Osteoporosis is a novel risk factor of infections and sepsis: A cohort study

All-in-one design of titanium-based dental implant systems for enhanced soft and hard tissue integration

Enhancing the sealing between titanium abutment and surrounding soft tissue is crucial for preventing peri-implantitis. Meanwhile, exploring non-invasive antibacterial strategies as alternatives for traditional antibiotic therapy is central to improving the effect of peri-implantitis treatment. Furthermore, facilitating effective integration between titanium implant and osteoporotic bone is the cornerstone for ensuring long-term implant stability in patients with osteoporosis. In light of this, this work innovatively constructed multifunctional vertical graphene-based coatings on titanium implants and abutments using plasma-enhanced chemical vapor deposition technology. The results demonstrated that the vertical graphene coatings promoted soft tissue sealing and exhibited inherent antibacterial activities with the bacteriostasis rates of 65.60 % against Staphylococcus aureus (S. aureus) and 43.89 % against Escherichia coli (E. coli) in vitro which could prevent early infections. Moreover, vertical graphene coatings presented photothermal antibacterial effects with the antibacterial rates of 99.99 % and 95.83 % for S. aureus in vitro and in vivo, respectively, and 92.23 % for E. coli in vitro under near-infrared irradiation, which provided a non-invasive and highly effective treatment option for peri-implantitis. Furthermore, teriparatide acetate was loaded on vertical graphene coatings which enhanced osseointegration between titanium implants and osteoporotic bone. By comprehensively considering the critical functional requirements of dental implants and abutments, this work meticulously designed vertical graphene-based coatings on titanium dental implant systems for soft and hard tissue integration. This innovative design demonstrates immense application potential, especially for dental implant restoration in patients with osteoporosis.

Progress in research on osteoporosis secondary to SARS-CoV-2 infection

The World Health Organization has declared that COVID-19 no longer constitutes a "public health emergency of international concern," yet the long-term impact of SARS-CoV-2 infection on bone health continues to pose new challenges for global public health. In recent years, numerous animal model and clinical studies have revealed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to secondary osteoporosis. The mechanisms involved are related to the virus's direct effects on bone tissue, dysregulation of the body's inflammatory response, hypoxia, noncoding RNA imbalance, and metabolic abnormalities. Although these studies have unveiled the connection between SARS-CoV-2 infection and osteoporosis, current research is not comprehensive and in depth. Future studies are needed to evaluate the long-term effects of SARS-CoV-2 on bone density and metabolism, elucidate the specific mechanisms of pathogenesis, and explore potential interventions. This review aims to collate existing research literature on SARS-CoV-2 infection-induced secondary osteoporosis, summarize the underlying mechanisms, and provide direction for future research.

Hospital-Treated Infections and 15-year Incidence of Musculoskeletal Disorders: A Large Population-Based Cohort Study

Background

Basic science evidence reveals interactions between the immune and bone systems. However, population studies linking infectious diseases and musculoskeletal (MSK) disorders are limited and inconsistent. We aimed to examine the risk of six main MSK disorders (osteoarthritis, rheumatoid arthritis, osteoporosis, gout, low back pain, and neck pain) following hospital-treated infections in a large cohort with long follow-up periods.

Methods

We analysed data from 502,409 UK Biobank participants. Participants free of specific MSK disorders at baseline were included in each analysis. Hospital-treated infections before baseline were identified using national inpatient data, while incident MSK outcomes were ascertained from inpatient records, primary care, and death registers. Participants with prior infections were propensity score matched (1:5) with those without. Hazard ratios (HRs) and absolute rate differences (ARDs) with 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. To assess potential reverse causality due to delayed diagnosis of preexisting illness, analyses were repeated excluding MSK disorder cases that occurred within the first 5 and 10 years post-baseline.

Results

A hospital-treated infection was associated with increased risks of all six MSK disorders, with particularly strong associations for osteoporosis (HR, 1.55 [1.48-1.63]; ARD, 1.48 [95% CI 1.29-1.68] per 1000 person-years) and rheumatoid arthritis (HR, 1.53 [1.41-1.65]; ARD, 0.58 [0.46-0.71] per 1000 person-years), while other disorders showed HRs of 1.28-1.32. Bacterial and viral infections showed similar associations, with MSK infections (generally stronger risk) and other locations both linked to increased risks. Associations remained significant even for incident cases that occurred more than 10 years post-baseline.

Conclusion

Hospital-treated infections are associated with long-term MSK disorder risks, regardless of pathogen type or disorder nature (inflammatory or degenerative). Long-term monitoring and care for MSK health in patients with prior hospital-treated infections are recommended.

Unravelling the pandemic: impaired bone metabolism and risk of SARS-CoV-2 infection

INTRODUCTION

While the impact of COVID-19 on bone metabolism has been extensively studied, the inverse relationship remains less understood. This study investigates whether impaired bone metabolism is associated with an increased risk of COVID-19 infection.

METHODS

We conducted a nested case-control study within a population-based cohort, incorporating Kaplan-Meier analysis (KMA) to assess time to infection (TTI) differences. Propensity score matching (1:2) was performed and validated through standardized mean differences (<0.10), variance ratio (=1), and McFadden's pseudo-R2 (=0), ensuring balanced covariates. Bone status was evaluated using a composite index (AOMI), which included five components: P1NP and CTX (bone turnover markers), total hip bone mineral density (BMD-TH), trabecular bone score (TBS), and integral volumetric BMD (IvBMD). Inflammation and insulin resistance (IR) were assessed by albumin-to-globulin ratio (AGR <1.50) and the TG/HDL ratio (>2.50 in women and >2.80 in men), respectively.

RESULTS

We analysed 294 COVID-19 cases and 528 controls. AOMI+ individuals had a higher prevalence of COVID-19 (41.5% vs. 33.2%; p = 0.031), an adverse lipid pattern ("A" profile: high ApoB, LDL and TC) and pronounced bone changes (higher P1NP and CTX, lower BMD-TH, TBS, and IvBMD). AOMI - individuals were more likely to have metabolic syndrome, displayed a different lipid profile ("B" profile: elevated TG, AIP, and TG/HDL ratio), fewer bone alterations, and lower COVID-19 prevalence. TG/HDL ratio was 1.66 ± 1 in "A" profile, while it was 2.85 ± 1.4 in "B" profile individuals (p = 0.0001). Age acted as an effect modifier, and lowest tercile significantly increased COVID-19 risk associated with AOMI+ [Mantel-Haenszel OR = 1.42 (95%CI: 1.08-1.9); p = 0.022]. KMA identified AOMI+ men and individuals of both sexes in lowest age tercile, as groups with shorter TTI: These younger individuals had high CTX (women), low TBS (men), and high ApoB (both). In multivariable analyses, plasma CTX levels negatively correlated with TTI (adjusted β= -0.325; p = 0.0001). AOMI+ status was associated with increased COVID-19 risk after controlling for confounders, including IR (adjusted OR = 1.51; 95%CI: 1.04-2.10; p = 0.027), although this association weakened when adjusting for AGR (95%CI: 0.99-2.28; p = 0.055). ANCOVA-estimated adjusted TBS means were lower in COVID-19 cases compared to controls (1.259 vs. 1.294; p = 0.013).

CONCLUSIONS

Impaired bone metabolism was found to be associated with increased COVID-19 risk, in a relationship potentially mediated by underlying inflammation. Elevated osteoclastic activity and a defined lipid profile with high ApoB, TC, LDL levels, played a crucial role in the results. Bone quality parameters more accurately captured COVID-19-related bone changes than BMD.

Fracture Risk Linked to Proton Pump Inhibitors Versus H2 Receptor Antagonists in Autoimmune Rheumatic and Gastrointestinal Disease Patients

OBJECTIVE

To understand if proton pump inhibitors (PPIs) usage associated with an increased risk of fractures among adult patients diagnosed with autoimmune rheumatic and gastrointestinal diseases, compared with H2 receptor antagonists (H2RAs) usage.

METHODS

We used the TriNetX US collaborative database for the study, which includes detailed demographic information, diagnostic and procedural data, medication details, laboratory results, genomic information, and healthcare utilization metrics. We analyzed 61 healthcare organizations to compare fracture risks associated with PPIs and H2RAs in adults, particularly those diagnosed with autoimmune rheumatic and gastrointestinal diseases. Propensity score matching acted as a control for demographic and clinical variables.

RESULTS

The study involved 1 717 598 patients, focusing on 16 299 who were new users of PPIs and 16 299 H2RAs users after propensity score matching. Over a 24-month follow-up period, no significant differences in fracture risks were observed between the PPI and H2RA groups in the overall cohort (hazard ratio, HR = 1.369, 95% confidence interval, CI = 0.933-2.009). However, subgroup analysis indicated that senior patients (≥ 65 years) who had been administered PPIs experienced a significantly higher risk of fractures (HR = 1.927 [1.153-3.221]), particularly non-vertebral fractures (HR = 2.379 [1.214-4.661]), when compared to their counterparts who had been prescribed H2RAs. Notably, the simultaneous use of PPIs and glucocorticoids further increased the fracture risk (HR = 4.273 [2.219-8.227]).

CONCLUSIONS

The study demonstrates that patients diagnosed with autoimmune rheumatic and gastrointestinal diseases who were aged 65+ face increased fracture risks when using PPIs, particularly when there is a simultaneous intake of glucocorticoids.

A superior tool for predicting sepsis in SAH patients: The nomogram outperforms SOFA score

OBJECTIVE

This study aimed to develop and validate a nomogram to predict the risk of sepsis in non-traumatic subarachnoid hemorrhage (SAH) patients using data from the MIMIC-IV database.

METHODS

A total of 803 SAH patients meeting the inclusion criteria were randomly divided into a training set (563 cases) and a validation set (240 cases). Independent prognostic factors were identified through forward stepwise logistic regression, and a nomogram was created based on these factors. The discriminative ability of the nomogram was assessed using the area under the receiver operating characteristic curve (AUC) and compared with the SOFA score. The model's consistency was evaluated using the C-index, and the improvement in performance over the SOFA score was calculated using integrated discrimination improvement (IDI) and net reclassification improvement (NRI).

RESULTS

Five independent predictive factors were identified through LASSO regression analysis: mechanical ventilation, hyperlipidemia, temperature, white blood cell count, and red blood cell count. The AUC of the nomogram in the training and validation sets were 0.854 and 0.824, respectively, both higher than the SOFA score. NRI and IDI results indicated that the nomogram outperformed the SOFA score in identifying sepsis risk. Calibration curves and the Hosmer-Lemeshow test demonstrated good calibration of the nomogram. Decision curve analysis showed that the nomogram had higher net benefit in clinical application.

CONCLUSION

The nomogram developed in this study performed excellently in predicting the risk of sepsis in SAH patients, surpassing the traditional SOFA scoring system, and has significant clinical application value.

Osteoporosis: Causes, Mechanisms, Treatment and Prevention: Role of Dietary Compounds

Osteoporosis is a chronic disease that is characterized by a loss of bone density, which mainly affects the microstructure of the bones due to a decrease in bone mass, thereby making them more fragile and susceptible to fractures. Osteoporosis is currently considered one of the pandemics of the 21st century, affecting around 200 million people. Its most serious consequence is an increased risk of bone fractures, thus making osteoporosis a major cause of disability and even premature death in the elderly. In this review, we discuss its causes, the biochemical mechanisms of bone regeneration, risk factors, pharmacological treatments, prevention and the effects of diet, focusing in this case on compounds present in a diet that could have palliative and preventive effects and could be used as concomitant treatments to drugs, which are and should always be the first option. It should be noted as a concluding remark that non-pharmacological treatments such as diet and exercise have, or should have, a relevant role in supporting pharmacology, which is the recommended prescription today, but we cannot ignore that they can have a great relevance in the treatment of this disease.

Effects of bone metabolism on hematopoiesis: A Mendelian randomization study

Objectives

Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal relationship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data.

Methods

Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders.

Results

BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemoglobin, and red blood cell count was observed, with beta ranging from -0.038 to -0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to -0.019) and white blood cell count (beta: 0.024 to -0.02). Results across TBBMD, LSBMD, and FNBMD were consistent.

Conclusions

This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.

Low Bone Mineral Density as a Predictor of Mortality and Infections in Stroke Patients: A Hospital-Based Study

CONTEXT

Low bone mineral density (BMD) has been linked to elevated risks of mortality and infections in the general population; however, its association with these outcomes in stroke patients remains unclear.

OBJECTIVE

This study aims to investigate the correlation between low BMD and risks of mortality and infections among stroke patients in a Taiwanese cohort.

METHODS

In this single-center retrospective cohort study, 905 stroke patients from a Taiwanese database (2000-2022) were analyzed. Patients were grouped based on BMD measurements of the femur and spine. The primary outcome was all-cause mortality, and secondary outcomes included urinary tract infection (UTI) and pneumonia. Accelerated failure time regression model analyses evaluated the association between BMD and these outcomes, while the Kaplan-Meier method and log-rank test assessed survival differences between groups.

RESULTS

Among the participants (average age 76.1 years, 70.5% female), 33.82% had osteopenia and 55.25% had osteoporosis. Stroke patients with lower spine and right femur BMD had significantly reduced survival rates, especially when the BMD value fell below 0.842 g/cm2 (spine), and 0.624 g/cm2 (right femur), respectively. Regarding secondary outcomes, lower spine BMD was significantly associated with an increased risk of UTI.

CONCLUSION

Low BMD, particularly in the femur and spine, is a significant predictor of mortality and UTI in stroke patients. These findings highlight the importance of assessing and managing BMD in stroke patients to improve outcomes and reduce complications.

Multidisciplinary approach and host optimization for fracture-related infection management

In orthopaedic trauma, fracture-related infections (FRI) are still dreadful challenges that can cause non-union, amputation and even death. Standardization of general treatment strategies for FRI is still lacking. Due to the complexity of FRI, a multidisciplinary approach addressing host status, state of the fracture and causative microorganism has been applied in the management of FRI. Surgical treatment, antibiotic therapy and host optimization for FRI were summarized and discussed. The goal of this review is to provide an overview and summary of current approaches of FRI management and to make suggestions on FRI prevention and treatment based on multidisciplinary principles.

GENETIC PREDICTION OF CAUSAL RELATIONSHIPS BETWEEN OSTEOPOROSIS AND SEPSIS: EVIDENCE FROM MENDELIAN RANDOMIZATION WITH TWO-SAMPLE DESIGNS

ABSTRACT

Background: Recent observational studies have suggested that osteoporosis may be a risk factor for sepsis. To mitigate confounding factors and establish the causal relationship between sepsis and osteoporosis, we conducted a two-sample Mendelian randomization analysis using publicly available summary statistics. Methods: Utilizing summary data from FinnGen Biobank, we employed a two-sample Mendelian randomization (MR) analysis to predict the causal relationship between osteoporosis and sepsis. The MR analysis primarily utilized the inverse variance weighted (IVW) method, supplemented by MR-Egger, weighted median, weighted mode, and simple mode analyses, with Bayesian weighted MR (BWMR) analysis employed for result validation. Sensitivity analyses included MR-PRESSO, "leave-one-out" analysis, MR-Egger regression, and Cochran Q test. Results: In the European population, an increase of one standard deviation in osteoporosis was associated with an 11% increased risk of sepsis, with an odds ratio (OR) of 1.11 (95% CI, 1.06-1.16; P = 3.75E-06). BWMR yielded an OR of 1.11 (95% CI, 1.06-1.67; P = 1.21E-05), suggesting osteoporosis as a risk factor for sepsis. Conversely, an increase of one standard deviation in sepsis was associated with a 26% increased risk of osteoporosis, with an OR of 1.26 (95% CI, 1.11-1.16; P = 0.45E-03). BWMR yielded an OR of 1.26 (95% CI, 1.09-1.45; P = 1.45E-03), supporting sepsis as a risk factor for osteoporosis. Conclusion: There is an association between osteoporosis and sepsis, with osteoporosis serving as a risk factor for the development of sepsis, while sepsis may also promote the progression of osteoporosis.

Calcification Formation for Development, Defense, and Repair of the Human Body?

Calcium deposits commonly occur in the human body in any type of tissue through an actively regulated process [...].

Synergistic combination of baicalein and rifampicin against Staphylococcus aureus biofilms

Staphylococcus aureus, a Gram-positive bacterium, is a predominant pathogen associated with various infections. The rapid emergence of antibiotic resistance has intensified the challenge of managing fracture-related infections in severe osteoporotic patients. Rifampicin, a potent antimicrobial agent employed against fracture and implant-related infections, necessitates combination therapies due to its susceptibility to antibiotic resistance. In this study, we explored the potential of baicalein, a bioactive flavonoid from Oroxylum indicum and Scutellaria baicalensis, in combination with rifampicin against S. aureus biofilms invitro. The minimum inhibitory concentration of baicalein and rifampicin were determined as 500 μg/mL and 12.5 ng/mL respectively. The synergistic activity of baicalein and rifampicin was determined by the fractional inhibitory concentration index (FICI) using checkerboard assay. The results showed the FICI of baicalein and rifampicin was lesser than 0.5, demonstrating synergistic effect. Furthermore, the efficacy of baicalein and rifampicin, both individually and in combination, was evaluated for biofilm inhibition and eradication. Scanning electron microscopy and confocal laser microscopy also confirmed that the synergistic combinations effectively removed most of the biofilms and partially killed pre-formed biofilms. In conclusion, the findings demonstrate that baicalein is as effective as rifampicin in inhibiting and eradicating S. aureus biofilms. Their combination exhibits synergistic effect, enhancing their bactericidal effect in completely eradicating S. aureus biofilms. The findings of this research underscore the research potential of combining baicalein and rifampicin as a novel therapeutic strategy against S. aureus biofilms, offering a promising direction for future research in the treatment of fracture-related S. aureus infections.

Systematic evaluation of vertebral bone quality score as an opportunistic screening method for BMD in spine surgery patients

PURPOSE

This study aimed to evaluate and compare the predictive value of vertebral bone quality (VBQ) score for low BMD and osteoporosis. Furthermore, we sought to enhance diagnostic effectiveness by integrating VBQ with easily accessible patient-specific factors.

METHODS

We retrospectively analyzed data from 180 patients. VBQ was obtained by preoperative MRI. Low BMD was classified as meeting the standards for either osteopenia or osteoporosis. The receiver operating characteristic curve analysis and multivariate logistic regression were used to detect the ability of variables to assess BMD. The z-test was used to compare the area under the curves of different variables.

RESULTS

VBQ was more effective in identifying low BMD than osteoporosis (AUC, 0.768 vs. 0.613, p = 0.02). Elevated VBQ (OR 6.912, 95% CI 2.72-17.6) and low BMI (0.858, 0.76-0.97) were risk factors for low BMD, while the risk factor for osteoporosis was age (1.067, 1.02-1.12), not VBQ. ROC analysis showed that AUCs were 0.613 for VBQ and 0.665 for age when screening for osteoporosis. The combined variable of VBQ, sex, age, and BMI obtained by logistic regression significantly improved the efficacy of BMD screening, with an AUC of 0.824 for low BMD and 0.733 for osteoporosis.

CONCLUSION

VBQ is better at detecting low BMD than identifying osteoporosis. The ability of VBQ to predict osteoporosis is limited, and a similar diagnostic efficacy can be achieved with age. Incorporating VBQ alongside demographic data enhances the efficiency of BMD assessment. With the development of artificial intelligence in medicine, this simple method is promising.

Bone health following paediatric and adolescent bariatric surgery: a systematic review and meta-analysis

Background

Childhood obesity is a pressing health crisis of epidemic proportions. Bariatric surgery (BS) is an effective weight loss solution however its role in the paediatric population is contentious owing to the paucity of weight specific and generalised health outcomes. This systematic review and meta-analysis aimed to assess the impact of paediatric BS on bone health.

Methods

This prospectively registered systematic review (PROSPERO ID: CRD42023432035) was performed in accordance with PRISMA guidelines. We searched MEDLINE (1946-1928 September 2023), EMBASE (1947-1928 September 2023) via the Ovid platform, and the Cochrane Review Library to identify scientific publications reporting bone outcome measures in patients under the age of 18 years who underwent BS. Meta-analysis was undertaken on post-operative weight and bone parameters in paediatric patients following BS. Outcomes were reported as weighted or standardized mean difference with 95 percent confidence intervals. Subgroup analysis by intervention, quality scoring and risk of bias were assessed.

Findings

Twelve studies with 681 patients across 5 countries (mean age 17 ± 0.57 years) were included. The quality of included studies was rated as high and there was substantial between-study heterogeneity for most factors included in the meta-analysis (I2 from 0% to 99.1%). Patients underwent Roux-en-Y gastric bypass (RYGB, n = 216), sleeve gastrectomy (SG, n = 257), gastric band (n = 184) or intragastric balloon placement (n = 24). BS was associated with significant weight reduction, body mass index (BMI) -12.7 kg/m2 (95% CI -14.5 to -10.9, p < 0.001), with RYGB being most effective, BMI -16.58 kg/m2 (95% CI -19.6 to -13.6, p < 0.001). Patients who underwent SG or RYGB had significantly lower lumbar bone mineral density, -0.96 g/cm2 (95% CI -0.1 to -0.03, p < 0.001), Z score, -1.132 (95% CI -1.8 to -0.45, p < 0.001) and subtotal body bone mineral density, -0.7 g/cm2 (95% CI -1.2 to -0.2, p < 0.001) following surgery. This was accompanied with higher markers of bone resorption, C-terminal telopeptide of type 1 collagen 0.22 ng/ml (95% CI 0.12-0.32, p < 0.001) and osteocalcin, 10.83 ng/ml (95% CI 6.01-15.67, p < 0.001). There was a significant reduction in calcium levels following BS, -3.78 mg/dl (95% CI -6.1 to -1.5, p < 0.001) but no difference in 25-hydroxyvitamin D, phosphate, bone alkaline phosphatase, procollagen type 1 N propeptide or parathyroid hormone.

Interpretation

BS effectively reduces weight in paediatric patients, but RYGB and SG may have adverse effects on bone health in the medium term. It is crucial to monitor and support bone health through appropriate nutritional supplementation and judicious follow-up. Long-term data is needed to fully understand the clinical implications of these findings on bone outcomes.

Funding

Medical Research Council (MRC), United Kingdom.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.

Implants coating strategies for antibacterial treatment in fracture and defect models: A systematic review of animal studies

Objective

Fracture-related infection (FRI) remains a major concern in orthopaedic trauma. Functionalizing implants with antibacterial coatings are a promising strategy in mitigating FRI. Numerous implant coatings have been reported but the preventive and therapeutic effects vary. This systematic review aimed to provide a comprehensive overview of current implant coating strategies to prevent and treat FRI in animal fracture and bone defect models.

Methods

A literature search was performed in three databases: PubMed, Web of Science and Embase, with predetermined keywords and criteria up to 28 February 2023. Preclinical studies on implant coatings in animal fracture or defect models that assessed antibacterial and bone healing effects were included.

Results

A total of 14 studies were included in this systematic review, seven of which used fracture models and seven used defect models. Passive coatings with bacteria adhesion resistance were investigated in two studies. Active coatings with bactericidal effects were investigated in 12 studies, four of which used metal ions including Ag+ and Cu2+; five studies used antibiotics including chlorhexidine, tigecycline, vancomycin, and gentamicin sulfate; and the other three studies used natural antibacterial materials including chitosan, antimicrobial peptides, and lysostaphin. Overall, these implant coatings exhibited promising efficacy in antibacterial effects and bone formation.

Conclusion

Antibacterial coating strategies reduced bacterial infections in animal models and favored bone healing in vivo. Future studies of implant coatings should focus on optimal biocompatibility, antibacterial effects against multi-drug resistant bacteria and polymicrobial infections, and osseointegration and osteogenesis promotion especially in osteoporotic bone by constructing multi-functional coatings for FRI therapy.

The translational potential of this paper

The clinical treatment of FRI is complex and challenging. This review summarizes novel orthopaedic implant coating strategies applied to FRI in preclinical studies, and offers a perspective on the future development of orthopaedic implant coatings, which can potentially contribute to alternative strategies in clinical practice.

Prognostic Value of Diaphragm Diameter, Muscle Volume, and Bone Mineral Density in Critically Ill COVID-19 Patients

Objective: We aimed to analyze the prognostic value of muscle volume (MV), bone mineral density (BMD), and diaphragm diameter (DD) in COVID-19. Method: The study included 498 patients admitted to the intensive care unit (ICU) with a positive polymerase chain reaction test for COVID-19 from March 11, 2020, through August 31, 2022. The patients' laboratory and demographic data of the patients at the time of ICU admission were recorded. MV, DD, and BMD measurements were performed using computed tomography examinations. Muscle index (MI) was calculated as MV/height2. Quartiles were determined for all 4 measurements. Patients in the lowest quartile were recorded as having low MV, MI, DD, and BMD values. The parameters were evaluated for the whole group and compared according to gender and mortality. The multiple regression analysis was performed for the prediction of mortality. Results: In the mortality group, the male and female patients had significantly statistically lower values in MV (P < .001 and P = .002, respectively), MI (P < .001 and P = .005, respectively), DD (P < .001 and P < .001, respectively), and BMD (P = .002 and P < .001, respectively). In the multiple regression analysis, low MI (OR: 2.03, 95% CI: 1.14-3.61, P = .016) and DD (OR: 10.47, 95% CI: 5.59-19.59, P < .001) values remained significant for the prediction of mortality. Conclusion: BMD is a risk factor for mortality in patients with severe COVID-19, but cannot be used as an independent predictor. However, MI and DD can be used as independent predictors of mortality even in severe cases.

Prognostic Value of Vertebral Bone Density in the CT Scans of Sepsis Patients Admitted to the Intensive Care Unit

AIM

To evaluate the prognostic value of vertebral bone mineral density (BMD) and its relationship with mortality using the computed tomography (CT) scans of sepsis patients admitted to the intensive care unit.

METHODS

In this retrospective study, patients diagnosed with sepsis at the intensive care unit between January and December 2022 were evaluated. Bone density was manually measured from the vertebral body using axial CT images. The relationship of clinical variables and patient outcomes with vertebral BMD, mortality, and mechanical ventilation was investigated. A lower BMD (osteoporosis) was defined as ≤100 HU.

RESULTS

The study included 213 patients (95 females, 44.6%). The mean age of all patients was 60.1±18.7 years. At least one comorbidity was present in 64.7% (n=138) of the patients, and the most common comorbidity was hypertension (n=73, 34.2%). The mortality rate was 21.1% (n=45), and the mechanical ventilation rate was 17.4% (n=37), both being statistically significantly higher among the patients with a lower BMD (36.4 vs. 12.9%; p<0.001 and 29.7 vs. 10.8%; p=0.001, respectively). The rate of a lower BMD was significantly higher in the mortality group (59.5 vs. 29.5%; p=0.001). In the regression analysis, a lower BMD [odds ratio (OR), 2.785; 95% confidence interval (CI): 1.231-6.346, p=0.014] was a significant independent predictor of mortality. Interobserver agreement for BMD measurement was excellent, with an intraclass correlation coefficient of 0.919 (95% CI: 0.904-0.951).

CONCLUSION

Vertebral BMD is a strong independent predictor of mortality and can be easily and reproducible evaluated on the thoracoabdominal CT images of patients admitted to the intensive care unit with a diagnosis of sepsis.

Incidence and treatment trends of infectious spondylodiscitis in South Korea: A nationwide population-based study

The incidence of infectious spondylodiscitis (IS) has increased in recent years due to an increase in the numbers of older patients with chronic diseases, as well as patients with immunocompromise, steroid use, drug abuse, invasive spinal procedures, and spinal surgeries. However, research focusing on IS in the general population is lacking. This study investigated the incidence and treatment trends of IS in South Korea using data obtained from the Health Insurance Review and Assessment Service. A total of 169,244 patients (mean age: 58.0 years) diagnosed from 2010 to 2019 were included in the study. A total of 10,991 cases were reported in 2010 and 18,533 cases in 2019. Hence, there was a 1.5-fold increase in incidence rate per 100,000 people from 22.90 in 2010 to 35.79 in 2019 (P < 0.05). The incidence rate of pyogenic spondylodiscitis per 100,000 people increased from 15.35 in 2010 to 33.75 in 2019, and that of tuberculous spondylodiscitis decreased from 7.55 in 2010 to 2.04 in 2019 (P < 0.05, respectively). Elderly individuals ≥ 60 years of age accounted for 47.6% (80,578 patients) of all cases of IS. The proportion of patients who received conservative treatment increased from 82.4% in 2010 to 85.8% in 2019, while that of patients receiving surgical treatment decreased from 17.6% to 14.2% (P < 0.05, respectively). Among surgical treatments, the proportions of corpectomy and anterior fusion declined, while proportion of incision and drainage increased (P < 0.05, respectively). The total healthcare costs increased 2.9-fold from $29,821,391.65 in 2010 to $86,815,775.81 in 2019 with a significant increase in the ratio to gross domestic product. Hence, this population-based cohort study demonstrated that the incidence rate of IS has increased in South Korea. The conservative treatment has increased, while the surgical treatment has decreased. The socioeconomic burden of IS has increased rapidly.

Mortality, complication risks, and clinical outcomes after surgical treatment of spinal epidural abscess: a comparative analysis of patients aged 18-64 years, 65-79 years, and ≥ 80 years, with a 3-year follow-up

Spinal epidural abscess (SEA) with pyogenic vertebral osteomyelitis (PVO) is a rare illness with a steadily increasing incidence. However, comparative analyses of young and older patients with SEA are lacking. We aimed to compare the clinical course of patients aged 18-64 years, 65-79 years, and ≥ 80 years undergoing surgery for SEA. Clinical and imaging data were retrospectively collected from the institutional database between September 2005 and December 2021. Ninety-nine patients aged 18-64 years, 45 patients aged 65-79 years, and 32 patients ≥ 80 years were enrolled. Patients ≥ 80 years presented with a poorer baseline history (9.2 ± 2.4), as indicated by the CCI, than their younger counterparts (18-74 years: 4.8 ± 1.6;6.5 ± 2.5; p < 0.001). Patients aged 65-79 years and 80 years had a significantly longer length of stay. In-hospital mortality was significantly higher in those aged ≥ 80 years compared to their younger counterparts (≥ 80 years, n = 3, 9.4% vs. 18-64 years, n = 0, 0.0%; 65-79 years, n = 0, 0.0%; p < 0.001), while no differences in 90-day mortality or 30-day readmission were observed. After surgery, a significant decrease in C-reactive protein levels and leukocytes and amelioration of motor scores were observed in all the groups. Of note, older age (> 65 years), presence of comorbidities, and poor preoperative neurological condition were significant predictors of mortality. Surgical management led to significant improvements in laboratory and clinical parameters in all age groups. However, older patients are prone to multiple risks, requiring meticulous evaluation before surgery. Nevertheless, the risk profile of younger patients should not be underestimated. The study has the limitations of a retrospective design and small sample size. Larger randomized studies are warranted to establish the guidelines for the optimal management of patients from every age group and to identify the patients who can benefit from solely conservative management.

Hydrogel Delivery of DNase I and Liposomal Vancomycin to Eradicate Fracture-related Methicillin-resistant Staphylococcus aureus Infection and Support Osteoporotic Fracture Healing

Fracture-related infection (FRI) is a devastating complication in orthopedic surgery. A recent study showed that FRI causes more severe infection and further delays healing in osteoporotic bone. Moreover, bacterial biofilm formed on implants cannot be eradicated by systemic antibiotics, warranting novel treatments. Here, we developed a DNase I and Vancomycin hydrogel delivery vehicle to eradicate Methicillin-resistant Staphylococcus aureus (MRSA) infection in vivo. Vancomycin was encapsulated in liposomes, and DNase I and Vancomycin/liposomal-Vancomycin was loaded on thermosensitive hydrogel. In vitro drug release test showed a burst release of DNase I (77.2%) within 72 hours and sustained release of Vancomycin (82.6%) up to day 14. The in vivo efficacy was evaluated in a clinically relevant ovariectomy (OVX) induced osteoporotic metaphyseal fracture model with MRSA infection, and a total of 120 Sprague Dawley rats were used. In the OVX with infection group, biofilm development caused a drastic inflammatory response, trabecular bone destruction, and non-union. In the DNase I and Vancomycin co-delivery hydrogel group (OVX-Inf-DVG), bacteria on bone and implant were eradicated. X-ray and micro-CT showed preservation of trabecular bone and bone union. HE staining showed the absence of inflammatory necrosis, and fracture healing was restored. The local elevation of TNF-α and IL-6 and increased number of osteoclasts were prevented in the OVX-Inf-DVG group. Our findings suggest that dual release of DNase I and Vancomycin initially followed by Vancomycin only later up to 14 days effectively eliminates MRSA infection, prevents biofilm development and provides a sterile environment to promote fracture healing in osteoporotic bone with FRI. STATEMENT OF SIGNIFICANCE: The biofilm formation on the implant is difficult to eradicate, causing recurrent infection and non-union in fracture-related infection (FRI). Here we developed a hydrogel therapy with high in vivo efficacy to eliminate MRSA biofilm infection in a clinically-relevant FRI model in osteoporotic bone. By loading DNase I and vancomycin/liposomal-vancomycin on thermosensitive poly-(DL-lactic acidco-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA hydrogel, a dual release of DNase I and Vancomycin was achieved whilst preserving enzyme activity. In this model, the progressive development of infection caused a drastic inflammatory response, osteoclastogenesis, trabecular bone destruction, and non-union of fracture. These pathological changes were successfully prevented by the dual delivery of DNase I and vancomycin. Our findings provide a promising strategy for FRI in osteoporotic bone.

Association between Metabolic Obesity Phenotypes and the Burden of Hospitalized Postmenopausal Patients Concomitant with Osteoporosis: A Retrospective Cohort Study Based on the National Readmission Database

BACKGROUND

The present definition of obesity based on body mass index (BMI) is not accurate and effective enough to identify hospitalized patients with a heavier burden, especially for postmenopausal hospitalized patients concomitant with osteoporosis. The link between common concomitant disorders of major chronic diseases such as osteoporosis, obesity, and metabolic syndrome (MS) remains unclear. Here, we aim to evaluate the impact of different metabolic obesity phenotypes on the burden of postmenopausal hospitalized patients concomitant with osteoporosis in view of unplanned readmissions.

METHODS

Data was acquired from the National Readmission Database 2018. The study population was classified into metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) patients. We estimated the associations between metabolic obesity phenotypes and 30- and 90-day unplanned readmissions. A multivariate Cox Proportional Hazards (PH) model was used to assess the effect of factors on endpoints, with results expressed as HR and 95% CI.

RESULTS

The 30-day and 90-day readmission rates for the MUNO and MUO phenotypes were higher than that of the MHNO group (all p < 0.05), whereas no significant difference was found between the MHNO and MHO groups. For 30-day readmissions, MUNO raised the risk mildly (hazard ratio [HR] = 1.110, p < 0.001), MHO had a higher risk (HR = 1.145, p = 0.002), and MUO further elevated this risk (HR = 1.238, p < 0.001). As for 90-day readmissions, both MUNO and MHO raised the risk slightly (HR = 1.134, p < 0.001; HR = 1.093, p = 0.014, respectively), and MUO had the highest risk (HR = 1.263, p < 0.001).

CONCLUSIONS

Metabolic abnormalities were associated with elevated rates and risks of 30- or 90-day readmission among postmenopausal hospitalized women complicated with osteoporosis, whereas obesity did not seem to be innocent, and the combination of these factors led to an additional burden on healthcare systems and individuals. These findings indicate that clinicians and researchers should focus not only on weight management but also metabolism intervention among patients with postmenopausal osteoporosis.