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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.

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.

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).)

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.)

Recent studies on insulin, leptin, osteocalcin (OCN), and bone remodeling have evoked interest in the interdependence of bone formation and energy household. Accordingly, this study attempts to investigate trauma specific hormone changes in a murine trauma model and its influence on fracture healing. Thereunto 120 female wild type (WT) and leptin-deficient mice underwent either long bone fracture (Fx), traumatic brain injury (TBI), combined trauma (Combined), or neither of it and therefore served as controls (C). Blood samples were taken weekly after trauma and analyzed for insulin and OCN concentrations. Here, WT-mice with Fx and, moreover, with combined trauma showed a greater change in posttraumatic insulin and OCN levels than mice with TBI alone. In the case of leptin-deficiency, insulin changes were still increased after bony lesion, but the posttraumatic OCN was no longer trauma specific. Four weeks after trauma, hormone levels recovered to normal/basal line level in both mouse strains. Thus, WT- and leptin-deficient mice show a trauma specific hyperinsulinaemic stress reaction leading to a reduction in OCN synthesis and release. In WT-mice, this causes a disinhibition and acceleration of fracture healing after combined trauma. In leptin-deficiency, posttraumatic OCN changes are no longer specific and fracture healing is impaired regardless of the preceding trauma.

Local pH is stated to acidify after bone fracture. However, the time course and degree of acidification remain unknown. Whether the acidification pattern within a fracture hematoma is applicable to adjacent muscle hematoma or is exclusive to this regenerative tissue has not been studied to date. Thus, in this study, we aimed to unravel the extent and pattern of acidification in vivo during the early phase post musculoskeletal injury. Local pH changes after fracture and muscle trauma were measured simultaneously in two pre-clinical animal models (sheep/rats) immediately after and up to 48 h post injury. The rat fracture hematoma was further analyzed histologically and metabolomically. In vivo pH measurements in bone and muscle hematoma revealed a local acidification in both animal models, yielding mean pH values in rats of 6.69 and 6.89, with pronounced intra- and inter-individual differences. The metabolomic analysis of the hematomas indicated a link between reduction in tricarboxylic acid cycle activity and pH, thus, metabolic activity within the injured tissues could be causative for the different pH values. The significant acidification within the early musculoskeletal hematoma could enable the employment of the pH for novel, sought-after treatments that allow for spatially and temporally controlled drug release.

Purpose: Developing a guideline for orthopedic trauma surgeons working in civilian trauma hospitals in low-income countries., Methods: This is a retrospective data analysis in a non-governmental organizational trauma hospital in Sierra Leone, Africa. Trauma victims (282), with 349 fractures, were admitted to the hospital 10/2015-01/2016. The incidence of open and closed fractures and the use of implants were evaluated., Results: The most common fractures were open and closed tibial shaft fractures and closed femoral shaft fractures in adults, and closed supracondylar humerus fractures in children. The most used implants were external fixators, K-wires, and intramedullary nails. External fixators were used for open fractures, K-wires for closed fractures in children, hand and foot, and nails for closed fractures of the lower extremity in adults. Plates were used the least and mostly for fractures of the upper extremity, the proximal tibia and malleolar region in adults. The complication rate was 5.67%., Conclusion: Surgeons in low-income country trauma hospitals should treat conservatively on outpatient basis only, to reduce the amount of stationary patients. Open fractures should be treated with external fixators, and closed fractures in children, hand and foot, with K-wires. Closed fractures in adults of the lower extremity should be nailed, and closed fractures in adults of the upper extremity can be treated with plates.

Objectives: The triage of trauma patients is based on patient-given information. The aim of the study was the accuracy of pain intensity, subjective functional impairment, trauma history, and clinical examination in identifying patients with fractures., Methods: We prospectively asked 436 patients with an extremity trauma whether they believed they had a fracture. Pain intensity and subjective functional impairment were also assessed. The physicians were also asked, based on trauma history and clinical examination., Results: The sensitivity and specificity of patient opinion and of the functional questions for fracture detection were low. The combination of history and clinical examination delivered the best results. There was only a slight difference in pain intensity between patients with and those without fractures., Conclusion: Fracture diagnosis based only on patient opinion or subjective functional impairment can be misleading. Pain intensity needs further investigation for its role in fracture detection.

Introduction: The combination of traumatic brain injury (TBI) and long-bone fractures has previously been reported to lead to exuberant callus formation. The aim of this experimental study was to radiographically and biomechanically study the effect of TBI on bone healing in a mouse model., Materials and Methods: 138 female C57/Black6N mice were assigned to four groups (fracture (Fx) / TBI / combined trauma (Fx/TBI) / controls). Femoral osteotomy and TBI served as variables: osteotomies were stabilized with external fixators, TBI was induced with controlled cortical impact injury. During an observation period of four weeks, in vivo micro-CT scans of femora were performed on a weekly basis. Biomechanical testing of femora was performed ex vivo., Results: The combined-trauma group showed increased bone volume, higher mineral density, and a higher rate of gap bridging compared to the fracture group. The combined-trauma group showed increased torsional strength at four weeks., Discussion: TBI results in an increased formation of callus and mineral density compared to normal bone healing in mice. This fact combined with a tendency towards accelerated gap bridging leads to increased torsional strength. The present study underscores the empirical clinical evidence that TBI stimulates bone healing. Identification of underlying pathways could lead to new strategies for bone-stimulating approaches in fracture care.