Sphingosine-1-phosphate promotes osteogenesis by stimulating osteoblast growth and neovascularization in a vascular endothelial growth factor-dependent manner

Sphingosine-1-phosphate (S1P) plays multiple roles in bone metabolism and regeneration. Here, we have identified a novel S1P-regulated osteoanabolic mechanism functionally connecting osteoblasts (OBs) to the highly specialized bone vasculature. We demonstrate that S1P/S1PR3 signaling in OBs stimulates vascular endothelial growth factor a (VEGFa) expression and secretion to promote bone growth in an autocrine and boost osteogenic H-type differentiation of bone marrow endothelial cells in a paracrine manner. VEGFa-neutralizing antibodies and VEGF receptor inhibition by axitinib abrogated OB growth in vitro and bone formation in male C57BL/6J in vivo following S1P stimulation and S1P lyase inhibition, respectively. Pharmacological S1PR3 inhibition and genetic S1PR3 deficiency suppressed VEGFa production, OB growth in vitro, and inhibited H-type angiogenesis and bone growth in male mice in vivo. Together with previous work on the osteoanabolic functions of S1PR2 and S1PR3, our data suggest that S1P-dependent bone regeneration employs several nonredundant positive feedback loops between OBs and the bone vasculature. The identification of this yet unappreciated aspect of osteoanabolic S1P signaling may have implications for regular bone homeostasis as well as diseases where the bone microvasculature is affected such as age-related osteopenia and posttraumatic bone regeneration.

Layer-by-Layer Deposition of Regenerated Silk Fibroin─An Approach to the Surface Coating of Biomedical Implant Materials

Biomaterials and coating techniques unlock major benefits for advanced medical therapies. Here, we explored layer-by-layer (LbL) deposition of silk fibroin (SF) by dip coating to deploy homogeneous films on different materials (titanium, magnesium, and polymers) frequently used for orthopedic and other bone-related implants. Titanium and magnesium specimens underwent preceding plasma electrolytic oxidation (PEO) to increase hydrophilicity. This was determined as surface properties were visualized by scanning electron microscopy and contact angle measurements as well as Fourier transform infrared spectroscopy (FTIR) analysis. Finally, biological in vitro evaluations of hemocompatibility, THP-1 cell culture, and TNF-α assays were conducted. A more hydrophilic surface could be achieved using the PEO surface, and the contact angle for magnesium and titanium showed a reduction from 73 to 18° and from 58 to 17°, respectively. Coating with SF proved successful on all three surfaces, and coating thicknesses of up to 5.14 μm (±SD 0.22 μm) were achieved. Using FTIR analysis, it was shown that the insolubility of the material was achieved by post-treatment with water vapor annealing, although the random coil peak (1640-1649 cm-1) and the α-helix peak (at 1650 cm-1) were still evident. SF did not change hemocompatibility, regardless of the substrate, whereas the PEO-coated materials showed improved hemocompatibility. THP-1 cell culture showed that cells adhered excellently to all of the tested material surfaces. Interestingly, SF coatings induced a significantly higher amount of TNF-α for all materials, indicating an inflammatory response, which plays an important role in a variety of physiological processes, including osteogenesis. LbL coatings of SF are shown to be promising candidates to modulate the body's immune response to implants manufactured from titanium, magnesium, and polymers. They may therefore facilitate future applications for bioactive implant coatings. However, further in vivo studies are needed to confirm the proposed effects on osteogenesis in a physiological environment.

Pharmacological elevation of sphingosine-1-phosphate by S1P lyase inhibition accelerates bone regeneration after post-traumatic osteomyelitis

Posttraumatic osteomyelitis and the ensuing bone defects are a debilitating complication after open fractures with little therapeutic options. We have recently identified potent osteoanabolic effects of sphingosine-1-phosphate (S1P) signalling and have now tested whether it may beneficially affect bone regeneration after infection. We employed pharmacological S1P lyase inhibition by 4-deoxypyrodoxin (DOP) to raise S1P levels in vivo in an unicortical long bone defect model of posttraumatic osteomyelitis in mice. In a translational approach, human bone specimens of clinical osteomyelitis patients were treated in organ culture in vitro with DOP. Bone regeneration was assessed by μCT, histomorphometry, immunohistology and gene expression analysis. The role of S1P receptors was addressed using S1PR3 deficient mice. Here, we present data that DOP treatment markedly enhanced osteogenesis in posttraumatic osteomyelitis. This was accompanied by greatly improved osteoblastogenesis and enhanced angiogenesis in the callus accompanied by osteoclast-mediated bone remodelling. We also identified the target of increased S1P to be the S1PR3 as S1PR3-/- mice showed no improvement of bone regeneration by DOP. In the human bone explants, bone mass significantly increased along with enhanced osteoblastogenesis and angiogenesis. Our data suggest that enhancement of S1P/S1PR3 signalling may be a promising therapeutic target for bone regeneration in posttraumatic osteomyelitis.

Improvement of Predictive Scores in Burn Medicine through Different Machine Learning Approaches

The mortality of severely burned patients can be predicted by multiple scores which have been created over the last decades. As the treatment of burn injuries and intensive care management have improved immensely over the last years, former prediction scores seem to be losing accuracy in predicting survival. Therefore, various modifications of existing scores have been established and innovative scores have been introduced. In this study, we used data from the German Burn Registry and analyzed them regarding patient mortality using different methods of machine learning. We used Classification and Regression Trees (CARTs), random forests, XGBoost, and logistic regression regarding predictive features for patient mortality. Analyzing the data of 1401 patients via machine learning, the factors of full-thickness burns, patient's age, and total burned surface area could be identified as the most important features regarding the prediction of patient mortality following burn trauma. Although the different methods identified similar aspects, application of machine learning shows that more data are necessary for a valid analysis. In the future, the usage of machine learning can contribute to the development of an innovative and precise predictive score in burn medicine and even to further interpretations of relevant data regarding different forms of outcome from the German Burn registry.

Autologous Reconstruction After Failed Implant-Based Breast Reconstruction: A Comparative Multifactorial Outcome Analysis

INTRODUCTION

Failure of an implant-based breast reconstruction often requires a change to an autologous procedure (salvage autologous breast reconstruction [Salv-ABR]). The aim of this study was to compare surgical and patient-reported outcomes of Salv-ABR to immediate or delayed-immediate ABR (I/DI-ABR), which has hardly been addressed in the existing literature.

METHODS

All patients undergoing Salv- or I/DI-ABR between January 2014 and December 2020 were asked to participate in this study. Complication rates, the aesthetic outcome (5-point Likert scale), and quality of life (EORTC QLQ-C30 and -BR23, Breast-Q, Center for Epidemiology Studies Depression Scale) were compared between both procedures.

RESULTS

Seventy patients participated in the study (Salv-ABR: n = 23; mean ± SD age, 53.5 ± 9.1 years; follow-up, 28.6 ± 18.5 month; I/DI-ABR: n = 45, mean ± SD age: 50.2 ± 7.3 years; follow-up, 32.8 ± 18.5 month). Main indication for Salv-ABR was a major capsular contracture (n = 14 [60.1%]). Early unplanned reoperation rates were significantly increased in the Salv-ABR (56.5% vs 14.9%; P < 0.01). Patients with I/DI-ABR showed a significantly improved overall aesthetic outcome (2.7 ± 0.9 vs 3.3 ± 0.7; P < 0.01) and scored significantly higher in several subscales of EORTC QLQ-C30/BR23 (Global Health Status, Role Functioning, Body Image; P < 0.05) and the Breast-Q (Psychosocial Well-being, Satisfaction with Breast; P < 0.05) compared with patients with Salv-ABR.

CONCLUSIONS

Salvage ABR is associated with a higher complication rate, compromised aesthetic outcome, and quality of life compared with I/DI-ABR. This should be considered and discussed with the patient when planning any kind of reconstructive breast surgery.

[Registry Research Funding of the German Society of Plastic, Reconstructive and Aesthetic Surgery (DGPRÄC) and Research Funding Report 2021/2022]

BACKGROUND

Research is an integral part of academic medicine. In plastic surgery, it sets the course for innovations in the specialty. The purpose of this study is to present the research performance of plastic surgeons in Germany for the period 2021/2022 and to compare it with previous periods.

MATERIALS AND METHODS

The directors of plastic surgical academic institutions reported all requested/approved and rejected research applications to public, non-public and industrial funding organizations. Data was gathered within an established online database. In addition, the DFG´s public database GEPRIS was screened for plastic surgical research grants. Data was also collected regarding research infrastructure and organization at the participating centers.

RESULTS

105 applications were reported to 54 different funding agencies from 20 plastic surgery centers. 37 funding applications were submitted to the major public funding agencies DFG, BMBF, BMWi, BMG, BMVg, G-BA and EU. Of these, 59,5% (22/37) were DFG, 13,5% (5/37) each BMBF and EU, 5,4% (2/37) BMWi, and 2,7% (1/37) each BMG, BMVg, and G-BA applications. The average funding volume of these proposals was 401,515 euros. Approved DFG proposals were most frequently assigned to the review board 205-27 Orthopedics, Trauma Surgery, Reconstructive Surgery (n=10/16, 62,5%). Over time, the research registry shows an increase in the number of proposals in general and those granted. 70,0% (14/20) of participating sites had their own experimental research laboratory, while only 40,0% (8/20) had their own clinical trial center.

CONCLUSION

The 2021/2022 Research Funding Report once again highlights the impressive research accomplishments of the plastic surgery community.

[Aggressive Fibromatosis: Retrospective Analysis of 110 Patients]

Aggressive fibromatosis, histologically classified as benign due to the absence of metastasis, is characterised by locally invasive and destructive growth with high recurrence rates after resection. For this reason, prognostic recurrence factors, in particular the extent of resection, are much debated, and treatment decisions seem challenging for interdisciplinary tumour conferences. Between the years 2000 and 2020, 110 patients with aggressive fibromatosis of the extremities or trunk received surgical treatment at BG University Hospital Bergmannsheil (Bochum, Germany). Univariate analyses were performed to detect any potential prognosis factors. The median follow-up time was 5.9 years. A total of 57 (51.8%) of these patients developed recurrence during this period. The 5-year recurrence-free survival was 52.9% (95% CI: 42.4-62.3) in the entire cohort. In R0-resected patients, the 5-year recurrence-free survival (RFS) was significantly better (p<0.001) at 69.2% compared with patients with R1 or R2-resected tumours (32.6%). Beyond that, no other significant influencing factors were identified. The results of this study indicate that R0 resection or R0 resectability were associated with a significantly better local control. The therapeutic recommendation for resection should be made individually by an interdisciplinary tumour board in due consideration of tumour progression, possible therapeutic alternatives, and foreseeable functional impairment.

Digital Media Play a Key Role in Influencing Female Breast Perception

The female breast is a symbol of femininity and plays a key role in the female body image. However, factors influencing the preferences for different breast shapes and sizes are still not elucidated. In particular, the role of the emerging social media in breast perception has not been analyzed yet. A representative cohort of 1,049 adults completed a web-based questionnaire containing hyperrealistic 3D models of the female breast in the United States. A machine-learning algorithm (Classification and Regression Tree [CART]) was implemented to identify the most influential factors. The study was able to identify the frequency of pornographic and social media consumption as the most influencing factor for altered breast preferences. Although digital media exposure did not alter satisfaction with the own breast among female participants, the tendency to undergo or history of conducted aesthetic surgery correlated with higher access frequency to digital media. Taken together, the overpowering impact of social media and pornographic consumption on the own body image was shown in preference alterations for different anatomical aspects of the breast in the whole population and distorted self-perception about the breast in female participants.

The Hypermetabolic Response to Burns and its Treatment: A Literature Review

Abstract:

Major burn injuries provoke a profound stress response marked by extreme hypermetabolism and impaired immune function. The physiological alterations to glucose, protein and lipid metabolism can be detected even years after the inciting burns injury and when untreated can lead to profound wasting, fatty liver, and even death. Therapeutic strategies which target these physiological disturbances are of paramount importance. Treating burn injuries begins with active cooling, to minimize loss of heat and water, and nutrition, to counteract the extensive catabolism. Providers should follow the strict guidelines published to ensure caloric requirements are met in adult and pediatric patients, with supplementation as indicated. Several pharmacotherapies have proven beneficial in helping to counteract and reverse these physiological changes by lowering insulin resistance, slowing catabolism, and minimizing loss of lean body mass. The most promising drugs include anabolic agents such as insulin, recombinant human growth hormone (rhGH), insulin-like growth factor 1 (IGF-1), metformin, beta-blockers, oxandrolone, and fenofibrate. Surgery is a necessary adjunct, either in the acute phase to debride compromised soft tissue and prevent compartment syndromes, but also in the chronic setting to release contractures and fibrotic strictures which may impair function. This narrative literature review provides a synopsis of our understanding of the hypermetabolic response to burn injury and discusses the different treatment options aiming to control postburn hypermetabolism and ultimately improve patient outcomes.

[Analysis of Efficency, Cost Structure and Revenues of ALT Free Flaps in Extremity Reconstruction]

Microvascular reconstructions can be lengthy procedures lasting the entire day. As a result of unforeseeable events, the standardization of these procedures can be challenging. Moreover, the length of these procedures varies strongly, which impedes adequate scheduling and, therefore, optimal capacity utilization. Within the years 2018-2020, the duration of ALT free flap extremity reconstructions was correlated with the experience of the microsurgeon (category 1:<50 free flaps life-time experience, category 2: 50-200, category 3:>200) and comorbidities. The resulting costs were compared with the matrix of the German DRG Institute InEK. The surgical experience of the microsurgeon had a significant impact on the duration of surgery in extremity reconstruction. In due consideration of potential complications, category 2 microsurgeons were 45 minutes faster and category 3 microsurgeons were 167 minutes faster than category 1 microsurgeons. Comorbidities, by contrast, did not have a significant impact on procedure duration. Cost analysis revealed deficits for these procedures in relation to the InEK matrix. However, an additional analysis showed that the duration of surgery was within the German average while costs for personnel/OR minute were slightly below the average. According to this calculation, costs for microsurgical training were approximately 1000€/case. The reimbursement for flaps in extremity reconstruction is not entirely mapped in the German DRG system. Given the longer procedure times, microsurgical training is associated with higher costs. Defining the duration of microsurgery based on the level of expertise should result in improved adherence to schedule and more efficient utilization of the valuable operating room time.

Comparative analysis of clinical outcome and quality of life between amputations and combined bone and flap reconstructions at the lower leg

PURPOSE

At the lower leg, soft tissue defects with exposed bones, tendons, or hardware require flap coverage. In this retrospective study, we analyzed combined bone and soft tissue reconstructions compared to amputations of the lower leg in a civilian setting.

MATERIALS AND METHODS

Patients who underwent combined bone and flap reconstruction (LR) or amputation (LA) of the lower leg were eligible for the study. Bone conditions included fractures and bony defects due to posttraumatic osteomyelitis and non-union. Besides the analysis of the medical history, the study included clinical examination including extremity functional scale (LEFS) and SF-36-questionnaire.

RESULTS

LEFS score was significantly higher in the LR group compared to the LA group. Importantly, 42% in the LR group as opposed to 80% in the LA group could not return to their occupation. Mean hospitalization was 119 in the LR and 49 days in the LA group. SF-36 body item scores were significantly higher in the LR group as compared to LA.

CONCLUSIONS

Patients undergoing complex extremity reconstructions, including flap transfer to the lower leg have better functionality and higher quality of life than amputated patients. These data emphasize the advantages of these procedures and justify reconstructive efforts for limb salvage. Level of Evidence III.Implications for RehabilitationAmputation and combined bone and flap reconstruction in severe injuries of the lower leg can imply functional disabilities even after successful treatment.Albeit longer hospitalizations, patients with complex reconstructions showed better functional outcomes and had a higher quality of life.Limb salvage showed better functional outcomes and a higher rate in reintegration to work as compared to limb amputation.These data emphasize the importance of complex bone and soft tissue reconstruction in this patient cohort.

Interethnic Influencing Factors Regarding Buttocks Body Image in Women from Nigeria, Germany, USA and Japan

BACKGROUND

Body image research deals a lot with awareness of the body as an entity. Studies that consider individual anatomical aspects and place them in an intercultural context are rarely present.

METHODS

For this purpose, general data, body perception and judgment of body images from 2163 (48% female and 52% male) participants from Germany, Nigeria, the USA and Japan were evaluated as part of a survey.

RESULTS

There were clear differences in the personal body image of the participants' own buttocks, the buttocks as a beauty ideal and the way in which dissatisfaction was dealt with in different countries. In addition to sexual well-being (importance score: 0.405 a.u.), the country of origin (0.353), media consumption (0.042) and one's own weight (0.069) were also identified as influencing factors for satisfaction with one's own buttocks. A clear evolution could be derived regarding a WHR (waist-to-hip ratio) of well below 0.7, which was consistently favored by the participants but also propagated by influencers through images (p < 0.001). In this context, participants who indicated celebrities as role models for the buttocks showed a correspondingly high level of dissatisfaction with their own buttocks (R = -0.207, p < 0.001, ρ = -0.218).

CONCLUSION

Overall, a highly significant correlation was shown between the consumption frequency of Instagram, TikTok and pornography with the negative perception of women's own buttocks.

Autologous vs. implant-based breast reconstruction after skin- and nipple-sparing mastectomy—A deeper insight considering surgical and patient-reported outcomes

Introduction

Autologous (ABR) and implant-based breast reconstruction (IBR) represent the most common procedures after skin- and nipple-sparing mastectomy. This cross-sectional study is a comprehensive analysis of ABR and IBR considering surgical and patient-reported outcomes.

Patients and methods

Eligible patients underwent breast reconstruction (ABR and IBR) after skin- and nipple-sparing mastectomy between January 2014 and December 2020. Outcome parameters included quality of life (European Organisation for Research and Treatment of Cancer - EORTC - QLQ30, BR23, Breast-Q, CES-D), complication rates, aesthetic result, and breast sensitivity.

Results

108 patients participated in the study (IBR: n = 72, age 48.9 ± 9.9 years; ABR: n = 36, age: 46.6 ± 7.3 years). Mean follow-up was 27.1 ± 9.3 (IBR) and 34.9 ± 20.5 (ABR), respectively. IBR patients suffered significantly more often from major complications (30.6% vs. 8.3%; p = 0.01), while ABR patients underwent secondary procedures significantly more often to improve the aesthetic result (55.6% vs. 29.2%, p = 0.004). Unilateral reconstructions revealed superior aesthetic results in ABR (n.s.), while in bilateral reconstruction IBR tended to score higher (n.s.). Scar evaluation resulted in a better result of IBR in both categories (p &lt; 0.01). Breast sensitivity was severely impaired in both groups. The Breast-Q revealed a significantly higher “patient satisfaction with breast” after ABR (p = 0.033), while the other QoL-tests and subscales showed no significant differences between the two procedures.

Conclusion

ABR is associated with a higher patient satisfaction despite the high probability of secondary procedures to improve the aesthetic outcome, whereas IBR-patients suffer more often from major complications. Furthermore, the laterality of reconstruction should be included in the individual decision-making process.

The Search for the Ideal Female Breast: A Nationally Representative United-States-Census Study

INTRODUCTION

Many studies have started to search for the perfect aesthetic breast in order to create a pars-pro-toto for reconstruction, but especially for aesthetic surgery. To date, no representative study with anatomically accurate models was performed.

METHODS

In an online based United-States-census-representative survey with 1049 participants, questions regarding the preferred breast were asked utilizing lifelike morphed 3D-generated female models for the first time. Attributes such as breast pole ratio, areola size, breast direction and projection were asked.

RESULTS

The results show that, contrary to what has been claimed in previous studies, an upper-pole-to-lower-pole ratio of 55:45 is preferred by both female and male participants. When it comes to breast size, on the other hand, there are clear gender-specific differences. While women opted for a cup size around B, the men preferred larger cup sizes. Moreover, the smallest depicted areola size of 30 mm was favored among all groups in the survey.

DISCUSSION

Most publications used rather detrimental models for their surveys. We therefore opted for computer-generated 3D models and varied their naturalness. This enabled us to ensure a more aesthetic and accurate illustration and thus obtained more comparable and reliable results paired with the representation of the US-population. Taken together this study unveiled unexpected insights into the population favored breast attributes that might change operative planning in breast surgery.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

TGF-beta pathway inhibition as the therapeutic acceleration of diabetic bone regeneration

Bone regeneration and fracture healing are impaired in diabetic patients due to defective functions of associated cells. Thus, the search for molecular causes and new treatment strategies are of particular clinical relevance. We investigated the gene expression profile of bones from type 2 diabetic (db^- /db^- ) mice and wild-type (wt) mice by comparative microarray analyses before and after placing tibial defects and examined the expression of several osteogenesis- and osteoclastogenesis-related markers by quantitative real-time polymerase chain reaction. In regenerating wt bones, pathways related to, for example, inhibition of matrix metalloproteases were activated, whereas in db^- /db^- bones activation of pathways related to, for example, osteoarthritis, transforming growth factor-beta (Tgfb), or hypoxia-inducible factor 1a were detected during regeneration. We defined the Tgfb pathway as a potential therapeutic target and locally applied a single dose (0.5 µg) of the Tgfb 1, 2, and 3 neutralizing antibody 1D11 on tibial defects in db^- /db^- mice (n = 7). Seven days postoperation, histological and immunohistochemical stainings were performed. Decreased bone regeneration, osteogenic differentiation, osteoclast invasion, and angiogenesis in db^- /db^- mice were significantly restored by local 1D11 application in comparison to the phosphate-buffered saline controls. Thus, local treatment of db^- /db^- bony defects with Tgfb neutralizing antibody 1D11 might be considered a good candidate for the successful acceleration of bone regeneration.

[Fatal necrotizing fasciitis with clostridium perfringens infection following resection of soft tissue sarcoma of the thigh]

We present the case of a 57-year-old male patient with a fatal outcome after resection of a soft tissue sarcoma of the lateral thigh. A polymicrobial surgical site infection with Staphylococcus lugdunensis and Clostridium perfringens caused fulminant necrotising fasciitis with an additional gas gangrene. The patient suffered a severe sepsis with consecutive haemolysis and multiorgan failure. The authors recapitulate the deadly progress of a rarely reported complication after oncological resection. The therapeutic approach and surgical interventions are discussed based on the current literature.

Superior Enhancement of Cutaneous Microcirculation Due to “Cyclic” Application of a Negative Pressure Wound Therapy Device in Humans – Local and Remote Effects

Objectives

Despite a common utilization of “Negative Pressure Wound Therapy” (NPWT) Devices in a wide range of specialties, some of the basic mechanisms of action of the techniques are still on debate. Conflicting results from prior studies demonstrate our lack of understanding how wound-bed perfusion or cutaneous microcirculation is affected by NPWT.

Methods

We conducted a prospective randomized study which included 45 healthy subjects to further investigate the acute effects of NPWT on cutaneous microcirculation underneath the applied dressing. Three modes of application, namely, continuous, intermittent, cyclic, were tested. Amongst others, measurements of elicited surface pressure and a comprehensive microcirculatory analysis were carried out by utilizing an O2C-device. For the detection of (systemic) remote effects, perfusion changes of the contra-lateral thigh were evaluated.

Results

All three tested modes of application led to a significant (p < 0.05) improvement in local tissue perfusion with an increased blood flow of max +151% and tissue oxygen saturation of +28.2% compared to baseline values. Surface pressure under the dressing significantly increased up to 29.29 mmHg due to the activation of the NPWT device. Continuous, intermittent, and cyclic application of negative pressure were accurately sensed by participants, resulting in reported pain values that mirrored the different levels of applied suction. Although the cyclic application mode showed the most pronounced effects regarding microcirculatory changes, no statistical significance between groups was observed.

Conclusion

We could demonstrate a significant improvement of cutaneous microcirculation under an applied NPWT dressing with favorable effects due to cyclic mode of application. An increased surface pressure leads to a better venous drainage of the tissue, which was shown to increase arterial inflow with a consecutive improvement of oxygen supply. Further research is warranted to evaluate our findings regarding wound bed perfusion in the clinical field with respect to formation of granulation tissue and wound healing.

Maggot Extract Interrupts Bacterial Biofilm Formation and Maturation in Combination with Antibiotics by Reducing the Expression of Virulence Genes

Biofilms are aggregates of bacteria encased in an extracellular polymer matrix that acts as a diffusion barrier protecting the microbial community. Bacterial communication occurs by small signaling molecules called quorum sensing (QS) factors, which are involved in the activation of virulence genes and formation of biofilms. Larvae of the green bottle blowfly Lucilia sericata remove necrotic tissue by mechanical action (debridement) and proteolytic digestion. We produced a freeze-dried storable powder from larval extract and investigated its therapeutic effect on biofilms. Larval extract in concentrations of 6 and 12 mg/mL in combination with 0.5% antibiotics (≙50 U/mL penicillin and 50 μg/mL streptomycin) diminished free-floating (planktonic) Pseudomonas aeruginosa maintenance, while it showed no effect on Staphylococcus aureus and was not toxic to dermal cells. We established an ex vivo human dermal wound model. Larval extract in concentrations of 24 and 75 mg/mL in the presence of antibiotics (0.5%) significantly destroyed the biofilm stability of both P. aeruginosa and S. aureus biofilms. Furthermore, SEM analyses revealed crack and gap formations on P. aeruginosa. biofilm surface and decreased expression of P. aeruginosa biofilm maturation and virulence genes (lasR, rhlR and rhlA) was observed after treatment by larval extract in combination with antibiotics.

Fanconi Anemia: Examining Guidelines for Testing All Patients with Hand Anomalies Using a Machine Learning Approach

Background: This study investigated the questionable necessity of genetic testing for Fanconi anemia in children with hand anomalies. The current UK guidelines suggest that every child with radial ray dysplasia or a thumb anomaly should undergo further cost intensive investigation for Fanconi anemia. In this study we reviewed the numbers of patients and referral patterns, as well as the financial and service provision implications UK guidelines provide. Methods: Over three years, every patient with thumb or radial ray anomaly referred to our service was tested for Fanconi Anemia. CART Analysis and machine learning techniques using Waikato Environment for Knowledge Analysis were applied to evaluate single clinical features predicting Fanconi anemia. Results: Youden Index and Predictive Summary Index (PSI) scores suggested no clinical significance of hand anomalies associated with Fanconi anemia. CART Analysis and attribute evaluation with Waikato Environment for Knowledge Analysis (WEKA) showed no single feature predictive for Fanconi anemia. Furthermore, none of the positive Fanconi anemia patients in this study had an isolated upper limb anomaly without presenting other features of Fanconi anemia. Conclusion: As a conclusion, this study does not support Fanconi anemia testing for isolated hand abnormalities in the absence of other features associated with this blood disease.

Wnt3a and ASCs are capable of restoring mineralization in staph aureus-infected primary murine osteoblasts

INTRODUCTION

Bone infections are one of the main reasons for impaired bone regeneration and non-union formation. In previous experimental animal studies we could already demonstrate that bone defects due to prior infections showed a markedly reduced healing capacity, which could effectively be enhanced via application of Wnt3a and Adipose-derived stromal cells (ASCs). For a more in-depth analysis, we investigated proliferation and mineralization of cultured osteoblasts infected with staph aureus and sought to investigate effects of Wnt3a and ASCs on infected osteoblasts.

MATERIALS AND METHODS

Primary murine osteoblasts were isolated from calvariae and infected with staph aureus. Infected osteoblasts received treatment via application of recombinant Wnt3a, ASC conditioned medium and were furthermore cocultured with ASCs. Osteoblasts were evaluated by Alamar blue assay for metabolic activity, TUNEL-assay for apoptosis, ALP and Alizarin Red staining for mineralization. In addition, immunoflourescent staining (IF) and qRT-PCR analyses were performed.

RESULTS

Infected osteoblasts showed a markedly reduced ability for mineralization and increased apoptosis, which could be restored to physiological levels by Wnt3a and ASC treatment. Interestingly, metabolic activity of osteoblasts seemed to be unaffected by staph aureus infection. Additional analyses of Wnt-pathway activity revealed effective enhancement of canonical Wnt-pathway activity in Wnt3a-treated osteoblasts.

CONCLUSIONS

In summary, we gained further osteoblast-related insights into pathomechanisms of reduced bone healing capacity upon infections.

Prophylactic lymphaticovenous anastomoses for resection of soft tissue tumors of the thigh to prevent secondary lymphedema-a retrospective comparative cohort analysis

BACKGROUND

Patients with soft tissue tumors of extremities are at risk to develop secondary lymphedema after tumor resection caused by disruption of lymphatic vessels and sclerosis. Subsequently, this study aimed to evaluate the beneficial effects of lymphaticovenous anastomoses (LVAs) after soft tissue tumor resection of the thigh in a prophylactic approach.

METHODS

In a retrospective cohort study, we compared eight patients with a median age of 68.5 years (49-80) who received LVAs in combination with tumor resection for treatment of soft tissue tumors of the thigh region with a prior cohort of 20 patients with a median age of 63.0 years (23-84) who received soft tissue sarcoma resection of the thigh region. All patients of LVA cohort received 1-2 LVAs (mean 1.25 ± 0.49) at the dorsum of the foot and three patients at the SEKI-point (mean 0.375 ± 0.51). Mean maximum tumor diameter of LVA group was 19.5 ± 5.2 cm and 12.3 ± 6.6 cm of control group. All patients receiving LVA were assessed for development of lymphedema via bilateral measurements of circumference and assessment of lymphedema quality of life index (LyQLI).

RESULTS

One of the eight patients who received LVAs showed moderate impairment in the LyQLI at a follow-up of 12 months while 45% of the control cohort complained about symptoms of secondary lymphedema at a median follow-up of 22 months (p-values LyQLI: p = .018 [physical domain]; p = .018 [psychosocial domain]; p = .020 [practical domain]).

CONCLUSION

LVAs performed in combination with tumor resection of thigh soft tissue tumors reduce negative consequences of lymph stasis and prevent development of secondary lymphedema.

Posttraumatic Lymphedema after Open Fractures of the Lower Extremity-A Retrospective Cohort Analysis

Secondary lymphedema is a very common clinical issue with millions of patients suffering from pain, recurrent skin infections, and the constant need for a decongestive therapy. Well-established as a consequence of oncologic procedures, secondary lymphedema is also a well-known phenomenon after trauma. However, precise epidemiological data of lymphedema progress upon severe extremity injuries are still missing. In the present work, we analyzed a patient cohort of 94 individuals who suffered open fractures of the lower extremity and soft tissue injury, of 2nd and 3rd grade according to Tscherne classification, between 2013 and 2019. Typical symptoms of lymphedema have been obtained via interviews and patient medical records in a retrospective cohort analysis. Of all patients, 55% showed symptoms of secondary lymphedema and 14% reported recurrent skin infections, indicating severe lymphedema. Furthermore, comparing patients with and without lymphedema, additional parameters, such as obesity, total number of surgeries, infections, and compartment syndrome, related to lymphedema progress could be identified. According to these data, posttraumatic secondary lymphedema has a highly underestimated clinical prevalence. Further prospective studies are needed to validate this first observation and to identify high-risk groups in order to improve patient’s health care.

Reconstruction of Septic Tibial Bone Defects With the Masquelet Technique and External Ring Fixation-A Low Healing Rate and High Complication and Revision Rates

OBJECTIVES

To evaluate the results of a series of septic tibial bone defects treated with the Masquelet technique and external ring fixation as a standardized treatment procedure.

DESIGN

Retrospective study.

SETTING

Level one trauma center.

PATIENTS/PARTICIPANTS

All patients 18 years of age or older with septic diaphyseal bone defects of the tibia who underwent induced membrane treatment with ring fixation at our institution between June 1, 2012, and November 31, 2017.

INTERVENTION

Staged management as described by Masquelet using an external ring fixator for definitive fixation.

MAIN OUTCOME MEASUREMENTS

Bony healing at the last follow-up and the time to healing in months. Functional results were assessed according to the scoring system of the Association for the Study and Application of Methods of Ilizarov. The secondary outcome measures were treatment failure and complications.

RESULTS

Thirty-one patients were treated, with a mean follow-up period of 33 months (range, 13-69 months). Overall, among 14 patients assessed as having achieved bone healing, an average of 3.7 surgical revisions were required. The mean healing time was 15.5 months (range, 6-49 months). According to the Association for the Study and Application of Methods of Ilizarov criteria, 7 patients were rated as "excellent" and 6 patients were rated as "good"; one patient showed "poor" functional results. A total of 17 cases of treatment failure and 36 complications were detected.

CONCLUSIONS

The combination of the Masquelet technique and external fixation yielded a low healing rate and was associated with a significant number of cases of treatment failure.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Skeletal stem and progenitor cells maintain cranial suture patency and prevent craniosynostosis

Cranial sutures are major growth centers for the calvarial vault, and their premature fusion leads to a pathologic condition called craniosynostosis. This study investigates whether skeletal stem/progenitor cells are resident in the cranial sutures. Prospective isolation by FACS identifies this population with a significant difference in spatio-temporal representation between fusing versus patent sutures. Transcriptomic analysis highlights a distinct signature in cells derived from the physiological closing PF suture, and scRNA sequencing identifies transcriptional heterogeneity among sutures. Wnt-signaling activation increases skeletal stem/progenitor cells in sutures, whereas its inhibition decreases. Crossing Axin2LacZ/+ mouse, endowing enhanced Wnt activation, to a Twist1+/- mouse model of coronal craniosynostosis enriches skeletal stem/progenitor cells in sutures restoring patency. Co-transplantation of these cells with Wnt3a prevents resynostosis following suturectomy in Twist1+/- mice. Our study reveals that decrease and/or imbalance of skeletal stem/progenitor cells representation within sutures may underlie craniosynostosis. These findings have translational implications toward therapeutic approaches for craniosynostosis.

Myostatin Deficiency Protects C2C12 Cells from Oxidative Stress by Inhibiting Intrinsic Activation of Apoptosis

Ischemia reperfusion (IR) injury remains an important topic in clinical medicine. While a multitude of prophylactic and therapeutic strategies have been proposed, recent studies have illuminated protective effects of myostatin inhibition. This study aims to elaborate on the intracellular pathways involved in myostatin signaling and to explore key proteins that convey protective effects in IR injury. We used CRISPR/Cas9 gene editing to introduce a myostatin (Mstn) deletion into a C2C12 cell line. In subsequent experiments, we evaluated overall cell death, activation of apoptotic pathways, ROS generation, lipid peroxidation, intracellular signaling via mitogen-activated protein kinases (MAPKs), cell migration, and cell proliferation under hypoxic conditions followed by reoxygenation to simulate an IR situation in vitro (hypoxia reoxygenation). It was found that mitogen-activated protein kinase kinase 3/6, also known as MAPK/ERK Kinase 3/6 (MEK3/6), and subsequent p38 MAPK activation were blunted in C2C12-Mstn^−/− cells in response to hypoxia reoxygenation (HR). Similarly, c-Jun N-terminal kinase (JNK) activation was negated. We also found the intrinsic activation of apoptosis to be more important in comparison with the extrinsic activation. Additionally, intercepting myostatin signaling mitigated apoptosis activation. Ultimately, this research validated protective effects of myostatin inhibition in HR and identified potential mediators worth further investigation. Intercepting myostatin signaling did not inhibit ROS generation overall but mitigated cellular injury. In particular, intrinsic activation of apoptosis origination from mitochondria was alleviated. This was presumably mediated by decreased activation of p38 caused by the diminished kinase activity increase of MEK3/6. Overall, this work provides important insights into HR signaling in C2C12-Mstn^−/− cells and could serve as basis for further research.

Hierarchical Ceramic Coating Reduces Adherence of Cells, Blood, Bacteria, and Tissue on Titanium Microsurgical Instruments

BACKGROUND

 Progress in the field of microsurgery allows more detailed reconstructions of the smallest tissue structures. The applied instruments are left with biological residues after coming into contact with body fluids or tissue, leading to compromised surgical precision. Designing of residue-free innovative instruments would reduce the necessity of subsidiary practices and would improve the surgical precision.

METHODS

 We designed a ceramic coating (Lotus ceramic coating system 26-LCC-26) that exhibits self-cleaning surface properties on coated titanium specimens. A titanium surface was modified by blasting technology and electropolishing, followed by applying a high-performance ceramic and sol-gel finish layer. The physical surface characterization was performed by scanning electron microscopy and measuring the contact angle. The cell-repellent properties and cytotoxicity were investigated using live-dead staining, BrdU, and lactate dehydrogenase assay. Furthermore, bacterial and fluid-adhesion tests were performed. Finally, blood compatibility was analyzed according to DIN ISO 10993.

RESULTS

 The composite system LCC-26 increased the hydrophobic character of the titanium surface (the water contact angle of 74.9 degrees was compared with 62.7 degrees of the uncoated native titanium; p < 0.01) and led to the fluid and cell-repellent properties shown by the reduction in fibroblast adherence by ∼50.7% (p < 0.05), the reduction in Staphylococcus aureus pathogen colonization by 74.1% (p < 0.001), and the decrease in erythrocyte adherence by 62.9% (p < 0.01). Furthermore, the LCC-26 coated titanium microforceps dipped in human whole blood exhibited blood-repellent character (reduction in blood adherence by 46.1%; p < 0.05). Additionally, cyto- and hemocompatibility was guaranteed in direct and indirect tests.

CONCLUSION

 Titanium surface modification on surgical instruments exhibits cell, bacteria, and blood-repellent properties with a full guarantee of cyto- and hemocompatibility. Thus, innovatively coated instruments could contribute to increased precision during microsurgical interventions and optimized medical operation routines in the future.

[Necrotizing Fasciitis]

Necrotizing fasciitis (NF) is a soft tissue infection spreading along the fasciae to the surrounding subcutaneous fat, overlying skin and finally musculature, that may rapidly lead to septic shock and death. In order to avoid a massive systemic spread of the infective process, an immediate and extensive radical debridement of necrotic tissues is mandatory complemented by a broad spectrum intravenous antibiotic therapy. Nevertheless, mortality is persistently high at 20-40 %. Because of the lack of specific clinical features in the initial stage of the disease, it is often underestimated or confused with cellulitis or abscess. Hence, early diagnosis is missed or delayed in 85 %-100 % of cases with the passage of valuable time.The aim of this review is to give an overview of the clinical and laboratory elements to be considered for diagnosis as well as the essential therapeutic patterns.

Deficiency of myostatin protects skeletal muscle cells from ischemia reperfusion injury

Ischemia reperfusion (IR) injury plays a pivotal role in many diseases and leads to collateral damage during surgical interventions. While most studies focus on alleviating its severity in the context of brain, liver, kidney, and cardiac tissue, research as regards to skeletal muscle has not been conducted to the same extent. In the past, myostatin (MSTN), primarily known for supressing muscle growth, has been implicated in inflammatory circuits, and research provided promising results for cardiac IR injury mitigation by inhibiting MSTN cell surface receptor ACVR2B. This generated the question if interrupting MSTN signaling could temper IR injury in skeletal muscle. Examining human specimens from free myocutaneous flap transfer demonstrated increased MSTN signaling and tissue damage in terms of apoptotic activity, cell death, tissue edema, and lipid peroxidation. In subsequent in vivo Mstn^Ln/Ln IR injury models, we identified potential mechanisms linking MSTN deficiency to protective effects, among others, inhibition of p38 MAPK signaling and SERCA2a modulation. Furthermore, transcriptional profiling revealed a putative involvement of NK cells. Collectively, this work establishes a protective role of MSTN deficiency in skeletal muscle IR injury.

Ilizarov bone transport using an intramedullary cable transportation system in the treatment of tibial bone defects

INTRODUCTION

Segmental tibia defects remain challenging for orthopedic surgeons to treat. The aim of this study was to demonstrate bone-related and functional outcomes after treatment of complex tibial bone defects using Ilizarov bone transport with a modified intramedullary cable transportation system (CTS).

PATIENTS AND METHODS

We conducted a single-center, retrospective study including all 42 patients treated for tibial bone loss via Ilizarov bone transport with CTS between 2005 and 2018. Bone-related and functional results were evaluated according to the Association for the Study and Application of Methods of Ilizarov (ASAMI) scoring system. Complication and failure rates were determined by the patients' medical files.

RESULTS

Patients had a mean age of 45.5 ± 15.1 years. The mean bone defect size was 7.7 ± 3.4 cm, the average nonunion scoring system (NUSS) score was 59 ± 9.5 points, and the mean follow-up was 40.8 ± 24.4 months (range, 13-139 months). Complete bone and soft tissue healing occurred in 32/42 patients (76.2%). These patients had excellent (10), good (17), fair (2), and poor (3) results based on the ASAMI functional score. Regarding bone stock, 19 patients had excellent, 10 good, and 3 fair results. In total, 37 minor complications and 62 major complications occurred during the study. In 7 patients, bone and soft tissue healing occurred after CTS failure with either an induced membrane technique or classic bone transport; 3 patients underwent lower leg amputation. Patients with treatment failure were significantly older (57.6 vs. 41.8 years; p = 0.003). Charlson score and treatment failure had a positive correlation (Spearman's rho 0.43; p = 0.004).

CONCLUSION

Bone transport using both intramedullary CTS and Ilizarov ring fixation is viable for treating patients with bone loss of the tibia and complex infection or soft tissue conditions. However, a high number of complications and surgical revisions are associated with the treatment of this severe clinical entity and should be taken into account.

Improvement of Superficial and Deep Cutaneous Microcirculation Due to Axillary Plexus Anesthesia Impaired by Smoking

Background: Understanding microvascular physiology is key to any reconstructive procedure. Current concepts in anesthesia increasingly involve regional peripheral nerve blockade during microvascular reconstructive procedures. Whereas favorable effects on perfusion due to these techniques have been reported earlier, little evidence focusing on its effects in most peripheral vascular compartments is available. Methods: A total of 30 patients who were to receive axillary plexus blockade (APB) were included. Microcirculatory assessment of the dependent extremity was conducted utilizing combined laser-Doppler flowmetry and white light spectroscopy. Two probes (1–2 and 7–8 mm penetration depth) were used to assess changes in microcirculation. Results: APB resulted in significant changes to both superficial and deep cutaneous microcirculation. Changes in blood flow were most prominent in superficial layers with a maximum increase of +617% compared to baseline values. Significantly lower values of +292% were observed in deep measurements. Consecutively, a significant enhancement in tissue oxygen saturation was observed. Further analysis revealed a significant impairment of perfusion characteristics due to reported nicotine consumption (max Bf: +936% vs. +176%). Conclusion: Cutaneous microcirculation is strongly affected by APB, with significant differences regarding microvascular anatomy and vascular physiology. Smoking significantly diminishes the elicited improvements in perfusion. Our findings could influence reconstructive strategies as well as dependent perioperative anesthetic management.

Controllable Factors to Reduce the Rate of Complications in Primary Breast Augmentation: A Review of the Literature

BACKGROUND

Aesthetic augmentation mammoplasties are one of the most demanded procedures performed in the aesthetic surgical sector. Because of the high epidemiological impact, the evaluation of measures to reduce the risk of complications is highly needed. The goal of this review is to evaluate the current literature for successful actions to reduce the risk of complications in aesthetic breast augmentation.

METHODS

We searched Medline-listed journals for "complications primary breast augmentation" and defined surgeon-dependent and patient-dependent factors within those.

RESULTS

Most of the strategies to reduce the risk of any complication are based on meticulous hygienic precautions and adequate training of the surgeon. The current literature suggests complications such as capsular contracture, infection and BIA-ALCL are closely linked with bacterial contamination and therefore can be avoided with different hygienic measures.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A novel titanium implant surface modification by plasma electrolytic oxidation (PEO) preventing tendon adhesion

Titanium is one of the most commonly used materials for implants in trauma applications due to its low density, high corrosion resistance and biocompatibility. Nevertheless, there is still a need for improved surface modifications of Titanium, in order to change surface properties such as wettability, antibacterial properties or tissue attachment. In this study, different novel plasma electrolytic oxidation (PEO) modifications have been investigated for tendon adhesion to implants commonly used in hand surgery. Titanium samples with four different PEO modifications were prepared by varying the electrolyte composition and analyzed with regards to their surface properties. Unmodified titanium blanks and Dotize® coating served as controls. Samples were examined using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), contact angle measuring system and analyzed for their biocompatibility and hemocompatibility (according to DIN ISO 10993-5 and 10,993-4). Finally, tendon adhesion of these specific surfaces were investigated by pull-off tests. Our findings show that surface thickness of PEO modifications was about 12-20 μm and had porous morphology. One modification demonstrated hydrophilic behavior accompanied by good biocompatibility without showing cytotoxic properties. Furthermore, no hemolytic effect and no significant influence on hemocompatibility were observed. Pull-off tests revealed a significant reduction of tendon adhesion by 64.3% (35.7% residual adhesion), compared to unmodified titanium (100%). In summary, the novel PEO-based ceramic-like porous modification for titanium surfaces might be considered a good candidate for orthopedic applications supporting a more efficient recovery.

TNF-α modulation via Etanercept restores bone regeneration of atrophic non-unions

Treatment of atrophic non-unions, especially in long bones is a challenging problem in orthopedic surgery due to the high revision and failure rate after surgical intervention. Subsequently, there is a certain need for a supportive treatment option besides surgical treatment. In our previous study we gained first insights into the dynamic processes of atrophic non-union formation and observed a prolonged inflammatory reaction with upregulated TNF-α levels and bone resorption. In this study we aimed to improve bone regeneration of atrophic non-unions via TNF-α modulation in a previously established murine femoral segmental defect model. Animals that developed atrophic non-unions of the femur after 5 and 10 weeks were treated systemically for 10 and 5 weeks with Etanercept, a soluble TNF-α antibody. μCT scans and histology revealed bony bridging of the fracture gap in the treatment group, while bone formation in control animals without treatment was not evident. Moreover, osteoclasts were markedly decreased via modulation of the RANKL/OPG axis due to Etanercept treatment. Additionally, immunomodulatory effects via Etanercept could be observed as further inflammatory agents, such as TGF-β, IL6, MMP9 and 13 were decreased in both treatment groups. This study is the first showing beneficial effects of Etanercept treatment on bone regeneration of atrophic non-union formation. Moreover, the results of this study provide a new and promising therapeutic option which might reduce the failure rate of revision surgeries of atrophic non-unions.

Burn Care in the Greek and Roman Antiquity

The last century brought about more rapid new developments in the treatment of burns, which significantly lowered the mortality of burn injuries. However, burns were already treated in antiquity, where the threshold from spirituality to scientific medicine originated. The existing literature on burn treatment is very limited and there are many cross-references, some of them incorrect. The aim of this work by an interdisciplinary team of historians and physicians is to offer a more precise reproduction of the burn treatment of Greek and Roman antiquity using original texts in context and with a modern scientific background. There are many sources from ancient doctors on the subject of burn treatment, as well as the treatment of burned-out wounds and frostbite, which have not yet been mentioned. The literature research also showed an understanding of scientific contexts in ancient medicine, such as antiseptics or rheology. Interestingly, there was a change in burn medicine from everyday Greek medicine to Roman military medicine with other burn patterns. The care of patients using analgetics and the therapy of burn shock arose from the literature. The ancient world is considered to be the foundation of medicine, but it is believed to have been based mainly on shamanism rather than science. However, already more than two millennia ago, burns were correctly assessed and treated according to today’s scientific standards and scientific relationships were recognized.

Optimizing remote ischemic conditioning (RIC) of cutaneous microcirculation in humans: Number of cycles and duration of acute effects

OBJECTIVE

Non-invasive Remote Ischemic Conditioning (RIC) offers an approach to reduce tissue damage in various organs/tissues. Besides attenuation of Ischemia-Reperfusion injury (I/R), beneficial effects on cutaneous microcirculation of free microsurgical flaps have been reported. Given the recency of this technique, there are considerable gaps in the current understanding of its mechanism of action. As a result, clinical transfer of RIC is prolongated in several fields. We aimed to optimize the RIC protocol by examination of different RIC-cycle numbers and its effect on changes of cutaneous microcirculation and duration.

METHODS

80 subjects were divided into groups (1, 3, 5, 7 RIC cycles). RIC was applied via an inflatable tourniquet. Cutaneous microcirculation was continuously assessed at the contralateral anterior lateral thigh utilizing a ©O2C-device continuously.

RESULTS

RIC caused significant and sustained changes in microcirculation. Four hours after completion of RIC, a maximum increase of +80.8% (CI 1.395-2.221) in blood flow and +23.5% (CI 1.098-1.372) in tissue oxygen saturation was measured (three-cycle group). A higher number of applied cycles was accompanied with significant higher mean pain.

CONCLUSION

Acute improvement of cutaneous microcirculation due to RIC lasted for at least 4 h after completion of the RIC-protocol. Dose-dependent effects of RIC are likely. With regard to the increase in pain, we recommend a RIC protocol of 3 cycles for future clinical application.

In-vivo comparison of the Ni-free steel X13CrMnMoN18-14-3 and titanium alloy implants in rabbit femora - A promising steel for orthopedic surgery

A variety of metallic biomaterials is used for fracture fixation. Allergic reactions towards nickel-containing steels urge the need for alternatives. The present study investigated the suitability of the nickel-free stainless steel P2000 in comparison to titanium alloy implants for bone surgical applications in a rabbit femora defect model. Thirty-six rabbits received two different cylindrical implants press-fit inserted into the distal femoral metaphysis. At day 0, 28, and 56, implant ingrowth was monitored by radiography; implant stability was assessed by pull-out torque measurements while bone-to-implant contact (BIC) was determined histomorphometrically. Radiography revealed comparable implant ingrowth after 1 and 2 months for both implant materials. The pull-out force of P2000 tended to be higher than that for titanium at day 28 (p = .076) but the values were comparable at day 56 (p = .905). At day 56, implant fixation was significantly increased compared to the day of surgery for both, P2000 (p = .030) and for titanium alloy (p = .026). Microscopic examination revealed that both implant types appeared to be well integrated and firmly anchored in the bone. BIC ratio of titanium alloy tended to be higher at day 28 (p = .079) but they did not differ significantly at day 56 (p = .711). In the present rabbit femora defect model, the nickel-free stainless steel P2000 provides primary stability and osseointegration comparable to that of titanium alloy implants.

[Registry Research Funding of the German Society of Plastic, Reconstructive and Aesthetic Surgeons (DGPRÄC) and Research Funding Report 2019/2020]

BACKGROUND

 Since 2015/16 the DGPRÄC collects, evaluates and publishes the research activities of academic sections, departments and clinics for plastic surgery at university hospitals in Germany, in order to raise the awareness of plastic surgical research performance.

MATERIALS AND METHODS

 The directors of plastic surgical academic institutions were contacted via the DGPRÄC and asked to report any requested/approved and rejected research applications to public, non-public and industrial funding organizations. Data was collected in our previously established online database: https://docs.google.com/forms/d/e/1FAIpQLSe6F5xmTyw-k7VKJx_2jkPA4LBXsA0sgBGMrC3rx_4bHj6uzQ/viewform?usp=sf_link. In addition, applications were identified via the DFG's public database GEPRIS.

RESULTS

 A total of 41 funding applications to the public funding institutes DFG, BMBF, BMWi, BMG and EU were identified. 75.6 % (31/41) of the applications had already been approved at the time of data collection, of which 77.4 % (24/31) were DFG, 9.7 % (3/31) were BMWi, 6.5 % (2/31) were EU and 3.2 % (1/31) were BMBF or BMG applications. The average funding amounted to 358 301 Euro. In 50.0 % (12/24) of the cases, the approved DFG proposals were assigned to the subject review board 205-27 Orthopedics, Trauma Surgery, Reconstructive Surgery.

CONCLUSION

 The continuous publication of plastic surgical research funding reports submitted by the convention of university plastic surgeons of the DGPRÄC portraits the excellent, collaborative research activity in the field of plastic surgery.

Comparative proteomic analysis of osteogenic differentiated human adipose tissue and bone marrow-derived stromal cells

Mesenchymal stromal cells are promising candidates for regenerative applications upon treatment of bone defects. Bone marrow‐derived stromal cells (BMSCs) are limited by yield and donor morbidity but show superior osteogenic capacity compared to adipose‐derived stromal cells (ASCs), which are highly abundant and easy to harvest. The underlying reasons for this difference on a proteomic level have not been studied yet. Human ASCs and BMSCs were characterized by FACS analysis and tri‐lineage differentiation, followed by an intraindividual comparative proteomic analysis upon osteogenic differentiation. Results of the proteomic analysis were followed by functional pathway analysis. 29 patients were included with a total of 58 specimen analysed. In these, out of 5148 identified proteins 2095 could be quantified in >80% of samples of both cell types, 427 in >80% of ASCs only and 102 in >80% of BMSCs only. 281 proteins were differentially regulated with a fold change of >1.5 of which 204 were higher abundant in BMSCs and 77 in ASCs. Integrin cell surface interactions were the most overrepresented pathway with 5 integrins being among the proteins with highest fold change. Integrin 11a, a known key protein for osteogenesis, could be identified as strongly up‐regulated in BMSC confirmed by Western blotting. The integrin expression profile is one of the key distinctive features of osteogenic differentiated BMSCs and ASCs. Thus, they represent a promising target for modifications of ASCs aiming to improve their osteogenic capacity and approximate them to that of BMSCs.

Antibiotic prophylaxis for prevention of wound infections after soft tissue sarcoma resection: A retrospective cohort study

BACKGROUND AND OBJECTIVES

The use of antibiotic prophylaxis for soft tissue sarcoma resection varies widely while little evidence on this topic exists. The aim of this study was to determine the impact of antibiotic prophylaxis on the occurrence of wound infections.

METHODS

A single institutional retrospective cohort study was performed on patients who underwent truncal or extremity soft tissue sarcoma resection. The use of antibiotic prophylaxis was assessed and univariate and multivariate analysis of predictors of wound infections was performed.

RESULTS

Nine hundred and fifty-eight patients could be included. Thirty-two percent of patients had no antibiotic prophylaxis, 44% of patients received single-shot prophylaxis, and 24% of patients received single-shot plus continued antibiotic treatment. Wound infections occurred in 140 patients (15%). Independent risk factors for wound infections upon multivariate analysis were obesity, high American Society of Anesthesiologists (ASA) status, high tumor size and grade, operation time over 120 minutes, and other complications. Antibiotic prophylaxis could not be identified as a protective factor in univariate or multivariate analysis.

CONCLUSIONS

A favorable effect of antibiotic prophylaxis on the occurrence of wound infections could not be observed. Although more studies on this subject are needed, our data do not support the general use of antibiotic prophylaxis for soft tissue sarcoma resection.

Perioperatives Management in der Mikrochirurgie – Konsensus-Statement der Deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie der peripheren Nerven und Gefäße

Perioperative management in microsurgery is a key element of success in reconstructive surgery. There are no uniform concepts for this in the German-speaking countries and individual schemes differ significantly from each other, as ascertained in an expert survey. In the course of the 41st Annual Conference of the German-speaking Working Group for Microsurgery (DAM) held in Munich in November 2019, concepts were evaluated and a survey was carried out and summarised as a position paper in due consideration of the scientific literature.

[Economic factors in microsurgery - Report of the consensus workshop of the German-Speaking Society for Microsurgery of Peripheral Nerves and Vessels - (DAM)]

In addition to outcome assessments, cost effectiveness of surgical treatments becomes increasingly important. Both, insurance companies and hospital administrations aim for short and efficient procedures to reduce costs.Microsurgical procedures are often surpassing traditional treatment options in terms of function and aesthetics. However, they are more expensive as they require a high level of surgical expertise, more theatre capacity and longer inpatient treatment. Adequate reimbursement is mandatory, if we want to continuously perform these procedures with the best possible quality and outcome. To cover the case-related expenses of each specialty, multidisciplinary procedures require appropriate distribution of reimbursements to each department.The main diagnosis as well as all complications and relevant comorbidities should be documented to obtain the correct DRG. The additional financial benefit of a microsurgical procedure in a multidisciplinary case can be calculated by specifying the procedural increment in pay. Therefore, a fair distribution of revenues to each participating department should be performed. Different models exist, which lead to a benefit in compensation for all departments. Unfortunately, distribution of resources is still insufficiently managed in many hospitals, which hampers high quality multidisciplinary microsurgical procedures. Still, picking the best possible procedure for our patients, independently of financial incentives, is of utmost importance.

Limb preserving surgery for soft-tissue sarcoma in the hand: a retrospective study of 51 cases

Our retrospective study analysed the long-term results of a conservative limb-preserving surgical strategy in 51 patients with soft-tissue sarcoma of the hand from a single institution. We assessed survival and prognostic factors, including the surgical margins. No transradial amputations were performed. Microscopically free resection margins were obtained in 45 of the patients. The remaining six patients had microscopically incomplete resection. Forty-four surviving patients had a median follow-up of 6.5 years (range 12-307), and one patient had no follow-up beyond 3 months following surgery. Among those patients, 29 had more than 5 years of follow-up. Five-year local-recurrence-free survival was 65%, metastasis-free survival was 84%, and disease-specific survival was 91%. Tumour size was predictive of all outcome parameters, but positive resection margins adversely affected local recurrence only. Survival was similar to the survival after a more radical surgical approach reported in the literature. Level of evidence: IV.

A chronic rejection model and potential biomarkers for vascularized composite allotransplantation

BACKGROUND

Chronic rejection remains the Achilles heel in vascularized composite allotransplantation. Animal models to specifically study chronic rejection in vascularized composite allotransplantation do not exist so far. However, there are established rat models to study chronic rejection in solid organ transplantation such as allogeneic transplantation between the rat strains Lewis and Fischer344. Thus, we initiated this study to investigate the applicability of hindlimb transplantation between these strains to imitate chronic rejection in vascularized composite allotransplantation and identify potential markers.

METHODS

Allogeneic hindlimb transplantation were performed between Lewis (recipient) and Fischer344 (donor) rats with either constant immunosuppression or a high dose immunosuppressive bolus only in case of acute skin rejections. Histology, immunohistochemistry, microarray and qPCR analysis were used to detect changes in skin and muscle at postoperative day 100.

RESULTS

We were able to demonstrate significant intimal proliferation, infiltration of CD68 and CD4 positive cells, up-regulation of inflammatory cytokines and initiation of muscular fibrosis in the chronic rejection group. Microarray analysis and subsequent qPCR identified CXC ligands 9-11 as potential markers of chronic rejection.

CONCLUSIONS

The Fischer344 to Lewis hindlimb transplantation model may represent a new option to study chronic rejection in vascularized composite allotransplantation in an experimental setting. CXC ligands 9-11 deserve further research to investigate their role as chronic rejection markers.

Regulatory aspects of myogenic factors GDF-8 and Follistatin on the intake of combined oral contraceptives

Combined oral contraceptives are one of the most prescribed drugs in the western world. While there is little evidence regarding effects of estrogen or gestagens on muscle metabolism, androgens are well-known for their anabolic characteristics. In this study, we seeked to investigate potential correlations of the myokines GDF-8, IGF-1 and Follistatin with female sexual hormones and likewise possible interactions with combined oral contraceptives (Dienogest and Ethyl Estradiol) intake. We obtained serum samples of young healthy women to measure hormone correlations. Furthermore, we simulated combined oral contraceptive blood circulating hormone concentrations to identify myogenic effects on HSkM in vitro. GDF-8, IGF-1 and Follistatin showed concentration correlations (p = .005) in overall patients' serum, while Follistatin as a promyogenic protein additionally showed a positive correlation with testosterone and estradiol (p < .05). Lower GDF-8 levels were also linked to a higher BMI (p = .009). Upon combined oral contraceptives (COC) intake, patients showed decreased GDF-8 (p = .006) but increased Follistatin (p = .0001) concentrations compared to patients without COC intake. In vitro, addition of Ethyl Estradiol and Dienogest to HSkM cells revealed a pro-myogenic, proliferative, chemosensitized pattern. Our data support a pro-myogenic effect of combined oral contraceptives.

Enzymatic debridement of hands with deep burns: a single center experience in the treatment of 52 hands

Background: Bromelain-based enzymatic debridement has been introduced as an alternative to surgical excision in deep partial thickness and full thickness burns. We aimed to analyze effectiveness and predictors of spontaneous epithelialization after enzymatic debridement of deep hand burns.Methods: All patients who received enzymatic debridement for deep partial thickness or full thickness burns of the hands at our institution in the last 5 years were identified. Demographic, clinical and outcome data were collected and analyzed. For patients with deep partial thickness burns, Kaplan-Meier log-rank and subsequent multivariate Cox-regression analysis were performed to identify predictors of spontaneous epithelialization.Results: 44 patients and 52 hands were treated in the observation period. Among these, 14 had full thickness burns and received split thickness skin grafts. In the 38 hands with deep partial thickness burns, predictors of 28-day epithelialization were total burn extent and mechanism of burn injury. During the first 3 years, 8 out of 13 treated deep partial thickness burns received split thickness skin grafts after a median of 3 days. The following 3 years, 5 out of 25 deep partial thickness burns received surgery after a median of 14 days.Conclusions: Enzymatic debridement is a useful tool in the treatment of burned hands but the decision-making and correct timing of operative intervention in deep partial thickness burns after debridement requires experience. In our cohort, spontaneous healing of deep partial thickness burns was best in patients with contact burns and less than 15% burn TBSA.

Predictors of oncologic outcome in patients with and without flap reconstruction after extremity and truncal soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) of the extremities or trunk often require plastic reconstructive transfer of vital tissue for wound closure after resection. Literature on the oncologic outcome of patients receiving flap closure in comparison with patients receiving primary wound closure is very limited.

METHODS

Patients who underwent resection of a primary extremity or truncal STS without dissemination at our institution between January 2000 until December 2015 were eligible for the study. Patients were divided into two groups based on type of soft tissue closure (primary or flap) while patients receiving skin grafting were excluded. Characteristics, oncologic outcome and prognostic factors of both groups were compared.

RESULTS

781 patients could be included, of these 200 had received flap closure and 581 primary wound closure. Tumors receiving flap closure were significantly smaller but were located in distal extremities and showed a trend towards prior neoadjuvant radiotherapy. Incidence of wound and general complications was similar in both groups. 5-year local recurrence free survival (LRFS, 71% vs. 69%) and 5-year disease specific survival (DSS, 84% vs. 88%) did not differ significantly between patients with primary closure and flap closure. Most important predictors in both groups were tumor size and grading with no major differences in analysis of predictors for both endpoints.

CONCLUSION

Plastic reconstructive surgery plays an important role in limb-conserving STS treatment. Complication rates of patients with flap coverage are not higher than of patients with primary wound closure and oncologic outcome is similar with no major differences in predictors of LRFS and DSS.

The Impact of Surgical Margins and Adjuvant Radiotherapy in Patients with Undifferentiated Pleomorphic Sarcomas of the Extremities: A Single-Institutional Analysis of 192 Patients

Background: Undifferentiated pleomorphic sarcomas are a frequent subtype within the heterogeneous group of soft tissue sarcomas. As the attainment of negative margins can be complicated at the extremities, we determined the prognostic significance of surgical margins in our patient population. Methods: We retrospectively determined the relationship between local recurrence-free survival (LRFS), overall survival (OS), and potential prognostic factors in 192 patients with UPS of the extremities who were suitable for surgical treatment in curative intent. The median follow-up time was 5.1 years. Results: The rates of LRFS and OS after 2 years were 75.7% and 87.2% in patients with R0-resected primary tumors and 49.1% and 81.8% in patients with R1/R2-status (LRFS: p = 0.013; OS: p = 0.001). Adjuvant radiotherapy significantly improved LRFS (5-year: 67.6% vs. 48.4%; p < 0.001) and OS (5-year: 82.8 vs. 61.8; p = 0.016). Both, negative margins and adjuvant radiotherapy were found to be independent prognostic factors in multivariate analysis. Conclusions: The data from this study could underscore the beneficial prognostic impact of negative margins on LRFS and OS. However, the width of negative margins seemed to be not relevant. Notably, adjuvant radiotherapy was not only able to decrease the risk of local failure but also improved OS in a significant manner.