. CONCLUSION: We found convincing evidence for good reliability, structural and concurrent validity of the RNLI in German sepsis survivors. We propose to use the RNLI in addition to generic health-related quality of life measures to assess the reintegration to normal living after sepsis.

Text-Based vs. Graphical Information Formats in Sepsis Prevention and Early Detection: A Randomized Controlled Trial on Informed Choice.

Sepsis is associated with 11 million global deaths annually. Although serious consequences of sepsis can generally be avoided with prevention and early detection, research has not yet addressed the efficacy of evidence-based health information formats for different risk groups. This study examines whether two evidence-based health information formats­text based and graphical­differ in how well they foster informed choice and risk and health literacy and in how well they support different sepsis risk groups. Based on a systematic literature review, two one-page educative formats on sepsis prevention and early detection were designed­one text based and one graphical. A sample of 500 German participants was randomly shown one of the two formats; they were then assessed on whether they made informed choices and on their risk and health literacy. For both formats, >70% of participants made informed choices for sepsis prevention and >75% for early detection. Compared with the graphical format, the text-based format was associated with higher degrees of informed choice (p = 0.012, OR = 1.818) and risk and health literacy (p = 0.032, OR = 1.710). Both formats can foster informed choices and risk and health literacy on sepsis prevention and early detection, but the text-based format appears to be more effective.

[White Paper - Improving the care of patients with impairments following sepsis and infections]. / White Paper ­ Verbesserung der Versorgungs- und Behandlungsangebote für Menschen mit Sepsis- und Infektionsfolgen.

Hundreds of thousands of individuals who experience lasting sequelae after sepsis and infections in Germany do not receive optimal care. In this White Paper we present measures for improvement, which were developed by a multidisciplinary expect panel as part of the SEPFROK project. Improved care rests on four pillars: 1. cross-sectoral assessment of sequelae and a structured discharge and transition management, 2. interdisciplinary rehabilitation and aftercare with structural support, 3. strengthening the specific health literacy of patients and families, and 4. increased research into causes, prevention and treatment of sequelae. To achieve this, appropriate cross-sectoral care structures and legal frameworks must be created.

Epidemiology and Costs of Postsepsis Morbidity, Nursing Care Dependency, and Mortality in Germany, 2013 to 2017.

Importance: Sepsis survivorship is associated with postsepsis morbidity, but epidemiological data from population-based cohorts are lacking. Objective: To quantify the frequency and co-occurrence of new diagnoses consistent with postsepsis morbidity and mortality as well as new nursing care dependency and total health care costs after sepsis. Design, Setting, and Participants: This retrospective cohort study based on nationwide health claims data included a population-based cohort of 23.0 million beneficiaries of a large German health insurance provider. Patients aged 15 years and older with incident hospital-treated sepsis in 2013 to 2014 were included. Data were analyzed from January 2009 to December 2017. Exposures: Sepsis, identified by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) hospital discharge codes. Main Outcomes and Measures: New medical, psychological, and cognitive diagnoses; long-term mortality; dependency on nursing care; and overall health care costs in survivors at 1 to 12, 13 to 24, and 25 to 36 months after hospital discharge. Results: Among 23.0 million eligible individuals, we identified 159 684 patients hospitalized with sepsis in 2013 to 2014. The mean (SD) age was 73.8 (12.8) years, and 75 809 (47.5%; 95% CI, 47.2%-47.7%) were female patients. In-hospital mortality was 27.0% (43 177 patients; 95% CI, 26.8%-27.3%). Among 116 507 hospital survivors, 86 578 (74.3%; 95% CI, 74.1%-74.6%) had a new diagnosis in the first year post sepsis; 28 405 (24.4%; 95% CI, 24.1%-24.6%) had diagnoses co-occurring in medical, psychological, or cognitive domains; and 23 572 of 74 878 survivors (31.5%; 95% CI, 31.1%-31.8%) without prior nursing care dependency were newly dependent on nursing care. In total, 35 765 survivors (30.7%; 95% CI, 30.4%-31.0%) died within the first year. In the second and third year, 53 089 (65.8%; 95% CI, 65.4%-66.1%) and 40 959 (59.4%; 95% CI, 59.0%-59.8%) had new diagnoses, respectively. Health care costs for sepsis hospital survivors for 3 years post sepsis totaled a mean of €29 088/patient ($32 868/patient) (SD, €44 195 [$49 938]). New postsepsis morbidity (>1 new diagnosis) was more common in survivors of severe sepsis (75.6% [95% CI, 75.1%-76.0%]) than nonsevere sepsis (73.7% [95% CI, 73.4%-74.0%]; P < .001) and more common in survivors treated in the intensive care unit (78.3% [95% CI, 77.8%-78.7%]) than in those not treated in the intensive care unit (72.8% [95% CI, 72.5%-73.1%]; P < .001). Postsepsis morbidity was 68.5% (95% CI, 67.5%-69.5%) among survivors without prior morbidity and 56.1% (95% CI, 54.2%-57.9%) in survivors younger than 40 years. Conclusions and Relevance: In this study, new medical, psychological, and cognitive diagnoses consistent with postsepsis morbidity were common after sepsis, including among patients with less severe sepsis, no prior diagnoses, and younger age. This calls for more efforts to elucidate the underlying mechanisms, define optimal screening for common new diagnoses, and test interventions to prevent and treat postsepsis morbidity.

Association between sepsis incidence and regional socioeconomic deprivation and health care capacity in Germany - an ecological study.

BACKGROUND: Sepsis is a substantial health care burden. Data on regional variation in sepsis incidence in Germany and any possible associations with regional socioeconomic deprivation and health care capacity is lacking. METHODS: Ecological study based on the nationwide hospital Diagnosis-related Groups (DRG) statistics data of 2016. We identified sepsis by ICD-10-codes and calculated crude and age-standardized incidence proportions in the 401 administrative German districts. Associations between socioeconomic and health care capacity indicators and crude and age-adjusted sepsis incidence were investigated by simple and multiple negative binomial (NB) regressions. RESULTS: In 2016, sepsis incidence was 178 per 100,000 inhabitants and varied 10-fold between districts. We found that the rate of students leaving school without certificate was significantly associated with crude and age-standardized explicit sepsis incidence in the simple and multiple NB regressions. While we observed no evidence for an association to the capacity of hospital beds and general practitioners, the distance to the nearest pharmacy was associated with crude- and age-standardized sepsis incidence. In the multiple regression analyses, an increase of the mean distance + 1000 m was associated with an expected increase by 21.6 [95% CI, 10.1, 33.0] (p < 0.001), and 11.1 [95% CI, 1.0, 21.2]/100,000 population (p = .026) after adjusting for age differences between districts. CONCLUSIONS: Residence in districts with lower socioeconomic status (e.g., less education) and further distance to pharmacies are both associated with an increased sepsis incidence. This warrants further research with individual-level patient data to better model and understand such dependencies and to ultimately design public health interventions to address the burden of sepsis in Germany.

Epidemiology of Sepsis Among Children and Neonates in Germany: Results From an Observational Study Based on Nationwide Diagnosis-Related Groups Data Between 2010 and 2016.

OBJECTIVES: Worldwide, more than half of all sepsis cases occur in pediatric and adolescent patients, particularly in neonates. Previous population-based studies in these age groups often were limited to either neonatal or pediatric patients admitted to ICUs. We aimed to investigate the overall and age-specific incidence and case fatality of sepsis in children in Germany, a high-income country with a total population of 82 million. DESIGN: Retrospective observational study based on the German Diagnosis-related Groups statistics of the years 2010-2016. SETTING: All acute care hospitals in Germany except for prison and psychiatric hospitals. PATIENTS: Pediatric patients less than or equal to 19 years with International Classification of Diseases, 10th Revision-coded sepsis, neonates with International Classification of Diseases, 10th Revision-coded neonatal sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed pediatric sepsis incidence in patients aged birth to less than or equal to 19 years old, case fatality, and underlying comorbidities, and neonatal sepsis incidence and case fatality within the neonatal period. We identified 14,635 pediatric sepsis cases among 15.4 million pediatric hospitalizations between 2010 and 2016 (= 0.1% of pediatric hospitalizations). The incidence of pediatric sepsis was 14 cases per 100,000 children between 0 and 19 years. Case fatality was 16.6% and decreased from 17.8% (2010) to 15.0% (2016). A total of 11.5% of hospital deaths in the age group 0-19 years were associated with pediatric sepsis. Sepsis incidence and case fatality were highest in children less than 1 year old and declined in older children and adolescents. Admissions with pediatric sepsis were more common in children with preexisting comorbidities compared with those without (0.52% vs 0.03% of pediatric admissions). In neonates, the incidence of neonatal sepsis was 1,006 cases per 100,000 live births. Case fatality was 3.9%. While 17.7% of very low birth weight infants had neonatal sepsis, only 2.1% of low birth weight and 0.6% of normal birth weight neonates were affected, respectively. CONCLUSIONS: Sepsis is also in Germany a common and frequently fatal condition in pediatric patients, particularly among neonates and children with comorbidities.

Mid-German Sepsis Cohort (MSC): a prospective observational study of sepsis survivorship.

PURPOSE: The Mid-German Sepsis Cohort (MSC) aims to investigate mid-term and long-term functional disabilities in sepsis survivors from intensive care unit (ICU) discharge until 1 year after. Secondary, post-acute mortality and morbidity, health-related quality of life and healthcare utilisation will be investigated. PARTICIPANTS: The MSC comprises adult (aged ≥18 years) patients who were treated for (severe) sepsis or septic shock on ICU. The participants were recruited between 15 April 2016 and 30 November 2018 from five German centres. Three thousand two hundred and ten patients with sepsis were identified, of which 1968 survived their ICU stay and were eligible for enrolment in the follow-up cohort. Informed consent for follow-up assessment was provided by 907 patients (46.1% of eligible patients). FINDINGS TO DATE: The recruitment of the participants for follow-up assessments and the baseline data collection is completed. Incidence of sepsis was 116.7 patients per 1000 ICU patients. In this cohort profile, we provide an overview of the demographics and the clinical characteristics of both the overall sepsis cohort and the ICU survivors who provided informed consent for follow-up assessment (907 out of 1968 ICU survivors (46.1%)). FUTURE PLANS: The follow-ups are conducted 3, 6 and 12 months after ICU discharge. Another yearly follow-up up to 5 years after ICU discharge is pursued. Several cooperation and satellite projects were initiated. This prospective cohort offers a unique resource for research on long-term sequelae of sepsis survivors. TRIAL REGISTRATION NUMBER: German Clinical Trials Registry (DRKS00010050).

Evaluating Different Equating Setups in the Continuous Item Pool Calibration for Computerized Adaptive Testing.

The increasing digitalization in the field of psychological and educational testing opens up new opportunities to innovate assessments in many respects (e.g., new item formats, flexible test assembly, efficient data handling). In particular, computerized adaptive testing provides the opportunity to make tests more individualized and more efficient. The newly developed continuous calibration strategy (CCS) from Fink et al. (2018) makes it possible to construct computerized adaptive tests in application areas where separate calibration studies are not feasible. Due to the goal of reporting on a common metric across test cycles, the equating is crucial for the CCS. The quality of the equating depends on the common items selected and the scale transformation method applied. Given the novelty of the CCS, the aim of the study was to evaluate different equating setups in the CCS and to derive practical recommendations. The impact of different equating setups on the precision of item parameter estimates and on the quality of the equating was examined in a Monte Carlo simulation, based on a fully crossed design with the factors common item difficulty distribution (bimodal, normal, uniform), scale transformation method (mean/mean, mean/sigma, Haebara, Stocking-Lord), and sample size per test cycle (50, 100, 300). The quality of the equating was operationalized by three criteria (proportion of feasible equatings, proportion of drifted items, and error of transformation constants). The precision of the item parameter estimates increased with increasing sample size per test cycle, but no substantial difference was found with respect to the common item difficulty distribution and the scale transformation method. With regard to the feasibility of the equatings, no differences were found for the different scale transformation methods. However, when using the moment methods (mean/mean, mean/sigma), quite extreme levels of error for the transformation constants A and B occurred. Among the characteristic curve method the performance of the Stocking-Lord method was slightly better than for the Haebara method. Thus, while no clear recommendation can be made with regard to the common item difficulty distribution, the characteristic curve methods turned out to be the most favorable scale transformation methods within the CCS.

Measurement Efficiency for Fixed-Precision Multidimensional Computerized Adaptive Tests: Comparing Health Measurement and Educational Testing Using Example Banks.

It is currently not entirely clear to what degree the research on multidimensional computerized adaptive testing (CAT) conducted in the field of educational testing can be generalized to fields such as health assessment, where CAT design factors differ considerably from those typically used in educational testing. In this study, the impact of a number of important design factors on CAT performance is systematically evaluated, using realistic example item banks for two main scenarios: health assessment (polytomous items, small to medium item bank sizes, high discrimination parameters) and educational testing (dichotomous items, large item banks, small- to medium-sized discrimination parameters). Measurement efficiency is evaluated for both between-item multidimensional CATs and separate unidimensional CATs for each latent dimension. In this study, we focus on fixed-precision (variable-length) CATs because it is both feasible and desirable in health settings, but so far most research regarding CAT has focused on fixed-length testing. This study shows that the benefits associated with fixed-precision multidimensional CAT hold under a wide variety of circumstances.

Heuristic Constraint Management Methods in Multidimensional Adaptive Testing.

Although multidimensional adaptive testing (MAT) has been proven to be highly advantageous with regard to measurement efficiency when several highly correlated dimensions are measured, there are few operational assessments that use MAT. This may be due to issues of constraint management, which is more complex in MAT than it is in unidimensional adaptive testing. Very few studies have examined the performance of existing constraint management methods (CMMs) in MAT. The present article focuses on the effectiveness of two promising heuristic CMMs in MAT for varying levels of imposed constraints and for various correlations between the measured dimensions. Through a simulation study, the multidimensional maximum priority index (MMPI) and multidimensional weighted penalty model (MWPM), as an extension of the weighted penalty model, are examined with regard to measurement precision and constraint violations. The results show that both CMMs are capable of addressing complex constraints in MAT. However, measurement precision losses were found to differ between the MMPI and MWPM. While the MMPI appears to be more suitable for use in assessment situations involving few to a moderate number of constraints, the MWPM should be used when numerous constraints are involved.

Biomechanical evaluation of the impact of various facet joint lesions on the primary stability of anterior plate fixation in cervical dislocation injuries: a cadaver study: Laboratory investigation.

OBJECT: Injuries of the subaxial cervical spine including facet joints and posterior ligaments are common. Potential surgical treatments consist of anterior, posterior, or anterior-posterior fixation. Because each approach has its advantages and disadvantages, the best treatment is debated. This biomechanical cadaver study compared the effect of different facet joint injuries on primary stability following anterior plate fixation. METHODS: Fractures and plate fixation were performed on 15 fresh-frozen intact cervical spines (C3-T1). To simulate a translation-rotation injury in all groups, complete ligament rupture and facet dislocation were simulated by dissecting the entire posterior and anterior ligament complex between C-4 and C-5. In the first group, the facet joints were left intact. In the second group, one facet joint between C-4 and C-5 was removed and the other side was left intact. In the third group, both facet joints between C-4 and C-5 were removed. The authors next performed single-level anterior discectomy and interbody grafting using bone material from the respective thoracic vertebral bodies. An anterior cervical locking plate was used for fixation. Continuous loading was performed using a servohydraulic test bench at 2 N/sec. The mean load failure was measured when the implant failed. RESULTS: In the group in which both facet joints were intact, the mean load failure was 174.6 ± 46.93 N. The mean load failure in the second group where only one facet joint was removed was 127.8 ± 22.83 N. In the group in which both facet joints were removed, the mean load failure was 73.42 ± 32.51 N. There was a significant difference between the first group (both facet joints intact) and the third group (both facet joints removed) (p < 0.05, Kruskal-Wallis test). CONCLUSIONS: In this cadaver study, primary stability of anterior plate fixation for dislocation injuries of the subaxial cervical spine was dependent on the presence of the facet joints. If the bone in one or both facet joints is damaged in the clinical setting, anterior plate fixation in combination with bone grafting might not provide sufficient stabilization; additional posterior stabilization may be needed.