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Kinga Ligeti, Lutz P Müller, Carsten Müller-Tidow, Thomas Weber Department of Hematology and Oncology, University Hospital Halle (Saale) and Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany Abstract: Posttransplant lymphoproliferative disease (PTLD) is a major complication after solid organ transplantation and allogeneic hematopoietic stem cell transplantation. The spectrum of PTLD ranges from benign hyperplasia to malignant lymphoma, representing one of the most relevant malignancies in these patients. Most PTLDs are driven by latent Epstein–Barr virus infections. The backbone of treatment is reduction of immunosuppression. Further treatment depends on the type of PTLD and the type of transplantation. A multidisciplinary approach involving transplant team, hematologists, and other disciplines is crucial for the diagnosis and treatment of PTLD and for concurrent preservation of the transplant function. In this study, known pathomechanisms, risk factors, preemptive management, and especially emerging treatment algorithms in PTLD were reviewed. Keywords: lymphoproliferative disease, Epstein-Barr virus, management, rituximab, ­preemptive therapy

Introduction: The Bartoníček/Rammelt classification is established for posterior malleolar fractures. It subdivides the fractures into 5 types and outlines treatment recommendations. This study aims to determine the intraobserver and interobserver reliability of the Bartoníček/Rammelt classification and investigates its applicability regarding treatment recommendations., Materials and Methods: Computed tomography (CT) scans of 80 ankle fractures with a posterior malleolar fracture were analyzed by four observers at two different time points 30 days apart (d1 and d2). Intrarater and interrater reliability was measured using kappa values. The corresponding surgery rates of the fracture subtypes were analyzed, and the surgery rates were correlated with fragment sizes and displacements., Results: A moderate interobserver reliability for d1 0.41 (CI 0.35-0.47) and d2 0.42 (CI 0.36-0.48) was detected. Intraobserver reliability was documented as perfect, with a mean kappa of 0.83. Type II fractures were operated on in 50% of cases. In 50% of type II cases, a nonoperative treatment was chosen. Fragment size correlated strongly with the chosen therapy, and osteosynthesis was performed significantly more often when the fragment size exceeded 3 cm 3 (P < .01)., Conclusions: The Bartoníček/Rammelt classification system showed moderate interobserver reliability and perfect to substantial intraobserver reliability. In clinical practice of this study cohort, the size of the posterior malleolar fragment rather than the dislocation and joint impaction seemed to have the decision to operate on type II or III fractures. Existing treatment recommendations based on the Bartoníček/Rammelt classification correspond to the therapy algorithm carried out in this cohort of patients. Levels of Evidence: Level III: Retrospective study., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Pneumatic tourniquets are frequently employed in extremity surgeries, aiming to enhance intraoperative visibility and minimize blood loss. Although their benefits and drawbacks have been extensively studied in lower limb operations, their impact on upper limb procedures, particularly elbow surgery, remains poorly understood. This study investigates the advantages and risks associated with pneumatic tourniquet used in elbow surgery., Methods: A retrospective analysis was conducted on 183 patients who underwent elbow surgery for fractures between January 2019 and September 2023. Patients were categorized into 2 groups: those who underwent surgery with a tourniquet (WT) and those without a tourniquet (NT). Subgroup analyses were performed based on fracture complexity. Data collected included patient characteristics, tourniquet usage, surgical duration, pre- and postoperative hemoglobin levels, C-reactive protein levels, pain assessments, opioid administration, hospital stay duration, follow-up, complications, and revisions. Statistical analyses were used to identify significant differences and correlations., Results: The use of a tourniquet in elbow surgery yielded several notable outcomes. Patients in the WT group experienced significantly shorter surgical durations and hospital stays. Hemoglobin drop was lower in the WT group, indicating reduced blood loss. However, there were no significant differences in postoperative pain, opioid consumption, or complications between the WT and NT groups. Subgroup analysis revealed that the recorded differences, particularly shorter surgical durations, were more pronounced in complex fractures., Conclusions: This study shows promising results in the use of pneumatic tourniquets in elbow surgery in terms of enhanced efficiency, reduced blood loss, and overall safety, without compromising patient outcomes. However, the potential influence of perioperative decision-making on tourniquet usage underscores the need for further research to elucidate its role and optimize its application, especially in complex elbow fractures., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: Searching for quick determinable biomarkers with high sensitivity and specificity is necessary to improve and optimise the early diagnosis of periprosthetic elbow infection (PEI). Therefore, this study's objective was to evaluate the diagnostic value of synovial fluid interleukin-6 (IL-6) levels for diagnosing PEI in total elbow arthroplasty., Method: Twelve prospective enrolled patients underwent total elbow arthroplasty revision surgery, during which synovial fluid was obtained. Between the initial implantation and the revision procedure were 33.5 ± 41 months (range, 2-144 months). Synovial fluid was collected for immediate IL-6 analysis parallel to the revision surgery. Furthermore, microbiological samples were obtained and analysed. Two groups were defined based on the microbiological results: non-infection and infection group. The ability of synovial fluid IL-6 analysis to predict infection status was explored using receiver operating characteristic curves and further statistical analysis., Results: Synovial fluid IL-6 analysis had a good diagnostic accuracy of 83% for PEI with an area under the curve of 0,79 and an ideal cutoff value (determined using Youden's criterion) of 15244 pg/mL., Discussion: This is the first study to clinically evaluate IL-6 as a diagnostical marker for periprosthetic joint infection (PJI) in total elbow arthroplasty. Our results suggest a good accuracy and high sensitivity for IL-6 to identify a PEI. The analysis of IL-6 can improve surgical decision-making regarding managing total elbow arthroplasty in terms of one- or two-staged revision., Conclusion: IL-6 can play an important role in the perioperative differentiation of infected and non-infected situations., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Short-term outcome of myeloablative (MAC) and reduced intensity (RIC) conditioning in the prospective randomized international EBMT RICMAC study in patients with myelodyplastic syndrome (MDS) was comparable but longer follow up is lacking. Patients with MDS aged 18-65 years were randomized to receive MAC (N = 64) with busulfan/cyclophosphamide or RIC (n = 65) with busulfan/fludarabine followed by stem cell transplantation -(HCT) from HLA matched or mismatched donor. After a median follow-up of 6.2 (0.4-12.5) years, 10-year OS and RFS were 54.0% and 43.9% for RIC and 44.4% and 44.2% for MAC (p = 0.15 and p = 0.78), respectively. Since the first report, 6 patients died on NRM, 4 after RIC, and 2 after MAC. Similarly, 8 patients relapsed (4 in each arm), increasing the number of relapsed patients to 28. The second HCT was performed in 18 pts, 8 in the MAC, and 10 in the RIC arm. In a multivariate analysis, ECOG status and chemotherapy prior to HCT were independent risk factors for OS and RFS, ECOG and low cytogenetic risk for NRM and chemotherapy prior to HCT for RI. Patients with low cytogenetic risk had better OS [p = 0.002], RFS [p = 0.02], and NRM (p = 0.015) after RIC as compared to MAC., (© 2024. The Author(s).)

Purpose: Indirect fixation of coronoid process fractures of the ulna, especially arthroscopically, offers the possibility to avoid extensive medial surgical approaches. However, optimal placement of K-wires for cannulated screw fixation is technically challenging. The aim of the present study was to present guide values for K-wire placement for indirect screw fixation of coronoid tip (COT) and anteromedial facet (AMF) fractures of the ulna., Methods: Computed tomography scans of the elbows of 197 patients with an uninjured ulna were identified and evaluated following a standard measuring protocol. Optimal placement of K-wires was defined as the bisector between the anterior and articular cortex while respecting a 1.6-mm safe zone for each placement. This placement of the K-wires in the COT and the AMF was analyzed by measuring the wire angulation in relation to the posterior ulnar cortex (AUC), the distance from the entry point to the posterior olecranon edge (DPE), and the intraosseous length (IOL). Because the coronoid has a curved shape, measurements of the COT and AMF were expected to differ significantly. Sex was also expected to influence measurements. To determine whether this optimal placement of K-wires can be reliably identified, interobserver and intraobserver reliabilities were evaluated., Results: To address tip fragments, we determined a mean AUC of 64°, DPE of 36 mm, and IOL of 38 mm. Regarding wire placement toward the AMF, the means for the AUC, DPE, and IOL were 79°, 27 mm, and 33 mm, respectively. Statistically significant differences were found between the COT and the AMF for the AUC, DPE, and IOL. Our measuring protocol showed good interobserver and intraobserver reliability., Conclusions: K-wire placement toward the COT demands a smaller angle, a longer IOL, and a more distal entry point than wires placed toward AMF. These differences reflect the curved and complex anatomy of the coronoid., Clinical Relevance: This measuring algorithm can be used to plan osteosynthesis, and the obtained reference values can help understand the coronoid's complex anatomy., (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Background: Chronic HCV infection leads to a complex interplay with adaptive immune cells that may result in B cell dyscrasias like cryoglobulinemia or lymphoma. While direct-acting antiviral therapy has decreased the incidence of severe liver damage, its effect on extrahepatic HCV manifestations such as B cell dyscrasias is still unclear., Methods: We sequenced B cell receptor (BCR) repertoires in patients with chronic HCV mono-infection and patients with HCV with a sustained virological response (SVR) after direct-acting antiviral therapy. This data set was mined for highly neutralizing HCV antibodies and compared to a diffuse large B cell lymphoma data set. The TKO model was used to test the signaling strength of selected B-BCRs in vitro. Single-cell RNA sequencing of chronic HCV and HCV SVR samples was performed to analyze the transcriptome of B cells with HCV-neutralizing antigen receptors., Results: We identified a B cell fingerprint with high richness and somatic hypermutation in patients with chronic HCV and SVR. Convergence to specific immunoglobulin genes produced high-connectivity complementarity-determining region 3 networks. In addition, we observed that IGHV1-69 CDR1 and FR3 mutations characterizing highly neutralizing HCV antibodies corresponded to recurrent point mutations found in clonotypic BCRs of high-grade lymphomas. These BCRs did not show autonomous signaling but a lower activation threshold in an in vitro cell model for the assessment of BCR signaling strength. Single-cell RNA sequencing revealed that B cells carrying these point mutations showed a persisting oncogenic transcriptome signature with dysregulation in signaling nodes such as CARD11, MALT1, RelB, MAPK, and NFAT., Conclusions: We provide evidence that lymphoma-like cells derive from the anti-HCV immune response. In many patients, these cells persist for years after SVR and can be interpreted as a mechanistic basis for HCV-related B cell dyscrasias and increased lymphoma risk even beyond viral elimination., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

This study provides a statistical forecast for the development of total elbow arthroplasties (TEAs) in Germany until 2045. The authors used an autoregressive integrated moving average (ARIMA), Error-Trend-Seasonality (ETS), and Poisson model to forecast trends in total elbow arthroplasty based on demographic information and official procedure statistics. They predict a significant increase in total elbow joint replacements, with a higher prevalence among women than men. Comprehensive national data provided by the Federal Statistical Office of Germany (Statistisches Bundesamt) were used to quantify TEA's total number and incidence rates. Poisson regression, exponential smoothing with Error-Trend-Seasonality, and autoregressive integrated moving average models (ARIMA) were used to predict developments in the total number of surgeries until 2045. Overall, the number of TEAs is projected to increase continuously from 2021 to 2045. This will result in a total number of 982 (TEAs) in 2045 of mostly elderly patients above 80 years. Notably, female patients will receive TEAs 7.5 times more often than men. This is likely influenced by demographic and societal factors such as an ageing population, changes in healthcare access and utilization, and advancements in medical technology. Our projection emphasises the necessity for continuous improvements in surgical training, implant development, and rehabilitation protocols.

Background: Coronal shear fractures of the capitellum are rare injuries which can be challenging to treat. The aim of this study was to compare the biomechanical properties of different internal screw fixation techniques for Dubberley type IA fractures of the capitellum., Methods: In this biomechanical study, Dubberley type IA fractures of the capitellum were created in 30 human fresh-frozen humeri. The specimens were then divided into 3 groups: fixation was either performed with 3 × 3.0 mm headless cannulated compression screws (HCCSs) in anteroposterior (AP) orientation (AP group), 3 × 3.0 mm HCCSs in posteroanterior (PA) orientation (PA group) or with 2 × 3.0 mm HCCSs in PA orientation and 1 × 3.0 mm HCCS in lateral orientation (LAT) group. Displacement under cyclic loading and ultimate load-to-failure were evaluated in all specimens., Results: There was no significant difference in fragment displacement after 2000 cycles between AP and PA groups (0.8 ± 0.5 mm vs. 0.8 ± 0.6 mm; P = .987) or PA and LAT groups (0.8 ± 0.6 mm vs. 0.8 ± 0.3 mm; P = .966). LAT group showed the highest load-to-failure (548 ± 250 N) without reaching statistically significant difference to AP group (388 ± 173 N; P = .101). There was also no significant difference between AP and PA groups (388 ± 173 N vs. 422 ± 114 N; P = .649)., Conclusions: Variations in screw placement had no statistically significant influence on cyclic displacement or load-to-failure in Dubberley Type IA fractures. However, fracture fixation in 2 planes-both the coronal and the sagittal plane-by adding a screw in a lateral to medial direction may be beneficial to increase primary stability., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Whether high-dose cytarabine-based salvage chemotherapy, administered to induce complete remission in patients with poor responsive or relapsed acute myeloid leukaemia scheduled for allogeneic haematopoietic stem-cell transplantation (HSCT) after intensive conditioning confers a survival advantage, is unclear., Methods: To test salvage chemotherapy before allogeneic HSCT, patients aged between 18 and 75 years with non-favourable-risk acute myeloid leukaemia not in complete remission after first induction or untreated first relapse were randomly assigned 1:1 to remission induction with high-dose cytarabine (3 g/m 2 intravenously, 1 g/m 2 intravenously for patients >60 years or with a substantial comorbidity) twice daily on days 1-3 plus mitoxantrone (10 mg/m 2 intravenously) on days 3-5 or immediate allogeneic HSCT for the disease control group. Block randomisation with variable block lengths was used and patients were stratified by age, acute myeloid leukaemia risk, and disease status. The study was open label. The primary endpoint was treatment success, defined as complete remission on day 56 after allogeneic HSCT, with the aim to show non-inferiority for disease control compared with remission induction with a non-inferiority-margin of 5% and one-sided type 1 error of 2·5%. The primary endpoint was analysed in both the intention-to-treat (ITT) population and in the per-protocol population. The trial is completed and was registered at ClinicalTrials.gov, NCT02461537., Findings: 281 patients were enrolled between Sept 17, 2015, and Jan 12, 2022. Of 140 patients randomly assigned to disease control, 135 (96%) proceeded to allogeneic HSCT, 97 (69%) after watchful waiting only. Of 141 patients randomly assigned to remission induction, 134 (95%) received salvage chemotherapy and 128 (91%) patients subsequently proceeded to allogeneic HSCT. In the ITT population, treatment success was observed in 116 (83%) of 140 patients in the disease control group versus 112 (79%) of 141 patients with remission induction (test for non-inferiority, p=0·036). Among per-protocol treated patients, treatment success was observed in 116 (84%) of 138 patients with disease control versus 109 (81%) of 134 patients in the remission induction group (test for non-inferiority, p=0·047). The difference in treatment success between disease control and remission induction was estimated as 3·4% (95% CI -5·8 to 12·6) for the ITT population and 2·7% (-6·3 to 11·8) for the per-protocol population. Fewer patients with disease control compared with remission induction had non-haematological adverse events grade 3 or worse (30 [21%] of 140 patients vs 86 [61%] of 141 patients, χ 2 test p<0·0001). Between randomisation and the start of conditioning, with disease control two patients died from progressive acute myeloid leukaemia and zero from treatment-related complications, and with remission induction two patients died from progressive acute myeloid leukaemia and two from treatment-related complications. Between randomisation and allogeneic HSCT, patients with disease control spent a median of 27 days less in hospital than those with remission induction, ie, the median time in hospital was 15 days (range 7-64) versus 42 days (27-121, U test p<0·0001), respectively., Interpretation: Non-inferiority of disease control could not be shown at the 2·5% significance level. The rate of treatment success was also not statistically better for patients with remission induction. Watchful waiting and immediate transplantation could be an alternative for fit patients with poor response or relapsed acute myeloid leukaemia who have a stem cell donor available. More randomised controlled intention-to-transplant trials are needed to define the optimal treatment before transplantation for patients with active acute myeloid leukaemia., Funding: DKMS and the Gert and Susanna Mayer Stiftung Foundation., Competing Interests: Declaration of interests MSt has served as a consultant for Pfizer, MSD, Bristol-Myers Squibb (BMS), Incyte, Takeda, and Amgen; as a speaker for Pfizer, Medac, MSD, Jazz Pharmaceuticals, Amgen, Novartis, Gilead, Celgene, BMS, AbbVie, and Incyte; has received research funding from Pfizer; and has received travel support from Medac and Pfizer. JMM received research funding from Janssen, Jazz, Astellas, and Novartis; consulting fees from Janssen, Roche, Gilead, AbbVie, Jazz Pharmaceuticals, Pfizer, Astellas, Novartis, AstraZeneca, and Glycostem; honoraria from Novartis, Roche, Janssen, AbbVie, Pfizer, Sanofi, Astellas, and BeiGene; and travel support from BeiGene. GB has received honoraria from Jazz Pharmaceuticals, Gilead Sciences, Novartis, BMS, and Otsuka; has served as a consultant for Novartis and Gilead Sciences; has received research funding from Novartis; and has received travel support from Gilead Sciences and Jazz Pharmaceuticals. LPM has served as a consultant for Pfizer, Amgen, Gilead Sciences, and Novartis; has received research funding from Amgen; and has received travel support from Gilead Sciences. CSchm has received honoraria for lectures, speaker bureaus, manuscript writing, and educational events from Novartis, Jazz Pharmaceuticals, and Neovii. SWK has received honoraria from Kosmas and Eickeler; and travel support from AbbVie, Jazz Pharmaceuticals, and Alexion Pharmaceuticals. WB has received lecture fees from Medac and participated in advisory boards for Gilead, Novartis, Miltenyi, Janssen, and BMS. EJ has received honoraria for lectures from BMS, Jazz Pharmaceuticals, Kite (a Gilead company), and Amgen; payment for expert testimony from Pierre Fabre; and travel support from Medac. UP has received consulting fees from Novartis, AbbVie, BMS, Silence, Sobi, AstraZeneca, Geron, GSK, Gilead, Jazz Pharmaceuticals, Syros, Akeso, Pierre Fabre, Curis, Galapagos, and Servier; honoraria for lectures from Novartis, AbbVie, BMS, and Janssen; travel support from AbbVie, Janssen, and Jazz Pharmazeuticals; and has participated in data safety monitoring board and advisory board meetings for AbbVie, Novartis, Jazz Pharmaceuticals, Nanexa, BMS, and Blueprint. SAK has served as a consultant for Novartis and Pfizer. MK has received lecture fees from Servier; travel support from Janssen and Kite (a Gilead company); and has participated in data safety monitoring and advisory board meetings for Gilead. KS-E has participated in data safety monitoring and advisory board meetings for Kite (a Gilead company). BH has received travel support from Jazz Pharmaceuticals, Janssen, and Kite (a Gilead company). FS has received lecture fees from Jazz Pharmaceuticals, Medac, and Pfizer; participated in advisory boards for Glycostem; and has received travel support from Servier, Medac, and Janssen. NA has received consulting fees from Amgen, Pfizer, AstraZeneca, and MSD and travel support from Amgen and Pfizer. BS has received travel support from AbbVie and Jazz Pharmaceuticals. CSchl has received honoraria from Novartis, AbbVie, Pfizer, AstraZeneca, and Jazz Pharmaceuticals; has served as a consultant for AbbVie, Jazz Pharmaceuticals, Pfizer, Novartis, Takeda, Roche, AstraZeneca, BMS and Celgene, Astellas Pharma, and Laboratories Delbert; has received research funding from AngioBiomed, Boehringer Ingelheim, and Jazz Pharmaceuticals; and has received travel support from Celgene, PharmaMar, Pfizer, AbbVie, and BMS and Celgene. KS received research funding from Active Biotech; has received honoraria from Novartis, BMS and Celgene, and GSK; has served as a consultant for Novartis, BMS and Celgene, and GSK; and has received travel support from Sobi. FL has received consulting fees, lecture fees, research support, and payments for expert testimony from Novartis and has participated in data safety monitoring board and advisory board meetings for Novartis, Pfizer, Incyte, and Biosciences. OK has received honoraria from Jazz Pharmaceuticals, Stemline Therapeutics, Janssen Oncology, and Pfizer and has received travel support from Jazz Pharmaceuticals and AstraZeneca. JScha has received travel support from Gilead and Jazz Pharmaceuticals. CRe has received travel support from Medac and Gilead Sciences. WEB holds stock and other ownership interests in Philogen; has received honoraria from Philogen; has served as a consultant for Philogen; has received research funding from Philogen; holds international patent rights for vascular targeting of tissue factor and siRNA targeting—so far without any return of money and is co-owner and CEO of two biotech start-ups, Anturec and Elvesca; has given expert testimony for Philogen; and has received travel and accommodation expenses from Philogen. HS holds stock and other ownership interests in Intellia Therapeutics, Biontech, and Arvin and Kymera; has received honoraria from Novartis, Robert-Bosch-Gesellschaft für Medizinische Forschung mbH, and Gilead Sciences; has served as a consultant for Gilead Sciences, IKP Stuttgart, and AbbVie; holds patent and other intellectual properties on Samhd1 modulation for treating resistance to cancer therapy, on oncogene redirection, on companion diagnostics for leukaemia treatment, and on markers for responsiveness to an inhibitor of FLT3. GE owns Cellex Cell Professionals. MB received honoraria from Jazz Pharmaceuticals, Alexion Pharmaceuticals, ActiTrexx, and MSD Oncology and has received travel support from Jazz Pharmaceuticals and MSD. J-HM has received consulting fees from Jazz Pharmaceuticals and Novartis; payments for lectures from BMS, Pfizer, Celgene, Novartis, Jazz Pharmaceuticals, BeiGene, and Daiichi Sankyo; and participated in data safety monitoring board or advisory board meetings for Pfizer and Daiichi Sankyo. JSche participated in advisory boards for AbbVie, AstraZeneca, BeiGene, BMS, Sanofi, Medac, MSD, and Janssen and received lecture fees from Astellas, AstraZeneca, BeiGene, BMS, Novartis, Eurocept, and Janssen. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: The anatomical reconstruction of the wrist is the aim when treating distal radius fractures. Current literature on the importance of preoperative reduction in fractures that are treated operatively is limited. Methods: This study investigated the effect of the preoperative closed reduction of distal radius fractures on the day of trauma and the time to surgery on postoperative palmar inclination. A total of eighty patients (48 females and 32 males, mean age 55.6 years) were studied retrospectively. All patients were treated with an open reduction and internal fixation. The palmar inclination angle was measured using X-rays by two investigators, and the interobservers and pre- and post-reduction parameters were compared. Results: When the surgical management of closed distal radius fractures is required, neither initial repositioning nor a delay of up to 14 days to the surgical treatment influences postoperative palmar inclination. Conclusions: The significance of preoperative reduction of distal radius fractures without neurovascular or extensive soft tissue damage is limited and is not leading to improved outcomes. When surgery is about to be performed, surgeons should carefully consider if reduction is really vital preoperatively. Level of evidence: III.

Purpose: Anatomical variations of the concave shaped retrocondylar ulnar groove (RUG) can contribute to ulnar nerve instability. However, there are currently limited available standardized data describing the anatomy of the RUG based on radiologic imaging, such as computed tomography (CT). This study aims to provide a comprehensive description and classification of RUG anatomy based on RUG angle measurements., Methods: 400 CT scans of the elbows of adults showing no signs of osseous damage were evaluated. RUG angles were measured in four anatomically defined axial planes that spanned from the proximal to the distal end of the RUG. Furthermore, distance measurements at the medial epicondyle were conducted. A classification system for the RUG is proposed based on the acquired RUG angles, aiming to categorize the individual angles according to the 25th and 75th percentiles., Results: RUG angles were significantly larger in males compared to females (p < 0.001) accompanied by larger distances including the off-set and height of the medial epicondyle (p < 0.001). RUG angles decreased from proximal to distal locations (p < 0.05)., Conclusion: This study revealed that men exhibited larger RUG angles compared to women, indicating a less-concave shape of the RUG in men. Introducing an objective RUG classification system can improve our understanding of anatomical variations and potentially find application in diagnostics and preoperative planning., (© 2024. The Author(s).)

Objective: The trochlea is of great importance for the stability of the elbow and its fixation in low transcondylar fractures of the distal humerus is especially challenging. The aim of this study was to determine the optimal trochlea fixation in double plate osteosynthesis of intraarticular distal humerus fractures., Methods: A low transcondylar, C3-type distal humerus fracture was created in 20 fresh-frozen human cadaveric humeri. The samples were then randomly divided into two groups of 10 specimens each. Double plate osteosynthesis was performed in both groups. In group A, the two most distal screws of the lateral plate were inserted into the trochlea fragment. In group B, these screws did not extend into the trochlea. Displacement under cyclic loading and ultimate failure loads were determined for all specimens., Results: Group A showed significantly less displacement under cyclic loading in each measurement interval (0.92 mm vs. 1.53 mm after 100 cycles, p = 0 0.006; 1.10 mm vs. 1.84 mm after 1000 cycles, p = 0.007; 1.18 mm vs. 1.98 mm after 2000 cycles, p = 0.008). The ultimate failure load was significantly higher in group A than in group B (345.61 ± 120.389 N vs. 238.42 ± 131.61 N, p = 0.037)., Conclusions: Fixation of the trochlea with interdigitating screws in double plate osteosynthesis of low-condylar type C distal humerus fractures results in superior construct stability., Level of Evidence: not applicable (biomechanical)., Competing Interests: Declaration of competing interest Sebastian Lappen is a consultant for Orthonika Ltd. Sebastian Siebenlist is a consultant for Arthrex Inc. Naples and Medi Bayreuth. No conflict of interest exists for Pavel Kadantsev, Stephanie Geyer., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: Olecranon fractures are classified using the commonly accepted Mayo classification. Its reliability has been analyzed by means of radiographs. A CT scan is often obtained due to joint involvement. Purpose of this study was to evaluate the intra- and interobserver reliability of the Mayo classification based on CT examination., Methods: Radiographic and CT images of 20 olecranon fractures were classified by four surgeons at two time points 30 days apart. Intra- and interobserver reliability were assessed using kappa coefficients., Results: Mean intraobserver reliability between X-rays was substantial and between CTs almost perfect (0.76 and 0.82, respectively). Mean interobserver reliability was fair for X-rays and moderate for CTs (0.32 and 0.44, respectively)., Conclusion: Despite the more detailed imaging compared with radiography only moderate interobserver reliability was found for the classification of olecranon fractures based on CT imaging. This might lead to inconsistent fracture classification in both scientific and clinical setting., Competing Interests: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (© 2024 The Authors.)

Traumatic triceps tendon ruptures are rare and known to result in substantial disability unless appropriate surgical treatment is performed. A traumatic rupture can occur due to a fall onto the outstretched hand. Tearing of the triceps tendon results in a valgus load onto the elbow, which can lead to injuries to the radial head/neck and/or the ulnar collateral ligament. Hence, attention must be paid to associated pathologies after diagnosis of rupture to the distal triceps tendon. Our surgical procedure in these cases includes diagnostic arthroscopy to detect concomitant injuries. In the following, we present three cases where we performed an open suture bridge repair of the triceps tendon followed by suture repair of the ulnar collateral ligament. All patients recovered well and reported no elbow pain or limited range of motion. The ASES and Mayo Elbow Performance scores were 100 at the 1-year follow-up., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Objectives: Buckle fractures of the distal forearm are a common fracture entity in children treated conservatively. Diagnostics primarily include radiographs in 2 planes. Inadequate images may occur in the mostly very young patients. Therefore, additional lateral radiographs are often obtained to assess a possible angular tilt. The aim of this study is to investigate whether a strictly lateral x-ray image has an influence on fracture management., Methods: Seventy-three children with buckle fractures of the distal forearm were included in this retrospective analysis. All cases were analyzed by quality of radiographs, necessity to obtain an additional lateral radiograph, and what influence on fracture management resulted. Follow-up was performed 2 to 4 weeks after immobilization., Results: Thirty-five girls and 38 boys with a mean age of 7.16 years were included; 40 had fractured right and 33 had fractured left arms, respectively. Isolated distal radius fractures occurred in 48 cases, isolated distal ulna fractures in 6 cases, and both bones in 19 cases. Initial radiographic images were evaluated as inadequate in 25 cases. In each of those cases, an additional lateral image was obtained by fluoroscopy without resulting in an alternated fracture management protocol, which was chosen conservatively in each case and resulted in excellent clinical outcome at follow-up examination., Conclusions: Based on our results, the acquisition of additional lateral radiographs seems to be unnecessary in the diagnostic procedure of buckle fractures of the distal forearm, in case a possible palmar or dorsal angulation cannot be entirely assessed on the initial set of radiographs. An additional lateral image had no influence on fracture management, which was chosen conservatively in every case and led to excellent clinical results.Level of evidence: level III., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: The purpose of the study was to determine if the sphericity of the thumb metacarpophalangeal (MCP) joint influences the joint's rotational axis (RA) and elongation patterns of the ulnar collateral ligament (UCL)., Methods: Ulnar collateral ligament origins and attachments of 28 fresh-frozen cadaveric thumbs were marked with a radiopaque marker. Lateral radiographs were obtained in neutral and 20°, 40°, and 60° of flexion. The dorsal and palmar joint gap and the length of four different UCL portions were digitally measured in all flexion states. The RA was determined by the intersection of the midshaft axis of the proximal phalanx in neutral and flexion states. Sphericity of the MCP joint was assessed using morphometric parameters. Joints were grouped as round or flat. Differences in all measured parameters between groups were analyzed., Results: During flexion, the dorsal joint gap increased by 322% in flat joints and 163% in round joints. The palmar joint gap decreased to 45% in flat joints and to 87% in round joints. The RA was at 29% of metacarpal height and 96% of metacarpal length in flat joints and at 40% of height and 86% of length in round joints. Maximum UCL elongation (111%) was noted at 40° flexion in the dorsal proper UCL in flat joints and at 60° flexion in the accessory UCL (117%) in round joints., Conclusions: In flat MCP joints, the RA is more dorsal and distal in the metacarpal head compared to round joints, resulting in a hinged flexion motion. Elongation of the UCL is highest at end flexion in round joints and highest at midflexion in flat joints., Clinical Relevance: The different kinematics of flat and round MCP joints may contribute to the understanding of the pathophysiology of UCL ruptures. The propensity of this injury and the position in which they occur may be affected by the MCP joint morphology., (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Stiffness and pain secondary to end-stage dysfunctional osteoarthritis of the elbow can pose a therapeutic dilemma. Although total elbow arthroplasty is successful in older patients with low functional demand, alternatives to joint replacement must be found in the younger, more active individual. Interposition arthroplasty provides a salvage option for young, high-demand patients who hope to minimize functional restrictions of the affected extremity. The procedure traditionally involves release of both collateral ligaments and the joint capsule, resulting in a higher risk for postoperative instability and complications. The present unilateral technique demonstrates an approach maintaining the integrity of the medial or lateral collateral ligament while still allowing secure graft fixation. Stability can usually be preserved without ligament reconstruction or hinged external fixation if the elbow was stable before surgery., (© 2023 The Authors.)

Purpose: A comprehensive analysis of the morphology of fractures of the coronoid process (CP) can aid diagnosis and guide treatment. The involvement of the radial notch of the ulna (RN)-e.g., in anterolateral facet fractures and transverse fractures of the CP-may influence the biomechanical conditions of the proximal radioulnar joint. However, the morphometric relation between the CP and the RN and the extent to what the proximal radioulnar joint can be affected in these types of fractures is unknown., Methods: A total of 113 embalmed, cadaveric ulnae were dissected. All soft tissue was removed. Strictly lateral, high-resolution photographs were taken and digitally analyzed. The height of the CP and its relation to the RN was measured. Sex differences and correlations between measured parameters were calculated., Results: Mean height of the CP was 16 mm (range: 12-23 mm; SD: 2). Mean height of the RN was 16 mm (11-25 mm; 2.2). The 50% mark of the CP corresponded to 18% (0-56%; 11.2) of the height of the RN. No significant differences were found between male and female specimens., Conclusion: The RN of the ulna extends only to a small part to the CP. Transverse or anterolateral fractures of less than 50% of the coronoid process may involve only a small portion of the proximal radioulnar joint., (© 2023. The Author(s).)

Purpose: After major COVID-19 lockdown measures were suspended in 2021, E-scooter mobility regrew rapidly. In the meantime, multiple studies were published on the potential risks for e-scooter drivers and the necessity for wearing protective equipment. But did the drivers learn their lessons?, Methods: We observed data of E-scooter-related accidents admitted to the emergency department of a level 1 German trauma center in the year 2021 and compared the data with our previous report (July 2019-July 2020)., Results: N = 97 E-scooter-related accidents were included, marking a 50% increase when compared to the previous observation. Most patients were young adults (28.18 ± 1.13 years) with a notable shift towards a male population (25 vs. 63, p = 0.007). While the injury pattern remained unchanged, injury severity, reflected by a significant increase in shock room treatments (p = 0.005), hospital admissions (p = 0.45), and ICU admissions (p = 0.028), increased. Lastly, we report a higher injury severity of patients driving under the influence of alcohol, expressed by significant differences in hospital admissions, shock room treatments, ICU admissions, intracerebral bleeding (p < 0.0001), and injuries requiring surgery (p = 0.0017)., Conclusion: The increase in injury severity and especially the substantial number of accidents due to driving under the influence of alcohol, are alarming for both trauma- and neurosurgeons. As the controversy surrounding the general use of E-scooters will continue, we urge representatives to intensify their efforts regarding prevention campaigns focusing on the potential dangers of E-scooters, especially when driving under the influence of alcohol., (© 2023. The Author(s).)

Introduction: The SARS-CoV-2 pandemic and its associated lockdowns had a profound effect on orthopedic trauma emergencies. This study aimed to investigate the patient volume and injury patterns at a level-one trauma center during the SARS-CoV-2 pandemic and compare them to the pre-pandemic conditions., Materials and Methods: A retrospective chart review of all patients who presented to the orthopedic trauma emergency department of a level-one trauma center in Cologne, Germany within a 2 year period from March 16th, 2019 to March 15th, 2020 (pre-pandemic control) and from March 16th, 2020 and March 15th, 2021 (pandemic) was performed. The pandemic year was separated into three periods: (1) first lockdown, (2) between lockdowns and (3) second lockdown. The absolute numbers of patient presentations, the Manchester triage score (MTS) and the relative proportion of patients with structural organ injuries, fractures and dislocations, of polytraumatized patients, of hospital admissions, of subsequent emergency or semi-elective surgeries and of work-related accidents were evaluated in comparison to the pre-pandemic control., Results: A total of 21,642 patient presentations were included in this study. Significantly less weekly orthopedic trauma emergency patient presentations were recorded during the pandemic (p < 0.01). The MTS was significantly lower during the first lockdown and between lockdowns (p < 0.01). The proportional incidence of overall structural organ injuries, fractures and dislocations, of upper limb fractures/dislocations, of hospital admissions and of patients requiring surgery was significantly increased during the pandemic (p ≤ 0.03). The proportional incidence of work-related injuries was significantly decreased during the pandemic (p < 0.01)., Conclusions: Orthopedic trauma emergency presentations were reduced during the SARS-CoV-2 pandemic. Due to the reluctancy of patients to visit the emergency department during the pandemic, the proportions of relevant injuries in general and of upper limb injuries in particular as well as of patients requiring hospital admission and trauma-related surgery were significantly increased., (© 2023. The Author(s).)

Purpose: Postoperative soft tissue swelling is a significant factor influencing outcomes after elbow surgery. It can crucially affect important parameters such as postoperative mobilization, pain, and subsequently the range of motion (ROM) of the affected limb. Furthermore, lymphedema is considered a significant risk factor for numerous postoperative complications. Manual lymphatic drainage is nowadays part of the standardized post-treatment concept, basing on the concept of activating the lymphatic tissue to absorb stagnated fluid from the tissue into the lymphatic system. This prospective study aims to investigate the influence of technical device-assisted negative pressure therapy (NP) on early functional outcomes after elbow surgery. NP was therefore compared to manual lymphatic drainage (MLD). Is a technical device-based NP suitable for treatment of lymphedema after elbow surgery?, Methods: A total of 50 consecutive patients undergoing elbow surgery were enrolled. The patients were randomized into 2 groups. 25 participants per group were either treated by conventional MLD or NP. The primary outcome parameter was defined as the circumference of the affected limb in cm postoperative up to seven days postoperatively. The secondary outcome parameter was a subjective perception of pain (measured via visual analogue scale, VAS). All parameters were measured on each day of postoperative inpatient care., Results and Conclusion: NP showed an overall equivalent influence compared to MLD in reducing upper limb swelling after surgery. Moreover, the application of NP showed a significant decrease in overall pain perception compared to manual lymphatic drainage on days 2, 4 and 5 after surgery (p <  0.05)., Conclusion: Our findings show that NP could be a useful supplementary device in clinical routine treating postoperative swelling after elbow surgery. Its application is easy, effective and comfortable for the patient. Especially due to the shortage of healthcare workers and physical therapists, there is a need for supportive measures which NP could be., (© 2023. The Author(s).)

Studies on graft reconstruction techniques for ruptured thumb metacarpophalangeal (MCP) ulnar collateral ligaments (UCL) do not consider the variety of MCP joint morphology. Optimal reconstruction method for flat MCP joints is therefore unclear. Twenty-four fresh-frozen, human thumbs were tested for flexion, extension and valgus stability of the MCP joint. After resection of the UCL, four reconstruction methods, differing in the metacarpal origin and phalangeal attachment, were performed on each specimen, which were then tested again in the same way. Specimens were grouped as 'round' or 'flat' depending on morphometric parameters and group differences were analysed. In flat joints, only the non-anatomical Glickel reconstruction and a modified Fairhurst reconstruction maintained normal mobility and stability. In round joints, only the Glickel reconstruction maintained normal mobility and stability. The original Fairhurst method and a modification with the origin palmar in the metacarpus were disadvantageous in both flat and round joints.

Elbow trauma is often accompanied by a loss of independence in daily self-care activities, negatively affecting patients' quality of life. Finite element models can help gaining profound knowledge about native human joint mechanics, which is crucial to adequately restore joint functionality after severe injuries. Therefore, a finite element model of the elbow is required that includes both the radio-capitellar and ulno-trochlear joint and is subjected to loads realistic for activities of daily living. Since no such model has been published, we aim to fill this gap. For comparison, 8 intact cadaveric elbows were subjected to loads of up to 1000 N, after they were placed in an extended position. At each load step, the displacement of the proximal humerus relative to the distal base plate was measured with optical tracking markers and the joint pressure was measured with a pressure mapping sensor. Analogously, eight finite element models were created based on subject-specific CT scans of the corresponding elbow specimens. The CT scans were registered to the positions of tantalum beads in the experiment. The optically measured displacements were applied as boundary conditions. We demonstrated that the workflow can predict the experimental contact pressure distribution with a moderate correlation, the experimental peak pressures in the correct joints and the experimental stiffness with moderate to excellent correlation. The predictions of peak pressure magnitude, contact area and load share on the radius require improvement by precise representation of the cartilage geometry and soft tissues in the model, and proper initial contact in the experiment., 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 © 2023 Elsevier Ltd. All rights reserved.)

Introduction: Nailing of the proximal humerus is an established method for the treatment of proximal humerus fractures. Choice of the correct length for potentially four proximal locking screws is essential for postoperative outcome. Due to positioning of the patient, intraoperative determination of the correct length of the anteroposterior (AP) screw with the x-ray beam is particularly challenging even for experienced surgeons. We hypothesized that there would be a correlation between the projected lengths of the different proximal locking screws and therefore the length of the AP-screw could be determined based on the three lateromedial (LM) screws., Materials and Methods: In this retrospective study (level of evidence: III) CT-scans of shoulders of 289 patients were 3D reconstructed with the program Horos. Using the manufacturer Stryker's instructions, the four proximal locking screws of the T2 Humeral Nail system were reproduced in the 3D reconstructed shoulders. The length of the AP-screw was correlated with the lengths of the LM-screws by Linear Regression and Multiple Linear Regression., Results: The results of this study showed that the lengths of proximal locking screws in proximal humeral nailing correlated significantly with each other. Based on the given data, a formula could be established to calculate the length of the AP-screw based on the lengths of the LM-screws with a probability of 76.5%., Conclusions: This study was able to show that the length of the AP-screw could be determined from the intraoperatively measured lengths of the LM-screws. As our findings base on measurements performed in CT scans, clinical studies are needed to support our data., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The optimal screw placement in arthroscopically assisted fixation of radial head fractures is still an issue and no guiding methods have been evaluated in the recent literature. The study hypothesis was that using a "reference k-wire" percutaneously inserted in and parallel to the radiocapitellar joint would enable to achieve a trajectory more parallel to the radial head articular surface as compared to a free-hand k-wire placement., Methods: Arthroscopically assisted placement of a k-wire in the radial head was performed in seven fresh-frozen human cadaver specimens by three surgeons. Three different techniques were evaluated: freehand drilling (technique A), placement using a "reference" k-wire in the radiocapitellar joint as a reference without (technique B), and with the AO parallel k-wire guide (technique C). Radiographs from all procedures were obtained and the inclination angle "α" between the k-wire and the articular surface of the radial head was measured and compared among the techniques., Results: Angles of 84 radiographs were obtained and showed a mean α angle of 30.1° ± 13° for technique A, 5.7° ± 4.5° for technique B, and 5.4° ± 3.7° for technique C. The angle α was significantly higher with technique A as compared to B (p < 0.0001) and C (p < 0.0001). There was no difference between methods B and C (n.s.). No difference was observed among the surgeons for all three methods (p = 0.66)., Conclusion: With the use of an additional "reference" k-wire placed in the radiocapitellar joint, the guiding k-wire for screw drilling can be placed almost parallel to the radial head joint line with limited variability and a good reproducibility during arthroscopically assisted radial head fracture fixation., Clinical Relevance: The here-presented method of an additional, percutaneous introduced "reference" k-wire is easily applicable and helpful to achieve parallel screw placement during arthroscopically assisted radial head fracture fixation., Level of Evidence: IV, biomechanical cadaver study., (© 2022. The Author(s).)

Introduction: The aim of the present study was to develop a technical process to reproducibly generate terrible triad injuries (TTI) in fresh-frozen human cadaveric specimens, while leaving the skin intact. Such "pre-fractured" specimens, used for scientific analysis and for surgical education, might help to improve current treatment, which is complex and prone to complications., Materials and Methods: To induce the desired fractures, a custom-made fracturing unit was used to apply an axial force on the extended cadaveric elbow specimens, with the forearm pronated and under valgus load. To simulate the valgus load, a pneumatic cylinder was developed to apply valgus stress to the joint by an additional force vector from the lateral side of the joint., Results: The success rate of TTI induction was 92.3% (12/13). Of the 12 radial head fractures, 3 (25%) were classified Mason type II and 9 (75%) Mason type III. The coronoid fractures were grouped in tip subtype 2 (5 fractures, 41.7%), anteromedial facet (AMF) subtype 2 (4 fractures, 33.3%), AMF subtype 3 (1 fracture, 8.3%) and basal subtype 1 (2 fractures, 16.7%)., Conclusions: The present study provides an instrument for successful and reproducible production of dislocation fracture patterns with their typical accompanying soft tissue lesions. The methodology might be applied on a broad basis to be able to perform biomechanical studies regarding primary stability of fixation concepts for TTI and to educate surgeons in a fairly realistic scenario with the surgical treatment of TTI., (© 2022. The Author(s).)

Engraftment and differentiation of donor hematopoietic stem cells is decisive for the clinical success of allogeneic stem cell transplantation (alloSCT) and depends on the recipient's bone marrow (BM) niche. A damaged niche contributes to poor graft function after alloSCT; however, the underlying mechanisms and the role of BM multipotent mesenchymal stromal cells (MSC) are ill-defined. Upon multivariate analysis in 732 individuals, we observed a reduced presence of proliferation-capable MSC in BM aspirates from patients (N = 196) who had undergone alloSCT. This was confirmed by paired analysis in 30 patients showing a higher frequency of samples with a lack of MSC presence post-alloSCT compared with pre-alloSCT. This reduced MSC presence was associated with reduced survival of patients after alloSCT and specifically with impaired graft function. Post-alloSCT MSC showed diminished in vitro proliferation along with a transcriptional antiproliferative signature, upregulation of epithelial-mesenchymal transition and extracellular matrix pathways, and altered impact on cytokine release upon contact with hematopoietic cells. To avoid in vitro culture bias, we isolated the CD146+/CD45-/HLA-DR- BM cell fraction, which comprised the entire MSC population. The post-alloSCT isolated native CD146+MSC showed a similar reduction in proliferation capacity and shared the same antiproliferative transcriptomic signature as for post-alloSCT colony-forming unit fibroblast-derived MSC. Taken together, our data show that alloSCT confers damage to the proliferative capacity of native MSC, which is associated with reduced patient survival after alloSCT and impaired engraftment of allogeneic hematopoiesis. These data represent the basis to elucidate mechanisms of BM niche reconstitution after alloSCT and its therapeutic manipulation., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

T-cell lymphomas are heterogeneous and rare lymphatic malignancies with unfavorable prognosis. Consequently, new therapeutic strategies are needed. The enhancer of zeste homologue 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 and responsible for lysine 27 trimethylation of histone 3. EZH2 is overexpressed in several tumor entities including T-cell neoplasms leading to epigenetic and consecutive oncogenic dysregulation. Thus, pharmacological EZH2 inhibition is a promising target and its clinical evaluation in T-cell lymphomas shows favorable results. We have investigated EZH2 expression in two cohorts of T-cell lymphomas by mRNA-profiling and immunohistochemistry, both revealing overexpression to have a negative impact on patients' prognosis. Furthermore, we have evaluated EZH2 inhibition in a panel of leukemia and lymphoma cell lines with a focus on T-cell lymphomas characterized for canonical EZH2 signaling components. The cell lines were treated with the inhibitors GSK126 or EPZ6438 that inhibit EZH2 specifically by competitive binding at the S -adenosylmethionine (SAM) binding site in combination with the common second-line chemotherapeutic oxaliplatin. The change in cytotoxic effects under pharmacological EZH2 inhibition was evaluated revealing a drastic increase in oxaliplatin resistance after 72 h and longer periods of combinational incubation. This outcome was independent of cell type but associated to reduced intracellular platinum. Pharmacological EZH2 inhibition revealed increased expression in SRE binding proteins, SREBP1/2 and ATP binding cassette subfamily G transporters ABCG1/2. The latter are associated with chemotherapy resistance due to increased platinum efflux. Knockdown experiments revealed that this was independent of the EZH2 functional state. The EZH2 inhibition effect on oxaliplatin resistance and efflux was reduced by additional inhibition of the regulated target proteins. In conclusion, pharmacological EZH2 inhibition is not suitable in combination with the common chemotherapeutic oxaliplatin in T-cell lymphomas revealing an EZH2-independent off-target effect.

The radiologic evaluation of the sagittal angulation of the distal humerus is commonly based on standard lateral radiographs. However, lateral radiographs do not allow to examine the lateral angulation of the capitulum and the trochlea, separately. Although this problem could be approached via computed tomography, there are no data available describing the difference between the angulation of the capitulum and trochlea. Therefore, we aimed to assess sagittal angles of the capitulum and trochlea in relation to the humeral shaft based on 400 CT-scans of the elbow in healthy adults. Angles were measured in sagittal planes at the capitulum center and three anatomically defined trochlea locations and were spanned between the axis of the joint component and the humerus shaft. Angles were tested for differences between measurement locations and correlation with patient characteristics (age, sex, trans-epicondylar distance). Angles increased from lateral to medial measurement locations (107.4 ± 9.6°, 167.4 ± 8.2°, 171.8 ± 7.3°, 179.1 ± 7.0°; p < 0.05). Largest angle differences were detected between the capitulum and trochlea with smallest angles measured at the capitulum. Patient characteristics did not correlate with angles (p > 0.05). Intra-rater-reliability was r = 0.79-0.86. As CT-imaging allows to distinguish between sagittal capitulum and trochlea locations, it might benefit the radiologic diagnostic of sagittal malalignments of the distal humerus at the capitulum and trochlea, separately., (© 2023. The Author(s).)

Introduction: Open reduction and internal fixation (ORIF) of comminuted coronal shear fractures of the distal humerus is challenging. When a concomitant lateral condyle fracture is present, it may be used for a trans-fracture approach to facilitate exposure and fracture reduction. This study aimed to investigate the frequency of lateral condyle fractures in coronal shear fractures of the distal humerus and analyze fracture reduction, fracture union and clinical results following ORIF through a trans-fracture approach., Materials and Methods: All adult patients who underwent treatment for an acute distal humerus fracture during a three-year period in our level-one trauma center were identified. All fractures were classified according to the Orthopaedic Trauma Association (OTA/AO) fracture classification system and all B3 fractures were classified according to the Dubberley classification. B3 fractures with a concomitant radial condyle fracture were identified. The clinical and radiological results, (Mayo Elbow Performance Score = MEPS, Visual Analogue Scale = VAS, range of motion), complications and revision surgeries were analyzed., Results: 53 patients (mean age 52 ± 19 years) were identified. 13 fractures (24.5%) were B3 fractures. Four of them (30.8%) had a concomitant radial condyle fracture. All of these patients underwent ORIF with headless cannulated compression screws and a (postero-)lateral locking plate through a trans-fracture approach. At a minimum follow-up of 24 months, the MEPS was 88 ± 12 points, the VAS was 2 ± 1 and the range of motion was 118° ± 12°. All fractures showed anatomic reduction. One patient developed partial avascular necrosis and underwent arthrolysis at 6 months. One patient underwent partial hardware removal and lateral collateral ligament bracing at 6 months., Conclusions: Lateral condyle fractures are present in about one third of coronal shear fractures of the distal humerus. This injury can be used for a trans-fracture approach to facilitate exposure and to reliably achieve anatomic fracture reduction., (© 2022. The Author(s).)

Introduction: In regard of surgical training, the reproducible simulation of life-like proximal humerus fractures in human cadaveric specimens is desirable. The aim of the present study was to develop a technique that allows simulation of realistic proximal humerus fractures and to analyse the influence of rotator cuff preload on the generated lesions in regards of fracture configuration., Materials and Methods: Ten cadaveric specimens (6 left, 4 right) were fractured using a custom-made drop-test bench, in two groups. Five specimens were fractured without rotator cuff preload, while the other five were fractured with the tendons of the rotator cuff preloaded with 2 kg each. The humeral shaft and the shortened scapula were potted. The humerus was positioned at 90° of abduction and 10° of internal rotation to simulate a fall on the elevated arm. In two specimens of each group, the emergence of the fractures was documented with high-speed video imaging. Pre-fracture radiographs were taken to evaluate the deltoid-tuberosity index as a measure of bone density. Post-fracture X-rays and CT scans were performed to define the exact fracture configurations. Neer's classification was used to analyse the fractures., Results: In all ten cadaveric specimens life-like proximal humerus fractures were achieved. Two III-part and three IV-part fractures resulted in each group. The preloading of the rotator cuff muscles had no further influence on the fracture configuration. High-speed videos of the fracture simulation revealed identical fracture mechanisms for both groups. We observed a two-step fracture mechanism, with initial impaction of the head segment against the glenoid followed by fracturing of the head and the tuberosities and then with further impaction of the shaft against the acromion, which lead to separation of the tuberosities., Conclusion: A high energetic axial impulse can reliably induce realistic proximal humerus fractures in cadaveric specimens. The preload of the rotator cuff muscles had no influence on initial fracture configuration. Therefore, fracture simulation in the proximal humerus is less elaborate. Using the presented technique, pre-fractured specimens are available for real-life surgical education., Level of Evidence: III., (© 2022. The Author(s).)

Background: Complex proximal humeral fracture ranks among the most common fracture types, especially in elderly patients. In locked plate fixation of proximal humerus fractures, the calcar is deciding for screws providing further medial column support. To date, the biomechanical effect of the length of these calcar screws is not well known. The purpose of this study was to analyze the effect of long calcar screws on fresh frozen prefractured cadaveric specimens., Methods: In the present biomechanical study, 8 pairs of cadaveric proximal humeri were fractured identically using a custom-made fracture simulator. ORIF was performed using a locking plate (PHILOS; Fa. Synthes). The specimens were tested in a biomechanical setup under increased axial load without any calcar screws installed, with short calcar screws and long calcar screws installed. Strain gages (4-wire-120 Ohm, Fa. Vishay) mounted on the locking plate were used to evaluate the fixation strain and to give an estimate for primary stability.., Results: The measured strain of the locking plate without calcar screws (804,64 µm/m) at maximum load (200 N) was significantly higher than with short (619,07 µm/m; p = 0.02) or long calcar screws (527,31 µm/m; p = 0.007). Additionally, strain with short calcar screws was noticeably higher in comparison to long calcar screws (619,07 µm/m vs. 527,31 µm/m; p = 0.03)., Conclusion: Use of calcar screws improves the stability of realistically impacted 3-part varus humeral fractures. Long calcar screws that are positioned as close as possible to the joint provide further primary stability compared to short calcar screws., Level of Evidence: Basic science study., (© 2022. The Author(s).)

Introduction: Stiffness after elbow injuries can severely limit daily life. If adequate conservative treatment does not result in satisfactory improvement of elbow function, surgical intervention should be considered. Whether an open or arthroscopic procedure is preferable is still a topic of debate and a systematic review of functional outcomes is lacking., Materials and Methods: We systematically reviewed the available literature searching electronic databases, MEDLINE using the PubMed interface and EMBASE, for studies published between 2013 and 2021. Primary objective was to compare open and arthroscopic arthrolysis' functional outcomes, respectively, especially ROM and MEPS, as well as the accompanied complications. The PRISMA guidelines were applied., Results: 27 studies comprising 1666 patients were included. 1059 patients (63.6%) were treated with open arthrolysis, and 607 patients (36.4%) were treated with arthroscopic arthrolysis. The results presented indicate satisfactory outcomes in open and arthroscopic arthrolysis with regard to functional outcome parameters. Treatment success, defined as excellent or good results according to the Mayo Elbow Performance Score, among the patients treated with an open procedure was 88.8%; 6.3% required revision whereas 18.1% had complications without the need for revision surgery. Within the cohort of arthroscopically treated patients, treatment success was 91.8%. Revisions and complications without further surgical intervention were significantly less frequent than in the open cohort, at 1.6% and 9.1%, respectively., Conclusions: Both open and arthroscopic arthrolysis provide good to excellent functional outcomes. Since the number of complications and revision increases with the invasiveness of the treatment, an arthroscopic procedure might be favored if feasible by indication. The role of forearm rotation and the use of a hinged external fixator remains of interest., Study Design: Level IV; Systematic review., (© 2022. The Author(s).)

Introduction: Varus posteromedial rotational injury mechanisms lead to fractures of the coronoids process' anteromedial facet. As these fractures are often unstable, rapid fracture treatment is vital to prevent progressive osteoarthritis., Materials and Methods: Twelve patients with a fracture of the anteromedial facet treated surgically were enrolled in the study. Computed tomography images were used to classify the fractures according to the system by O'Driscoll et al. Clinical follow-up included each patient's medical record, surgical treatment algorithm, all complications encountered during the follow-up period, Disabilities of the arm, shoulder, and hand score, subjective elbow value, and pain., Results: A total of 8 men (66.7%) and 4 women (33.3%) were treated surgically and followed-up after a mean period of 45 ± 23 months. The mean DASH score was 11.9 ± 12.9 points. One patient complained of transient neuropathy in the innervation area of the ulnar nerve, however, this existed already pre-operatively and resolved after less than three months., Conclusions: The presented patient cohort shows that AMF fracture of the coronoid process are unstable lesions according to the bony instability and the frequently ruptured collateral ligament complexes which need to be addressed. The MCL seems to be affected more frequently than previously appreciated., Level of Evidence: Level IV; Case Series; Treatment Study., Competing Interests: Declaration of Competing Interest All Authors have received financial research support by Medartis and IBRA. Kilian Wegmann and Lars Peter Müller are paid consultants for Medartis and Arthrex. Michael Hackl has a travelling fellowship sponsored by Wright/Tornier. He is further a speaker and course instructor for Medartis and Arthrex., (Copyright © 2023. Published by Elsevier Ltd.)

Importance: The ideal postremission strategy in intermediate-risk acute myeloid leukemia (AML) in first complete remission (CR) has been a matter of debate., Objective: To explore the optimal therapy for patients with intermediate-risk AML after first complete remission., Design, Settings, and Participants: This investigator-initiated, open-label, 2-armed, phase 3 randomized clinical trial assessed patients at 16 hospitals in Germany from February 2, 2011, until July 1, 2018. Key eligibility criteria included cytogenetically defined intermediate-risk AML according to Medical Research Council classification, first CR or CR with incomplete blood cell count recovery after conventional induction therapy, age of 18 to 60 years, and availability of a human leukocyte antigen (HLA)-matched sibling or unrelated donor. A detailed statistical analysis plan was written and finalized on July 7, 2020. Data were exported for analysis on April 13, 2021., Interventions: Patients were randomized 1:1 to receive allogeneic hematopoietic cell transplantation (HCT) or high-dose cytarabine for consolidation and salvage HCT only in case of relapse. Strata for randomization included age (18-40 vs 41-60 years), NPM1 and CEBPA variation status, and donor type (unrelated vs related)., Main Outcomes and Measures: End points included overall-survival as the primary outcome and disease-free survival, cumulative incidence of relapse, treatment-related mortality, and quality of life measured according to the Medical Outcomes Study 36-Item Short-Form Health Survey as secondary outcomes., Results: A total of 143 patients (mean [SD] age, 48.2 [9.8] years; 81 [57%] male) with AML who fulfilled the eligibility criteria were randomized. In the intention-to-treat analysis, the probability of survival at 2 years was 74% (95% CI, 62%-83%) after primary allogeneic HCT and 84% (95% CI, 73%-92%) after consolidation chemotherapy (P = .22). Disease-free survival after HCT at 2 years was 69% (95% CI, 57%-80%) compared with 40% (95% CI, 28%-53%) after consolidation chemotherapy (P = .001). Allogeneic HCT during the first CR was associated with a cumulative incidence of relapse at 2 years of 20% (95% CI, 13%-31%) compared with 58% (95% CI, 47%-71%; P < .001). Nonrelapse mortality at 2 years after primary allogeneic HCT was 9% (95% CI, 5%-19%) and 2% (95% CI, 0%-11%) after consolidation chemotherapy (P = .005). Similar outcomes were observed when analyses were confined to the 96 patients at intermediate risk according to the European Leukemia Network classification. Most importantly, all 41 patients relapsing after consolidation chemotherapy (36 hematologic, 4 molecular, and 1 extramedullary) proceeded to allogeneic HCT. No significant differences in health-related quality of life measures were observed between groups., Conclusions and Relevance: Primary allogeneic HCT during first CR was not associated with superior overall survival compared with consolidation chemotherapy in patients 60 years or younger with intermediate-risk AML during the first CR and an available donor., Trial Registration: ClinicalTrials.gov Identifier: NCT01246752.

Background: Lateral collateral ligament (LCL) tears are frequently observed in fractures and dislocations of the elbow. Recent biomechanical evidence suggests that additional ligament augmentation may improve repair stability. The aim of this biomechanical in-vitro study was to compare the resistance of a locking suture repair of the LCL with a ligament augmentation technique., Material and Methods: Eight fresh frozen cadaveric elbows were evaluated for stability against varus/posterolateral rotatory forces (3 Nm). A strain gauge (µm/m; negative values) was placed at the origin and insertion of the lateral ulnar collateral ligament (LUCL) and cyclic loading was performed for 1000 cycles. We analyzed three distinct scenarios: (A) native LCL, (B) locking transosseou suture repair of the LCL, (C) simple LCL repair with additional ligament augmentation of the LUCL., Results: The mean measured strain was - 416.1 µm/m (A), - 618 µm/m (B) and - 288.5 µm/m (C) with the elbow flexion at 90°; the strain was significantly higher in scenario B compared to C (p = .01). During the cyclic load (1000) the mean measured strain was - 523.1 µm/m (B) and - 226.3 µm/m (C) with the elbow flexion at 60°; the strain was significantly higher in scenario B compared to C (p = .01). No significant difference between the first and the last cycles was observed (p = .09; p = .07). One failure of the LCL repair was observed after 1000 cycles; none of the ligament augmentations failed., Conclusion: Ligament augmentation (C) provides higher resistance compared to the native LCL (A) and to the locking suture repair technique (B). Both techniques, however, hold up during 1000 cycles. While ligament augmentation might enhance the primary stability of the repair, future clinical studies have to show whether this increase in resistance leads to negative effects like higher rates of posttraumatic elbow stiffness., Level of Evidence: Basic science study, biomechanics., (© 2022. The Author(s).)

Background: Knee Spacers are required in two-stage revision surgery of periprosthetic joint infection of the knee. Extended bone and ligamentous defects are often temporarily arthrodised via a static spacer. Regarding their weight-bearing potential and construction, there is no current consent. Our aim was to evaluate three individual static spacer variants with regard to their axial loading capacity., Methods: The static spacer variants were tested in a cadaver model. One after the other, a spacer with metal-reinforced rods, a spacer without metal reinforcement and a rod-less spacer were implanted and tested up to an axial loading of 1000 Newton. Target parameters were plastic deformation, stiffness and spacer movement at both the femoral and tibial surface. Loading was applied up to 1000 Newton. Radiological controls of the bone substance were performed., Findings: The spacer variants did not differ regarding deformation, stiffness or spacer movement. However, deformation increased significantly with the axial load in all spacer variants. Radiographs showed no fracture or spacer-dislocation resulting from testing., Interpretation: While the spacer reinforcement or the sheer presence of a rod did not influence the axial loading capacity in this in vitro study, weightbearing should be discouraged to limit further bone erosion., 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 © 2022 Elsevier Ltd. All rights reserved.)

With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2022 IPEM. Published by Elsevier Ltd. All rights reserved.)

Purpose: Interposition arthroplasty for the post-traumatic osteoarthritic elbow is a salvage procedure used in young and active patients and remains a rare and unexplored therapeutic option., Methods: We systematically reviewed the available literature searching electronic databases, MEDLINE using the PubMed interface and EMBASE. The primary objective was to synthesize functional outcomes and to investigate revision frequencies, but also complication and subsequent surgery rates among patients with surviving grafts. The preferred reporting guidelines for systematic reviews and meta-analyses guidelines were applied., Results: Five studies were left for inclusion, all retrospective in design, comprising 67 patients. The mean age was 40 years, the mean follow-up period was 61 months, and 68.2% of the patients treated were male. Eleven patients (16.4%) were treated with fascia lata autografts, and 56 patients (83.6%) were treated with Achilles tendon allografts. The graft survived in 53 patients (79.1%); the post-operative Mayo Elbow Performance Score averaged 69 points. Fourteen patients (20.9%) required revision surgery. In the setting of graft survival, 39.1% of patients had complications not requiring further surgical treatment and 5.7% of patients with surviving grafts needed subsequent operative treatment within the follow-up period., Conclusion: Given graft survival, this systematic review demonstrated satisfactory functional outcomes following interposition arthroplasty of the post-traumatic osteoarthritic elbow, however, associated with a cumulative complication and subsequent operative treatment rate of 44.8%. In addition, a revision rate of 20.9% needs to be expected. Varus-valgus instability in the pre-operative clinical assessment seems to be associated with unsatisfactory post-operative elbow function. The superiority of either of the two main reported graft methods (fascia lata autograft and Achilles tendon allograft) remains pending, and the role of an external fixator in preventing post-operative instability remains unresolved., (© 2022. The Author(s).)

Background: The purpose of this study was to investigate the primary stability and displacement tendencies of an external fixation system in 2 different configurations in comparison to locking plate fixation in a 3-part proximal humeral fracture model., Methods: Twenty-one fresh-frozen human cadaveric proximal humeral specimens were divided into 3 groups of 7 stripped specimens. An unstable 3-part fracture of the proximal humerus was set. Construct A consisted of the Galaxy Fixation Shoulder System, with fixation in accordance with the manufacturer's recommended technique (3 pairs of threaded wires). Construct B was fixed with an additional pair of threaded wires according to the recommendations of Gumina et al (4 pairs of threaded wires). The remaining 7 specimens were fixed with a locking plate. By use of an optical motion capture system, relative motion at the fracture site and failure load were evaluated during a cyclic loading protocol., Results: Plate osteosynthesis showed the highest cyclic load to failure (895 ± 239 N; range, 597-1135 N), followed by construct B (692 ± 121 N; range, 432-788 N) and construct A (350 ± 190 N; range, 139-615 N). Statistically significant differences were found between plating and construct A (P < .001), between plating and construct B (P = .031), and between construct B and construct A (P = .013). Relative motion at the fracture site, in terms of change in distance during cyclic loading, was lowest with construct B measured at the peak load of 395 N after 11 steps (1.73 ± 1.98 mm; range, 0.53-5.96 mm) and highest with construct A (8.46 ± 10.67 mm; range, 2.26-20.79 mm). Angular change measured at the peak load after 11 steps was lowest with construct B (1.19° ± 0.36°; range, 0.59°-1.7°) and highest with construct A (2.44° ± 1.63°; range, 0.77°-4.04°). Statistically significant differences were found between construct A and construct B and between construct A and plating at various steps of cyclic loading., Conclusion: In this biomechanical study of unstable 3-part proximal humeral fractures, locking plate osteosynthesis demonstrated the highest possible load application. External fixator application with 8 threaded wires (construct B) revealed the least relative motion at the fracture site, without a statistically significant difference compared with locking plates. It therefore represents another valid technique for treatment regarding primary stability. The use of external fixator application with 6 threaded wires (construct A) resulted in the lowest stability and the highest rates of displacement., (Copyright © 2022 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Recipients of allogeneic stem cell transplantation (alloSCT) are at high risk for contracting infectious diseases with high morbidity and mortality. Coronavirus disease 2019 (COVID-19) is a viral respiratory disease that can lead to severe pneumonia and acute respiratory distress syndrome, with a potentially fatal outcome. In this retrospective study conducted on behalf of the German Cooperative Transplant Study Group, we aimed to analyze risk factors, disease course, and outcomes of COVID-19 in patients who underwent alloSCT. AlloSCT recipients who became infected with SARS-CoV-2 at German and Austrian transplant centers between February 2020 and July 2021 were included. Classification of COVID-19 severity into mild, moderate-severe, or critical disease and division of the course of the pandemic into 4 phases were done according to the German Robert Koch Institute. The main endpoint was overall mortality at the end of follow-up. We further analyzed the need for treatment in an intensive care unit (ICU) and the severity of disease. Risk factors were evaluated using univariate and multivariate analyses, and survival analysis was performed using Kaplan-Meier method. The study cohort comprised 130 patients from 14 transplant centers, with a median age at diagnosis of COVID-19 of 59 years (range, 20 to 81 years) and a median interval between alloSCT and COVID-19 of 787 days (range, 19 to 8138 days). The most common underlying diseases were acute myeloid leukemia (45.4%) and lymphoma (10.8%). The majority of patients (84.9%) were infected in the later phases of the pandemic; 20.8% had moderate-severe disease, 12.3% had critical disease, and 19.2% were treated in an ICU. After a median follow-up of 127 days, overall mortality was 16.2%, 52.0% among patients treated in an ICU. Risk factors for mortality in multivariate analysis were active disease (odds ratio [OR], 4.46), infection with SARS-CoV-2 ≤365 days after alloSCT (OR, 5.60), age >60 years (OR, 5.39), and ongoing immunosuppression with cyclosporine (OR, 8.55). Risk factors for developing moderate-severe or critical disease were concurrent immunosuppression (OR, 4.06) and age >40 years (OR, 4.08). Patients after alloSCT exhibit a substantially increased mortality risk after COVID-19 infection compared with the normal population, without considerable improvement over the course of the pandemic. Risk factors include age, early infection post-alloSCT, and active immunosuppression. Further studies are needed to improve prevention and treatment in this high-risk patient group., (Copyright © 2022 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Introduction: Preventing nerve injury is critical in elbow surgery. Distal extension of medial approaches, required for coronoid fracture fixation and graft-replacement, may endanger the median nerve. This study aims to describe an easily identifiable and reproducible anatomical landmark to localize the median nerve distal to the joint line and to delineate how its relative position changes with elbow flexion and forearm rotation., Materials and Methods: The median nerve and the ulnar insertion of the brachialis muscle were identified in eleven fresh-frozen cadaveric specimens after dissection over an extended medial approach. The elbow was brought first in full extension and then in 90° flexion, and the shortest distance between the two structures was measured while rotating the forearm in full pronation, neutral position and full supination., Results: The distance between the median nerve and the brachialis insertion was highest with the elbow flexed and the forearm in neutral position. All distances measured in flexion were larger than those in extension, and all distances measured from the most proximal point of the brachialis insertion were larger than those from the most distal point. Distances in pronation and in supination were smaller than to those in neutral forearm position., Conclusions: The ulnar insertion of the brachialis is a reliable landmark to localize and protect the median nerve at the level of the coronoid base. Elbow flexion and neutral forearm position increase significantly the safety margins between the two structures; this information suggests some modifications to the previously described medial elbow approaches., Level of Evidence: Basic Science Study., (© 2021. The Author(s).)

Purpose: E-scooters are a new type of urban transportation utilized in Germany since June 2019, primarily in larger cities in the context of sharing offers. Such electrically operated standing scooters can be driven at a maximum speed of 20 km/h. A helmet is not mandatory. The aim of this prospective study is to document the injury patterns over the period of 1 year and compare our findings with already available data., Methods: Over a period of 1 year (July 2019-July 2020), data on E-scooter-related accidents treated at a level 1 trauma center of a major German city were prospectively documented. Injury patterns were analyzed, and epidemiological data evaluated., Results: Fifty-nine (35 female, 24 male) accidents were included in the observation period. Mean age of accident victims was 30.03 years (± 9.32). Alcohol influence at the time of accident was detected in 9 cases (15.25%). Many of the accident victims suffered multiple injuries. Most of the injuries were upper (50.84%) and lower extremity (47.45%) as well as craniofacial injuries (62.71%). A helmet was not worn in any of the cases., Conclusion: In the year following their introduction, E-scooter-related accidents have led to an additional burden on the emergency capacities of the involved University Hospital, especially in the summer months of 2019. Protective equipment is de facto not worn. Injuries to the extremities, head, and face were most common. None of the accident victims died. This coincides with results from other major cities in national and international comparison. A more intensive education about injury consequences of unprotected E-scooter use and the discussion of a possible obligation to wear a helmet and further protection equipment for the extremities should take place., (© 2021. The Author(s).)