Fracture non-union represents a complex clinical challenge resulting from an incompletely understood interplay between mechanical and biological factors. Infection frequently contributes to non-union but many cases are misdiagnosed due to a lack of classical clinical symptoms. This study characterized peripheral blood mononuclear cells (PBMCs) from aseptic non-union (NU-AS, n = 24) and fracture-related infected non-union (NU-FRI, n = 20), and compare them to healed controls (H, n = 18). High-dimensional mass cytometry (CyTOF) revealed significant elevations of regulatory T cells (Tregs; p = 0.0028) and T helper 1 (Th1) cells (p = 0.0073), and reduced expression of the activation marker CD38 in CD4+ T cells (p = 0.0016) and Tregs (p = 0.0017) in NU compared to H. In a subgroup analysis between NU-AS and NU-FRI, monocyte and CD38+ Treg cell counts provided excellent diagnostic potential, with the combination achieving a sensitivity of 100% and a specificity of 91.7%. These findings highlight an important role of the activation marker CD38 in diagnosing chronic subclinical infection, which promises earlier identification of appropriate management of these patients.

Nonunions and fracture-related infections represent a significant complication in orthopedic and trauma care, with their incidence rising due to an aging, more comorbid global population and the escalating threat of multi-resistant pathogens. This narrative review highlights pivotal advancements in diagnostics and therapeutic approaches, while also providing an outlook on future directions. Diagnostic methodologies have significantly evolved from traditional cultures to sophisticated molecular techniques like metagenomic next-generation sequencing and advanced imaging. Simultaneously, therapeutic strategies have undergone substantial refinement, encompassing orthoplastic management for infected open fractures and the innovative application of antibiotic-loaded bone substitutes for local drug delivery. The effective integration of these possibilities into daily patient care critically depends on specialized centers. These institutions play an indispensable role in managing complex cases and fostering innovation. Despite considerable progress over the past 25 years, ongoing research, interdisciplinary collaboration, and a steadfast commitment to evidence-based practice remain crucial to transforming management for the future.

The management of complex limb injuries has evolved from a survival-focused approach to one emphasizing functional preservation, patient autonomy and reintegration. Historically, high amputation rates were due to limited vascular repair techniques and prolonged ischemia, particularly during World War II. Pioneering vascular interventions during the Korean and Vietnam Wars, coupled with advances in evacuation and early stabilization, significantly improved limb salvage outcomes. The advent of microsurgery and the orthoplastic approach further revolutionized treatment, facilitating early soft tissue coverage and biologically robust reconstructions. Despite these advancements, modern conflicts - especially those involving improvised explosive devices - present challenges of scale, resource constraints and delayed evacuations, necessitating flexible, phase-based care strategies. Contemporary decision-making increasingly involves patient-centered shared consent processes and must balance surgical feasibility with psychosocial and rehabilitative factors. Studies such as METALS and LEAP highlight that elective amputation may yield comparable, if not superior, outcomes in some cases, especially when supported by advanced prosthetic technologies. This review advocates for a strategic orthoplastic framework where early biological reconstruction, rather than anatomical perfection, guides decision-making. Rehabilitation is reframed as a parallel and integral process rather than a post-surgical adjunct, beginning from the acute phase and continuing iteratively throughout recovery. Utilizing ICF-based tools and patient-reported outcome measures allows individualized goal-setting and dynamic evaluation. Moreover, holistic rehabilitation - especially in military settings - demands interdisciplinary collaboration, early planning, and recognition of personal and environmental factors. Rehabilitation-specific counselling is crucial for both upper and lower extremity injuries, particularly given the psychological, functional, and social consequences of amputation or salvage. Ultimately, successful outcomes hinge not solely on surgical excellence but on the integration of rehabilitation planning, shared decision-making, and patient empowerment throughout the continuum of care.

During the COVID-19 pandemic restrictions such as social distancing, lockdowns and mask mandates were imposed by Germany’s government. After these interventions were abolished, an increase in group A streptococcal infections, including necrotizing fasciitis, was observed in our Level 1 trauma center. The aim of this study was to evaluate the incidence of type I and type II necrotizing fasciitis (NF) before, during and after the COVID-19 pandemic. 165 patients with severe NF, treated in our Level 1 trauma center, were included between 2010 and 2023. Patients were categorized into a pre-mask, mask and post-mask group, according to their date of admission relative to the COVID-19 pandemic. Clinical parameters and patient characteristics were assessed between groups. In the pre-mask group, type I NF (69

Treatment algorithms for fracture nonunion depend on the presence or absence of bacterial infection. However, it is often impossible to identify infection preoperatively. While some infections may present with clinical signs of infection, low-grade infections lack infection signs and have a clinical presentation similar to aseptic nonunion. The clinical relevance of low-grade infection in nonunion is not entirely clear. Therefore, the aim of this study was to evaluate the role of low-grade infection in the development and management of lower extremity nonunion. A prospective multicenter clinical study enrolled patients with femoral or tibial shaft nonunion and regular healed fractures, scheduled for nonunion revision and routine implant removal, respectively. Preoperatively, serum markers including C-reactive protein (CRP), leukocytes, and procalcitonin were determined, clinical infection signs were recorded, and a suspected septic or aseptic diagnosis was made prior to surgery and further diagnostics. Tissue samples were collected for microbiology and histopathology, and osteosynthesis material for sonication. Nonunion patients were followed for twelve months, during which the definitive diagnosis of "septic" or "aseptic" nonunion was made according to diagnostic criteria for fracture-related infection. One hundred and ten patients with nonunion and 34 patients with regular healed fractures were included. Sixty-two nonunion patients were diagnosed as aseptic, 22 with expected and confirmed infection, and 23 with unexpected low-grade infection. Three patients had an unclear diagnosis. Low-grade infection was detected in 28 % of presumed aseptic nonunion patients. Sensitivity and specificity for the suspected diagnosis were 49 % and 95 %, respectively. The suspected diagnosis had a significant impact on revision strategy. All medians of the preoperative blood values were within the reference ranges except for CRP, which was slightly elevated in the expected and confirmed infected nonunion group. Expected and confirmed septic nonunion and unexpected low-grade infected nonunion demonstrated a similar bacterial spectrum. While 10 % of patients with aseptic nonunion required follow-up surgeries, re-operation rates were higher in patients with low-grade infection and expected and confirmed infection at 30 % and 64 %, respectively. Patients with low-grade infections were treated less frequently with systemic antibiotics and for a shorter duration than patients with expected and confirmed infections, with no significant difference in healing rate which was 83 % in low-grade and 62 % in expected and confirmed infections. The healing rate of aseptic nonunion was 90 %. A limitation of this study is the limited number of tissue samples for microbiological and histopathological diagnostics in the suspected aseptic nonunion cohort, which may have led to an underestimation of the low-grade infection rate. Our findings suggest that unexpected low-grade infection is frequently associated with nonunion. While expected and confirmed infected nonunion differs significantly from aseptic nonunion, low-grade infected nonunion is very similar to aseptic nonunion, except for intraoperative bacterial detection. In addition to antibiotic therapy, surgical nonunion revision with implant exchange and debridement appears to be highly effective in achieving consolidation of low-grade infected nonunion.

Background/Objectives: Although extensive research on risk factors for nonunion development has been published, clinicians frequently rely on heuristic reasoning—intuitive, experience-based decision-making—to predict nonunions. However, the accuracy of these intuitive assessments and the influence of clinician experience remain uncertain. This study aims to assess clinicians’ diagnostic accuracy in predicting nonunion, investigate the impact of experience on predictive performance, and identify patient-specific factors contributing to diagnostic errors. Methods: This retrospective, multi-center cohort study included 98 patients with surgically treated tibial shaft fractures between 2018 and 2023 from four level-one trauma centers in Germany. Fracture outcomes were classified as either nonunion (n = 20) or regular fracture healing (n = 78). Patient cases were presented to 24 clinicians. Each clinician independently assessed preoperative and postoperative biplanar X-rays and patient histories to predict fracture healing. Results: Clinicians’ sensitivity significantly improved from 50.4% to 60.2%, while specificity declined (74.0% to 70.7%) with the addition of postoperative information. No significant differences in predictive performance were observed across different levels of clinician experience. Changes in assessment after reviewing postoperative information were equally likely to be beneficial or detrimental. Certain patient factors, including obesity and smoking, influenced prediction errors. Conclusions: This study is the first to assess heuristic reasoning in nonunion prediction. The findings suggest that clinician experience does not significantly enhance diagnostic accuracy under limited-information conditions. Patients should be informed that predicting individual nonunion risk remains challenging. Larger studies are needed to explore the role of patient-specific factors and refine clinical decision-making in fracture healing prognosis.

Treatment guidelines for fracture nonunion differ based on the presence or absence of infection. Low-grade infections without preoperative clinical signs of infection are difficult to distinguish from aseptic cases. Membrane filtration of sonication fluid (MF) has been shown to be a useful method for identifying septic nonunion. Therefore, the aim of this study was to evaluate the diagnostic value of MF in differentiating low-grade infected nonunion from aseptic cases. A prospective multicenter clinical study enrolled 75 patients with femoral or tibial shaft nonunion with planned revision surgery and without clinical suspicion of infection. During revision surgery, tissue from the nonunion zone was sampled for culture and histopathology, and the implant for sonication with MF and colony forming unit (CFU) quantification. Infection was diagnosed according to the diagnostic criteria for fracture-related infection. The diagnostic performance of MF CFU count was evaluated by receiver operating characteristic (ROC) curve and compared with that of tissue culture (TC), sonication fluid broth culture (SFC), and Histopathological Osteomyelitis Evaluation Score (HOES). Fifty-three nonunion cases were aseptic, and 22 had a low-grade infection. ROC curve had an area under the curve of 0.84. The optimal CFU cutoff to discriminate between low-grade infected and aseptic nonunion was 11.1 CFU/10 mL sonication fluid with 64% sensitivity and 89% specificity. SFC showed a higher sensitivity of 82% but a lower specificity of 81%. The sensitivity and specificity of TC were 77% and 96%, respectively, and those of HOES were 9% and 87%, respectively. Implementation of MF in clinical diagnostics as an adjunct to TC may improve the differential diagnosis between low-grade infected nonunion and aseptic nonunion.

The management of soft tissue damage during fracture treatment requires surgical proficiency and meticulous care adhering to established treatment protocols. This approach is paramount for minimizing the risk of potentially limb- or even life-threatening complications such as fracture-related infection (FRI) in all age groups. There is a general consensus on essential measures such as wound assessment, surgical debridement and early use of antibiotics. Treatment should always be based on the correct classification of the fracture and the corresponding soft tissue injury, but needs to be adapted to the individual patient considering general health status, secondary diagnoses and currently available treatment options.

Background: The aim of this study was to evaluate detection rates and risk factors for unsuspected proof of bacteria, as well as clinical and radiologic outcomes following femoral shaft nonunion without clinical signs of infection treated by a single-stage surgical revision procedure including reamed intramedullary exchange nailing. Methods: A retrospective cohort study was performed in a European level I trauma center between January 2015 and December 2022. Fifty-eight patients were included who underwent reamed intramedullary exchange nailing as a single-step procedure for surgical revision of posttraumatic diaphyseal femoral nonunion without any indications of infection in medical history and without clinical signs of local infection. Clinical details of the patients were analyzed and functional and radiologic long-term outcomes were determined. Results: In all patients, with and without proof of bacteria osseous, healing could be observed. The physical component summary of the SF-12 demonstrated significantly better results at least one year after the final surgical revision in case of a negative bacterial culture during exchange nailing. Conclusions: Clinical long-term outcomes demonstrated a trend towards better results following femoral shaft nonunion revision if there was no evidence for the presence of low-grade infected nonunion. In this case, a single-stage surgical procedure may be recommended.

Fracture-related infections caused by mucormycosis are rare and potentially fatal. Evidence-based experience with its treatment is limited, and surgical management ranges from limb salvage to amputation, with indications not always clear. A 56-year-old woman was admitted after an aircraft accident, sustaining major trauma injuries, including a Gustilo-Anderson type III open ankle joint fracture. Initial damage control surgery with external fixation ensued, followed by secondary, definitive internal fixation with plate and screws. The patient developed a fracture-related infection in the ankle caused by Mucor velutinosus. Despite its invasive growth and tenacity, surgical debridement combined with systemic and local antifungal therapy led to remission in this immunocompetent patient. The ankle arthrodesis achieved bone union with a hexapod fixator 10 months post-trauma. In the treatment of opportunistic invasive mucormycosis, a multidisciplinary approach is necessary, especially in patients suffering major trauma injuries. Through apt diagnosis and thorough treatment by experienced surgeons, infectiologists, and pathologists, successful limb salvage may be attained in patients with an otherwise intact immune system, and amputation can be prevented.

Although fracture-related infection (FRI) is a serious complication following bone fractures, a comprehensive definition and diagnostic criteria have only emerged in recent years. According to this consensus definition, the diagnosis of FRI is based on preoperative and intraoperative suggestive or confirmatory criteria. Serum markers, histology, and microbiological cultures are considered to play a crucial role in the FRI diagnostic pathway. However, at the time of publication of the FRI consensus definition in 2018 and its update in 2020, limited data was available on the accuracy of these diagnostic methods. This review aims to provide an overview of recent publications and discuss whether new evidence has been obtained regarding the value of these current diagnostic techniques.Meanwhile, several studies have confirmed the limited prognostic value of C-reactive protein, erythrocyte sedimentation ratio, and white blood cell count. Other serologic markers for preoperative diagnosis of FRI with promising diagnostic performance are d-dimer, plasma fibrinogen, platelet count to mean platelet volume ratio, and a risk prediction model that includes soft tissue injury type and fracture complexity in addition to blood markers. However, their true diagnostic value in daily clinical practice needs to be investigated in further studies. Data on histology in FRI diagnosis is still limited, but its potential as a confirmatory criterion seems to lie in its high specificity. Recent studies indicate that tissue culture exhibits moderate sensitivity and high specificity, with sensitivity improvements achieved by sampling of five specimens and long-term culture. Implant sonication also appears to enhance the sensitivity of culture and the detection rate of polymicrobial infections.In conclusion, the true value of diagnostic techniques is difficult to assess, in part because it is measured against a gold standard that is itself imperfect and still evolving, but also because of methodological differences in sample processing or the use of different thresholds. Nevertheless, this review has identified that the value of current diagnostic techniques is high when used in combination. To draw more accurate conclusions about the value of serum markers, histology, and culture including sonication, future studies should be prospective and utilize a greater standardization in sampling and methodological protocols.

Background: Segmental bone transport using intramedullary or extramedullary techniques is one of the most commonly used procedures for bone defect management in the diaphyseal region of long bones.Objective: The purpose of this work is to provide an overview of the historical development and general principles as well as the current status of extramedullary and intramedullary techniques of bone segment transport. In addition, own results on internal segmental bone transport are presented.Material and methods: A retrospective database analysis included all patients between May 2019 and January 2021 who underwent segmental bone transport via a fully implantable intramedullary segment transport nail system. In addition to the radiological outcome, the clinical outcome was assessed using the lower extremity functional scale (LEFS).Results: A total of 9 patients (8 male, 1 female; age 41.7 +/- 3.9 years) could be included. The cause of the segmental bone defect was chronic fracture-related infection in all cases. The segmental defect size was 62 +/- 10 mm. Sufficient bridging of the bone defect was achieved in all patients, with a mean distraction rate of 0.9 +/- 0.1 mm per day. Bony consolidation of the regeneration was achieved after 292 +/- 57 days, and final bony consolidation of the docking zone was achieved after 469 +/- 116 days. At 22 +/- 3 months after implantation of the segmental transport nail, the LEFS demonstrated a result of 59 +/- 4 points. No recurrence of infection or regeneration failure occurred.Conclusion: The aim of treating segmental bone defects, in addition to reconstructing a load-bearing bone, is to restore correct joint angles, leg length, and leg axis without torsional deviation and can be achieved via classical external segmental bone transport. In recent years, internal segmental bone transport has been developed as an alternative. It remains to be seen whether the preliminary and reproducibly good clinical and radiological results of segmental transport nails can be confirmed for widespread use in the future.

Große Knochendefekte an der unteren Extremität sind sowohl für Patienten als auch für die behandelnden Unfallchirurgen eine große Herausforderung. Die Therapie richtet sich nach der Größe und Lokalisation des Defekts, aber auch patientenspezifische Faktoren wie die Weichteilsituation und vorliegende systemische Erkrankungen müssen in der Behandlungsstrategie berücksichtigt werden. Die Osteodistraktion ist gerade bei großen Knochendefekten über 3 cm eine ausgezeichnete Technik. Sie ist jedoch langwierig und wurde bis zu der Entwicklung von Distraktionsnägeln über einen Fixateur externe durchgeführt. In diesem Beitrag wird das Vorgehen – mit entsprechenden Möglichkeiten und Grenzen – bei der Behandlung von Knochendefekten der unteren Extremität mithilfe des neuen „Plate-assisted-bone-segment-transport“(PABST)-Verfahrens vorgestellt.

AimTreatment algorithms for fracture-related nonunion depend on the presence or absence of bacterial infection. However, the manifestation of septic nonunion varies. Low-grade infections, unlike manifest infections, lack clinical signs of infection and present similarly to aseptic nonunion. The clinical importance of low-grade infection in nonunion is not entirely clear. Therefore, the aim of this study was to evaluate the clinical relevance of low-grade infection in the development and management of femoral or tibial nonunion.MethodA prospective, multicenter clinical study enrolled patients with nonunion and regular healed fractures. Preoperatively, complete blood count without differential, C-reactive protein (CRP), and procalcitonin were obtained, clinical signs of infection were recorded, and a suspected septic or aseptic diagnosis was made based on history and clinical examination. During surgical nonunion revision or routine implant removal, tissue samples were collected for microbiology and histopathology, and osteosynthesis material for sonication. Nonunion patients were followed for 12 months. Definitive diagnosis of “septic” or “aseptic” nonunion was made according to diagnostic criteria for fracture-related infection, considering the results of any further revision surgery during follow-up.Results34 patients with regular healed fractures were included. 62 nonunion patients were diagnosed as aseptic, 22 with manifest, and 23 with low-grade infection. The positive predictive value was 88% and the negative predictive value 72% for the suspected diagnosis. The nonunion groups had significantly higher CRP levels than the regular healer group. Differentiation between septic and aseptic nonunion based on blood values was not possible. Low-grade infection demonstrated less frequently histopathologic signs of infection than manifest infection (22% vs. 50%, p=0.048), with 15% of regular healers having histopathologic signs of infection. Cutibacterium acnes was less present in manifest compared to low-grade infection (p=0.042). Healing rates for septic nonunion involving C. acnes were significantly lower for manifest infection (20%) than for low-grade infection (100%, p=0.002). Patients with low-grade infection were treated with systemic antibiotics less frequently than patients with manifest infection (p=0.026), with no significant difference in healing rate (83% vs. 64%), which was slightly lower for low-grade infection than for aseptic nonunion (90%).ConclusionsLow-grade infections play a significant role in nonunion development and are difficult to diagnose preoperatively due to the lack of clinical signs of infection and unremarkable blood counts. However, our results imply that for low-grade infections, antibiotic therapy may not always be mandatory to heal the nonunion. This study was supported by the German Social Accident Insurance (FF-FR0276).

Background Septic and aseptic nonunion require different therapeutic strategies. However, differential diagnosis is challenging, as low-grade infections and biofilm-bound bacteria often remain undetected. Therefore, the examination of biofilm on implants by sonication and the evaluation of its value for differentiating between femoral or tibial shaft septic and aseptic nonunion in comparison to tissue culture and histopathology was the focus of this study. Materials and methods Osteosynthesis material for sonication and tissue samples for long-term culture and histopathologic examination from 53 patients with aseptic nonunion, 42 with septic nonunion and 32 with regular healed fractures were obtained during surgery. Sonication fluid was concentrated by membrane filtration and colony-forming units (CFU) were quantified after aerobic and anaerobic incubation. CFU cut-off values for differentiating between septic and aseptic nonunion or regular healers were determined by receiver operating characteristic analysis. The performances of the different diagnostic methods were calculated using cross-tabulation. Results The cut-off value for differentiating between septic and aseptic nonunion was ≥ 13.6 CFU/10 ml sonication fluid. With a sensitivity of 52% and a specificity of 93%, the diagnostic performance of membrane filtration was lower than that of tissue culture (69%, 96%) but higher than that of histopathology (14%, 87%). Considering two criteria for infection diagnosis, the sensitivity was similar for one tissue culture with the same pathogen in broth-cultured sonication fluid and two positive tissue cultures (55%). The combination of tissue culture and membrane-filtrated sonication fluid had a sensitivity of 50%, which increased up to 62% when using a lower CFU cut-off determined from regular healers. Furthermore, membrane filtration demonstrated a significantly higher polymicrobial detection rate compared to tissue culture and sonication fluid broth culture. Conclusions Our findings support a multimodal approach for the differential diagnosis of nonunion, with sonication demonstrating substantial usefulness. Level of Evidence : Level 2 Trial registration DRKS00014657 (date of registration: 2018/04/26)

Introduction: Surgical site infections after operative stabilization of pelvic and acetabular fractures are rare but serious complications. The treatment of these infections involves additional surgical procedures, high health care costs, a prolonged stay, and often a worse outcome. In this study, we focused on the impact of the different causing bacteria, negative microbiological results with wound closure, and recurrence rates of patients with implant-associated infections after pelvic surgery. Material and Methods: We retrospectively analyzed a study group of 43 patients with microbiologically proven surgical site infections (SSI) after surgery of the pelvic ring or the acetabulum treated in our clinic between 2009 and 2019. Epidemiological data, injury pattern, surgical approach, and microbiological data were analyzed and correlated with long-term follow-up and recurrence of infection. Results: Almost two thirds of the patients presented with polymicrobial infections, with staphylococci being the most common causing agents. An average of 5.7 (±5.4) surgical procedures were performed until definitive wound closure. Negative microbiological swabs at time of wound closure were only achieved in 9 patients (21%). Long-term follow-up revealed a recurrence of infection in only seven patients (16%) with an average interval between revision surgery and recurrence of 4.7 months. There was no significant difference of recurrence rate for the groups of patients with positive/negative microbiology in the last operative revision (71% vs. 78%). A positive trend for a correlation with recurrent infection was only found for patients with a Morel–Lavallée lesion due to run-over injuries (30% vs. 5%). Identified causing bacteria did not influence the outcome and rate of recurrence. Conclusion: Recurrence rates after surgical revision of implant-associated infections of the pelvis and the acetabulum are low and neither the type of causing agent nor the microbiological status at the timepoint of wound closure has a significant impact on the recurrence rate.

Large bone defects of the lower extremities are challenging for both patients and the treating orthopedic surgeons. The treatment is determined by the size and location of the defect; however, patient-specific factors, such as the soft tissue situation and the presence of systemic comorbidities must be taken into consideration in the treatment strategy. Osteodistraction is an excellent technique especially for large bone defects exceeding 3 cm; however, it is time-consuming and required external fixation prior to the development of motorized distraction nails. This article describes the procedure for the treatment of large bone defects of the lower extremities, with its possibilities and limitations, using the novel plate-assisted bone segment transport (PABST) procedure.

Aim Differentiation of infected (INF) nonunion from aseptic (AS) nonunion is crucial for the choice of intra- and postoperative treatment. Preoperative diagnosis of infected nonunion is challenging, especially in case of low-grade infection lacking clinical signs of infection. Standard blood markers such as C-reactive protein or leucocyte count do not aid in preoperative diagnosis. Proteomic profiling has shown promising results for differentiation of numerous chronic disease states, and in this study was applied to preoperative blood samples of patients with nonunion in an attempt to identify potential biomarkers. Method This prospective multicenter study enrolled patients undergoing revision surgery of femur or tibia nonunion. Patients with implant removal after regular fracture healing (HEAL) were included as a control-group. Preoperative blood samples, intraoperative tissue samples, sonication of osteosynthesis material and 1-year-follow-up questionnaire were taken. Nonunion patients were grouped into INF or AS after assessing bacterial culture and histopathology of retrieved samples. Diagnosis of infection followed the fracture related infection consensus group criteria, with additional consideration of healing one year after revision surgery. Targeted proteomics was used to investigate a predefined panel of 45 cytokines in preoperative blood samples. Statistical differences were calculated with Kruskal Wallis and Dunn's post hoc test. Cytokines with less than 80% of samples being above the lower limit of detection range (LLDR) were excluded for this study. Results We recruited 62 AS, 43 INF and 32 HEAL patients. Patients in the two nonunion groups (INF and AS) did not differ concerning smoking, diabetes or initial open or closed fracture. Thirty-two cytokines were above LLDR in >80% of patients. INF patients showed a significant difference in expression of 8 cytokines compared to AS, with greatest differences observed for Macrophage Colony Stimulating Factor 1 (MCSF-1) and Hepatocyte Growth Factor (HGF) ( p <0.01). In comparing AS with HEAL patients, 9 cytokines displayed significant differences, including interleukin (IL)-6, Vascular Endothelial Growth Factor A (VEGFA), Matrix Metalloproteinase 1 (MMP-1). Comparison of INF with HEAL patients revealed significantly different expression of 20 cytokines, including. IL-6, IL-18, VEGFA or MMP-1. Conclusions Our study revealed differences in plasma cytokine profile of blood samples from INF and AS patients. Although no single biomarker is sufficient to differentiate these patients preoperatively in isolation, future multivariant analysis of this cytokine data in combination with clinical characteristics may provide valuable diagnostic insights. Funded by German Social Accident Insurance (FF-FR 0276) and AO Trauma (AR2021_04).

Der knöcherne Segmenttransport unter Anwendung intra- oder extramedullärer Verfahren stellt im Schaftbereich langer Röhrenknochen eines der häufigsten Verfahren zum knöchernen Defektmanagement dar. Diese Arbeit soll einen Überblick über die historische Entwicklung und allgemeine Prinzipien sowie über den aktuellen Stand der extra- und intramedullären Techniken des Knochensegmenttransports geben. Außerdem werden eigene Ergebnisse zum internen Segmenttransport präsentiert. In eine retrospektiven Datenbankanalyse wurden alle Patienten zwischen Mai 2019 und Januar 2021 eingeschlossen, bei denen der Knochensegmenttransport über ein vollständig implantierbares Segmenttransportnagelsystem durchgeführt wurde. Neben dem radiologischen Outcome wurde das klinische Ergebnis anhand der Lower Extremity Functional Scale (LEFS) erhoben. Es konnten 9 Patienten (8 Männer, eine Frau; Alter 41,7 ± 3,9 Jahre) eingeschlossen werden. Ursache für den segmentalen Knochendefekt war in allen Fällen eine chronische frakturassoziierte Infektion. Die segmentale Defektgröße betrug 62 ± 10 mm. Bei allen Patienten konnte eine suffiziente Überbrückung des Knochendefektes erzielt werden, wobei die mittlere Distraktionsgeschwindigkeit 0,9 ± 0,1 mm/Tag betrug. Die knöcherne Konsolidierung des Regenerats wurde nach 292 ± 57 Tagen und die abschließende knöcherne Konsolidierung der Dockingzone nach 469 ± 116 Tagen erreicht. In der LEFS ergab sich 22 ± 3 Monate nach Implantation des Segmenttransportnagels ein Ergebnis von 59 ± 4 Punkten. Ein Infektrezidiv bzw. Regeneratversagen trat in keinem Fall auf. Das Ziel der Behandlung segmentaler Knochendefekte liegt neben der Rekonstruktion eines lasttragenden Knochens in der Wiederherstellung korrekter Gelenkwinkel, Beinlänge und Beinachsen ohne Torsionsabweichung und lässt sich über den klassischen externen Knochensegmenttransport erreichen. In den letzten Jahren wurde alternativ der interne Segmenttransport entwickelt. Es bleibt abzuwarten, ob sich die vorläufigen und reproduzierbar guten klinischen und radiologischen Ergebnisse der Segmenttransportnägel in Zukunft auch in breiter Anwendung bestätigen lassen.