The immune response after fracture trauma is different in old compared to young patients

Correlation between Peripheric Blood Markers and Surgical Invasiveness during Humeral Shaft Fracture Osteosynthesis in Young and Middle-Aged Patients

The treatment for humeral shaft fractures (HSFs) is still controversial, consisting of a wide variety of orthopedic osteosynthesis materials that imply different grades of invasiveness. The aim of this study is to investigate the correlation between inflammatory blood-derived markers and the magnitude of the surgical procedure in young and middle-aged patients who sustained these fractures. Observational, retrospective research was conducted between January 2018 and December 2023. It followed patients diagnosed with recent HFSs (AO/OTA 12-A and B) and followed operative treatment. They were split in two groups, depending on the surgical protocol: group A, operated by closed reduction and internal fixation (CRIF) with intramedullary nails (IMNs), and group B, operated by open reduction and internal fixation (ORIF) with dynamic compression plates (DCPs). Statistically significant differences (p < 0.05) between the two groups could be observed in injury on the basis of surgery durations, surgical times, pre- and postoperative neutrophil-per-lymphocyte ratio (NLR), postoperative platelet-per-lymphocyte ratio (PLR), monocyte-per-lymphocyte ratio (MLR), systemic inflammatory index (SII), systemic inflammatory response index (SIRI) and aggregate inflammatory systemic index (AISI). The multivariate regression model proposed revealed that NLR > 7.99 (p = 0.007), AISI > 1668.58 (p = 0.008), and the surgical times (p < 0.0001) are strongly correlated to the magnitude of the surgical protocol followed. Using receiver operating characteristic (ROC) curve analysis, a balanced reliability was determined for both postoperative NLR > 7.99 (sensitivity 75.0% and specificity 75.6) and AISI > 1668.58 (sensitivity 70.6% and specificity 82.2%). Postoperative NLR and AISI as inflammatory markers are highly associated with the magnitude of surgical trauma sustained during humeral shaft fracture osteosynthesis in a younger population.

Temporal dynamics of immune-stromal cell interactions in fracture healing

Bone fracture repair is a complex, multi-step process that involves communication between immune and stromal cells to coordinate the repair and regeneration of damaged tissue. In the US, 10% of all bone fractures do not heal properly without intervention, resulting in non-union. Complications from non-union fractures are physically and financially debilitating. We now appreciate the important role that immune cells play in tissue repair, and the necessity of the inflammatory response in initiating healing after skeletal trauma. The temporal dynamics of immune and stromal cell populations have been well characterized across the stages of fracture healing. Recent studies have begun to untangle the intricate mechanisms driving the immune response during normal or atypical, delayed healing. Various in vivo models of fracture healing, including genetic knockouts, as well as in vitro models of the fracture callus, have been implemented to enable experimental manipulation of the heterogeneous cellular environment. The goals of this review are to (1): summarize our current understanding of immune cell involvement in fracture healing (2); describe state-of-the art approaches to study inflammatory cells in fracture healing, including computational and in vitro models; and (3) identify gaps in our knowledge concerning immune-stromal crosstalk during bone healing.

Transfusion futility thresholds and mortality in geriatric trauma: Does frailty matter?

BACKGROUND

Data on massive transfusion (MT) in geriatric trauma patients is lacking. This study aims to determine geriatric transfusion futility thresholds (TT) and TT variations based on frailty.

METHODS

Patients from 2013 to 2018 TQIP database receiving MT were stratified by age and frailty. TTs and outcomes were compared between geriatric and younger adults and among geriatric adults based on frailty status.

RESULTS

The TT was lower for geriatric than younger adults (34 vs 39 units; p ​= ​0.03). There was no difference in TT between the non-frail, frail, and severely frail geriatric adults (37, 30 and 25 units, respectively, p ​> ​0.05). Geriatric adults had higher mortality than younger adults (63.1% vs 45.8%, p < 0.01). Non-frail geriatric adults had the highest mortality (69.4% vs 56.5% vs 56.2%, p < 0.01).

CONCLUSIONS

Geriatric patients have a lower TT than younger adults, irrespective of frailty. This may help improve outcomes and optimize MT utilization.

Systemic inflammatory and gut microbiota responses to fracture in young and middle-aged mice

Age is a patient-specific factor that can significantly delay fracture healing and exacerbate systemic sequelae during convalescence. The basis for this difference in healing rates is not well-understood, but heightened inflammation has been suggested to be a significant contributor. In this study, we investigated the systemic cytokine and intestinal microbiome response to closed femur fracture in 3-month-old (young adult) and 15-month-old (middle-aged) female wild-type mice. Middle-aged mice had a serum cytokine profile that was distinct from young mice at days 10, 14, and 18 post-fracture. This was characterized by increased concentrations of IL-17a, IL-10, IL-6, MCP-1, EPO, and TNFα. We also observed changes in the community structure of the gut microbiota in both young and middle-aged mice that was evident as early as day 3 post-fracture. This included an Enterobacteriaceae bloom at day 3 post-fracture in middle-aged mice and an increase in the relative abundance of the Muribaculum genus. Moreover, we observed an increase in the relative abundance of the health-promoting Bifidobacterium genus in young mice after fracture that did not occur in middle-aged mice. There were significant correlations between serum cytokines and specific genera, including a negative correlation between Bifidobacterium and the highly induced cytokine IL-17a. Our study demonstrates that aging exacerbates the inflammatory response to fracture leading to high levels of pro-inflammatory cytokines and disruption of the intestinal microbiota.

Vaccine promotion strategies in community pharmacy addressing vulnerable populations: a scoping review

CONTEXT

Social determinants of health are drivers of vaccine inequity and lead to higher risks of complications from infectious diseases in under vaccinated communities. In many countries, pharmacists have gained the rights to prescribe and administer vaccines, which contributes to improving vaccination rates. However, little is known on how they define and target vulnerable communities.

OBJECTIVE

The purpose of this study is to describe how vulnerable communities are targeted in community pharmacies.

METHODS

We performed a systematic search of the Embase and MEDLINE database in August 2021 inspired by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocols (PRISMA ScR). Articles in English, French or Spanish addressing any vaccine in a community pharmacy context and that target a population defined as vulnerable were screened for inclusion.

RESULTS

A total of 1039 articles were identified through the initial search, and 63 articles met the inclusion criteria. Most of the literature originated from North America (n = 54, 86%) and addressed influenza (n = 29, 46%), pneumococcal (n = 14, 22%), herpes zoster (n = 14, 22%) or human papilloma virus vaccination (n = 14, 22%). Lifecycle vulnerabilities (n = 48, 76%) such as age and pregnancy were most often used to target vulnerable patients followed by clinical factors (n = 18, 29%), socio-economical determinants (n = 16, 25%) and geographical vulnerabilities (n = 7, 11%). The most frequently listed strategy was providing a strong recommendation for vaccination, promotional posters in pharmacy, distributing leaflet/bag stuffers and providing staff training. A total of 24 barriers and 25 facilitators were identified. The main barriers associated to each vulnerable category were associated to effective promotional strategies to overcome them.

CONCLUSION

Pharmacists prioritize lifecycle and clinical vulnerability at the expense of narrowing down the definition of vulnerability. Some vulnerable groups are also under targeted in pharmacies. A wide variety of promotional strategies are available to pharmacies to overcome the specific barriers experienced by various groups.

In primary total hip arthroplasty, the direct anterior approach leads to higher levels of creatine kinase and lower levels of C-reactive protein compared to the posterolateral approach: a propensity score matching analysis of short-term follow-up data

BACKGROUND

This retrospective study compares the invasiveness of the direct anterior approach (DAA) and the posterolateral approach (PLA) in total hip arthroplasty (THA) by assessing three widely used inflammation-related serum markers in the first ten post-operative days.

METHODS

The database of our institution was mined for primary THAs conducted by the DAA or the PLA from February 2020 to June 2022. Demographics and creatine kinase (CK), C-reactive protein (CRP), and white blood cells were compared. Propensity Score Matching (PSM) analysis (1:1 ratio) was conducted based on multiple variables.

RESULTS

PSM analysis yielded 44 pairs of DAA and PLA patients. CK was significantly higher (p < 0.001) in the DAA than in the PLA group on postoperative day (POD) 2, 5 and 10. The POD2, POD5 and POD10 CK/preoperative CK ratio was 12.9, 5.0 and 0.8 in DAA and 8.8, 3.3 and 0.6 in PLA (p = 0.017, p = 0.012 and p = 0.025, respectively). The POD2, POD5 and POD10 CRP/preoperative CRP ratio was 95.1, 65.6 and 22.8 in PLA and 34.7, 23.3 and 8.9 in DAA (p < 0.001, p = 0.002 and p < 0.001, respectively).

CONCLUSION

PSM analysis of early postoperative CK and CRP values demonstrated that the DAA should be considered as a less stressful approach, not as a muscle-sparing or a minimally invasive THA approach.

Postoperative systemic inflammatory dysregulation and corticosteroids: a narrative review

In some patients, the inflammatory-immune response to surgical injury progresses to a harmful, dysregulated state. We posit that postoperative systemic inflammatory dysregulation forms part of a pathophysiological response to surgical injury that places patients at increased risk of complications and subsequently prolongs hospital stay. In this narrative review, we have outlined the evolution, measurement and prediction of postoperative systemic inflammatory dysregulation, distinguishing it from a healthy and self-limiting host response. We reviewed the actions of glucocorticoids and the potential for heterogeneous responses to peri-operative corticosteroid supplementation. We have then appraised the evidence highlighting the safety of corticosteroid supplementation, and the potential benefits of high/repeated doses to reduce the risks of major complications and death. Finally, we addressed how clinical trials in the future should target patients at higher risk of peri-operative inflammatory complications, whereby corticosteroid regimes should be tailored to modify not only the a priori risk, but also further adjusted in response to markers of an evolving pathophysiological response.

Cardiac alterations following experimental hip fracture - inflammaging as independent risk factor

Background

Cardiac injuries following trauma are associated with a worse clinical outcome. So-called trauma-induced secondary cardiac injuries have been recently described after experimental long bone fracture even in absence of direct heart damage. With the progressive aging of our society, the number of elderly trauma victims rises and therefore the incidence of hip fractures increases. Hip fractures were previously shown to be associated with adverse cardiac events in elderly individuals, which have mainly been attributed to pre-conditioned cardiac diseases. The aim of the present study was to investigate the effect of hip fractures on the heart in healthy young and middle-aged mice.

Materials and Methods

Young (12-week-old) and middle-aged (52-week-old) female C57BL/6 mice either received an intramedullary stabilized proximal femur fracture or sham treatment. The observation time points included 6 and 24 h. Systemic levels of pro-inflammatory mediators as well as local inflammation and alterations in myocardial structure, metabolism and calcium homeostasis in left ventricular tissue was analyzed following hip fracture by multiplex analysis, RT-qPCR and immunohistochemistry.

Results

After hip fracture young and middle-aged mice showed increased systemic IL-6 and KC levels, which were significantly elevated in the middle-aged animals. Furthermore, the middle-aged mice showed enhanced myocardial expression of HMGB1, TLR2/4, TNF, IL1β and NLRP3 as well as considerable alterations in the myocardial expression of glucose- and fatty acid transporters (HFABP, GLUT4), calcium homeostasis proteins (SERCA) and cardiac structure proteins (desmin, troponin I) compared to the young animals following hip fracture.

Conclusion

Young and middle-aged mice showed local myocardial alterations, which might predispose for the development of secondary cardiac injury following hip fracture. Age and the age-associated phenomenon of ‘inflammaging’ seemed to be an independent risk factor aggravating and accelerating cardiac alterations following hip fracture.

Modulating macrophage polarization for the enhancement of fracture healing, a systematic review

Background

All fracture repairs start with the innate immune system with the inflammatory response known as the inflammatory stage guided and driven by the secretion of chemokine by the ruptured tissue, followed by the sequential recruitment of neutrophils, monocytes and macrophages. These innate immune cells would infiltrate the fracture site and secrete inflammatory cytokines to stimulate recruitment of more immune cells to arrive at the fracture site coordinating subsequent stages of the repair process. In which, subsidence of pro-inflammatory M1 macrophage and transformation to anti-inflammatory M2 macrophages promotes osteogenesis that marks the start of the anabolic endochondral stage.

Methods

Literature search was performed on Pubmed, Embase, and Web of Science databases (last accessed 15th April 2021) using “macrophage AND fracture”. Review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.

Results

Eleven pre-clinical animal studies out of 429 articles were included in this systematic review according to our inclusion and exclusion criteria. All of which investigated interventions targeting to modulate the acute inflammatory response and macrophage polarization as evident by various markers in association with fracture healing outcomes.

Conclusion

This systematic review summarizes attempts to modulate the innate immune response with focuses on promoting macrophage polarization from M1 to M2 phenotype targeting the enhancement of fracture injury repair. Methods used to achieve the goal may include applications of damage-associated molecular pattern (DAMP), pathogen-associated molecular pattern (PAMP) or mechanical stimulation that hold high translational potentials for clinical application in the near future.

The promising roles of macrophages in geriatric hip fracture

As aging becomes a global burden, the incidence of hip fracture (HF), which is the most common fracture in the elderly population and can be fatal, is rapidly increasing, and its extremely high fatality rate places significant medical and financial burdens on patients. Fractures trigger a complex set of immune responses, and recent studies have shown that with aging, the immune system shows decreased activity or malfunctions in a process known as immune senescence, leading to disease and death. These phenomena are the reasons why elderly individuals typically exhibit chronically low levels of inflammation and increased rates of infection and chronic disease. Macrophages, which are key players in the inflammatory response, are critical in initiating the inflammatory response, clearing pathogens, controlling the innate and adaptive immune responses and repairing damaged tissues. Tissue-resident macrophages (TRMs) are widely present in tissues and perform immune sentinel and homeostatic functions. TRMs are combinations of macrophages with different functions and phenotypes that can be directly influenced by neighboring cells and the microenvironment. They form a critical component of the first line of defense in all tissues of the body. Immune system disorders caused by aging could affect the biology of macrophages and thus the cascaded immune response after fracture in various ways. In this review, we outline recent studies and discuss the potential link between monocytes and macrophages and their potential roles in HF in elderly individuals.

A Systematic Review and Meta-Analysis Examining the Impact of Age on Perioperative Inflammatory Biomarkers

BACKGROUND

Dysregulation of immune responses to surgical stress in older patients and those with frailty may manifest as differences in inflammatory biomarkers. We conducted a systematic review and meta-analysis to examine differences in perioperative inflammatory biomarkers between older and younger patients, and between patients with and without frailty.

METHODS

MEDLINE, Embase, Cochrane, and CINAHL databases were searched (Inception to June 23, 2020). Observational or experimental studies reporting the perioperative level or activity of biomarkers in surgical patients stratified by age or frailty status were included. The primary outcome was inflammatory biomarkers (grouped by window of ascertainment: pre-op; post-op: <12 hours, 12-24 hours, 1-3 days, 3 days to 1 week, and >1 week). Quality assessment was conducted using the Newcastle-Ottawa Scale. Inverse-variance, random-effects meta-analysis was conducted.

RESULTS

Forty-five studies (4263 patients) were included in the review, of which 36 were pooled for meta-analysis (28 noncardiac and 8 cardiac studies). Two studies investigated frailty as the exposure, while the remaining investigated age. In noncardiac studies, older patients had higher preoperative levels of interleukin (IL)-6 and C-reactive protein (CRP), lower preoperative levels of lymphocytes, and higher postoperative levels of IL-6 (<12 hours) and CRP (12-24 hours) than younger patients. In cardiac studies, older patients had higher preoperative levels of IL-6 and CRP and higher postoperative levels of IL-6 (<12 hours and >1 week).

CONCLUSIONS

Our findings demonstrate a paucity of frailty-specific studies; however, the presence of age-associated differences in the perioperative inflammatory response is consistent with age-associated states of chronic systemic inflammation and immunosenescence. Additional studies assessing frailty-specific changes in the systemic biologic response to surgery may inform the development of targeted interventions.

Differential miRNA Expression in Osteoporotic Elderly Patients with Hip Fractures Compared to Young Patients

BACKGROUND

The expression pattern of micro-RNAs (miRNA) has been implicated in the pathomechanism of various bone disorders, and has a role in differentiation of osteoblasts and osteoclasts. The purpose of the study was to investigate the differential miRNA profiles of osteoporotic hip fractures compared to young patients with hip fractures.

METHODS

Blood samples from ten osteoporosis patients and ten young, healthy patients, presenting with acute hip fractures were collected and subjected to an initial miRNA profiling to detect those miRNAs with significant variations between the two groups based on polymerase chain reactions performed in duplicate. A real-time quantitative polymerase chain reaction-based analysis was then performed for validation of specific miRNAs that were significantly different between the two groups.

RESULTS

A total of 182 miRNAs were analyzed. Thirty-nine of them showed significant differences between the two groups in the initial miRNA profiling. The validation results suggested that five miRNAs related to bone metabolism had significantly different expression among the osteoporotic hip fracture group compared to the young, healthy group: miR-23b-3p and miR-140-3p were up-regulated; miR-21-5p, miR-122-5p and miR-125b-5p were down-regulated.

CONCLUSIONS

Differential expression of selected miRNAs in patients with osteoporotic hip fracture suggests a possible role of miRNAs as potential biomarkers in prevention or timely prediction of osteoporotic fractures in the elderly. Further research is required to elucidate the mechanism of their involvement in osteoporosis.

LEVEL OF EVIDENCE

Not applicable.

Impact of Donor Age on the Osteogenic Supportive Capacity of Mesenchymal Stromal Cell-Derived Extracellular Matrix

Mesenchymal stromal cells (MSC) have been proposed as an emerging cell-based therapeutic option for regenerative medicine applications as these cells can promote tissue and organ repair. In particular, MSC have been applied for the treatment of bone fractures. However, the healing capacity of these fractures is often compromised by patient's age. Therefore, considering the use of autologous MSC, we evaluated the impact of donor age on the osteogenic potential of bone marrow (BM)-derived MSC. MSC from older patients (60 and 80 years old) demonstrated impaired proliferative and osteogenic capacities compared to MSC isolated from younger patients (30 and 45 years old), suggesting that aging potentially changes the quantity and quality of MSC. Moreover, in this study, we investigated the capacity of the microenvironment [i.e., extracellular matrix (ECM)] to rescue the impaired proliferative and osteogenic potential of aged MSC. In this context, we aimed to understand if BM MSC features could be modulated by exposure to an ECM derived from cells obtained from young or old donors. When aged MSC were cultured on decellularized ECM derived from young MSC, their in vitro proliferative and osteogenic capacities were enhanced, which did not happen when cultured on old ECM. Our results suggest that the microenvironment, specifically the ECM, plays a crucial role in the quality (assessed in terms of osteogenic differentiation capacity) and quantity of MSC. Specifically, the aging of ECM is determinant of osteogenic differentiation of MSC. In fact, old MSC maintained on a young ECM produced higher amounts of extracellularly deposited calcium (9.10 ± 0.22 vs. 4.69 ± 1.41 μg.μl-1.10-7 cells for young ECM and old ECM, respectively) and up-regulated the expression of osteogenic gene markers such as Runx2 and OPN. Cell rejuvenation by exposure to a functional ECM might be a valuable clinical strategy to overcome the age-related decline in the osteogenic potential of MSC by recapitulating a younger microenvironment, attenuating the effects of aging on the stem cell niche. Overall, this study provides new insights on the osteogenic potential of MSC during aging and opens new possibilities for developing clinical strategies for elderly patients with limited bone formation capacity who currently lack effective treatments.

Fluoride-Induced Expression of Neuroinflammatory Markers and Neurophysiological Regulation in the Brain of Wistar Rat Model

Excess fluoride intake has been linked with various pathological conditions. The objective of the present study was to understand the role of fluoride in neurotoxic, neuroinflammatory, and neurodegenerative changes in the brain tissue of Wistar rats. Wistar rats were fed with water containing 20-100 ppm (ppm) sodium fluoride (NaF). An array of neurotransmitters (acetylcholine, dopamine, epinephrine, norepinephrine, serotonin, histamine, and glutamate) expression levels were estimated with respect to different fluoride concentrations. Additionally, its effect on the expression levels of specific neuroinflammatory markers (iNOS, COX-2, TNF-α, PKC, VEGF, and HSP-70) in brain tissues of Wister rats was assessed. An increase in NaF concentration resulted in increased fluoride deposition in the brain which in turn caused increase levels of epinephrine, histamine, serotonin, and glutamate and decreased levels of norepinephrine, acetylcholine, and dopamine in a dose-dependent manner. Tissue fluoride levels of the hippocampus, neocortex, cerebellum, spinal cord, and sciatic nerve increased significantly in fluoride fed rats. Transmission electron microscopy in the experimental animals revealed axon deterioration, myelin sheath degeneration, and dark cells with scanty cytoplasm in the spinal cord and sciatic nerve. Additionally, vacuolated swollen mitochondria were observed in the neocortex, hippocampus, and cerebellum. Results suggest excess fluoride intake modulates a set of biological marker and promote neuroinflammatory and neurodegenerative condition in Wister rats. Therefore, we conclude that the accumulation of NaF alters the neurological function which leads to neurodegenerative disorders.

Is Timing to Surgery an Independent Risk Factor for Complications Following Operative Treatment of Periprosthetic Lower Extremity Fractures?

OBJECTIVE

To identify whether timing to surgery was related to major 30-day morbidity and mortality rates in periprosthetic hip and knee fractures [OTA/AO 3 (IV.3, V.3), OTA/AO 4 (V4)].

DESIGN

Retrospective database review.

SETTING

Hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

PATIENTS

Patients in the NSQIP database with periprosthetic hip or knee fractures between 2007 and 2015.

INTERVENTION

Surgical management of periprosthetic hip and knee fractures including revision or open reduction internal fixation.

MAIN OUTCOME MEASUREMENTS

Major 30-day morbidity and mortality after operative treatment of periprosthetic hip or knee fractures.

RESULTS

A total of 1265 patients, mean age 72, including 883 periprosthetic hip and 382 periprosthetic fractures about the knee were reviewed. Delay in surgery greater than 72 hours is a risk factor for increased 30-day morbidity in periprosthetic hip and knee fractures [relative risk = 2.90 (95% confidence interval: 1.74-4.71); P-value ≤ 0.001] and risk factor for increased 30-day mortality [relative risk = 8.98 (95% confidence interval: 2.14-37.74); P-value = 0.003].

CONCLUSIONS

Using NSQIP database to analyze periprosthetic hip and knee fractures, delay to surgery is an independent risk factor for increased 30-day major morbidity and mortality when controlling for patient functional status and comorbidities. Although patient optimization and surgical planning are paramount, minimizing extended delays to surgery is a potentially modifiable risk factor in the geriatric periprosthetic lower extremity fracture patient.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Bone Allograft and Locking Plate for Severe Proximal Humeral Fractures: Early and Late Outcomes

Background

Early failure of osteosyntheses is common even with use of locking plates. In patients with comminuted fractures and epiphyseal osseous defects, we performed a series of osteosyntheses by locking plate in combination with an allograft bone augmentation. Because of encouraging short-term results in the literature, we assumed that the method could be a potential alternative to a reverse shoulder prosthesis.

Material/Methods

Twenty-six patients with a dislocated proximal humeral fracture (Neer IV/V/VI) were studied. A lyophilized allogeneic bone graft was used to reinforce the humeral head fragments before locking plate osteosynthesis. The outcomes of fractures were assessed with Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley (Constant) scores, range of motion, a visual analog scale, and with radiological testing. The Constant-Murley scores were the endpoint of our study.

Results

The Neer classification of the fractures was type IV in 4 patients, type V in 20 patients, and type VI in 2 patients. The mean DASH score was 52.85 (range, 4.17–79.3) and the mean Constant score was 39.26 (range, 17–88). We observed late necrosis of the humeral head in 15 of 24 patients (62.5%), although early radiological follow-up showed that the humeral head had been anatomically reconstructed.

Conclusions

Long-term follow-up demonstrated inferior functional results, as displayed by poor Constant scores. There was a high incidence of necrosis, in spite of initial anatomical reconstruction. Biointegration of the allogeneic bone graft and revascularization of the humeral head fragments could be impaired in geriatric patients who have gross dislocation. Therefore, augmentation of the humeral head with allogeneic bone grafts cannot be recommended in these patients.

Older patients with proximal femur fractures and SARS-CoV-2 infection - An observational study

Background: Older patients are at increased risk of severe COVID-19 infection and associated mortality. There are limited data evaluating the outcome of older patients with hip fractures treated during the COVID-19 pandemic, and it has been suggested that these patients should be treated non-operatively due to high mortality risk. The aim of this study was to report the outcomes of COVID-19 infected hip fracture patients treated at a single centre. Methods: This was a retrospective cohort study. Data were collected from February 2020 (after the first confirmed COVID-19 infected patient was reported in the Midlands region of the UK). All patients admitted to the hospital with femoral neck fractures were included. Patient demographics, comorbidity, COVID-19 status, and short-term clinical outcomes were obtained by review of electronic medical records. The outcomes of COVID-19 infected patients were compared with non-COVID-19 patients treated during the study period. Results: Twenty-nine patients were included (mean age of 80 years), of whom 14 (48%) were tested positive for COVID-19 infection in the postoperative period. Overall, 26 patients (90%) underwent surgical treatment. COVID-19 infected patients had significantly higher Charlson comorbidity scores compared to the control group (5 vs. 4; p = 0.047). Only 5 COVID-19 infected patients (36%) required supplemental oxygen therapy in the postoperative period, and no patients required respiratory or other organ support. The 30-day mortality rate in COVID-19 patients was 14% compared to 0% in the negative controls (p = 0.22). Interpretation: COVID-19 infection did not increase the mortality rate of older patients undergoing surgery for hip fractures during the pandemic. The authors recommend careful assessment of patient fitness and prompt surgical treatment. In addition, it was noted that nearly all admissions were either given large boluses of Vitamin D or were on maintenance supplementation, which may have affected the severity of the response to COVID-19 infections.

Bifidobacterium adolescentis supplementation attenuates fracture-induced systemic sequelae

The gut microbiota is an important contributor to both health and disease. While previous studies have reported on the beneficial influences of the gut microbiota and probiotic supplementation on bone health, their role in recovery from skeletal injury and resultant systemic sequelae remains unexplored. This study aimed to determine the extent to which probiotics could modulate bone repair by dampening fracture-induced systemic inflammation. Our findings demonstrate that femur fracture induced an increase in gut permeability lasting up to 7 days after trauma before returning to basal levels. Strikingly, dietary supplementation with Bifidobacterium adolescentis augmented the tightening of the intestinal barrier, dampened the systemic inflammatory response to fracture, accelerated fracture callus cartilage remodeling, and elicited enhanced protection of the intact skeleton following fracture. Together, these data outline a mechanism whereby dietary supplementation with beneficial bacteria can be therapeutically targeted to prevent the systemic pathologies induced by femur fracture.

Effect of donor age and 3D-cultivation on osteogenic differentiation capacity of adipose-derived mesenchymal stem cells

Background and Purpose: Age and co-morbidities compromise healing tendencies of traumatic fractures in geriatric patients. Non-healing fractures may need regenerative medicine techniques involving autologous mesenchymal stem cells (MSCs). Donor age may affect the viability and differentiation capacity of MSCs. We investigated age-related differences in adipose-derived MSCs (AMSCs) concerning osteogenic potential in 2D and 3D cultivation. Materials and Methods: AMSCs were harvested from young (mean age: 37.5 ± 8.6 years) and old (mean age: 75.8 ± 9.2 years) patients. Cells were induced to osteogenic differentiation and cultivated in 2D and 3D for 14 days. Alkaline phosphatase (ALP) activity, mineralization and gene expression were investigated. Results: ALP activity revealed highest levels in 3D of old AMSCs after 14 days. ALP expression showed significant rises in old vs. young cells in 2D (p = 0.0024). Osteoprotegerin revealed the highest levels in old AMSCs in 2D. Highest osteocalcin levels presented in young cells compared to old cells in 2D (p = 0.0258) and young cells in 3D (p = 0.0014). Conclusion: 3D arrangement of old AMSCs without growth factors is not ensuring superior osteogenesis in vitro. AMSCs, especially cells from older patients, reveal higher osteogenic potential in 2D than in 3D. 3D arrangement favors osteogenic potential of young cells.

Geriatric Polytrauma-Cardiovascular and Immunologic Response in a Murine Two-Hit Model of Trauma

BACKGROUND

The aims of the present study were to establish a clinically relevant two-hit model with trauma/hemorrhage followed by sepsis in older mice and investigate age-dependent cardiovascular and immunologic specificities under these conditions.

MATERIALS AND METHODS

In aged mice (12, 18, and 24 mo old), a femur fracture followed by hemorrhage was induced. After resuscitation, animals were monitored for 72 h before sepsis was induced. Vital signs were monitored during shock. Systemic interleukin (IL)-6 levels were measured daily. Expression of sarcoplasmic or endoplasmic reticulum calcium ATPase (SERCA) and IL-6 receptor were analyzed in heart, lung, and liver tissues.

RESULTS

After induction of shock, mean arterial pressure decreased significantly in all groups (12 mo, P < 0.001; 18 mo, P < 0.001; 24 mo, P = 0.013). Compared with younger animals, 24-mo old mice were not able to adequately compensate for hypovolemia by an increase of heart rate (P = 0.711). Expression of SERCA2 (P = 0.002) and IL-6 receptor on myocytes (P = 0.037), lung (P = 0.005), and liver (P = 0.009) tissues were also lowest in this group. Systemic IL-6 values showed the most distinct posttraumatic response in 24-mo-old mice (P = 0.016). Survival rate decreased significantly with increased age (P = 0.005).

CONCLUSIONS

The increased mortality rate in older animals was associated with a limited compensatory physiological response and a more distinct immunologic reaction after trauma and sepsis. A decreased SERCA2 expression and missing feedback loops due to a reduced density of organ bound immune receptors might represent possible explanations for the observed age-dependent differences.

Systemic Bone Loss After Fracture

A history of prior fracture is the most reliable indicator of prospective fracture risk. Increased fracture risk is not confined to the region of the prior fracture, but is operant at all skeletal sites, providing strong evidence of systemic bone loss after fracture. Animal and human studies suggest that systemic bone loss begins shortly after fracture and persists for several years in humans. In fact, bone quantity and bone quality may never fully return to their pre-fracture levels, especially in older subjects, demonstrating a need for improved understanding of the mechanisms leading to systemic bone loss after fracture in order to reduce subsequent fracture risk. Although the process remains incompletely understood, mechanical unloading (disuse), systemic inflammation, and hormones that control calcium homeostasis may all contribute to systemic bone loss. Additionally, individual factors can potentially affect the magnitude and time course of systemic bone loss and recovery. The magnitude of systemic bone loss correlates positively with injury severity and age. Men may also experience greater bone loss or less recovery than women after fracture. This review details the current understanding of systemic bone loss following fracture, including possible underlying mechanisms and individual factors that may affect this injury response.

Risk factors for ischemic stroke post bone fracture

Stroke is one of the most devastating complications after bone fracture. However, due to the rarity of the complication, the risk factor for post fracture stroke remains unknown. We retrospectively reviewed 2914 fractured adults referred to the first affiliated hospital of Xi'an Jiaotong University, a regional referral center of China, from January 2008 to May 2013. As a result, among the 2914 patients, 13 of them had newly onset stroke within a median of 4 days after bone fractures (ranging from 1 to 25 days). The overall prevalence of post fracture stroke was 0.446%. The post fracture stroke prevalence in patients older than 68 years old was 3.542%. Compared to patients with vertebral (0.124%) and femur (0.619%) fractures, patients with hip fractures had a higher prevalence of post fracture stroke (2.320%) (P < 0.001). Univariate analysis showed that hyperlipidemia, history of prior fracture, more comorbidities, higher CHADS2 score and higher neutrophil counts at admission were more often observed among patients who had post fracture stroke (P < 0.05). With the multiple logistic regression analysis, we identified that history of prior fracture was an independent risk factor for post fracture ischemic stroke (OR = 6.417, 95% CI = 1.581-26.051, P = 0.009). Our study illustrates that the history of prior fracture is associated with a 6.4-fold increase in the risk of post fracture ischemic stroke.

Posterolateral vs Direct Anterior Approach in Total Hip Arthroplasty (POLADA Trial): A Randomized Controlled Trial to Assess Differences in Serum Markers

BACKGROUND

The direct anterior approach (DAA) for total hip arthroplasty has claimed to be a true tissue-sparing minimally invasive approach that has less tissue damage and a faster recovery when compared to the posterolateral approach (PLA). The aim of this randomized controlled trial is to measure the differences in serum markers and functional outcomes between the DAA and PLA for total hip arthroplasty.

METHODS

Forty-six patients were prospectively included and randomized for either the DAA (n = 23) or PLA (n = 23). All surgical procedures were performed by 3 well-trained orthopedic surgeons. The degree of tissue damage was assessed by measuring creatine kinase (CK) and C-reactive protein levels (CRP) preoperatively and 2 hours, 1 day, 2 weeks, and 6 weeks postoperatively. Generalized linear mixed models analyses were used to assess differences between serum markers over time; correction for possible confounding factors was performed. The Hip disability and Osteoarthritis Outcome Score and the Harris Hip Score were assessed preoperatively and 6 weeks postoperatively.

RESULTS

There were no differences in patient demographics. The DAA had a longer operative time (P = .001). CK and CRP levels increased postoperatively, but no significant differences between the groups were found on any of the time points. Functional outcomes were also similar in both approaches.

CONCLUSION

No difference in tissue damage measured with serum markers CK and CRP were found between the DAA and PLA for total hip arthroplasty.

Nutritional intervention in cognitively impaired geriatric trauma patients: a feasibility study

Background

Most studies focusing on improving the nutritional status of geriatric trauma patients exclude patients with cognitive impairment. These patients are especially at risk of malnutrition at admission and of worsening during the perioperative fasting period. This study was planned as a feasibility study to identify the difficulties involved in including this high-risk collective of cognitively impaired geriatric trauma patients.

Patients and methods

This prospective intervention study included cognitively impaired geriatric patients (Mini–Mental State Examination <25, age >65 years) with hip-related fractures. We assessed Mini Nutritional Assessment (MNA), Nutritional Risk Screening (NRS 2002), body mass index, calf circumference, American Society of Anesthesiologists’ classification, and Braden Scale. All patients received parenteral nutritional supplementation of 800 kcal/d for the 96-hour perioperative period. Serum albumin and pseudocholinesterase were monitored. Information related to the study design and any complications in the clinical course were documented.

Results

A total of 96 patients were screened, among whom eleven women (median age: 87 years; age range: 74–91 years) and nine men (median age: 82 years; age range: 73–89 years) were included. The Mini–Mental State Examination score was 9.5 (0–24). All patients were manifestly undernourished or at risk according to MNA and NRS 2002. The body mass index was 23 kg/m² (13–30 kg/m²), the calf circumference was 29.5 cm (18–34 cm), and the mean American Society of Anesthesiologists’ classification status was 3 (2–4). Braden Scale showed 18 patients at high risk of developing pressure ulcers. In all, 12 patients had nonsurgical complications with 10% mortality. Albumin as well as pseudocholinesterase dropped significantly from admission to discharge. The study design proved to be feasible.

Conclusion

The testing of MNA and NRS 2002 was feasible. Cognitively impaired trauma patients proved to be especially at risk of malnutrition. Since 96 hours of parenteral nutrition as a crisis intervention was insufficient, additional supplementation could be considered. Laboratory and functional outcome parameters for measuring successive supplementation certainly need further evaluations involving randomized controlled trials.

The effect of concomitant peripheral injury on traumatic brain injury pathobiology and outcome

Background

Traumatic injuries are physical insults to the body that are prevalent worldwide. Many individuals involved in accidents suffer injuries affecting a number of extremities and organs, otherwise known as multitrauma or polytrauma. Traumatic brain injury is one of the most serious forms of the trauma-induced injuries and is a leading cause of death and long-term disability. Despite over dozens of phase III clinical trials, there are currently no specific treatments known to improve traumatic brain injury outcomes. These failures are in part due to our still poor understanding of the heterogeneous and evolving pathophysiology of traumatic brain injury and how factors such as concomitant extracranial injuries can impact these processes.

Main body

Here, we review the available clinical and pre-clinical studies that have investigated the possible impact of concomitant injuries on traumatic brain injury pathobiology and outcomes. We then list the pathophysiological processes that may interact and affect outcomes and discuss promising areas for future research. Taken together, many of the clinical multitrauma/polytrauma studies discussed in this review suggest that concomitant peripheral injuries may increase the risk of mortality and functional deficits following traumatic brain injury, particularly when severe extracranial injuries are combined with mild to moderate brain injury. In addition, recent animal studies have provided strong evidence that concomitant injuries may increase both peripheral and central inflammatory responses and that structural and functional deficits associated with traumatic brain injury may be exacerbated in multiply injured animals.

Conclusions

The findings of this review suggest that concomitant extracranial injuries are capable of modifying the outcomes and pathobiology of traumatic brain injury, in particular neuroinflammation. Though additional studies are needed to further identify the factors and mechanisms involved in central and peripheral injury interactions following multitrauma and polytrauma, concomitant injuries should be recognized and accounted for in future pre-clinical and clinical traumatic brain injury studies.

Predictors of Infective Outcomes Following Hip Fracture: A Cohort Study

Objectives: This study sought to assess the value of differing pre-operative measures in prediction of post-operative non-surgical site infection (NSSI) and length of hospital stay following hip fracture surgery. Methods: All patients admitted during a one year period with a hip fracture to our department were included in the study (n=207). Primary outcome measures were ten independent risk factors correlated to the development of non-surgical site infection following surgery for hip fracture. Secondary outcome measures were duration of hospital stay and inpatient mortality. Results: The patients who had severe cognitive impairment had a 71.0% risk of developing non-surgical site infection. Patients who had multiple medical co-morbidities also had increased risk of developing non-surgical site infection at 59.1%. Patients who developed NSSI on average stayed in hospital 13.1 days longer than patients who did not (31.6 vs. 18.5, p < .001). Conclusions: This study demonstrates the importance of reducing post-operative infection in hip fracture patients in view of reducing morbidity, mortality and cost. These patients can be stratified by risk factors and interventions can be employed in view of reducing inpatient post-operative infection rates in this cohort.

The Neutrophil to Lymphocyte Ratio on Admission and Short-Term Outcomes in Orthogeriatric Patients

AIM

To investigate the association of the neutrophil to lymphocyte ratio (NLR) at admission with presence of fracture, comorbid conditions, and its prognostic value for short-term outcomes in orthogeriatric patients.

METHODS

On 415 consecutive patients (mean age 78.8 ±8.7[SD] years, 281 women, 255 with a non-vertebral bone fracture, including 167 with a hip fracture, HF) admitted to the Department of Orthopaedic Surgery at the Canberra hospital (2010 - 2011) data on clinical and laboratory characteristics were collected prospectively. The validation dataset included 294 consecutive patients (mean age 82.1 ± 8.0 years, 72.1% women) with HF.

RESULTS

Multivariate regression revealed four variables, presence of HF, hypoalbuminaemia (<33g/L), anaemia (<120g/L) and hyperparathyroidism (PTH>6.8 pmol/L), as independent determinants of admission NLR≥5.1. There was a dose-graded relationship between presence of fracture, especially HF, postoperative complications and levels of NLR categorized as tertiles. Compared to patients with NLR<5.1(first tertile), patients with NLR 5.1-8.5 (second tertile) had a 1.8-, 3.1-, 2.6-, and 2.5-fold higher risk for presence of any fracture, HF, developing postoperative myocardial injury (troponin I rise) and a high inflammatory response/infection (CRP>100mg/L after the 3rd postoperative day), respectively, while in subjects with NLR>8.5 (third tertile) these risks were 2.6-, 4.9-, 5.9- and 4.5-times higher, respectively; subjects with NLR>8.5 had a 9.7 times higher chance of dying in the hospital compared to patients with NLR 5.1-8.5; the NLR retained its significance on multivariate analyses. The NLR ≥5.1 predicted postoperative myocardial injury with an area under the curve (AUC) of 0.626, CRP>100mg/L with AUC of 0.631 and the NLR >8.5 predicted in-hospital mortality with an AUC of 0.793, showing moderately high sensitivity (86.7%, 80% and 90%, respectively) and negative predictive value (92.9%, 71.2%, 99.6%, respectively), but low specificity. Admission NLR was superior to other, except hypoalbuminaemia, prognostic markers; combined use of both NLR≥5.1 and albumin<33g/L only moderately increased the accuracy of prediction. The validation study confirmed the prognostic value of the admission NLR.

CONCLUSIONS

In orthogeriatric patients, high NLR on admission is an independent indicator of fracture presence, a significant risk factor and moderate predictor of postoperative myocardial injury, high inflammatory response/infection and in-hospital death.

Influence of Fracture Stability on Early Patient Mortality and Reoperation After Pertrochanteric and Intertrochanteric Hip Fractures

OBJECTIVES

To determine the influence of fracture stability on early patient mortality and complications requiring reoperation after trochanteric hip fracture.

DESIGN

Prospective consecutive cohort study.

SETTING

The orthopaedic unit of a public teaching hospital.

PARTICIPANTS

Seven hundred twenty-eight patients with 743 consecutive stable (n = 446) pertrochanteric and unstable (n = 297) pertrochanteric or intertrochanteric fractures (median age: 84 years, 71% females) resulting from a low-impact injury and surgically managed. Mean follow-up of surviving patients was 4 years (range: 2-6 years).

INTERVENTION

Fracture fixation by dynamic hip screw extramedullary device or intramedullary nail (Austofix or Gamma3) based on surgeon preference.

MAIN OUTCOME MEASURES

Mortality within 6 and 12 months and surgical complications requiring device reoperation within 12 months of surgery (multivariate logistic regression and Kaplan-Meier survival analyses).

RESULTS

Patients with unstable fractures were at 1.61 times (95% confidence interval: 1.18-2.21, P = 0.003) and 1.37 times (95% confidence interval: 1.02-1.83, P = 0.037) greater odds of dying within 6 and 12 months, respectively, than those with stable fractures. Older age, male gender, higher American Society of Anesthesiologists classification, in residential care, and inpatient-reported medical complications were also independent risk factors for early mortality. Increasing fracture instability and fixation using the Austofix nail were associated with early device reoperation. Comparable results were reported for the dynamic hip screw and Gamma3 nail, although the Gamma3 nail may offer advantages for more complex unstable fractures.

CONCLUSIONS

Fracture instability influences early mortality after surgical fixation of trochanteric hip fracture. The Austofix double lag screw device had suboptimal results.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Immunesenescence and inflammaging: A contributory factor in the poor outcome of the geriatric trauma patient

Compared to younger patients, traumatic injury in older patients is associated with increased mortality and a range of adverse outcomes such as higher rates of infectious episodes, longer length of hospital stay and poor functional outcome at follow up. Data emerging from human and murine-based studies suggest age-related changes in immune function, collectively termed immunesenescence, and the chronic sub-clinical systemic inflammatory state of older adults, termed inflammaging, may contribute to these poor outcomes. Here, we review the findings of these studies, whose results demonstrate that the geriatric trauma patient elicits an immune response to injury that is distinct to that of younger adults, being characterised by reduced immune cell activation, impaired function and abnormal haematopoiesis, defects that are accompanied by an altered inflammatory response that fails to return to a homeostatic baseline in the days following injury. Although considerable evidence is accumulating that demonstrates clear and significant age-related differences in the immune and inflammatory response to traumatic injury, our current understanding of the mechanism(s) that underlie these changes is limited. Future studies that provide a mechanistic explanation for the unique immune and inflammatory response of older adults to traumatic injury are therefore essential if we are to determine whether manipulation of the immune system has potential as a future therapeutic strategy by which to improve the outcome of the geriatric trauma patient.