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Purpose: The aim of this study was to demonstrate, whether the degree of limb alignment correction in varus knee osteoarthritis correlated with an increase in ankle symptoms and to define a cut-off value concerning the degree of correction above which to expect ankle problems.Methods: Ninety-nine consecutive patients with preoperative intraarticular varus knee deformities who underwent total knee arthroplasty were retrospectively analyzed. Patients were examined clinically (Knee Society Score, Forgotten Joint Score, Foot Function Index, Range of Motion of the knee and ankle joint, pain scales) as well as radiologically. The mean follow-up time was 57 months.Results: The degree of operative limb alignment correction strongly correlated with the Foot Function Index (R = 0.91, p < 0.05). Given this, higher degrees of knee malalignment corrections were associated with worse postoperative outcomes in the knee and ankle joint-despite postoperative improved joint line orientations. Subsequently, a cut-off value for arthritic varus deformities (14.5°) could be calculated, above which the prevalence of ankle symptoms increased manifold [OR = 15.6 (3.2-77.2 95% CI p < 0.05)]. Furthermore, ROM restrictions in the subtalar joint were associated with a worse outcome in the ankle joint.Conclusions: When correcting excessive intraarticular varus knee osteoarthritis, surgeons have to be aware of possible postoperative ankle symptoms and should consider ankle deformities or decreased subtalar ROM before operative procedures.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Varus or valgus deformities in knee osteoarthritis may have a crucial impact on ankle subtalar range of motion (ROM) and ligamentous stability. The purpose of this study was to assess whether the grade of ankle eversion and inversion rotation stability was influenced by frontal deformities of the knee joint. Methods: Patients who were planned to undergo total knee arthroplasty (TKA) were prospectively included in this study. Patients were examined radiologically (mechanical tibiofemoral angle (mTFA), hindfoot alignment view angle (HAVA), anterior distal tibia angle (ADTA)) and clinically (ROM of the knee and ankle joint, foot function index, knee osteoarthritis outcome score). Ankle stability was assessed using an ankle arthrometer (AA) to test inversion/eversion (ie) rotation and anterior/posterior (ap) displacement stability of the ankle joint. Correlations were calculated using Pearson's coefficient, and differences between two independent groups of nonparametric data were calculated using a two-sided Wilcoxon signed rank test. Results: Eighty-two (varus n = 52, valgus n = 30) patients were included. The preoperative mTFA significantly correlated with the HAVA (Pearson's correlation = − 0.72, p < 0.001). Laxity testing of the ankle demonstrated that in both varus and valgus knee osteoarthritis, higher grades of mTFA did not correlate with the inversion or eversion capacity of the ankle joint. The ADTA significantly correlated with the posterior displacement of the ankle joint (cor = 0.24, p = 0.049). Conclusions: This study could not confirm that higher degrees of frontal knee deformities in osteoarthritis were associated with increasing grades of ligamentous ankle instabilities or a reduced ROM of the subtalar joint. Level of evidence: II. [ABSTRACT FROM AUTHOR]

Introduction: Regional health care networks with interfaces between clinics, general practitioners and patients can act faster when utilizing digital measures. This manuscript describes the establishment of an online video consultation service in a clinic and its broad health care region to exemplify challenges and solutions for potential future approaches from a management perspective.Method: The underlying pilot project was planned and implemented for follow-up monitoring and consultative presentation of orthopedic and trauma patients within the Bundeswehr Medical Service from 2018 to 2020. With predominantly positive evaluation results regarding quality and acceptance among users, this research investigated organizational and processual aspects including total quality management, strategic control and change management approaches.Results: The affected main and subprocesses of patient treatment could be streamlined by the project, as physician recommendations and arrangements could be accelerated and patient travel could be significantly reduced. A SWOT and portfolio analysis showed a high potential for improving existing patient treatment processes for health care enterprises via the use of digital technology. The involved staff should be strategically included at an early stage and continuously involved. By means of a PDCA cycle, the processes of the given project could be exemplarily illustrated with an outlook in the future.Discussion: It has proven successful to consciously use management approaches to establish telemedical integrated care structures in a health region. Recommendations for the strategic introduction of an online video consultation for regional network strengthening and care development for a patient-oriented increase in efficiency could be compiled. [ABSTRACT FROM AUTHOR]

Background: Video consultations have proven to be an efficient source of support for patient-doctor interactions and have become increasingly used in orthopedics, especially during the COVID-19 pandemic. This study analyzed both patients' and doctors' acceptance of an orthopedic telemedical consultation (OTC) and compared the results of OTC examinations to the results of live consultation (LC) to identify discrepancies.Methods: The study was carried out in an orthopedic department of a German hospital between 2019 and 2020. After written informed consent was obtained, patients voluntarily presented for follow-up by OTC and LC. The experience with and attitudes toward OTC among both patients and doctors was evaluated (using Likert scale-scored and open questions, 26 to 28 items). The results of the OTC and LC examinations were compared using a 12-item checklist. The data were analyzed by quantitative and qualitative statistics.Results: A total of 53 patients were included, each of whom completed an OTC and an LC. The OTC was rated as pleasant, and the experience was rated as very satisfying (average rating on a 5-point Likert scale, with 1 indicating strong agreement: doctors: 1.2; patients: 1.3). Various technical and organizational challenges were identified. Compared to LC, OTC showed no significant differences in patient history or in inspection, palpation, or active range of motion results. Only for the functional or passive joint assessment did LC show significantly higher suitability (p < 0.05) than OTC. Recommendations for further procedures did not differ significantly between OTC and LC.Conclusions: Because of the high acceptance and the objective benefits of OTC and the similarity of clinical results with LC, OTC is recommendable for orthopedic follow-up examinations. To better assess joint functionality, meaningful digital alternatives for established examination methods should be further investigated. [ABSTRACT FROM AUTHOR]

Introduction: Leptin is a pleiotropic hormone that regulates food intake and energy homeostasis with enigmatic effects on bone development. It is unclear if leptin promotes or inhibits bone growth. The aim of this study was to characterize the micro-architecture and mechanical competence of femur bones of leptin-deficient mice., Materials and Methods: Right femur bones of 15-week old C57BL/6 (n = 9) and leptin-deficient (ob/ob, n = 9) mice were analyzed. Whole bones were scanned using micro-CT and morphometric parameters of the cortex and trabeculae were assessed. Elastic moduli were determined from microindentations in midshaft cross-sections. Mineral densities were determined using quantitative backscatter scanning electron microscopy. 3D models of the distal femur metaphysis, cleared from trabecular bone, were meshed and used for finite element simulations of axial loading to identify straining differences between ob/ob and C57BL/6 controls., Results: Compared with C57BL/6 controls, ob/ob mice had significantly shorter bones. ob/ob mice showed significantly increased cancellous bone volume and trabecular thickness. qBEI quantified a ∼7% lower mineral density in ob/ob mice in the distal femur metaphysis. Indentation demonstrated a significantly reduced Young's modulus of 12.14 [9.67, 16.56 IQR] GPa for ob/ob mice compared to 23.12 [20.70, 26.57 IQR] GPa in C57BL/6 mice. FEA revealed greater deformation of cortical bone in ob/ob as compared to C57BL/6 mice., Conclusion: Leptin deficient ob/ob mice have a softer cortical bone in the distal femur metaphysis but an excessive amount of cancellous bone, possibly as a response to increased deformation of the bones during axial loading. Both FEA and direct X-ray and electron microscopy imaging suggest that the morphology and micro-architecture of ob/ob mice have inferior biomechanical properties suggestive of a reduced mechanical competence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Intrawound application of vancomycin is becoming increasingly controversial for the prevention of surgical site infection (SSI). As children undergoing spinal fusion for secondary scoliosis are at high risk for SSIs, evidence regarding the impact of intraoperative vancomycin installation on SSI rates in these patients is of utmost importance. Methodology: A single surgeon cohort of patients under 18 years of age undergoing surgery for secondary scoliosis in 2017 was analyzed with regard to the development of SSIs requiring surgical revision and adverse events. Use of vancomycin was restricted to cases with higher risk of infection. Patients undergoing distraction surgery for growing devices were excluded. Results: After exclusions, 64 patients remained (vancomycin n = 39, control n = 25). The SSI rates were 12.8% in patients receiving vancomycin (n = 5/39) and 4% in the control group (n = 1/25, p = 0.785). None of the patients suffered from adverse events. Univariable logistic regression revealed younger age ( p = 0.03) and meningomyelocele as predictors for SSI ( p = 0.006), while the high-risk group receiving vancomycin was not at higher odds for SSI, also after adjustment for possible confounders such as age or MMC ( p = 0.031; p = 0.009). Discussion: SSI rates were comparable between groups, suggesting a normalization of SSI risk in the vancomycin-treated patients with a preoperatively increased risk of SSI. Future, larger studies in these rare diseases are needed to confirm these results.

Traumatic brain injury (TBI) leads to skeletal changes, including bone loss in the unfractured skeleton, and paradoxically accelerates healing of bone fractures; however, the mechanisms remain unclear. TBI is associated with a hyperadrenergic state characterized by increased norepinephrine release. Here, we identified the β 2 -adrenergic receptor (ADRB2) as a mediator of skeletal changes in response to increased norepinephrine. In a murine model of femoral osteotomy combined with cortical impact brain injury, TBI was associated with ADRB2-dependent enhanced fracture healing compared with osteotomy alone. In the unfractured 12-week-old mouse skeleton, ADRB2 was required for TBI-induced decrease in bone formation and increased bone resorption. Adult 30-week-old mice had higher bone concentrations of norepinephrine, and ADRB2 expression was associated with decreased bone volume in the unfractured skeleton and better fracture healing in the injured skeleton. Norepinephrine stimulated expression of vascular endothelial growth factor A and calcitonin gene-related peptide-α (αCGRP) in periosteal cells through ADRB2, promoting formation of osteogenic type-H vessels in the fracture callus. Both ADRB2 and αCGRP were required for the beneficial effect of TBI on bone repair. Adult mice deficient in ADRB2 without TBI developed fracture nonunion despite high bone formation in uninjured bone. Blocking ADRB2 with propranolol impaired fracture healing in mice, whereas the ADRB2 agonist formoterol promoted fracture healing by regulating callus neovascularization. A retrospective cohort analysis of 72 patients with long bone fractures indicated improved callus formation in 36 patients treated with intravenous norepinephrine. These findings suggest that ADRB2 is a potential therapeutic target for promoting bone healing.

Background: In the context of the COVID-19 pandemic, video consultations have gained importance in orthopaedic and traumatological departments. In current literature, different adaptations of classic joint and functional examinations have been described for the virtual examination., Methodology: A systematic review of current literature on adaptations for the virtual joint and functional examination in orthopaedics and trauma surgery was performed over PubMed (January 2010 to April 2021). The identified examination methods were then summarised systematically according to body region and pathology. Each examination was then described in detail and depicted in an exemplary picture., Results: In total 17 articles were identified and included in the analysis. Most of the examinations employed classical examination methods which were adapted so that they could be performed by the patient independently. Everyday items were described as supporting tools. In five publications, orthopaedic examinations performed in video consultations were compared to the classical examination. Results of functional examinations showed less agreement with results of classical orthopaedic examinations when compared to inspection and ROM-testing., Conclusion: Current literature offers a substantial repertoire of examination options that can be used in the orthopaedic and traumatological video consultation. The reported examinations are mostly oriented to classical orthopaedic examinations. In future digital examinations have to be validated and possibly further adapted in future., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Objective animal health evaluation is essential to determine welfare and discomfort in preclinical in vivo research. Body condition scores, body weight, and grimace scales are commonly used to evaluate well-being in murine rheumatoid arthritis (RA) and osteoarthritis experiments. However, nest-building, a natural behavior in mice, has not yet been evaluated in wild type (WT) or genetically modified rodents suffering from collagen antibody-induced arthritis (CAIA). To address this, we analyzed nesting behavior in WT mice, calcitonin gene-related peptide alpha-deficient (αCGRP -/- ) mice, and calcitonin receptor-deficient (Calcr -/- ) mice suffering from experimental RA compared to healthy control (CTRL) groups of the same genotypes. CAIA was induced in 10-12-week-old male mice, and clinical parameters (body weight, grip strength, clinical arthritis score, ankle size) as well as nesting behavior were assessed over 10 or 48 days. A slight positive association between the nest score and body weight and grip strength was found for animals suffering from CAIA. For the clinical arthritis score and ankle size, no significant associations were observed. Mixed model analyses confirmed these associations. This study demonstrates that clinical effects of RA, such as loss of body weight and grip strength, might negatively affect nesting behavior in mice. Assessing nesting behavior in mice with arthritis could be an additional, non-invasive and thus valuable health parameter in future experiments to monitor welfare and discomfort in mice. During severe disease stages, pre-formed nest-building material may be provided to animals suffering from arthritis., (© 2023. The Author(s).)

Background: The vasoactive neuropeptide calcitonin gene-related peptide alpha (αCGRP) enhances nociception in primary knee osteoarthritis (OA) and has been shown to disrupt cartilage and joint integrity in experimental rheumatoid arthritis (RA). Little is known about how αCGRP may alter articular structures in primary OA. We investigated whether αCGRP modulates local inflammation and concomitant cartilage and bone changes in a murine model of age-dependent OA., Methods: Sixteen- to 18-month-old αCGRP-deficient mice (αCGRP -/- aged ) were compared to, first, age-matched wild type (WT aged ) and, second, young 4- to 5-month-old non-OA αCGRP-deficient (αCGRP -/- CTRL ) and non-OA WT animals (WT CTRL ). αCGRP levels were measured in serum. Knee and hip joint inflammation, cartilage degradation, and bone alterations were assessed by histology (OARSI histopathological grading score), gene expression analysis, and µ-computed tomography., Results: WT aged mice exhibited elevated αCGRP serum levels compared to young WT CTRL animals. Marked signs of OA-induced cartilage destruction were seen in WT aged animals, while αCGRP -/- aged mice were mostly protected from this effect. Age-dependent OA was accompanied by an increased gene expression of pro-inflammatory Tnfa, Il1b, and Il6 and catabolic Mmp13, Adamts5, Ctsk, Tnfs11 (Rankl), and Cxcl12/Cxcr4 in WT aged but not in αCGRP -/- aged mice. αCGRP-deficiency however further aggravated subchondral bone sclerosis of the medial tibial plateau and accelerated bone loss in the epi- and metaphyseal trabecular tibial bone in age-dependent OA., Conclusions: Similar to its function in experimental RA, αCGRP exerts a dual pro-inflammatory and bone-protective function in murine primary OA. Although anti-CGRP treatment was previously not successful in reducing pain in OA clinically, these data underline a crucial pathophysiological role of αCGRP in age-related OA., (© 2023. The Author(s).)

After periprosthetic joint infection (PJI)-dependent revision surgery, a significantly elevated number of patients suffer from prosthesis failure due to aseptic loosening and require additional revision surgery despite clearance of the initial infection. The mechanisms underlying this pathology are not well understood, as it has been assumed that the bone stock recovers after revision surgery. Despite clinical evidence suggesting decreased osteogenic potential in PJI, understanding of the underlying biology remains limited. In this study, we investigated the impact of PJI on bone homeostasis in a two-stage exchange approach at explantation and reimplantation. Sixty-four human tibial and femoral specimens (20 control, 20 PJI septic explantation, and 24 PJI prosthesis reimplantation samples) were analyzed for their bone microstructure, cellular composition, and expression of relevant genetic markers. Samples were analyzed using X-ray microtomography, Alcian blue and tartrate-resistant acid phosphatase staining, and RT-qPCR. In patients with PJI, bone volume (BV/TV; 0.173 ± 0.026; p < 0.001), trabecular thickness (164.262 ± 18.841 μm; p < 0.001), and bone mineral density (0.824 ± 0.017 g/cm 2 ; p = 0.049) were reduced; trabecular separation (1833.939 ± 178.501 μm; p = 0.005) was increased. While prevalence of osteoclasts was elevated (N.Oc/BS: 0.663 ± 0.102, p < 0.001), osteoblast cell numbers were lower at explantation (N.Ob/BS: 0.149 ± 0.021; p = 0.047). Mean expression of bone homeostasis markers osteocalcin, osteopontin, Runx2, TSG-6, and FGF-2 was significantly reduced at prosthesis explantation. Despite partial recovery, all analyzed parameters were still significantly impacted at reimplantation. In contrast, mean expression of osteoclastogenesis-stimulating cytokine IL-17a was significantly increased at both explantation and reimplantation. In this study, we found a strong and lasting impact of PJI on the bone homeostasis on a molecular, cellular, and microstructural level. These changes may be responsible for the increased risk of prosthesis failure due to aseptic loosening. Our data suggest there is significant potential in modulating bone homeostasis to improve prosthesis fixation and long-term clinical outcome in affected patients. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)., (© 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).)

Purpose: Resuscitative thoracotomies (RT) are the last resort to reduce mortality in patients suffering severe trauma. In recent years, indications for RT have been extended from penetrating to blunt trauma. However, discussions on efficacy are still ongoing, as data on this rarely performed procedure are often scarce. Therefore, this study analyzed RT approaches, intraoperative findings, and clinical outcome measures following RT in patients with cardiac arrest following blunt trauma., Methods: All patients admitted to our level I trauma center's emergency room (ER) who underwent RT between 2010 and 2021 were retrospectively analyzed. Retrospective chart reviews were performed for clinical data, laboratory values, injuries observed during RT, and surgical procedures. Additionally, autopsy protocols were assessed to describe injury patterns accurately., Results: Fifteen patients were included in this study with a median ISS of 57 (IQR 41-75). The 24-h survival rate was 20%, and the total survival rate was 7%. Three approaches were used to expose the thorax: Anterolateral thoracotomy, clamshell thoracotomy, and sternotomy. A wide variety of injuries were detected, which required complex surgical interventions. These included aortic cross-clamping, myocardial suture repairs, and pulmonary lobe resections., Conclusion: Blunt trauma often results in severe injuries in various body regions. Therefore, potential injuries and corresponding surgical interventions must be known when performing RT. However, the chances of survival following RT in traumatic cardiac arrest cases following blunt trauma are small., (© 2023. The Author(s).)

Impaired fracture healing is of high clinical relevance, as up to 15% of patients with long-bone fractures display non-unions. Fracture patients also include individuals treated with selective norepinephrine reuptake inhibitors (SNRI). As SNRI were previously shown to negatively affect bone homeostasis, it remained unclear whether patients with SNRI are at risk of impaired bone healing. Here, we show that daily treatment with the SNRI reboxetine reduces trabecular bone mass in the spine but increases cortical thickness and osteoblast numbers in the femoral midshaft. Most importantly, reboxetine does not impair bone regeneration in a standardized murine fracture model, and even improves callus bridging and biomechanical stability at late healing stages. In sum, reboxetine affects bone remodeling in a site-specific manner. Treatment does not interfere with the early and intermediate stages of bone regeneration and improves healing outcomes of the late-stage fracture callus in mice., Competing Interests: J.K. and S.T. disclose support for the research of this work from the German Research Foundation [grant numbers KE 2179/2-3 and TS 303/2-3]., (© 2023 The Author(s).)

Traumatic brain injury (TBI) is associated with a hyperadrenergic state and paradoxically causes systemic bone loss while accelerating fracture healing. Here, we identify the beta2-adrenergic receptor (Adrb2) as a central mediator of these skeletal manifestations. While the negative effects of TBI on the unfractured skeleton can be explained by the established impact of Adrb2 signaling on bone formation, Adrb2 promotes neovascularization of the fracture callus under conditions of high sympathetic tone, including TBI and advanced age. Mechanistically, norepinephrine stimulates the expression of Vegfa and Cgrp primarily in periosteal cells via Adrb2, both of which synergistically promote the formation of osteogenic type-H vessels in the fracture callus. Accordingly, the beneficial effect of TBI on bone repair is abolished in mice lacking Adrb2 or Cgrp, and aged Adrb2-deficient mice without TBI develop fracture nonunions despite high bone formation in uninjured bone. Pharmacologically, the Adrb2 antagonist propranolol impairs, and the agonist formoterol promotes fracture healing in aged mice by regulating callus neovascularization. Clinically, intravenous beta-adrenergic sympathomimetics are associated with improved callus formation in trauma patients with long bone fractures. Thus, Adrb2 is a novel target for promoting bone healing, and widely used beta-blockers may cause fracture nonunion under conditions of increased sympathetic tone.

Background: Procalcitonin (PCT) is applied as a sensitive biomarker to exclude bacterial infections in patients with rheumatoid arthritis (RA) flare-ups. Beyond its diagnostic value, little is known about the pathophysiological role of PCT in RA., Methods: Collagen antibody-induced arthritis (CAIA) was induced in Calca-deficient mice (Calca -/- ), lacking PCT (n = 15), and wild-type (WT) mice (n = 13), while control (CTRL) animals (n = 8 for each genotype) received phosphate-buffered saline. Arthritis severity and grip strength were assessed daily for 10 or 48 days. Articular inflammation, cartilage degradation, and bone lesions were assessed by histology, gene expression analysis, and µ-computed tomography., Results: Serum PCT levels and intra-articular PCT expression increased following CAIA induction. While WT animals developed a full arthritic phenotype, Calca-deficient mice were protected from clinical and histological signs of arthritis and grip strength was preserved. Cartilage turnover markers and Tnfa were exclusively elevated in WT mice. Calca-deficient animals expressed increased levels of Il1b. Decreased bone surface and increased subchondral bone porosity were observed in WT mice, while Calca-deficiency preserved bone integrity., Conclusion: The inactivation of Calca and thereby PCT provided full protection from joint inflammation and arthritic bone loss in mice exposed to CAIA. Together with our previous findings on the pathophysiological function of Calca-derived peptides, these data indicate an independent pro-inflammatory role of PCT in RA., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Introduction: Fibrin stabilizing factor (FXIII) plays a crucial role in blood clotting, tissue repair, and immune defense. FXIII deficiency after trauma can lead to prolonged wound healing due to persistent infections or coagulation disorders. The aim of this study was to describe the prevalence of acquired FXIII deficiency after trauma and to provide a description of the time-course changes of important coagulation parameters in relation to FXIII activity. In this context, patient characteristics, laboratory data, and treatment modalities were examined with respect to their influence on FXIII activity. Furthermore, the effects of in vitro administration of FXIII on clot firmness and outcomes in patients with severe traumatic brain injury were investigated., Patients and Methods: Two trauma cohorts (A and B) were examined prospectively in a two-center study, and another (cohort C) was examined retrospectively. In cohort A (trauma patients, n=880) routine laboratory tests were conducted, and FXIII activity was measured. In cohort B (polytrauma patients, n=26), additional clinical parameters were collected, and in-vitro FXIII administration and rotational thromboelastometry (ROTEM) analyses were performed. In cohort C (polytrauma patients with severe traumatic brain injury [sTBI], n=84), the impact of initially measured FXIII activity on clinical outcomes after sTBI was investigated using the modified Rankin Scale (mRS) at least 6 months after trauma., Results: The prevalence of FXIII activity <70% in cohort A was 12.4%, with significant differences in age, Hb, fibrinogen, and Hct levels, platelet count, aPTT, and INR (vs. prevalence of FXIII activity >70%). Cohort B showed a decrease in FXIII activity from 85% to 58% after 7 days. FXIII deficiency correlated with time after trauma, aPTT, and fibrinogen level, lactate, and Hb levels. In-vitro administration of FXIII showed a positive influence on clot firmness due to improved maximum clot firmness (MCF in FIBTEM) and reduced maximum lysis (ML in EXTEM). Finally, a significant difference in FXIII activity between patients after sTBI with good and poor clinical outcomes was observed 6 months after trauma., Conclusion: We demonstrated that trauma-associated FXIII deficiency is a common coagulation disorder, with FXIII deficiency increasing further in the first 7 days after trauma, the period of early surgical care. In vitro administration of FXIII was able to demonstrate significant clot stabilizing effects. For trauma patients with sTBI, FXIII activity could serve as a prognostic parameter, as it differed significantly between patients with good and poor clinical outcomes., Competing Interests: Declaration of Competing Interest The Center for Musculoskeletal Surgery (CMSC) Charité - University Medicine Berlin, Germany was provided with TEG machines, TEG reagent and fibrogramin for in-vitro FXIII assays by CSL Behring Germany for the cohort B studies (cohort A/C no support). Christian Kleber has received honoraria from CSL Behring, Germany, which also supported the funding of the open access publication. The remaining authors have disclosed that they do not have any conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Bone has a remarkable endogenous regenerative capacity that enables scarless healing and restoration of its prior mechanical function, even under challenging conditions such as advanced age and metabolic or immunological degenerative diseases. However - despite much progress - a high number of bone injuries still heal with unsatisfactory outcomes. The mechanisms leading to impaired healing are heterogeneous, and involve exuberant and non-resolving immune reactions or overstrained mechanical conditions that affect the delicate regulation of the early initiation of scar-free healing. Every healing process begins phylogenetically with an inflammatory reaction, but its spatial and temporal intensity must be tightly controlled. Dysregulation of this inflammatory cascade directly affects the subsequent healing phases and hinders the healing progression. This Review discusses the complex processes underlying bone regeneration, focusing on the early healing phase and its highly dynamic environment, where vibrant changes in cellular and tissue composition alter the mechanical environment and thus affect the signalling pathways that orchestrate the healing process. Essential to scar-free healing is the interplay of various dynamic cascades that control timely resolution of local inflammation and tissue self-organization, while also providing sufficient local stability to initiate endogenous restoration. Various immunotherapy and mechanobiology-based therapy options are under investigation for promoting bone regeneration., (© 2023. Springer Nature Limited.)

Increasing patient inflow into the emergency department makes it necessary to optimize triage management. The scope of this work was to determine simple factors that could detect fractures in patients without the need for specialized personnel. Between 2014 and 2015, 798 patients were admitted to an orthopedic emergency department and prospectively included in the study. The patients received a questionnaire before contacting the doctor. Objective and subjective data were evaluated to determine fracture risk for the upper and lower extremities. The highest risk for fractures in one region was the hip (73.21%; n = 56), followed by the wrist (60.32%; n = 63) and the femoral shaft (4 of 7, 57.14%; n = 7). The regions with the lowest risk were the knee (8.41%; n = 107), the ankle (18.29%; n = 164), and the forearm shaft (30.00%; n = 10). Age was a predictor for fracture: patients older than 59 years had a risk greater than 59.26%, and patients older than 90 years had a risk greater than 83.33%. The functional questions could exclude fractures. Three factors seem to be able to predict fracture risk: the injured region, the patient's age, and a functional question. They can be used for a probatory heuristic that needs to be proven in a prospective way.

Despite the general success of total knee arthroplasty (TKA), addressing periprosthetic joint infection (PJI) and the resulting long-term complications is a growing medical need given the aging population and the increasing demand for arthroplasty. A larger proportion of patients face revision surgery because of the long-term complication of aseptic loosening despite clearance of the infection. The pathomechanisms leading to prosthetic loosening are not understood as it has been widely assumed that the bone stock recovers after explantation revision surgery. While clinical observations suggest a reduced osteogenic potential in patients with PJI, knowledge regarding the relevant biology is sparse. In the present study, we investigated the inflammatory impact of PJI on the bone and bone marrow in the vicinity of the joint. Additionally, we evaluated changes in the local inflammatory environment in a 2-stage exchange at both explantation and reimplantation., Methods: In this study, we analyzed 75 human bone and bone-marrow specimens (obtained from 65 patients undergoing revision arthroplasty with cement for the treatment of PJI) for markers of inflammation. Samples were analyzed using hematoxylin and eosin overview staining, fluorescent immunohistochemical staining, flow cytometry, and polymerase chain reaction (PCR)., Results: Leukocyte prevalence was significantly elevated at explantation (femur, +218.9%; tibia, +134.2%). While leukocyte prevalence decreased at reimplantation (femur, -49.5%; tibia, -34.2%), the number of cells remained significantly higher compared with the control group (femur, +61.2%; tibia, +54.2%). Expression of inflammatory markers interleukin (IL)-1α (femur, +2,748.7%; tibia, +1,605.9%), IL-6 (femur, +2,062.5%; tibia, +2,385.7%), IL-10 (femur, +913.7%; tibia, +897.5%), IL-12 (femur, +386.1%; tibia, +52.5%), IL-18 (femur, +805.3%; tibia, +547.7%), and tumor necrosis factor (TNF)-α (femur, +296.9%; tibia, +220.9%) was significantly elevated at prosthesis explantation in both femoral and tibial specimens. Expression remained significantly elevated at reimplantation for all inflammatory markers except IL-12 compared with the control group. Conversely, there were only limited inflammatory changes in the bone marrow environment., Conclusions: The present study demonstrated a strong and lasting upregulation of the proinflammatory environment in the joint-surrounding osseous scaffold in patients with PJI. Our data suggest that modulating the inflammatory environment has substantial potential to improve the clinical outcome in affected patients., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSOA/A462)., (Copyright © 2023 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Background: Knife crime has increased considerably in recent years in Northern Europe. Affected patients often require immediate surgical care due to traumatic organ injury. Yet, little is known about clinically relevant routine laboratory parameters in stab injury patients and how these are associated with intensive care unit (ICU) admission, hospitalization and number of surgeries., Methods: We retrospectively analyzed 258 stab injury cases between July 2015 and December 2021 at an urban Level I Trauma Center. Annual and seasonal incidences, injury site, injury mechanism, Injury Severity Score (ISS), and surgical management were evaluated. First, correlations between routine laboratory parameters for hematology, coagulation, and serum biochemistry (peak, and Δ (change from admission to peak within 3 days following admission)) and length of hospital stay, ICU stay, and number of surgeries were assessed using Spearman's rank correlation coefficients. Second, multivariable Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were conducted to identify parameters predictive of clinical outcomes. Third, longitudinal developments of routine laboratory parameters were assessed during hospital admission., Results: In 2021, significantly more stab injuries were recorded compared with previous years and occurred less during winter compared with other seasons. Mean ISS was 8.3 ± 7.3, and ISS was positively correlated with length of hospital and ICU stay (r = 0.5-0.8, p < 0.001). Aspartate transaminase (AST) (Δ) (r = 0.690), peak C-reactive protein (CrP) (r = 0.573), and erythrocyte count (Δ) (r = 0.526) showed the strongest positive correlations for length of ICU stay for penetrating, thoracoabdominal, and organ injuries, respectively. No correlations were observed between routine laboratory parameters and number of surgeries. For patients with penetrating injuries, LASSO-selected predictors of ICU admission included ISS, pH and lactate at admission, and Δ values for activated partial thromboplastin time (aPTT), K + , and erythrocyte count. CrP levels on day 3 were significantly higher in patients with penetrating (p = 0.005), thoracoabdominal (p = 0.041), and organ injuries (p < 0.001) compared with those without., Conclusion: Our data demonstrate an increase in stab injury cases in 2021 and an important link between changes in routine laboratory parameters and ICU admission and hospitalization. Monitoring ISS and changes in AST, CrP, erythrocyte count, pH, lactate, aPTT, and K + may be useful to identify patients at risk and adjust surgical and ICU algorithms early on., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Maleitzke, Zhou, Zocholl, Fleckenstein, Back, Plewe, Weber, Winkler, Stöckle, Tsitsilonis and Märdian.)

The murine collagen antibody-induced arthritis (CAIA) model resembles various features of human rheumatoid arthritis and is based on the intraperitoneal or intravenous injection of autoantibodies against type II collagen. Here, we present a standardized protocol for the intraperitoneal injection of arthritis-inducing autoantibodies in mice, followed by a description of daily arthritis assessments. We then detail the steps to harvest joint and bone tissues for histological, radiological, and molecular analyses. We highlight animal welfare and 3 R considerations for experimental arthritis studies. For complete details on the use and execution of this protocol, please refer to Maleitzke et al. (2021, 2022)., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Health-related mobile applications (apps) are rapidly increasing in number. There is an urgent need for assessment tools and algorithms that allow the usability and content criteria of these applications to be objectively assessed. The aim of this work was to establish and validate a concept for orthopedic societies to rate health apps to set a quality standard for their safe use., Methods: An objective rating concept was created, consisting of nine quality criteria. A self-declaration sheet for app manufacturers was designed. Manufacturers completed the self-declaration, and the app was examined by independent internal reviewers. The pilot validation and analysis were performed on two independent health applications. An algorithm for orthopedic societies was created based on the experiences in this study flow., Results: "Sprunggelenks-App" was approved by the reviewers with 45 (98%) fulfilled criteria and one (2%) unfulfilled criterion. "Therapie-App" was approved, with 28 (61%) met criteria, 6 (13%) unfulfilled criteria and 12 (26%) criteria that could not be assessed. The self-declaration completed by the app manufacturer is recommended, followed by a legal and technical rating performed by an external institution. When rated positive, the societies' internal review using independent raters can be performed. In case of a positive rating, a visual certification can be granted to the manufacturer for a certain time frame., Conclusion: An objective rating algorithm is proposed for the assessment of digital health applications. This can help societies to improve the quality assessment, quality assurance and patient safety of those apps. The proposed concept must be further validated for inter-rater consistency and reliability.

Introduction: Treating severely injured patients requires numerous critical decisions within short intervals in a highly complex situation. The coordination of a trauma team in this setting has been shown to be associated with multiple procedural errors, even of experienced care teams. Machine learning (ML) is an approach that estimates outcomes based on past experiences and data patterns using a computer-generated algorithm. This systematic review aimed to summarize the existing literature on the value of ML for the initial management of severely injured patients., Methods: We conducted a systematic review of the literature with the goal of finding all articles describing the use of ML systems in the context of acute management of severely injured patients. MESH search of Pubmed/Medline and Web of Science was conducted. Studies including fewer than 10 patients were excluded. Studies were divided into the following main prediction groups: (1) injury pattern, (2) hemorrhage/need for transfusion, (3) emergency intervention, (4) ICU/length of hospital stay, and (5) mortality., Results: Thirty-six articles met the inclusion criteria; among these were two prospective and thirty-four retrospective case series. Publication dates ranged from 2000 to 2020 and included 32 different first authors. A total of 18,586,929 patients were included in the prediction models. Mortality was the most represented main prediction group ( n  = 19). ML models used were artificial neural network ( n  = 15), singular vector machine ( n  = 3), Bayesian network ( n  = 7), random forest ( n  = 6), natural language processing ( n  = 2), stacked ensemble classifier [SuperLearner (SL), n  = 3], k-nearest neighbor ( n  = 1), belief system ( n  = 1), and sequential minimal optimization ( n  = 2) models. Thirty articles assessed results as positive, five showed moderate results, and one article described negative results to their implementation of the respective prediction model., Conclusions: While the majority of articles show a generally positive result with high accuracy and precision, there are several requirements that need to be met to make the implementation of such models in daily clinical work possible. Furthermore, experience in dealing with on-site implementation and more clinical trials are necessary before the implementation of ML techniques in clinical care can become a reality., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2022 Baur, Gehlen, Scherer, Back, Tsitsilonis, Kabir and Osterhoff.)

In the present report, a case of a healthy, 38-year-old male recreational marathon runner who presented in the emergency department is discussed. He was diagnosed with a stress fracture of the femoral neck and treated surgically using a dynamic hip screw (DHS). One year after surgery, the patient was able to return to most of his previous sports activities. In the present report, the existing literature on the subject is exhibited and the points of interest in terms of incidence, risk factors, diagnosis, classification, treatment, and long-term outcome are analyzed. We suggest operative treatment of stress fractures of the femoral neck even in cases of complete undisplaced ones. This way, the risk of a displacement is counteracted, and patients can quickly return to daily activities without having to withstand long-term immobilization., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Purpose: The aim of this study was to assess the mid-term clinical outcome of the ankle joint after total knee arthroplasty (TKA) in high-grade valgus osteoarthritis., Methods: In this case-control study, n = 36 patients with a preoperative mechanical tibiofemoral angle (mTFA) ≥ 15° who underwent TKA between December 2002 and December 2012 were included. The control group (mTFA < 15°) of n = 60 patients was created using case matching. Radiological [mechanical tibiofemoral angle (mTFA) and ankle joint orientation to the ground (G-AJLO)] and clinical parameters [Foot Function Index (FFI), Knee Society Score, Forgotten Joint Score, and Range of Motion (ROM)] were analysed. The mean follow-up time was 59 months (IQR [56, 62])., Results: The degree of correcting the mTFA by TKA significantly correlated with the postoperative FFI (R = 0.95, p < 0.05), although the knee and ankle joint lines were corrected to neutral orientations. A cut-off value of 16.5° [AUC 0.912 (0.85-0.975 95% CI), sensitivity = 0.8, specificity = 0.895] was calculated, above which the odds ratio (OR) for developing ankle symptoms increased vastly [OR 34.0 (9.10-127.02 95% CI)]. ROM restrictions of the subtalar joint displayed a strong significant correlation with the FFI (R = 0.74, p < 0.05), demonstrating that decreased ROM of the subtalar joint was associated with aggravated outcomes of the ankle joint., Conclusions: In this study, higher degrees of leg axis correction in TKA were associated with increased postoperative ankle symptoms. When TKA is performed in excessive valgus knee osteoarthritis, surgeons should be aware that this might trigger the onset or progression of ankle symptoms, particularly in cases of a stiff subtalar joint., Level of Evidence: III., (© 2020. The Author(s).)

Intermittent injections of parathyroid hormone (iPTH) are applied clinically to stimulate bone formation by osteoblasts, although continuous elevation of parathyroid hormone (PTH) primarily results in increased bone resorption. Here, we identified Calca, encoding the sepsis biomarker procalcitonin (ProCT), as a novel target gene of PTH in murine osteoblasts that inhibits osteoclast formation. During iPTH treatment, mice lacking ProCT develop increased bone resorption with excessive osteoclast formation in both the long bones and axial skeleton. Mechanistically, ProCT inhibits the expression of key mediators involved in the recruitment of macrophages, representing osteoclast precursors. Accordingly, ProCT arrests macrophage migration and causes inhibition of early but not late osteoclastogenesis. In conclusion, our results reveal a potential role of osteoblast-derived ProCT in the bone microenvironment that is required to limit bone resorption during iPTH., (© 2022. The Author(s).)

Pharmacological application of teleost calcitonin (CT) has been shown to exert chondroprotective and anti-resorptive effects in patients with rheumatoid arthritis (RA). However, the role of endogenous CT that signals through the calcitonin receptor (CTR) remains elusive. Collagen II antibody-induced arthritis (CAIA) was stimulated in wild type (WT) and CTR-deficient (Calcr -/- ) mice. Animals were monitored over 10 or 48 days. Joint inflammation, cartilage degradation, and bone erosions were assessed by clinical arthritis score, histology, histomorphometry, gene expression analysis, and μ-computed tomography. CAIA was accompanied by elevated systemic CT levels and CTR expression in the articular cartilage. Inflammation, cartilage degradation, and systemic bone loss were more pronounced in Calcr -/- CAIA mice. Expression of various pro-inflammatory, bone resorption, and catabolic cartilage markers were exclusively increased in Calcr -/- CAIA mice. Endogenous CT signaling through the mammalian CTR has the potential to protect against joint inflammation, cartilage degradation, and excessive bone remodeling in experimental RA., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)

Purpose: Lisfranc injuries are rare and often pose a challenge for surgeons, particularly in initially missed or neglected cases. The evidence on which subtypes of Lisfranc injuries are suitable for conservative treatment or should undergo surgery is low. The aim of this study was to retrospectively analyze treatment decisions of Lisfranc injuries and the clinical outcome of these patients within the last ten years., Methods: All patients treated due to a Lisfranc injury in a German level I trauma centre from January 2011 until December 2020 were included in this study. Radiologic images and medical data from the patient files were analyzed concerning the classification of injury, specific radiologic variables, such as the Buehren criteria, patient baseline characteristics, and patient outcome reported with the Foot Function Index (FFI)., Results: Ninety-nine patients were included in this study (conservative = 20, operative = 79). The overall clinical outcome assessed by the FFI was good (FFI sum 23.93, SD 24.93); patients that were identified as suitable for conservative treatment did not show inferior functional results. Qualitative radiological factors like the grade of displacement and the trauma mechanism were more strongly associated with the decision for surgical treatment than quantitative radiologic factors such as the distance from the first to the second metatarsal bone., Conclusion: If the indication for conservative or operative treatment of Lisfranc injuries is determined correctly, the clinical outcome can be comparable. These decisions should be based on several factors including quantitative and qualitative radiologic criteria, as well as the trauma mechanism., (© 2021. The Author(s).)

Background: E-scooter usage was lawfully approved in Germany in June 2019. Since then, a marked increase of e-scooter drivers has been noticed. Evidence concerning factors that may affect the severity of these injuries is limited. The study aimed to retrospectively analyze e-scooter-related injuries in a major German city., Methods: All patients admitted to the emergency department of a level I trauma center in Berlin, Germany, between June 15, 2019, and December 15, 2019, were retrospectively reviewed. Patients involved in an e-scooter accident were included in this study, and medical reports were analyzed., Results: In the study period, 43 patients were involved in an e-scooter accident and could be included in this study. The median age of the patients was 30 years (interquartile range [IQR], 24.50-39.50 years), with 19 (44.2%) being female patients. The median Injury Severity Score of all patients was 2.0, with the highest Abbreviated Injury Scale (AIS) of 3.00 (IQR, 2.00-3.00) and was recorded as thoracic injuries. Seven patients had extremity fractures, of which 4 had to be stabilized operatively. In 12 patients (27.9%), the accidents occurred under the influence of alcohol., Conclusions: The majority of injuries reported in this study were associated with a relatively low AIS, possibly due to strict local speed limits. Nonetheless, e-scooter usage bears risks of sustaining severe injuries to the head, face, and extremities, particularly under the influence of alcohol or when illegally ignoring local laws., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2021 by The Korean Orthopaedic Association.)

Purpose: Aim of this retrospective cohort study was the comparison of the transiliac fixator (TIFI) and spinopelvic fixation (SPF) for fixation of dorsal pelvic ring fractures in terms of clinical outcome, complications, and quality of life. Methods: Thirty-eight patients (23 men, 15 women; mean age 47 ± 19 years) with dorsal pelvic ring fractures (type-C-injuries after AO/OTA) that have been stabilized by either TIFI (group TIFI, n = 22) or SPF (group SPF, n = 16) between May 2015 and December 2018 were retrospectively reviewed. Outcome measurements included demographic data, perioperative parameters, and complications and were obtained from the medical information system. Quality of life was assessed using the German version of the short form 36 (SF-36) and short muskuloskeletal function assessment (SMFA-D). Clinical results were assessed using Merle d'Aubigné-Score, Iowa Pelvic Score, and Majeed Pelvic Score. Results: Both groups show relatively good post-operative results, which has previously been reported. Quality of life was comparable in both groups. Group TIFI was slightly superior regarding complication rates, cutting/suture time, and fluoroscopy time. Group SPF seemed to be superior regarding pain and pelvic scores. Conclusion: None of the methods could demonstrate significant superiority over the other. Management of pelvic injuries remains a highly individual challenge adapted to the individual patients' condition. Nevertheless, if fractures allow for stabilization with TIFI, the use of this method should be taken into consideration as a less invasive and more tissue-conserving approach., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Seemann, Hempel, Rußow, Tsitsilonis, Stöckle and Märdian.)

Objectives In recent years; increasing evidence pointed out the clinical importance of adipose tissue (AT) distribution in various patient populations. In particular, visceral adipose tissue (VAT), when compared to subcutaneous adipose tissue (SAT), was found to play a pivotal role in the development of inflammatory reaction. The aim of the present study was to examine whether body fat distribution has an impact on the development of systemic inflammatory response syndrome (SIRS) in patients with polytrauma. Methods In our retrospective study; we filtered our institution records of the German Trauma Registry (Trauma Register DGU) from November 2018 to April 2021 and included 132 adult polytrauma patients with injury severity score (ISS) >16. Subsequently; we measured the visceral and subcutaneous adipose tissue area based on whole-body CT scan and calculated the ratio of VAT to SAT (VSr). Thereafter, the patient population was evenly divided into three groups; respectively VSr value less than 0.4 for the first group (low ratio), 0.4-0.84 for the second group (intermediate ratio), and greater than 0.84 for the third group (high ratio). Considering the other influencing factors; the groups were further divided into subgroups in the respective analysis according to gender (male/female), BMI (<25 or ≥25), and ISS (<26 or ≥26). Result VSr was an independent factor from body mass index (BMI) (r 2 = 0.003; p = 0.553). VSr in male patients was significantly higher ( p < 0.001). Patients with low VSr had higher ISS scores ( p = 0.028). Polytrauma patients with higher VSr tended to have lower SIRS scores and significant differences of SIRS score were found on multiple days during the whole hospitalization period. In the low VAT/SAT group, male patients, and patients with BMI greater than 25, both exhibited higher SIRS scores during hospital stay (day 16: p = 0.01; day 22: p = 0.048 and p = 0.011; respectively). During hospitalization, patients with higher ISS score (≥26) in the low VSr group was found to have higher SIRS score (day 16; p = 0.007). Over the hospital stay; serum markers of CRP; CK; and leukocyte in patients with low VSr were higher than those in patients in the intermediate and high VSr groups; with significant difference discovered on multiple days (day 16: 0.014; day 22: p = 0.048). Conclusion Lower VSr is associated with increased inflammatory response and worse clinical outcome in patients with polytrauma. Furthermore; VSr is an independent factor providing additional information to BMI.

Traumatic spinal cord injury (TSCI), commonly caused by high energy trauma in young active patients, is frequently accompanied by traumatic brain injury (TBI). Although combined trauma results in inferior clinical outcomes and a higher mortality rate, the understanding of the pathophysiological interaction of co-occurring TSCI and TBI remains limited. This review provides a detailed overview of the local and systemic alterations due to TSCI and TBI, which severely affect the autonomic and sensory nervous system, immune response, the blood-brain and spinal cord barrier, local perfusion, endocrine homeostasis, posttraumatic metabolism, and circadian rhythm. Because currently developed mesenchymal stem cell (MSC)-based therapeutic strategies for TSCI provide only mild benefit, this review raises awareness of the impact of TSCI-TBI interaction on TSCI pathophysiology and MSC treatment. Therefore, we propose that unravelling the underlying pathophysiology of TSCI with concomitant TBI will reveal promising pharmacological targets and therapeutic strategies for regenerative therapies, further improving MSC therapy.

Talar dislocations are rare injuries of the foot and ankle and require quick and decisive diagnostic and therapeutic decisions. Evidence concerning the treatment and outcome of these injuries is sparse. The aim of this study was to analyze all talar dislocations of the last ten years treated in a large German level I trauma center in an effort to add to the experience on these injuries., Methods: All patients with a talar dislocation injury were retrospectively included. Medical reports, x-ray and computertomography scans were analyzed for the sex, age, trauma mechanism, and injury classifications as well as for the clinical outcome as measured by the Foot Function Index (FFI)., Results: A total of 18 patients were included in this study: Luxatio pedis cum talo (n = 1), Luxatio tali totalis (n = 3), Luxatio pedis sub talo (n = 14). Analysis of the therapeutic algorithms revealed that only one patient was treated conservatively, the other 17 patients underwent operation. In most cases, stabilization was achieved using an external fixator and if necessary, the subtalar and talonavicular joints were temporarily stabilized using K-wires. The mean follow-up time was 4.25 years (2.05 SD) and the mean FFI-sum score 45.00 (42.26 SD). Two patients required subtalar fusion two years after the injury., Conclusion: Isolated talar dislocations can have a good outcome and be effectively treated in the emergency setting by basic techniqes if neurovasular structures are not injured. Often, these injuries are associated with fractures of adjacent bones which then need complex reconstruction., Competing Interests: All authors declare that they have no conflict of interest., (© 2021.)

What constitutes a "good osteosynthesis"? Although the question seems trivial, on closer inspection there are manifold influencing factors that affect fracture healing, so that this question is ultimately not that easy to answer. The first steps are already set with taking the patient history and initial diagnostics. An adequate analysis of the fracture with a coherent preoperative concept for stabilization based on the latest scientific findings and a subsequent adequate implementation of the planning in the operating room make the success of an osteosynthesis and thus a "good osteosynthesis". Digital support is playing an increasingly important role in this field. This review article deals with the topic in depth and summarizes the most important elements of the necessary cascade., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: While potentially timesaving, there is no program to automatically transform diagnosis codes of the ICD-10 German modification (ICD-10-GM) into the injury severity score (ISS)., Objective: To develop a mapping method from ICD-10-GM into ICD-10 clinical modification (ICD-10-CM) to calculate the abbreviated injury scale (AIS) and ISS of each patient using the ICDPIC-R and to compare the manually and automatically calculated scores., Methods: Between January 2019 and June 2021, the most severe AIS of each body region and the ISS were manually calculated using medical documentation and radiology reports of all major trauma patients of a German level I trauma centre. The ICD-10-GM codes of these patients were exported from the electronic medical data system SAP, and a Java program was written to transform these into ICD-10-CM codes. Afterwards, the ICDPIC-R was used to automatically generate the most severe AIS of each body region and the ISS. The automatically and manually determined ISS and AIS scores were then tested for equivalence., Results: Statistical analysis revealed that the manually and automatically calculated ISS were significantly equivalent over the entire patient cohort. Further sub-group analysis, however, showed that equivalence could only be demonstrated for patients with an ISS between 16 and 24. Likewise, the highest AIS scores of each body region were not equal in the manually and automatically calculated group., Conclusion: Though achieving mapping results highly comparable to previous mapping methods of ICD-10-CM diagnosis codes, it is not unrestrictedly possible to automatically calculate the AIS and ISS using ICD-10-GM codes., Competing Interests: The authors have declared that no competing interests exist.

Fracture healing represents a dynamic and complex process which depends on the balanced activities of a broad array of different cell types and signaling pathways. Here, we describe a femoral osteotomy protocol for mice, using an external fixator to stabilize the fractured bone. Depending on experimental requirements, the size of the osteotomy gap can be adjusted. Taken together, this protocol describes a highly standardized and reproducible murine model for morphologic and biomolecular assessment of the fracture healing process. For complete details on the use and execution of this protocol, please refer to Appelt et al. (2020)., Competing Interests: The author declares no competing interests., (© 2021 The Author(s).)

Despite significant advances in surgical techniques, treatment options for impaired bone healing are still limited. Inadequate bone regeneration is not only associated with pain, prolonged immobilization and often multiple revision surgeries, but also with high socioeconomic costs, underlining the importance of a detailed understanding of the bone healing process. In this regard, we previously showed that mice lacking the calcitonin receptor (CTR) display increased bone formation mediated through the increased osteoclastic secretion of sphingosine-1-phosphate (S1P), an osteoanabolic molecule promoting osteoblast function. Although strong evidence is now available for the crucial role of osteoclast-to-osteoblast coupling in normal bone hemostasis, the relevance of this paracrine crosstalk during bone regeneration is unknown. Therefore, our study was designed to test whether increased osteoclast-to-osteoblast coupling, as observed in CTR-deficient mice, may positively affect bone repair. In a standardized femoral osteotomy model, global CTR-deficient mice displayed no alteration in radiologic callus parameters. Likewise, static histomorphometry demonstrated moderate impairment of callus microstructure and normal osseous bridging of osteotomy ends. In conclusion, bone regeneration is not accelerated in CTR-deficient mice, and contrary to its osteoanabolic action in normal bone turnover, osteoclast-to-osteoblast coupling specifically involving the CTR-S1P axis, may only be of minor relevance during bone healing.

(1) Background: Clinical approaches have depicted interconnectivity between the Achilles tendon and the plantar fascia. This concept has been applied in rehabilitation, prevention, and in conservative management plans, yet potential anatomical and histological connection is not fully understood. (2) Objective: To explore the possible explanation that the calcaneus acts as a hypomochlion. (3) Methods: 2 databases (Pubmed and Livivo) were searched and studies, including those that examined the relationship of the calcaneus to the Achilles tendon and plantar fascia and its biomechanical role. The included studies highlighted either the anatomical, histological, or biomechanical aspect of the lower limb. (4) Results: Seventeen studies were included. Some studies depicted an anatomical connection that slowly declines with age. Others mention a histological similarity and continuity via the paratenon, while a few papers have brought forward mechanical reasoning. (5) Conclusion: The concept of the calcaneus acting as a fulcrum in the lower limb can partially be supported by anatomical, histological, and biomechanical concepts. Despite the plethora of research, a comprehensive understanding is yet to be investigated. Further research exploring the precise interaction is necessary.