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Aims: Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the Staphylococcus aureus phage 191219 and gentamicin against haematogenous and early-stage biofilm implant-related infections in Galleria mellonella. Methods: For the haematogenous infection, G. mellonella larvae were implanted with a Kirschner wire (K-wire), infected with S. aureus, and subsequently phages and/or gentamicin were administered. For the early-stage biofilm implant infection, the K-wires were pre-incubated with S. aureus suspension before implantation. After 24 hours, the larvae received phages and/or gentamicin. In both models, the larvae also received daily doses of phages and/or gentamicin for up to five days. The effect was determined by survival analysis for five days and quantitative culture of bacteria after two days of repetitive doses. Results: In the haematogenous infection, a single combined dose of phages and gentamicin, and repetitive injections with gentamicin or in combination with phages, resulted in significantly improved survival rates. In the early-stage biofilm infection, only repetitive combined administration of phages and gentamicin led to a significantly increased survival. Additionally, a significant reduction in number of bacteria was observed in the larvae after receiving repetitive doses of phages and/or gentamicin in both infection models. Conclusion: Based on our results, a single dose of the combination of phages and gentamicin is sufficient to prevent a haematogenous S. aureus implant-related infection, whereas gentamicin needs to be administered daily for the same effect. To treat early-stage S. aureus implant-related infection, repetitive doses of the combination of phages and gentamicin are required. Cite this article: Bone Joint Res 2024;13(8):383–391.

Aims: Fracture-related infections (FRIs) are a devastating complication of fracture management. However, the impact of FRIs on mental health remains understudied. The aim of this study was a longitudinal evaluation of patients’ psychological state, and expectations for recovery comparing patients with recurrent FRI to those with primary FRI. Methods: A prospective longitudinal study was conducted at a level 1 trauma centre from January 2020 to December 2022. In total, 56 patients treated for FRI were enrolled. The ICD-10 symptom rating (ISR) and an expectation questionnaire were assessed at five timepoints: preoperatively, one month postoperatively, and at three, six, and 12 months. Results: Recurrent FRI cases consistently exceeded the symptom burden threshold (0.60) in ISR scores at all assessment points. The difference between preoperative-assessed total ISR scores and the 12-month follow-up was not significant in either group, with 0.04 for primary FRI (p = 0.807) and 0.01 for recurrent FRI (p = 0.768). While primary FRI patients showed decreased depression scores post surgery, recurrent FRI cases experienced an increase, reaching a peak at 12 months (1.92 vs 0.94; p < 0.001). Anxiety scores rose for both groups after surgery, notably higher in recurrent FRI cases (1.39 vs 1.02; p < 0.001). Moreover, patients with primary FRI reported lower expectations of returning to normal health at three (1.99 vs 1.11; p < 0.001) and 12 months (2.01 vs 1.33; p = 0.006). Conclusion: The findings demonstrate the significant psychological burden experienced by individuals undergoing treatment for FRI, which is more severe in recurrent FRI. Understanding the psychological dimensions of recurrent FRIs is crucial for comprehensive patient care, and underscores the importance of integrating psychological support into the treatment paradigm for such cases. Cite this article: Bone Jt Open 2024;5(7):621–627.

Aims: Periprosthetic joint infection (PJI) demonstrates the most feared complication after total joint replacement (TJR). The current work analyzes the demographic, comorbidity, and complication profiles of all patients who had in-hospital treatment due to PJI. Furthermore, it aims to evaluate the in-hospital mortality of patients with PJI and analyze possible risk factors in terms of secondary diagnosis, diagnostic procedures, and complications. Methods: In a retrospective, cross-sectional study design, we gathered all patients with PJI (International Classification of Diseases (ICD)-10 code: T84.5) and resulting in-hospital treatment in Germany between 1 January 2019 and 31 December 2022. Data were provided by the Institute for the Hospital Remuneration System in Germany. Demographic data, in-hospital deaths, need for intensive care therapy, secondary diagnosis, complications, and use of diagnostic instruments were assessed. Odds ratios (ORs) with 95% confidence intervals (CIs) for in-hospital mortality were calculated. Results: A total of 52,286 patients were included, of whom 1,804 (3.5%) died. Hypertension, diabetes mellitus, and obesity, the most frequent comorbidities, were not associated with higher in-hospital mortality. Cardiac diseases as atrial fibrillation, cardiac pacemaker, or three-vessel coronary heart disease showed the highest risk for in-hospital mortality. Postoperative anaemia occurred in two-thirds of patients and showed an increased in-hospital mortality (OR 1.72; p < 0.001). Severe complications, such as organ failure, systemic inflammatory response syndrome (SIRS), or septic shock syndrome showed by far the highest association with in-hospital mortality (OR 39.20; 95% CI 33.07 to 46.46; p < 0.001). Conclusion: These findings highlight the menace coming from PJI. It can culminate in multi-organ failure, SIRS, or septic shock syndrome, along with very high rates of in-hospital mortality, thereby highlighting the vulnerability of these patients. Particular attention should be paid to patients with cardiac comorbidities such as atrial fibrillation or three-vessel coronary heart disease. Risk factors should be optimized preoperatively, anticoagulant therapy stopped and restarted on time, and sufficient patient blood management should be emphasized. Cite this article: Bone Jt Open 2024;5(4):367–373.

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.

Fracture-related infections can be challenging, particularly with concomitant severe bone defects and multi-resistant microorganisms. We present a case of a 42-year-old patient with a fracture-related infection following a war injury from a gunshot, resulting in a 12-cm subtrochanteric segmental bone defect and the detection of four different multi-resistant Gram-negative bacteria. Due to antibiotic drug resistance, treatment with bacteriophages was considered. Phage susceptibility testing revealed the activity of a commercially available bacteriophage cocktail (Intesti bacteriophage, Eliava Institute, Tbilisi, Georgia). This phage cocktail was included in a modified two-stage Masquelet technique. During the first intervention, the bone was debrided and samples for microbiological and phage testing were harvested. The indwelling intramedullary rod was removed, and the bone defect was filled with a PMMA spacer loaded with colistin and the bone stabilized with a plate. During the second procedure, the PMMA spacer was removed and a silver-coated angular stable plate was implanted. The bone defect was filled with a fibular autograft and allograft cancellous bone chips. At the end of the procedure, the Intesti bacteriophage cocktail was injected into a DAC hydrogel and this bacteriophage hydrogel composite was then put onto the angular stable plate. Postoperatively the wound fluid was collected over 72 h, and high-throughput metagenomic sequencing was performed. This showed a time-dependent release of the bacteriophages in the wound fluid, with a relatively high concentration after 12 h, decreasing to DNA copies of 0 after 72 h. Furthermore, we have assessed the release of phages from DAC gel and the effect of DAC gel on the phages in vitro. The results showed a stable and rapid release of phages from the DAC gel (~1×103 PFU/mL). The clinical course of the patient showed no relapse of the infection with good bone consolidation of the bone defect after 1 year without the need for any surgical revision. To the best of our knowledge, this is the first case that shows the detection of bacteriophage DNA copies by high-throughput metagenomics sequencing in a patient with a complex fracture-related infection. Successful treatment of this case encourages further investigation of bacteriophage therapy in patients with complex bone and joint infections.

The efficient operation of cellular networks requires careful tuning of configuration parameters, such as the transmit power or antenna tilts, to adequately balance interference while providing the necessary capacity to the connected UEs. As manual tuning of these parameters is typically unfeasible, several automated coverage and capacity optimization methods have been proposed. However, most existing solutions are either based on poorly scalable black-box optimization methods or solely consider interference management, while omitting the potential of congested cells. In this work, we instead propose a differentiable framework for cellular network optimization, centered around the end-user throughput, that enables load-aware tuning of network parameters through gradient descent. Hereby, we approach the problem from a data-driven perspective, and include dedicated model subcomponents derived from monitoring data, which enable the calibration to site-specific traffic patterns and KPI measurements. We validate our approach for joint transmit power optimization in a real-world network layout with $\approx 150$ cells in two frequency bands. In our evaluation, the gradient descent-based optimization reliably reduces the outage ratio for different levels of demand, while the black-box baseline struggles to explore the large search space. Our results further reveal substantial differences between the proposed load-aware and commonly used SINR-based objectives, for which we repeatably obtain unbalanced network configurations with severely congested cells. In contrast, the proposed end-user throughput objective promotes a balanced network configuration, providing adequate resources to the connected UEs while also limiting interference.

Aims: This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated. Methods: A total of ten orthopaedic surgeons classified 20 cases of PJI based on the PJI-TNM classification. Subsequently, the classification was re-evaluated using the PJI-TNM app. Classification accuracy was calculated separately for each subcategory (reinfection, tissue and implant condition, non-human cells, and morbidity of the patient). Fleiss’ kappa and Cohen’s kappa were calculated for interobserver and intraobserver reliability, respectively. Results: Overall, interobserver and intraobserver agreements were substantial across the 20 classified cases. Analyses for the variable ‘reinfection’ revealed an almost perfect interobserver and intraobserver agreement with a classification accuracy of 94.8%. The category 'tissue and implant conditions' showed moderate interobserver and substantial intraobserver reliability, while the classification accuracy was 70.8%. For 'non-human cells,' accuracy was 81.0% and interobserver agreement was moderate with an almost perfect intraobserver reliability. The classification accuracy of the variable 'morbidity of the patient' reached 73.5% with a moderate interobserver agreement, whereas the intraobserver agreement was substantial. The application of the app yielded comparable results across all subgroups. Conclusion: The PJI-TNM classification system captures the heterogeneity of PJI and can be applied with substantial inter- and intraobserver reliability. The PJI-TNM educational app aims to facilitate application in clinical practice. A major limitation was the correct assessment of the implant situation. To eliminate this, a re-evaluation according to intraoperative findings is strongly recommended. Cite this article: Bone Joint Res 2024;13(1):19–27.

Background: While MRI is the primary diagnostic tool for the diagnosis of spondylodiscitis, the role of [18F]-fluorodeoxyglucose ([18F]FDG) PET/CT is gaining prominence. This study aimed to determine the frequency of [18F]FDG PET/CT usage and its impact on the in-hospital mortality rate in patients with spondylodiscitis, particularly in the geriatric population. Methods: We conducted a Germany-wide cross-sectional study from 2019 to 2021 using an open-access, Germany-wide database, analyzing cases with ICD-10 codes M46.2-, M46.3-, and M46.4- (‘Osteomyelitis of vertebrae’, ‘Infection of intervertebral disc (pyogenic)’, and ‘Discitis unspecified’). Diagnostic modalities were compared for their association with in-hospital mortality, with a focus on [18F]FDG PET/CT. Results: In total, 29,362 hospital admissions from 2019 to 2021 were analyzed. Of these, 60.1% were male and 39.9% were female, and 71.8% of the patients were aged 65 years and above. The overall in-hospital mortality rate was 6.5% for the entire cohort and 8.2% for the geriatric subgroup (p < 0.001). Contrast-enhanced (ce) MRI (48.1%) and native CT (39.4%) of the spine were the most frequently conducted diagnostic modalities. [18F]FDG PET/CT was performed in 2.7% of cases. CeCT was associated with increased in-hospital mortality (OR = 2.03, 95% CI: 1.90–2.17, p < 0.001). Cases with documented [18F]FDG PET/CT showed a lower frequency of in-hospital deaths (OR = 0.58, 95% CI: 0.18–0.50; p = 0.002). This finding was more pronounced in patients aged 65 and above (OR = 0.42, 95% CI: 0.27–0.65, p = 0.001). Conclusions: Despite its infrequent use, [18F]FDG PET/CT was associated with a lower in-hospital mortality rate in patients with spondylodiscitis, particularly in the geriatric cohort. This study is limited by only considering data on hospitalized patients and relying on the assumption of error-free coding. Further research is needed to optimize diagnostic approaches for spondylodiscitis.

BackgroundPyogenic vertebral osteomyelitis (VO) represents a clinical challenge and is linked to substantial morbidity and mortality. This study aimed to examine mortality as well as potential risk factors contributing to in-hospital mortality among patients with VO.MethodsThis retrospective analysis involved patients receiving treatment for VO at University Regensburg in Germany from January 1, 2000, to December 3, 2020. It included in-hospital mortality rate, comorbidities and pathogens. Patients were identified using ICD-10 diagnosis codes: M46.2, M46.3, M46.4, and M46.5. Kaplan–Meier probability plots and odds ratios (OR) for mortality were calculated.ResultsOut of the total cohort of 155 patients with VO, 53 patients (34.1%) died during a mean follow-up time of 87.8 ± 70.8 months. The overall mortality was 17.2% at one year, 19.9% at two years and 28.3% at five years. Patients with congestive heart failure (p = 0.005), renal disease (p

Aims: This work aimed at answering the following research questions: 1) What is the rate of mechanical complications, nonunion and infection for head/neck femoral fractures, intertrochanteric fractures, and subtrochanteric fractures in the elderly USA population? and 2) Which factors influence adverse outcomes? Methods: Proximal femoral fractures occurred between 1 January 2009 and 31 December 2019 were identified from the Medicare Physician Service Records Data Base. The Kaplan-Meier method with Fine and Gray sub-distribution adaptation was used to determine rates for nonunion, infection, and mechanical complications. Semiparametric Cox regression model was applied incorporating 23 measures as covariates to identify risk factors. Results: Union failure occured in 0.89% (95% confidence interval (CI) 0.83 to 0.95) after head/neck fracturs, in 0.92% (95% CI 0.84 to 1.01) after intertrochanteric fracture and in 1.99% (95% CI 1.69 to 2.33) after subtrochanteric fractures within 24 months. A fracture-related infection was more likely to occur after subtrochanteric fractures than after head/neck fractures (1.64% vs 1.59%, hazard ratio (HR) 1.01 (95% CI 0.87 to 1.17); p < 0.001) as well as after intertrochanteric fractures (1.64% vs 1.13%, HR 1.31 (95% CI 1.12 to 1.52); p < 0.001). Anticoagulant use, cerebrovascular disease, a concomitant fracture, diabetes mellitus, hypertension, obesity, open fracture, and rheumatoid disease was identified as risk factors. Mechanical complications after 24 months were most common after head/neck fractures with 3.52% (95% CI 3.41 to 3.64; currently at risk: 48,282). Conclusion: The determination of complication rates for each fracture type can be useful for informed patient-clinician communication. Risk factors for complications could be identified for distinct proximal femur fractures in elderly patients, which are accessible for therapeutical treatment in the management. Cite this article: Bone Jt Open 2023;4(10):801–807.

Background: Late-stage pressure sore (PS) patients are particularly susceptible to osteomyelitis (OM), as bony prominences commonly constitute the focal point of the ulcer. There are lack of data regarding the associated factors and the clinical relevance of this diagnosis in the context of PS treatment. Methods: This retrospective analysis investigated the clinical characteristics, blood markers indicative of infection in PS patients, and development of histologically evident OM. A total of 125 patient were included from 2014 to 2019. The patient records were especially scanned for histological diagnosis of OM. Results: OM was detected in 39% (37/96) of the samples taken during the index procedure. OM prevalence increased to 56% (43/77) at the second and 70% (41/59) at the third debridement. Therefore, the diagnosis of OM was acquired during treatment in 35 cases. Patients diagnosed with initial OM presented significantly higher blood markers, indicative of infection upon admission. Only patients with consistent OM (three positive biopsies) showed higher flap revision rates. Conclusion: This study found no compelling evidence linking OM to worse clinical outcomes in PS patients. In the absence of elevated inflammatory markers, reducing bone biopsy frequency and adopting a less aggressive bone debridement approach may help prevent OM in PS patients.

Prosthetic joint infections (PJIs) can have disastrous consequences for patient health, including removal of the device, and placement of cemented implants is often required during surgery to eradicate PJIs. In translational research, in vivo models are widely used to assess the biocompatibility and antimicrobial efficacy of antimicrobial coatings and compounds. Here, we aim to utilize Galleria mellonella implant infection models to assess the antimicrobial activity of antibiotic-loaded bone cement (ALBC) implants. Therefore, we used commercially available bone cement loaded with either gentamicin alone (PALACOS R+G) or with a combination of gentamicin and vancomycin (COPAL G+V), compared to bone cement without antibiotics (PALACOS R). Firstly, the in vitro antimicrobial activity of ALBC was determined against Staphylococcus aureus. Next, the efficacy of ALBC implants was analyzed in both the G. mellonella hematogenous and early-stage biofilm implant infection model, by monitoring the survival of larvae over time. After 24 h, the number of bacteria on the implant surface and in the tissue was determined. Larvae receiving dual-loaded COPAL G+V implants showed higher survival rates compared to implants loaded with only gentamicin (PALACOS R+G) and the control implants without antibiotics (PALACOS R). In conclusion, G. mellonella larvae infection models with antibiotic-loaded bone cements are an excellent option to study (novel) antimicrobial approaches.

Abstract Proximal femoral fractures are a serious complication, especially for elderly patients. Detailed epidemiological analyzes provide a valuable resource for stakeholders in the health care system in order to foresee future development possibly influenceable by adaption of therapeutic procedures and prevention strategies. This work aimed at answering the following research questions: (1) What are the incidence rates of proximal femoral fractures in the elderly U.S. population? (2) What is the preferred treatment procedure for these fractures? Proximal femoral fractures occurred between January 1, 2009 and December 31, 2019 in patients ≥ 65 years were identified from the Medicare Physician Service Records Data Base. The 5% sample of Medicare beneficiaries, equivalent to the records from approximately 2.5 million enrollees formed the basis of this study. Fractures were grouped into head/neck, intertrochanteric, and subtrochanteric fractures. The overall incidence rate, age and sex specific incidence rates as well as incidence rate ratios were calculated. Common Procedural Terminology (CPT) codes were used to identify procedures and operations. In 2019, a total number of 7982 femoral head/neck fractures was recorded. In comparison to 9588 cases in 2009, the incidence substantially decreased by 26.6% from 666.7/100,000 inhabitants to 489.3/100,000 inhabitants (z = − 5.197, p

Abstract Background Indications for total hip arthroplasties (THA) differ from primary osteoarthritis (OA), which allows elective surgery through femoral neck fractures (FNF), which require timely surgical care. The aim of this investigation was to compare mortality and revisions in THA for primary OA and FNF. Methods Data collection for this study was performed using the German Arthroplasty Registry (EPRD) with analysis THA for the treatment of FNF and OA. Cases were matched 1:1 according to age, sex, body mass index (BMI), cementation, and the Elixhauser score using Mahalanobis distance matching. Results Overall 43,436 cases of THA for the treatment of OA and FNF were analyzed in this study. Mortality was significantly increased in FNF, with 12.6% after 1 year and 36.5% after 5 years compared with 3.0% and 18.7% in OA, respectively (p

Aims: The aim of this investigation was to compare risk of infection in both cemented and uncemented hemiarthroplasty (HA) as well as in total hip arthroplasty (THA) following femoral neck fracture. Methods: Data collection was performed using the German Arthroplasty Registry (EPRD). In HA and THA following femoral neck fracture, fixation method was divided into cemented and uncemented prostheses and paired according to age, sex, BMI, and the Elixhauser Comorbidity Index using Mahalanobis distance matching. Results: Overall in 13,612 cases of intracapsular femoral neck fracture, 9,110 (66.9%) HAs and 4,502 (33.1%) THAs were analyzed. Infection rate in HA was significantly reduced in cases with use of antibiotic-loaded cement compared with uncemented fixated prosthesis (p = 0.013). In patients with THA no statistical difference between cemented and uncemented prosthesis was registered, however after one year 2.4% of infections were detected in uncemented and 2.1% in cemented THA. In the subpopulation of HA after one year, 1.9% of infections were registered in cemented and 2.8% in uncemented HA. BMI (p = 0.001) and Elixhauser Comorbidity Index (p < 0.003) were identified as risk factors of periprosthetic joint infection (PJI), while in THA cemented prosthesis also demonstrated an increased risk within the first 30 days (hazard ratio (HR) = 2.73; p = 0.010). Conclusion: The rate of infection after intracapsular femoral neck fracture was statistically significantly reduced in patients treated by antibiotic-loaded cemented HA. Particularly for patients with multiple risk factors for the development of a PJI, the usage of antibiotic-loaded bone cement seems to be a reasonable procedure for prevention of infection. Cite this article: Bone Joint Res 2023;12(5):331–338.

Abstract The aim of this cross-sectional study was to present the nationwide rates of hospitalized patients with vertebral fractures over one decade and to comprehensively analyze the treatment characteristics and direct costs incurred in 2019. Therefore, the trends in the incidence rate were quantified based on annual ICD-10 diagnosis codes from all German medical facilities between 2009 and 2019, provided by the Federal Statistical Office (Destatis). The ICD-10 Codes “S12.0-2; S22.0-; S32.0-, and S32.1-2” were evaluated. The relative change from 2009 through 2019 was determined. Using data from the Institute for Hospital Remuneration Systems (InEK) for 2019 the secondary diagnoses, OPS-codes, intensive care unit (ICU) treatment, in-hospital mortality, the proportion of G-DRGs and cumulative costs were evaluated. The documented number of vertebral fractures increased by 45.6% between 2009 and 2019 to an incidence of 150.7 per 100,000 inhabitants. The lumbar spine was most commonly affected with an incidence of 70.5/100,000 inhabitants in 2019 (46.8% of all vertebral fractures). The highest increases were seen in the numbers of subaxial cervical fractures (+ 121.2%) and sacral fractures (+ 306.6%). Of all vertebral fractures in 2019, 63.7% were diagnosed in women and 69.0% in patients aged 70 years or older. Osteoporosis was documented in 17.9% of cases as a concomitant diagnosis. In 10.1% of all cases, an ICU treatment was documented. The in-hospital mortality was 2.0% in 2019. I68D was the most frequently used G-DRG code, accounting for 33.3% of cases. The total direct costs for inpatient treatment in 2019 amounted to €589,205,715. The evaluation of 955,091 vertebral fractures showed a sharp increase in the nation-wide incidence rate. The presented age and sex distribution, the comorbidity profile and the in-hospital mortality rate indicate the importance of comprehensive geriatric assessment and emphasize the need for spinal care centers to be established.

Abstract Proximal femoral fractures are a serious complication, especially for elderly patients. Therefore, we have aimed to answer the following research question: What is the postfracture mortality rate in the elderly population and what are associated risk factors? For this, proximal femoral fractures that occurred between 1 January 2009 and 31 December 2019 were identified from the Medicare Physician Service Records database. The Kaplan–Meier (KM) method with the Fine and Gray subdistribution adaptation was used to determine rates of mortality. A semiparametric Cox regression model was applied, incorporating 23 measures as covariates to identify risk factors. The estimated 1 year mortality rate was 26.8% after head/neck fracture, 28.2% after intertrochanteric fracture, and 24.2% after subtrochanteric fracture. Male sex, age over 70 years, chronic obstructive pulmonary disease (COPD), cerebrovascular disease, chronic kidney disease, a concomitant fracture, congestive heart failure, diabetes mellitus, hypertension, insulin use, ischemic heart disease, morbid obesity, osteoporosis, tobacco dependence, and median household income were determined as risk factors for increased mortality. An early assessment of individual risk factors accessible for therapeutic treatment is crucial in the management of proximal femur fractures to aid in attempts at reducing the high mortality apparent in the elderly US population.

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Abstract Background Femoral neck fractures (FNF) are among the most common fractures in Germany and are often treated by hemiarthroplasty (HA). The aim of this study was to compare the occurrence of aseptic revisions after cemented and uncemented HA for the treatment of FNF. Secondly, the rate of pulmonary embolism was investigated. Methods Data collection for this study was performed using the German Arthroplasty Registry (EPRD). HAs after FNF were divided into subgroups stratified by stem fixation (cemented vs uncemented) and paired according to age, sex, BMI, and the Elixhauser score using Mahalanobis distance matching. Results Examination of 18,180 matched cases showed a significantly increased rate of aseptic revisions in uncemented HA (p

Abstract Osteoarthritis is a degenerative joint disease associated with pain, loss of function and reduced quality of life. Concomitant psychological disorders can significantly influence treatment outcomes. Therefore, we aimed to answer the following research questions: (1) How has the incidence of primary coxarthrosis and gonarthrosis developed over the last decade? (2) How high is the prevalence of osteoarthritis patients with concomitant psychological diagnoses? (3) Which psychological comorbidities are most prevalent in coxarthrosis and gonarthrosis patients, respectively? For this cross-sectional study, a dataset provided by the Federal Statistical Office (Destatis) consisting of annual, Germany-wide ICD-10 diagnosis codes from 2009 to 2019 was analysed. Incidences of the codes “M16.1” and “M17.1”, unilateral primary coxarthrosis and unilateral primary gonarthrosis, were quantified. Prevalence rates of secondary diagnoses of the chapter F of the ICD-10 were determined. Incidences were 230.7/100,000 inhabitants for coxarthrosis and 224.2/100,000 inhabitants for gonarthrosis. Patients with psychological comorbidities constituted 9.0% of coxarthrosis cases and 8.9% of gonarthrosis cases, respectively. Between 2009 through 2019, the proportion of patients with a concomitant “F” diagnoses of the ICD-10 increased by + 37.8% for coxarthrosis and by 17.9% for gonarthrosis. The most prevalent secondary diagnoses were affective disorders (F3), whereby numbers increased over the years. Increasing psychological comorbidities advocate for the implementation of screening tools, prevention strategies, interdisciplinary approaches and psychological support in the treatment of osteoarthritis.

Aims: The optimal choice of management for proximal humerus fractures (PHFs) has been increasingly discussed in the literature, and this work aimed to answer the following questions: 1) what are the incidence rates of PHF in the geriatric population in the USA; 2) what is the mortality rate after PHF in the elderly population, specifically for distinct treatment procedures; and 3) what factors influence the mortality rate? Methods: PHFs occurring between 1 January 2009 and 31 December 2019 were identified from the Medicare physician service records. Incidence rates were determined, mortality rates were calculated, and semiparametric Cox regression was applied, incorporating 23 demographic, clinical, and socioeconomic covariates, to compare the mortality risk between treatments. Results: From 2009 to 2019, the incidence decreased by 11.85% from 300.4 cases/100,000 enrollees to 266.3 cases/100,000 enrollees, although this was not statistically significant (z = -1.47, p = 0.142). In comparison to matched Medicare patients without a PHF, but of the same five-year age group and sex, a mean survival difference of -17.3% was observed. The one-year mortality rate was higher after nonoperative treatment with 16.4% compared to surgical treatment with 9.3% (hazard ratio (HR) = 1.29, 95% confidence interval (CI) 1.23 to 1.36; p < 0.001) and to shoulder arthroplasty with 7.4% (HR = 1.45, 95% CI 1.33 to 1.58; p < 0.001). Statistically significant mortality risk factors after operative treatment included age older than 75 years, male sex, chronic obstructive pulmonary disease (COPD), cerebrovascular disease, chronic kidney disease, a concomitant fracture, congestive heart failure, and osteoporotic fracture. Conclusion: Mortality risk factors for distinct treatment modes after PHF in elderly patients could be identified, which may guide clinical decision-making. Cite this article: Bone Joint Res 2023;12(2):103–112.

Cellular operators tightly monitor their networks to keep up with the market demand and frequently benchmark their performance against competitors. Typical benchmarking tests compare key performance indicators, quality of service, and quality of experience parameters on the city- and regional levels using user-collected crowdsourced data or drive test measurements. However, time-variant parameters and different user mobility patterns can bias the performance comparison. Designing a measurement sampling strategy that deals with such issues is critical for achieving a valid benchmark. Whether we would like to determine how many tiles of a map have to be measured in drive tests or how many samples we need from crowdsourced data to reach an estimate with the required accuracy, sampling theory can provide us with an answer. Since propagation conditions depend on user mobility and measurement environment, splitting the data set into groups or strata allows us to attain an unbiased estimate with fewer samples, thus allowing for a fair comparison to other mobile network operators with minimum effort measurements. In this work, we characterize the performance of different sampling methods on the simulated data set while investigating specific use cases to reveal scenarios where the stratification method pays off. We further analyze the sampling methods on two real-world crowdsourced data sets from a major Austrian operator. By stratifying the data into meaningful strata, we obtain the required number of areas and measurements in each stratum while remaining under the pre-set estimation error level. To our knowledge, this is the first study on sampling methodologies applied to real-world crowdsourced cellular measurements.

BackgroundIdentifying novel biomarkers that are both specific and sensitive to periprosthetic joint infection (PJI) has the potential to improve diagnostic accuracy and ultimately enhance patient outcomes. Therefore, the aim of this systematic review is to identify and evaluate the effectiveness of novel biomarkers for the diagnosis of PJI.MethodsWe searched the MEDLINE, EMBASE, PubMed, and Cochrane Library databases from January 1, 2018, to September 30, 2022, using the search terms “periprosthetic joint infection,” “prosthetic joint infection,” or “periprosthetic infection” as the diagnosis of interest and the target index, combined with the term “marker.” We excluded articles that mentioned established biomarkers such as CRP, ESR, Interleukin 6, Alpha defensin, PCT (procalcitonin), and LC (leucocyte cell count). We used the MSIS, ICM, or EBJS criteria for PJI as the reference standard during quality assessment.ResultsWe collected 19 studies that analyzed fourteen different novel biomarkers. Proteins were the most commonly analyzed biomarkers (nine studies), followed by molecules (three studies), exosomes (two studies), DNA (two studies), interleukins (one study), and lysosomes (one study). Calprotectin was a frequently analyzed and promising marker. In the scenario where the threshold was set at ≥50-mg/mL, the calprotectin point-of-care (POC) performance showed a high sensitivity of 98.1% and a specificity of 95.7%.ConclusionNone of the analyzed biomarkers demonstrated outstanding performance compared to the established parameters used for standardized treatment based on established PJI definitions. Further studies are needed to determine the benefit and usefulness of implementing new biomarkers in diagnostic PJI settings.

IntroductionFracture-related infection is a devastating complication confronting the patient with several challenges. To improve the management and to enhance the patients’ wellbeing the focus of this study was to understand the emotional impact and patients’ experiences during the process to identify challenges, difficulties, and resources. For this, a qualitative content analysis of semi-structured interviews according to Graneheim and Lundman was performed.MethodsIn total n = 20 patients of a German university orthopedic trauma centre specialized in bone and joint infections were recruited using a purposive sampling strategy. The patients were treated at the hospital between 2019 and 2021 and underwent at least one surgery. Individual in-person interviews were performed by one researcher based on a semi-structured guide, which was previously conceptualized. Content analysis according to Graneheim and Lundman was performed on the transcripts by two of the researchers independently.ResultsThe following major themes emerged: (i) the emotional and mental aspects highlighting the fact that FRI patients faced severe restrictions in their day-to-day life, which resulted in dependency on others and frustration, as well as future concerns showing that patients could not overcome a state of anxiety and fear even after successful treatment, (ii) socioeconomic consequences confronting patients with consequences on the job and in finances where they often feel helpless, and (iii) resources emphasizing the role of spirituality as a coping strategy and yoga exercises for keeping the positivity.ConclusionThis study emphasized the challenge of fracture-related infection management and associated consequences from the patients’ perspective. Not being well informed about possible negative outcomes or restrictions makes it harder for patients to accept the situation and patients expressed a need for better information and certainty. Also, patients developed constant anxiety and other psychological disturbances, highlighting the potential benefit of psychological support and patient-peer support to exchange experiences.

Providing simultaneously autotrophic and heterotrophic carbon sources is a promising strategy to overcome the limits of autotrophic syngas fermentations. D-xylose and L-arabinose are particularly interesting as they can be obtained by the hydrolysis of lignocellulosic biomass. The individual conversion of varying initial concentrations of these pentoses and D-fructose as reference was studied with C. autoethanogenum in fully controlled stirred-tank reactors with a continuous syngas supply. All mixotrophic batch processes showed increased biomass and product formation compared to an autotrophic reference process. Simultaneous CO and D-xylose or L-arabinose conversion was observed in contrast to D-fructose. In the mixotrophic batch processes with L-arabinose or D-xylose, the simultaneous CO and sugar conversion resulted in high final alcohol-to-acid ratios of up to 58 g g−1. L-arabinose was superior as a mixotrophic carbon source because biomass and alcohol concentrations (ethanol and 2,3-butanediol) were highest, and significant amounts of meso-2,3-butanediol (>1 g L−1) in addition to D-2,3-butanediol (>2 g L−1) were solely produced with L-arabinose. Furthermore, C. autoethanogenum could not produce meso-2,3 butanediol under purely heterotrophic conditions. The mixotrophic production of meso-2,3-butanediol from L-arabinose and syngas, both available from residual lignocellulosic biomass, is very promising for use as a monomer for bio-based polyurethanes or as an antiseptic agent.

AimsThis observational cross-sectional study aimed to answer the following questions: 1) how has nonunion incidence developed from 2009 to 2019 in a nationwide cohort; 2) what is the age and sex distribution of nonunions for distinct anatomical nonunion localizations; and 3) how high were the costs for surgical nonunion treatment in a level 1 trauma centre in Germany?MethodsData consisting of annual International Classification of Diseases (ICD)-10 diagnosis codes from German medical institutions from 2009 to 2019, provided by the Federal Statistical Office of Germany (Destatis), were analyzed. Nonunion incidence was calculated for anatomical localization, sex, and age groups. Incidence rate ratios (IRRs) were determined and compared with a two-sample z-test. Diagnosis-related group (DRG)-reimbursement and length of hospital stay were retrospectively retrieved for each anatomical localization, considering 210 patients.ResultsIn 2019, a total of 11,840 nonunion cases (17.4/100,000 inhabitants) were treated. In comparison to 2018, the incidence of nonunion increased by 3% (IRR 1.03, 95% confidence interval (CI) 0.53 to 1.99, p = 0.935). The incidence was higher for male cases (IRR female/male: 0.79, 95% CI 0.76 to 0.82, p = 0.484). Most nonunions occurred at the pelvic and hip region (3.6/100,000 inhabitants, 95% CI 3.5 to 3.8), followed by the ankle and foot as well as the hand (2.9/100,000 inhabitants each). Mean estimated DRG reimbursement for in-hospital treatment of nonunions was highest for nonunions at the pelvic and hip region (€8,319 (SD 2,410), p < 0.001).ConclusionDespite attempts to improve fracture treatment in recent years, nonunions remain a problem for orthopaedic and trauma surgery, with a stable incidence throughout the last decade.Cite this article: Bone Joint Res 2022;11(8):541–547.

Abstract Background Periprosthetic joint infection represents a major complication in orthopaedics and trauma surgery. For an ideal management approach, it is important to understand the distinct challenges for all persons involved in the treatment. Therefore, it was aimed at investigating (1) the impact of periprosthetic joint infection (PJI) on the well-being of nursing staff to (2) identify challenges, which could be improved facilitating the management of PJI. Methods This is a qualitative interview study. In total, 20 nurses of a German university orthopedic trauma center specialized on infectious complications were recruited using a purposive sampling strategy. Content analysis was performed on transcripts of individual in-person interviews conducted between March 2021 and June 2021. Results Three major themes could be extracted including (i) feelings associated with the management of PJI and the need for emotional support, illustrating the negative emotional impact on nurses, whereby receiving collegial support was perceived as an important coping strategy, (ii) patients’ psychological burden, highlighting the nurses’ lack of time to address mental issues adequately and, (iii) realization of the severity of PJI and compliance problems. Conclusion Identified facilitating factors for PJI management include strengthening of mental care in the treatment of PJI, providing opportunities for exchange among multidisciplinary team members and implementing compliance-enhancing strategies. The findings of this study can be beneficial for improving professionals’ satisfaction, optimising the work environment, creating organizational structures which enhance opportunities for exchange and preventing mental health issues among the nursing team.

Harvesting of tricortical bone graft from the iliac crest is an integral part of bone defect reconstruction in orthopaedic surgery. There are several options for filling the iliac crest defect area to avoid hematoma, pain, hernias and cosmetic issues, including different gelatin-based and other alternative biomaterials. Recently, a novel rattan-wood based not-sintered hydroxyapatite and beta-tricalcium phosphate material (b.Bone™, GreenBone ORTHO S.p.A Faenza, Italy) was shown to promote bone healing in an experimental setting. The goal of the current work is to report clinical and radiographical outcomes of a consecutive case series of 9 patients with defect filling at the iliac crest with this novel scaffold biomaterial after tricortical bone graft harvesting with a minimum follow-up of 6 months. All 9 patients (8 male, 1 female) with an average age of 42.7 years (range: 18–76 years) had tricortical bone graft harvesting from the iliac crest for different reconstructive procedures at the extremities and received blocks of the biomaterial with an average size of 26.3 × 16.8 × 10 mm (length, height, width; range: 15 × 15 × 10 to 40 × 20 × 10 mm). Intraoperative handling of the biomaterial was easy and the blocks could be customized to the individual size of the defect with standard surgical instruments and were press-fitted into the defect. All 9 patients showed uneventful wound healing at the iliac crest and 7 patients reported no pain (VAS: 0) and two patients only mild pain (VAS:1 and VAS:3) after an average follow-up of 9.8 months (range: 6–16 months). There was no post-operative hematoma, surgical revision or other implant-related complications at the iliac crest. In all patients, good radiographical integration without dislocation of the implant and good bony integration was observed. The use of this novel biomaterial for iliac crest defect filling was associated with good clinical and radiographical outcomes after an average follow-up of 9.8 months.

Aims: Bone regeneration during treatment of staphylococcal bone infection is challenging due to the ability of Staphylococcus aureus to invade and persist within osteoblasts. Here, we sought to determine whether the metabolic and extracellular organic matrix formation and mineralization ability of S. aureus-infected human osteoblasts can be restored after rifampicin (RMP) therapy. Methods: The human osteoblast-like Saos-2 cells infected with S. aureus EDCC 5055 strain and treated with 8 µg/ml RMP underwent osteogenic stimulation for up to 21 days. Test groups were Saos-2 cells + S. aureus and Saos-2 cells + S. aureus + 8 µg/ml RMP, and control groups were uninfected untreated Saos-2 cells and uninfected Saos-2 cells + 8 µg/ml RMP. Results: The S. aureus-infected osteoblasts showed a significant number of intracellular bacteria colonies and an unusual higher metabolic activity (p < 0.005) compared to uninfected osteoblasts. Treatment with 8 µg/ml RMP significantly eradicated intracellular bacteria and the metabolic activity was comparable to uninfected groups. The RMP-treated infected osteoblasts revealed a significantly reduced amount of mineralized extracellular matrix (ECM) at seven days osteogenesis relative to uninfected untreated osteoblasts (p = 0.007). Prolonged osteogenesis and RMP treatment at 21 days significantly improved the ECM mineralization level. Ultrastructural images of the mineralized RMP-treated infected osteoblasts revealed viable osteoblasts and densely distributed calcium crystal deposits within the extracellular organic matrix. The expression levels of prominent bone formation genes were comparable to the RMP-treated uninfected osteoblasts. Conclusion: Intracellular S. aureus infection impaired osteoblast metabolism and function. However, treatment with low dosage of RMP eradicated the intracellular S. aureus, enabling extracellular organic matrix formation and mineralization of osteoblasts at later stage. Cite this article: Bone Joint Res 2022;11(5):327–341.

In urban scenarios, network planning requires awareness of the notoriously complex propagation environment by accounting for blocking, diffraction, and reflection on buildings. To this end, deep learning-based signal-strength prediction directly operating on environmental data has recently gained attention, mainly as a computationally efficient alternative to ray-tracing. Our work combines RSRP measurements from an extensive drive-test campaign in a live 4G network with a 3D city model for the largest real-world assessment of such data-driven schemes to date. We compare three different encodings of the propagation environment and find that a neural network operating on a full 3D representation of the surroundings performs best with an RMSE of $7.06~dB$ . It is followed by a model using only the direct path profile with $7.78~dB$ and a reference neural network utilizing a binary line of sight indicator achieving $8.76~dB$ . The large size of our data set allows us to address several open questions regarding the inner workings of these black box approaches. In particular, we elaborate on different evaluation strategies, highlighting the importance of spatial separation of train and test areas, as the rich environmental data implicitly provides a spatial reference. Through model explainability, we further identify the area along the direct path between the user equipment and the transmitter as the input region with the highest feature importance — questioning the common practice of including large buffer areas. Evaluating the models in scenarios with artificially placed base stations reveals that the measurement campaign offers a sufficient basis for a prototypical network planner. The trained models, which we make publicly available, exhibit the dominant propagation mechanisms in urban areas and generate spatially consistent and physically sound signal-strength maps.

Background: Pin site infection is a frequent complication after external fixation. However, no consensus on the optimal pin site care protocols exists. Objectives: This study aimed at providing an overview of currently applied pin site care protocols and evaluating their efficiency in terms of infection rates. Data Sources: A systematic search of PubMed, Medline, Embase, and Cochrane Library databases was performed. Study eligibility criteria, participants, and interventions: Comparative studies of pin site care protocols reporting the infection rate as complication related to external fixator application as an outcome were eligible for inclusion. Study Appraisal and Synthesis Methods: The ROBINS-I tool was used to assess the risk of bias in nonrandomized studies. The Effective Public Health Practice Project (EPHPP) tool and Coleman Methodology Score were applied for publication quality assessment. Results: A total of 380 manuscripts were screened, yielding an inclusion of 20 articles reporting on 1428 patients. Of these, 17 (85%) studies compared different materials and antimicrobial agents, whereby 9 of these found significant differences. Three studies compared pin site care with no pin site care, and the optimal pin site care frequency was addressed in three studies. None of them reported a statistically significant difference between daily or weekly pin site care. Limitations: Pin site care protocols in the literature are heterogeneous. Conclusions and Implications of Key Findings: No recommendation can be drawn regarding the optimal cleansing solution and dressing type. However, based on this review, a benefit of pin site care compared to no pin site care is suggested. Further, minimal pin care was not associated with significantly worse outcomes, and hence, the need of laborious protocols including frequent cleaning or the use of antimicrobial agents remains questionable.

Although mobile communication has become ubiquitous in our modern society, operators typically treat the underlying networking infrastructure in a secretive manner. However, detailed topology information is a key enabler for operator benchmarking and can serve as ground-truth data for system-level simulations or user equipment localization schemes. Still, existing approaches for base station localization that are either based on received signal strength or on the spatial distribution of measurements are not accurate enough for such use cases. Accordingly, we propose a localization scheme that operates on end-user measurements of the 4G & 5G timing advance parameter, which acts as a quantized distance measure between the user equipment and the base station. By directly incorporating GPS noise, multipath propagation, and quantization into our stochastic system model, we obtain an estimator that offers a reliable measure of confidence and requires only the configuration of two hyperparameters with a dedicated physical interpretation. We evaluate our approach using a set of drive-test measurements consisting of 190 LTE eNodeBs with ground-truth locations confirmed by an Austrian mobile network operator. Our selective estimator can either operate without prior knowledge, resulting in mean distance errors of below 100 m, or in a classification setup, where it correctly identifies up to 95% of eNodeBs from a set of candidate cell tower locations. To allow for reproducibility, we make our dataset and a reference implementation publicly available.

Abstract Background Antibiotic-containing cement and bone graft substitute-coated orthopedic implants provide the advantages of simultaneous local antibiotic delivery and internal stable fixation, aiding in both infection eradication and osseous healing. Standardized protocols pertaining to implant coating techniques in various clinical and particularly intraoperative settings are scarce, and available literature is limited. This systematic review aims to provide a summary of the available current literature reporting on custom-made coating techniques of orthopedic implants, indications, outcomes, and associated complications in clinical use. Methods A systematic search of the literature in PubMed, Medline, Embase, and Cochrane Library databases was performed in accordance with PRISMA guidelines. Articles reporting specifically on custom-made coating techniques of orthopedic implants in a clinical setting were eligible. Results A total of 41 articles with a cumulative total number of 607 cases were included. Indications for treatment mostly involved intramedullary infections after previous plate osteosynthesis or nailing. A variety of implants ranging from intramedullary nails, plates, wires, and rods served as metal cores for coating. Polymethylmethacrylate (PMMA) bone cement was most commonly used, with vancomycin as the most frequently added antibiotic additive. Chest tubes and silicone tubes were most often used to mold. Common complications are cement debonding and breakage of the metallic implant. Conclusion Adequate coating techniques can reduce the burden of treatment and be associated with favorable outcomes. Lack of general consensus and heterogeneity in the reported literature indicate that the perfect all-in-one implant coating method is yet to be found. Further efforts to improve implant coating techniques are warranted. Level of evidence III.

The treatment of open tibia fractures with plate fixation bears a high risk for the development of a fracture-related infection. Here we present a case of an 80-year-old female with a Gustilo-Anderson type II open distal tibial shaft fracture with an indwelling knee prosthesis. The case was successfully treated with a 2-stage procedure with initial external fixation and subsequent open reduction and plate fixation with a custom-made ultrathin silver plasma-coated locking plate. Plate fixation was the preferred method as the indwelling knee prosthesis prevented the use of a standard intramedullary tibia nail. The fracture healed uneventfully without any signs of infections and the patient achieved full weight-bearing with a normal gait and without any pain after three months. Radiographical full bridging of the initial fracture area was seen after 5 months without any signs of infection or fracture healing disturbances. After an overall follow-up of 12 months, there were no signs of silver associated or other adverse events. Thus, ultrathin silver plasma coating seems to be helpful in the treatment open fractures with plate fixation to prevent fracture-related infections.

Abstract Background Unicompartimental knee arthroplasty (UKA) is a promising and increasing application to treat unicompartimental knee osteoarthritis. However, revision arthroplasty numbers after UKA are unknown. Therefore, aim of this study was to determine the nationwide burden of revision after UKA by answering the following questions: (1) How did numbers of revision UKA procedures developed over the last decade as a function of age and gender? (2) How high is the percentage of revision UKA procedures due to infection? (3) Which therapy strategy was chosen for surgical treatment of aseptic revision UKA? Methods Revision arthroplasty rates as a function of age, gender, infection and type of prosthesis were quantified based on Operation and Procedure Classification System codes using revision knee arthroplasty data from 2008 to 2018, provided by the Federal Statistical Office of Germany (Destatis). Results Over the last decade, revision UKA increased by 46.3% up to 3105 procedures in 2018. A trend towards higher numbers in younger patients was observed. Septic interventions constituted 5.7% of all revisions, whereby total procedures increased by 67.1% from 2008 through 2018. The main treatment strategy was an exchange to a bicondylar surface replacement prosthesis, which was done in 63.70% of all cases, followed by exchange to a femoral and tibial shaft-anchored (16.2% of all revisions). Conclusion The increasing number of revision arthroplasty after UKA in Germany, especially in younger patients and due to infection, underlines the need for future efforts to improve treatment strategies beyond UKA to delay primary arthroplasty and avoid periprosthetic joint infection.

Abstract Issues of energy efficiency, latency and reliability have engaged researchers' attention in wireless communications for a long time due to their importance in the dependable delivery of data over wireless networks. The emergence of M2M communication and IoT has intensified this attention because energy efficiency and latency are critical factors affecting their performance. In this paper, a scheduler is designed by utilising the probability density function of the signal‐to‐noise ratio of Rayleigh fading channels to define a threshold used for resource allocation. This threshold, combined with the mean SNR of an M2M device, determines whether or not an M2M device is eligible for scheduling, given its instantaneous channel conditions. The trade‐off between energy efficiency, latency and packet drop of this proposed scheduling strategy is investigated. The performance of the proposed scheduler is compared to round robin, maximum throughput, and proportional fair schedulers. Compared to these standard scheduling strategies, the scheduler provides the advantage of trading off latency for energy efficiency by tuning the threshold parameter.

Introduction Periprosthetic joint infection (PJI) is a devastating complication in orthopaedic and trauma surgery, which puts a high burden on the patients involving recurrent hospitalisation, prolonged courses of antibiotic medication, severe pain and long periods of immobility as well as high levels of psychological distress. Thus, this multicentre study aims at implementing body-oriented psychotherapy in clinical practice and evaluating its therapeutic effect on the quality of life.Methods and analysis A prospective, parallel two-armed randomised controlled trial with approximately n=270 patients with verified PJI treated surgically with a one-staged exchange, or a two-staged exchange will be conducted. Functional relaxation (FR) therapy will be implemented as a group therapy. FR originally belongs to the psychodynamically based body-oriented psychotherapy. Intervention techniques consist of minute movements of small joints, which are performed during relaxed expiration accompanied by an exploration of differences of body feelings. A group will include 3–8 patients, led by a specialist physiotherapist certified in FR once a week. The participants are consecutively admitted to the class and participate in 12 sessions. The control group will consist of patients receiving an unspecific ‘placebo relaxation’ intervention for the same duration. The primary efficacy endpoint is the mental component summary and physical component summary of quality of life assessed by the 36-Item Short Form Health Survey (SF-36) after 6 months. Secondary outcomes include SF-36 scores after 12 months, consumption of pain medication, mobility measured by the Parker mobility score and the physical activity measured by daily steps with an accelerometer (actibelt).Ethics and dissemination Approval from the Ethical Committee of the University Hospital Regensburg was received (file number: 21-2226-101). Written, informed consent to participate will be obtained from all participants. Results will be made available in the form of peer-reviewed publications and presentation in congresses.Trial registration number DRKS00028881; German Clinical Trials Register.

BackgroundAntimicrobial coating of intramedullary nails with polymethyl methacrylate (PMMA) bone cement promises infection control and stabilization for subsequent bone healing. However, when removing the implant, bone cement can debond and remain in the medullary cavity of the long bones, representing a nidus for reinfection. This work presents a technique comprising reinforcement of PMMA-coated intramedullary nails with cerclage wire to prevent such problems in patients treated for fracture-related infection (FRI) or knee periprosthetic joint infection (PJI) with a static spacer as temporary arthrodesis allowing weight-bearing in the implant-free interval. Outcomes of this surgical treatment were evaluated in terms of (i) associated complications and (ii) patient-reported quality of life.MethodsIn this retrospective case series, 20 patients with PJI (n = 14, 70%) and FRI (n = 6, 30%) treated with PMMA-coated intramedullary nails reinforced with cerclage wire between January 2021 and July 2021 were included. Quality of life during the implant-free interval was evaluated with the EQ-5D, SF-36, and an ICD-10 based psychological symptom rating and compared with previously analyzed cohorts of successfully treated PJI and FRI patients in whom eradication of infection and stable bone consolidation was achieved.ResultsComplications during the implant-free interval comprised a broken nail in one case (5.0%) and a reinfection in one case (5.0%). Coating-specific side effects and cement debonding during removal did not occur. The mean physical health component score of SF-36 was 26.1 ± 7.6, and the mean mental health component score reached a value of 47.1 ± 18.6. The mean EQ-5D index value was 0.36 ± 0.32 and the mean EQ-5D visual analogue scale rating was 47.4 ± 19.4. The scores were significantly lower than those in the successfully treated FRI cohort but not in the PJI cohort. The mean ICD-10-based symptom rating scores revealed psychological symptom burden on the depression scale and enhanced levels of anxiety in comparison with healed FRI and PJI patients.ConclusionReinforcement of PMMA bone cement-coated implants seems to be a reasonable treatment option to create a temporary arthrodesis, preventing detachment of the bone cement when the implant was removed.Level of Evidence: IV.

Abstract We aimed to answer the following questions: (1) How did numbers of revision knee arthroplasty procedures develop in Germany over the last decade compared to primary TKA? (2) How high was the percentage of septic interventions in knee prosthesis revisions? (3) Which treatment strategy was chosen for surgical treatment of knee PJI? Revision arthroplasty rates as a function of age, gender, infection and type of prosthesis were quantified based on Operation and Procedure Classification System codes using revision knee arthroplasty data from 2008 to 2018, provided by the Federal Statistical Office of Germany (Destatis). In 2018, a total number 23,812 revision knee arthroplasties were performed in Germany, yielding an overall increase of 20.76% between 2008 and 2018. In comparison, primary TKA procedures increased by 23.8% from 152,551 performed procedures in 2008 to 188,866 procedures in 2018. Hence, 12.6% of knee arthroplasties required a revision in 2018. Septic interventions increased by 51.7% for all revisions. A trend towards higher numbers in younger patients was observed. Compared to 2008, 17.41% less DAIR procedures were performed, whereby single-stage and two- or multi-stage change increased by 38.76% and 42.76% in 2018, respectively. The increasing number of revision knee arthroplasty in Germany, especially in younger patients and due to infection, underlines the need for future efforts to improve treatment strategies to delay primary arthroplasty and avoid periprosthetic joint infection.

Abstract Background The epidemiology of osteomyelitis in Germany is unknown, which makes it difficult to estimate future demands. Therefore, we aimed to analyse how the numbers of cases have developed over the last decade as a function of osteomyelitis subtype, age group, gender, and anatomical localization. Methods Osteomyelitis rates were quantified based on annual ICD-10 diagnosis codes from German medical institutions between 2008 through 2018, provided by the Federal Statistical Office of Germany (Destatis). Results Overall osteomyelitis prevalence increased by 10.44% from 15.5 to 16.7 cases per 100,000 inhabitants between 2008 through 2018. Out of 11,340 cases in 2018, 47.6% were diagnosed as chronic, 33.2% as acute and 19.2% as unspecified osteomyelitis. Men were often affected than women with 63.4% of all cases compared to 36.6%. The largest proportion of patients comprised the age group 60–69 years (22.1%), followed by 70–79 years (21.7%). A trend towards more osteomyelitis diagnoses in older patients was observed. Lower extremities were most frequently infected with 73.8% of all cases in 2018 (+ 10.8% change). Conclusions Osteomyelitis remains a serious problem for orthopedic and trauma surgery. Prevention methods and interdisciplinary approaches are strongly required.

Introduction In the background of the aging population, an increase of geriatric patients with specific age-related co-morbidities has already been seen over the years for proximal femur fractures in orthopaedic surgery as well as other medical disciplines. However, the geriatric aspect has not been well recognized in periprosthetic joint infection (PJI) patients so far. Therefore, this paper seeks to provide an overview on the co-morbidities of PJI patients with respect to the definition of geriatric patients. Material and methods In this single-center retrospective study, patients treated between 2007 and 2020 for PJI were included (n = 255). Patients were defined as geriatric according to the consensus definition criteria of the Federal Working Group of Clinical Geriatric Facilities e.V., the German Society for Geriatrics e.V. and the German Society for Gerontology and Geriatrics e.V. based on age (≤70 years), geriatric multimorbidity and the Barthel index (≤30). Results Applying the criteria defined 184 of the 255 (72.2%) PJI patients as geriatric infection patients. Regarding geriatric comorbidity, incontinence was most prevalent (38.1%), followed by immobility (25.6%). Comparing the geriatric infection patients with those classified as non-geriatric (n = 71 ) revealed that geriatric patients had a longer hospital stay and spent more days in the intensive care unit (ICU). Also, the amputation rate and the 5-year mortality rate was significantly increased (n = 15, 8.2% vs n = 1, 1.4%, P = .007 and n = 24, 13.0% vs n = 5, 7.0%, P = .005). The Barthel index showed a significant correlation with mortality ( r = −.22, P = .011). Discussion We propose to use the term orthogeriatric infection patients in those cases in order to focus treatment not only on the orthopaedic infections but also on the important geriatric aspects. Conclusion The inclusion of geriatric physicians into the multidisciplinary team approach for PJI patients might be beneficial.

Aims: We aimed to evaluate the long-term impact of fracture-related infection (FRI) on patients’ physical health and psychological wellbeing. For this purpose, quality of life after successful surgical treatment of FRIs of long bones was assessed. Methods: A total of 37 patients treated between November 2009 and March 2019, with achieved eradication of infection and stable bone consolidation after long bone FRI, were included. Quality of life was evaluated with the EuroQol five-dimension questionnaire (EQ-5D) and German Short-Form 36 (SF-36) outcome instruments as well as with an International Classification of Diseases of the World Health Organization (ICD)-10 based symptom rating (ISR) and compared to normative data. Results: With a mean follow-up of 4.19 years (SD 2.7) after the last surgery, the mean SF-36 score was 40.1 (SD 14.6) regarding the physical health component and 48.7 (SD 5.1) regarding the mental health component, compared to German normative values of 48.4 (SD 9.2) (p < 0.001) and 50.9 (SD 8.8) (p = 0.143). The mean EQ-5D index reached 0.76 (SD 0.27) with a mean EQ-5D visual analogue scale (VAS) rating of 65.7 (SD 22.7) compared to reference scores of 0.88 (p < 0.001) and 72.9 (p < 0.001). Mean scores of the ISR did not reveal significant psychological symptom burden, while an individual analysis showed moderate to severe impairments in 21.6% (n = 8) of the patients. Conclusion: Even a mean 4.2 years (SD 2.7) after surgically successful treatment of FRI of long bones, patients report significantly lower quality of life in comparison to normative data. Future clinical studies on FRIs should focus on patient-related outcome measures enabling best possible shared treatment decision-making. Prevention methods and interdisciplinary approaches should be implemented to improve the overall quality of life of FRI patients.

Abstract The epidemiology of fracture-related infection (FRI) is unknown, which makes it difficult to estimate future demands and evaluate progress in infection prevention. Therefore, we aimed to determine the nationwide burden’s development over the last decade as a function of age group and gender. FRI prevalence as a function of age group and gender was quantified based on annual ICD-10 diagnosis codes from German medical institutions between 2008 through 2018, provided by the Federal Statistical Office of Germany (Destatis). The prevalence of FRI increased by 0.28 from 8.4 cases per 100,000 inhabitants to 10.7 cases per 100,000 inhabitants between 2008 and 2018. The proportion of fractures resulting in FRI increased from 1.05 to 1.23%. Gender distribution was equal. Patients aged 60–69 years and 70–79 years comprised the largest internal proportion with 20.2% and 20.7%, respectively, whereby prevalence increased with age group. A trend towards more diagnoses in older patients was observed with a growth rate of 0.63 for patients older than 90 years. Increasing rates of fracture-related infection especially in older patients indicate an upcoming challenge for stakeholders in health care systems. Newly emerging treatment strategies, prevention methods and interdisciplinary approaches are strongly required.

Abstract Background Along with emerging open access journals (OAJ) predatory journals increasingly appear. As they harm accurate and good scientific research, we aimed to examine the awareness of predatory journals and open access publishing among orthopaedic and trauma surgeons. Methods In an online survey between August and December 2019 the knowledge on predatory journals and OAJ was tested with a hyperlink made available to the participants via the German Society for Orthopaedics and Trauma Surgery (DGOU) email distributor. Results Three hundred fifty orthopaedic and trauma surgeons participated, of which 291 complete responses (231 males (79.4%), 54 females (18.6%) and 5 N/A (2.0%)) were obtained. 39.9% were aware of predatory journals. However, 21.0% knew about the “Directory of Open Access Journals” (DOAJ) as a register for non-predatory open access journals. The level of profession (e.g. clinic director, consultant) (p = 0.018) influenced the awareness of predatory journals. Interestingly, participants aware of predatory journals had more often been listed as corresponding authors (p

Abstract Background Implant-associated infections depict a major challenge in orthopedics and trauma surgery putting a high burden on the patients and health care systems, strongly requiring improvement of infection prevention and of clinical outcomes. One strategy includes the usage of antimicrobial-coated implants. We evaluated outcomes after surgical treatment using a gentamicin-coated nail on (i) treatment success in terms of bone consolidation, (ii) absence of infection, and (iii) patient-reported quality of life in a patient cohort with high risk of infection/reinfection and treatment failure. Methods Thirteen patients with open tibia fractures (n = 4), non-unions (n = 2), and fracture-related infection (n = 7) treated with a gentamicin-coated intramedullary nail (ETN ProtectTM) were retrospectively reviewed. Quality of life was evaluated with the EQ-5D, SF-36, and with an ICD-10-based symptom rating (ISR). Results At a mean follow-up of 2.8 years, 11 of the 13 patients (84.6%) achieved bone consolidation without any additional surgical intervention, whereas two patients required a revision surgery due to infection and removal of the implant. No specific implant-related side effects were noted. Quality of life scores were significantly lower compared to a German age-matched reference population. The mean ISR scores revealed mild psychological symptom burden on the scale depression. Conclusion The use of a gentamicin-coated intramedullary nail seems to be reasonable in open fractures and revision surgery for aseptic non-union or established fracture-related infection to avoid infection complications and to achieve bony union. Despite successful treatment of challenging cases with the gentamicin-treated implant, significantly reduced quality of life after treatment underlines the need of further efforts to improve surgical treatment strategies and psychological support.

Abstract Unicompartimental and total knee arthroplasty is one of the most successful and most performed operations worldwide. In the last years the number of primary knee arthroplasty increased constantly. The aim of this study is to analyze the rising numbers of primary knee arthroplasty and to see how it is used in Germany. In this retrospective study data, provided by the Federal Statistical Office of Germany from 2008 to 2018 was analyzed, using operation codes from the German procedure classification system and characteristics like age, sex and type of the prosthesis. We found a slight increase of unicompartimental and total knee arthroplasty over the investigated 10 years from 150.504 in 2008 up to 168.479 procedures in 2018, with a maximum of 169.334 in 2017. Most patients were female and over 65 years old. Interestingly, there was an obvious decrease of regular TKA in the year 2013, with a relevant impact on the total number of procedures. In the following years the number rised again reaching the former level in 2015 and is still increasing. The highest increase was found in partial knee arthroplasty, with a constant rise every year, starting with 7988 in 2008 up to 21.072 in 2018. In contrast, we found a relevant reduction of constrained prosthesis in primary TKA, whereas the number of semi-constrained prosthesis in primary TKA is again rising after a decrease in 2015. We found that the number of bicondylar TKA and especially UKA increased from 2008 to 2018. Regarding an aging population, we can expect a rising number for Primary knee arthroplasty and in consequence a rising number of revision arthroplasty in the future. This will be a challenging cost factor for the healthcare system in Germany.

Angiogenesis is the process of new blood vessels growing from existing vasculature. Visualizing them as a three-dimensional (3D) model is a challenging, yet relevant, task as it would be of great help to researchers, pathologists, and medical doctors. A branching analysis on the 3D model would further facilitate research and diagnostic purposes. In this paper, a pipeline of vision algorithms is elaborated to visualize and analyze blood vessels in 3D from formalin-fixed paraffin-embedded (FFPE) granulation tissue sections with two different staining methods. First, a U-net neural network is used to segment blood vessels from the tissues. Second, image registration is used to align the consecutive images. Coarse registration using an image-intensity optimization technique, followed by finetuning using a neural network based on Spatial Transformers, results in an excellent alignment of images. Lastly, the corresponding segmented masks depicting the blood vessels are aligned and interpolated using the results of the image registration, resulting in a visualized 3D model. Additionally, a skeletonization algorithm is used to analyze the branching characteristics of the 3D vascular model. In summary, computer vision and deep learning is used to reconstruct, visualize and analyze a 3D vascular model from a set of parallel tissue samples. Our technique opens innovative perspectives in the pathophysiological understanding of vascular morphogenesis under different pathophysiological conditions and its potential diagnostic role.

Background: Antibiotic-loaded bone cement in arthroplasties is currently experiencing increased usage. Therefore, single and double antibiotic-loaded bone cements are commercially available and used in orthopedic surgery. The aim of this investigation was to compare the clinical use of single compared to dual antibiotic-loaded bone cement for implant fixation after femoral neck fracture. Further infection rates were to be compared in (partial) arthroplasty for the treatment of femoral neck fracture for both treatment options. Methods: On the basis of the German Arthroplasty Registry (EPRD), all cases of femoral neck fracture treated with hemiarthroplasty (HA), or total hip arthroplasty (THA) with single and dual antibiotic-loaded bone cement, were included into the data analysis. The infection risk was compared using Kaplan-Meier estimates. Results: In total, 26,845 cases (HA 76.3%–THA: 23.7%) with femoral neck fracture were included. Within recent years, an increasing usage of dual antibiotic-loaded cement in Germany, with a current proportion of 7.30% in arthroplasty procedures for femoral neck fracture treatment, has been observed. In patients treated with HA, the proportion of dual antibiotic-loaded cement was 7.86%, while in those treated with THA, 5.46% of all prostheses were fixated with a two antibiotic component cement. For all arthroplasty procedures using single antibiotic-loaded bone cement after six months 1.8%, after one year 1.9%, and after five years 2.3%, of the cases failed due to periprosthetic joint infection (PJI), while in the same time period, in cases with dual antibiotic-loaded bone cement 1.5%, 1.5% and 1.5% suffered from infection (p = 0.34). A infection rate of 1.1% after HA with dual antibiotic-loaded bone cement was reported, compared to a 2.1% infection rate whilst using single antibiotic-loaded bone cement after five years (p = 0.098). The number required for treatment when using HA was 91. Conclusions: The use of dual antibiotic-loaded bone cement is increasingly used in arthroplasty procedures after femoral neck fractures. It demonstrates a reduction of PJI after HA and seems, therefore, to be a useful method for the prevention of infection, especially in patients with increased risk factors for PJI.

Osteomyelitis is a difficult-to-treat disease with high chronification rates. First studies suggest increases in mitochondrial fission and mitochondrial dysfunction as possible contributors to the accumulation of intracellular reactive oxygen species and thereby to the cell death of infected bone cells. The aim of the present study is to analyze the ultrastructural impact of bacterial infection on osteocytic and osteoblastic mitochondria. Human infected bone tissue samples were visualized via light microscopy and transmission electron microscopy. Osteoblasts, osteocytes and their mitochondria were analyzed histomorphometrically and compared with the control group of noninfectious human bone tissue samples. The results depicted swollen hydropic mitochondria including depleted cristae and a decrease in matrix density in the infected samples. Furthermore, perinuclear clustering of mitochondria could also be observed regularly. Additionally, increases in relative mitochondrial area and number were found as a correlate for increased mitochondrial fission. In conclusion, mitochondrial morphology is altered during osteomyelitis in a comparable way to mitochondria from hypoxic tissues. This gives new perspectives on the treatment strategies since the manipulation of mitochondrial dynamics may improve bone cell survival as a potential new target for the therapy of osteomyelitis.