Free Flaps for Skin and Soft Tissue Reconstruction in the Elderly Patient: Indication or Contraindication.

BACKGROUND: Increased lifespan and the improvement of medical treatment have given rise to research in reconstructive procedures in elderly patients. Higher postoperative complication rates, longer rehabilitation, and surgical difficulties remain a problem in the elderly. We asked whether a free flap in elderly patients is an indication or a contraindication and performed a retrospective, monocentric study. METHODS: Patients were divided into two groups (YOUNG 0-59 years; OLD > 60 years). The endpoint was the survival of flaps and their dependence on patient- and surgery-specific parameters using multivariate analysis. RESULTS: A total of 110 patients (OLD n = 59) underwent 129 flaps. The chance of flap loss increased as soon as two flaps were performed in one surgery. Anterior lateral thigh flaps had the highest chance for flap survival. Compared with the lower extremity, the head/neck/trunk group had a significantly increased chance of flap loss. There was a significant increase in the odds of flap loss in linear relation to the administration of erythrocyte concentrates. CONCLUSION: The results confirm that free flap surgery can be indicated as a safe method for the elderly. Perioperative parameters such as two flaps in one surgery and transfusion regimens must be considered as risk factors for flap loss.

[Academic Careers in Medicine: a Sex-Related Analysis of Career Goals]. / Akademische Karriere in der Medizin: eine geschlechterbezogene Analyse zu beruflichen Zielen.

AIM OF THE STUDY: For female and male physicians of the clinical-academic mid-level staff, working conditions as well as the attitude towards profession and career play a decisive role. For years, there has been an increasing proportion of women in medicine. Despite this increase, a significant sex incongruence is still evident, especially in academic medicine. The aim of this work was to analyze current opinions of female and male physicians on sex-related aspects for career. METHODS: By means of an online survey, medical mid-level staff from university and peripheral hospitals were asked about professional biographical as well as career-related topics and the data analyzed in terms of the sexes. RESULTS: Compared to their male counterparts, female physicians had lower career goals and mainly aimed to qualify as senior physicians. Women planned to have families and raise children earlier in their careers. Men were more likely to have their professional careers in mind during the same time period. Although only just under 47% of respondents considered an academic career to be worthwhile, 65% continued to rate the acquisition of an academic title highly. When evaluating equal treatment by superiors, female physicians tended to feel disadvantaged in their professional careers compared to male physicians. Thus, physicians rated the treatment by their respective superiors as characterized by the quality of the work (44% for both genders of superiors) or dependent on sympathy (female superiors 30%; male superiors 24%). Female physicians, however, saw a preference for male colleagues in 37% of male superiors. CONCLUSION: Despite a significantly larger proportion of women in medicine for decades, there is still an incongruence in sexes in favor of men in management positions. The professional and private goals of women and men differ significantly depending on their age decade. The academic career per se is increasingly losing importance, although the acquisition of academic degrees still seems to be desirable. Therefore, to improve the future of academic medicine, significant structural changes are needed to enable projectable career paths (e. g., tenure track, assistant professorship, young medical professionals model) for mid-level academic staff.

[Balancing Family and Career in Medicine: Greatly Desired but Given Little Consideration Results of the Study Arm VI of the KARiMED Study]. / Vereinbarkeit von Familie und Beruf in der Medizin: vom großen Wunsch und wenig Berücksichtigung.

AIM OF THE STUDY: Family life and professional practice are both highly important for young physicians. Accordingly, a good balancing of both areas of life is necessary. Despite political framework conditions and legal requirements that have been in place for years, implementation of measures to achieve this seems to be difficult, especially in medicine, and is associated with great reservations and problems on the part of those involved. METHODS: By means of an online survey, the medical mid-level staff from university and peripheral hospitals was questioned on topics related to family, children and professional biographical as well as career-relevant topics and subsequently analyzed on a gender-specific basis. RESULTS: Of the study participants, 65.1% were married and already had children or expressed a desire to have children (86.0%). Most were employed full-time (80.8%). The majority of part-time employees were female (87.4%). For 34.6%, there was a career break of 18.5±21.3 months, 87.8% of which were taken due to pregnancy or children. Female physicians generally took significantly more parental leave than male physicians (6-12 months: females 62.2%; males 22.4%; 12 months or more: females 25.2%; males 6.6%). Family planning received little support from superiors (21.2% much to very much support) and 45.6% reported having experienced problems with their return to work or career advancement. Almost 60% of the participants did not have any specific working time models in their own hospital for employees with children who need to be cared for. CONCLUSION: In order to implement a work-life balance for physicians, changes are first and foremost necessary on the part of the institutions. In addition, the respective superiors must rethink in order to enable a parallelization of these two areas of their employees' lives. However, young physicians must also rethink their view of this issue. Demanding changes in labor law while continuing traditional family constellations at home does not seem to do address this issue adequately.

Improving Vascularization of Biomaterials for Skin and Bone Regeneration by Surface Modification: A Narrative Review on Experimental Research.

Artificial tissue substitutes are of great interest for the reconstruction of destroyed and non-functional skin or bone tissue due to its scarcity. Biomaterials used as scaffolds for tissue regeneration are non-vascularized synthetic tissues and often based on polymers, which need ingrowth of new blood vessels to ensure nutrition and metabolism. This review summarizes previous approaches and highlights advances in vascularization strategies after implantation of surface-modified biomaterials for skin and bone tissue regeneration. The efficient integration of biomaterial, bioactive coating with endogenous degradable matrix proteins, physiochemical modifications, or surface geometry changes represents promising approaches. The results show that the induction of angiogenesis in the implant site as well as the vascularization of biomaterials can be influenced by specific surface modifications. The neovascularization of a biomaterial can be supported by the application of pro-angiogenic substances as well as by biomimetic surface coatings and physical or chemical surface activations. Furthermore, it was confirmed that the geometric properties of the three-dimensional biomaterial matrix play a central role, as they guide or even enable the ingrowth of blood vessels into a biomaterial.

Facilitation of adhesion and spreading of endothelial cells on silicone oxide-coated dacron material by microwave-excited low-pressure plasma.

OBJECTIVES: Autologous transplants are still the means of choice for bypass surgery. In addition to good tolerability, there is a reduced thrombogenicity and fewer neointima hyperplasia compared to artificial materials. However, since viable transplants are limited, attempts are being made to improve existing artificial vascular prosthesis material. Next to the reduction of thrombogenicity, a rapid endothelialization of the vascular graft should reduce intimal hyperplasia and thus prevent stenoses. The effect of newly developed silicon oxide coatings on the growth of endothelial cells was therefore the goal of this work in a cell culture study. METHODS: A woven, uncoated polyethylene terephthalate (PET) vessel prosthesis was used. The coating process was carried out in a low-pressure plasma reactor in a multi-step process. After preparation of the vacuum chamber hexamethyldisiloxane (HDMSO) with oxygen was evaporated using argon plasma. By this an approx. 1 nm thin adhesion promoter layer was separated from plasma and HMDSO. The silicone oxide barrier layer was applied to the PET vessel samples. The carbon content of the layer could be selectively altered by changing the HMDSO oxygen flow ratio, resulting in coatings of 100 nm, 500 nm, and 1,000 nm. In addition, two different oxygen-to-HMDSO ratios were used. To achieve a carbon coating as low as possible, the ratio was set to 200:1. A carbon-rich layer was obtained with the 1:1 setting. The various coatings were then examined for their surface texture by scanning electron microscopy (SEM) as well as by cell culture experiments for cell viability and growth using EA.hy 926 cells. RESULTS: SEM showed no changes in the surface morphology; however a layer thickness of 1,000 nm showed peeled off coating areas. Alamar blue assays showed a significantly higher metabolic activity (p=0.026) for the coating 500 nm, ratio 200:1 compared to untreated control samples and a significantly lower metabolic activity (p=0.037) of the coating 500 nm, ratio 1:1 compared to the coating 500 nm, ratio 200:1. This underlines the apparent tendency of the 1:1 coating to inhibit the metabolic activity of the cells, while the 200:1 coating increases the activity. Fluorescence microscopy after calcein acetoxymethyl ester (AM) staining showed no significant difference between the different coatings and the uncoated PET material. However, a tendency of the increased surface growth on the coating 500 nm, ratio 200:1, is shown. The coatings with the ratio 1:1 tend to be less densely covered. CONCLUSIONS: The results of this work indicate a great potential in the silicon coating of vascular prosthesis material. The plasma coating can be carried out easy and gently. Cell culture experiments demonstrated a tendency towards better growth of the cells on the 200:1 ratio coating and a poorer growth on the carbon-rich coating 1:1 compared to the uncoated material. The coating with silicon oxide with a thickness of 500 nm and an oxygen-HMDSO ratio of 200:1, a particularly low-carbon layer, appears to be a coating, which should therefore be further investigated for its effects on thrombogenicity and intimal hyperplasia.

Wound Healing and Therapy in Soft Tissue Defects of the Hand and Foot from a Surgical Point of View.

Wounds and tissue defects of the hand and foot often lead to severe functional impairment of the affected extremity. Next to general principles of wound healing, special functional and anatomic considerations must be taken into account in the treatment of wounds in these anatomical regions to achieve a satisfactory reconstructive result. In this article, we outline the concept of wound healing and focus on the special aspects to be considered in wounds of the hand and foot. An overview of different treatment and dressing techniques is given with special emphasis on the reconstruction of damaged structures by plastic surgical means.

Effects of Extracorporeal Shock Waves on Microcirculation and Angiogenesis in the in vivo Wound Model of the Diver Box.

INTRODUCTION: Extracorporeal shock waves (ESWs) have been shown to have a positive effect on skin wound healing; however, little is known on the regeneration of the microcirculation and angiogenesis as well as the different application modes. METHODS: A total of 40 BALB/c mice were provided with dorsal skin fold chambers and were divided into 3 therapy groups (n = 30) and one control group (n = 10). The 3 therapy groups were treated with shock waves at different pulse rates (500-1,000 pulses/min) and application frequencies (day 0 and day 6 or day 0 only). Photographic documentation and intravital microscopy were carried out on day 1, 2, 4, and 6 after wounding. RESULTS: Using the newly developed Diver Box, shock waves could be applied in vivo without mechanical tissue damage. Shock wave therapy to skin wounds demonstrated to induce faster wound closure rates in the beginning than controls in groups with higher pulse rates and frequencies of the shock waves. Furthermore, the regeneration of microcirculation and perfusion in the healing skin was significantly improved after the application of, in particular, higher pulse rates as given by increased numbers of perfused capillaries and functional vessel density. The study of inflammation showed, especially in high-pulse ESW groups, higher leukocyte counts, and rolling leukocytes over time until day 6 as a response to the induction of inflammatory reaction after ESW application. Angiogenesis showed a marked increase in positive areas as given by sprouts, coils, and recruitments in all ESW groups, especially between days 4 and 6. CONCLUSION: The major findings of this trial demonstrate that ESW therapy to skin wounds is effective and safe. This is demonstrated by the initially faster wound closure rate, but later the same wound closure rate in the treatment groups than in controls. Furthermore, during the regeneration of microcirculation and perfusion in the healing skin, a significant improvement was observed after the application of, in particular, higher ESW pulse rates, suggesting an ESW-related increase in nutrient and oxygen supply in the wound tissue.

[Change of perception of aged male attractiveness by conventional or male facelift: 3D simulation study of a new facelift concept for men]. / Veränderung der Wahrnehmung männlicher Attraktivität im Alter durch Standard- oder männliche Gesichtsstraffung: 3D-Simulationsstudie eines neuen Facelift-Konzeptes für Männer.

BACKGROUND: Facelift is now the fourth most common aesthetic procedure in men. Facial ageing is very different in men and women. Therefore, individual techniques are used since a uniform concept for the surgical facelift in men does not exist. This study aims to evaluate a gender-specific facelift concept especially developed for men. MATERIAL AND METHODS: Women and men (n = 10 each) were subjected to a three-dimensional face scan and a subsequent simulation of a V-shaped lift vector (standard lift) and a new facelift concept especially for men in a double T shape (male lift). In an online survey with 262 participants, the simulated as well as the unchanged images were presented and the attributes masculinity, femininity, attractiveness and youthfulness were queried. Statistical models were used to identify attributes of lifting as well as other factors and differences between the simulations. RESULTS: Facelift changes are generally associated with a significant improvement in the attributes of youthfulness and attractiveness compared with unchanged control faces. As expected, a male lift leads to masculinisation, while a standard lift leads to feminisation, regardless of the sex of the subjects. The male lift led to higher values for the attribute attractiveness in male subjects, as did the standard lift in female subjects. The standard lift developed for women is indeed more suitable for women and is associated with a significantly higher probability for the attribute youthfulness, whereas this is not the case in the newly introduced male lift concept. CONCLUSION: The new facelift concept for male patients is significantly associated with masculinity and attractiveness, while the standard lift suitable for women is associated with significantly higher evaluations of femininity and youthfulness. The results of the SIMALIFT study are the first evidence of the need for a more differentiated, gender-specific approach to facelifting.

In-vivo monitoring of infection via implantable microsensors: a pilot study.

The most common complication after implantation of foreign material is infection, leading to implant failure and severe patient discomfort. Smoldering-infections proceed inapparently and might not get verified by radiological diagnostics. Early identification of this type of infection might significantly reduce the rate of complications. Therefore, we manufactured a microsensor strip in a hybrid of thin-film and laminate technology in a wafer-level process. It comprises electrochemical, amperometric microsensors for glucose, oxygen and lactate as well as an integrated reference electrode. Microsensors have been implanted in the mouse dorsal skin fold chamber, which got inoculated with a human-pathogen bacterial strain. A selective signal could be measured for all parameters and time points. The infection led to measurable changes of the wound environment as given by a decrease of the oxygen- as well as the glucose-concentration while the lactate concentration increased markedly over time. The given results in this study are the first hints on a promising new tool and should therefore be interpreted as a proof of the principle to show the functionality of the microsensors in an in vivo setting. These microsensors could be used to monitor smoldering infections of implantable foreign materials reducing foreign implant associated complications.

Localized eosinophilic fasciitis (Shulman's disease) as a differential diagnosis of nerve compression syndrome.

A 46-year-old man presented with clinical signs of nerve compression syndrome of his right ulnar nerve as confirmed by nerve conduction studies. Unexpectedly, clinical examination and magnetic resonance imaging (MRI) revealed a subcutaneous tumor of 5×2 cm above the ulnar groove. Surgical exploration and histopathology of biopsies demonstrated the nerve distended and entrapped into an eosinophilic, inflammatory tissue. This rare condition is consistent with localized eosinophilic fasciitis, with no systemic manifestations. There are reports of isolated forearm versions of the disease. However, none occurred with the entrapment of a peripheral nerve appearing as a peripheral nerve tumor, yet. Consequentially, the presented patient would not have benefitted from further surgical neurolysis or tumor debulking, as eosinophilic fasciitis is an inflammatory and systemic disease. The patient's symptoms decreased spontaneously after 4 weeks of postsurgical treatment, including nonsteroidal anti-inflammatory drugs (NSAIDs). Altogether, this case proved the necessity to regard even rare diseases as a potential cause of entrapment of peripheral nerves. This should lead surgeons to critical, differential diagnostic thinking and suggest that systemic diseases may be encountered during surgery due to their capability to mimic peripheral nerve tumors.

Skin Wound Healing: An Update on the Current Knowledge and Concepts.

BACKGROUND: The integrity of healthy skin plays a crucial role in maintaining physiological homeostasis of the human body. The skin is the largest organ system of the body. As such, it plays pivotal roles in the protection against mechanical forces and infections, fluid imbalance, and thermal dysregulation. At the same time, it allows for flexibility to enable joint function in some areas of the body and more rigid fixation to hinder shifting of the palm or foot sole. Many instances lead to inadequate wound healing which necessitates medical intervention. Chronic conditions such as diabetes mellitus or peripheral vascular disease can lead to impaired wound healing. Acute trauma such as degloving or large-scale thermal injuries are followed by a loss of skin organ function rendering the organism vulnerable to infections, thermal dysregulation, and fluid loss. METHODS: For this update article, we have reviewed the actual literature on skin wound healing purposes focusing on the main phases of wound healing, i.e., inflammation, proliferation, epithelialization, angiogenesis, remodeling, and scarring. RESULTS: The reader will get briefed on new insights and up-to-date concepts in skin wound healing. The macrophage as a key player in the inflammatory phase will be highlighted. During the epithelialization process, we will present the different concepts of how the wound will get closed, e.g., leapfrogging, lamellipodial crawling, shuffling, and the stem cell niche. The neovascularization represents an essential component in wound healing due to its fundamental impact from the very beginning after skin injury until the end of the wound remodeling. Here, the distinct pattern of the neovascularization process and the special new functions of the pericyte will be underscored. At the end, this update will present 3 topics of high interest in skin wound healing issues, dealing with scarring, tissue engineering, and plasma application. CONCLUSION: Although wound healing mechanisms and specific cell functions in wound repair have been delineated in part, many underlying pathophysiological processes are still unknown. The purpose of the following update on skin wound healing is to focus on the different phases and to brief the reader on the current knowledge and new insights. Skin wound healing is a complex process, which is dependent on many cell types and mediators interacting in a highly sophisticated temporal sequence. Although some interactions during the healing process are crucial, redundancy is high and other cells or mediators can adopt functions or signaling without major complications.

[Assessment of the significance and the requirements of medical postdoctoral lecture qualifications in Germany by the assessment committees]. / Bewertung des Stellenwerts und der Voraussetzungen der medizinischen Habilitation in Deutschland durch die beurteilenden Kommissionen.

OBJECTIVE: The postdoctoral medical lecture qualification (Habilitation) represents the highest academic qualification in Germany, which is successfully completed by approximately 850 candidates in medicine and health sciences per year. However, there is only a limited number of respective academic positions available. In addition, structures in education and society have changed over the last years, challenging the importance of this specific German qualification. The aim of this study was to elicit the opinions of members of German habilitation committees concerning the requirements, processes and the overall importance of the postdoctoral medical lecture qualification. Furthermore we wanted to evaluate potential needs for reforms. METHODS: The online survey was conducted asking for biographic parameters, subjective ratings and potential needs for reforms concerning the postdoctoral medical lecture qualification (PLQ). RESULTS: The PLQ was rated high in significance by 71.3 % of the committee members. According to the medical understanding of the Humboldt triad (research, teaching, patient care), research (94.3 %) and teaching (89.7 %) have been rated as the most important requirements for a PLQ. Asked for the motivation to undertake a PLQ, 91.0 % of the members gave the joy of doing research, 78.2 % the joy of teaching and 65.5 % better career prospects perspectives as their reason. The recognition of a Ph.D. degree as being equivalent to a German PQL was clearly rejected by the survey respondents (58.6 %: no equivalence). The majority is against the abolition of the German PLQ. However, there is a definite desire for reform, preferably concerning internal obstacles such as the dependence on full professors, more transparency in the PLQ process, but also the demand for a federal standard PLQ regulation. CONCLUSION: From the committee members' point of view the German PLQ has still a role to play and, despite controversy, is still regarded as a timely qualification. However, there is clear-cut evidence for local, national and international reforms in order to create equality of opportunity for the candidates and to open up suitable career options.

Low-intensity pulsed ultrasound as a useful adjuvant during distraction osteogenesis: a prospective, randomized controlled trial.

BACKGROUND: Low-intensity pulsed ultrasound (LIPUS) was proven to have a positive impact on bone healing in animal and clinical studies. METHODS: In this prospective, randomized controlled trial the effect of LIPUS during distraction osteogenesis was investigated. Thirty-six patients who underwent distraction osteogenesis (>2 cm) were enrolled. Sixteen patients in the treatment group received LIPUS, and 20 patients as control group did not. Ultrasound treatment device was transcutaneously applied at the distraction gap for 20 minutes daily (frequency 1.5 MHz, signal burst with 200 µs, signal repetition frequency 1.0 kHz, intensity 30 mW/cm(2)). Evaluation of patients was performed by standard radiographs every 3 weeks to 4 weeks. RESULTS: Average transport distance was 7.0 cm in the ultrasound group and 6.3 cm in the control group. Mean Paley index for the ultrasound group was 1.09 mo/cm and 1.49 mo/cm for the control group. Mean distraction consolidation index for the ultrasound group was 32.8 d/cm and 44.6 d/cm for the control group. The calculated indices indicated no significant statistical difference between the two groups (p < 0.116) but the fixator gestation period could be decreased for 43.6 days in the treatment group. CONCLUSIONS: Therapeutic application of LIPUS during callus distraction constitutes a useful adjuvant treatment during distraction osteogenesis and has a positive effect on healing time with no negative effects.

Pressure garment therapy alone and in combination with silicone for the prevention of hypertrophic scarring: randomized controlled trial with intraindividual comparison.

BACKGROUND: Published trials evaluating pressure garment and/or silicone therapy as a treatment for hypertrophic burn scarring are of poor quality and highly susceptible to bias. The authors' aim was to compare the efficacy of pressure garment therapy alone and in combination with silicone gel sheet or spray therapy for the prevention of hypertrophic scarring. METHODS: The authors conducted an open, single-center, randomized controlled study with intraindividual comparison of study preparations and control to standard treatment. Forty-three consecutive patients with two comparable areas of split-thickness graft burn wounds were recruited into the study, and 38 patients were followed up for 18 months. All patients received compression garments and were randomized to one of two treatment groups: (1) self-drying silicone spray and compression versus compression alone and (2) silicone sheeting and compression versus compression alone. Clinical assessment, measurement of scar redness, height, and photographic documentation of each treated area were performed at different visits over an 18-month follow-up period. Significance was tested using repeated-measures analyses and Wilcoxon paired-sample signed rank tests. RESULTS: Use of pressure garment therapy alone produced results equivalent to those of combined silicone and pressure garment therapy in the prevention of hypertrophic scars. The efficacy of silicone spray therapy was comparable to that of silicone gel sheet therapy in the prevention of hypertrophic scars. Patients treated with silicone spray had fewer side effects when compared with the silicone sheet group. CONCLUSION: Multimodal therapy with silicone and pressure garment therapy failed to prevent hypertrophic scars beyond that observed with pressure garment therapy alone. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Surface modification by glow discharge gasplasma treatment improves vascularization of allogenic bone implants.

Sufficient induction of blood vessel ingrowth decisively influence transplant functionality. In this study, microvascular response to transplants of surface modified bone substitutes were assessed in vivo. The surface modification of allogenic bone substitutes (dehydrated human femoral head) was achieved in a double-conductive low-pressure gasplasma reactor (Ar(2) /O(2) , 13.65 MHz, 1,000 W, 5 Pa). The modified bone substitutes (n = 10) as well as untreated bone substitutes serving as controls (n = 10) were placed into the dorsal skinfold chamber of female balb/c mice (n = 10). Dynamic assessment of microcirculatory parameters was performed using intravital fluorescence microscopy during an implantation period of 10 days. The angiogenic response was found markedly accelerated in gasplasma-treated bone. Compared to untreated implants, the gasplasma-activated bone substitutes showed significantly higher microvascular density on days 5 and 10. The quantification of the microvascular diameters, red blood cell velocity, and microvascular permeability displayed stable perfusion and vascular integrity of the newly developed blood vessels throughout the 10-day observation period. The surface activation via cold low-pressure glow discharge gasplasma supports the vascular integration of allogenic bone by earlier induction of the angiogenesis.

Enhanced neovascularization of dermis substitutes via low-pressure plasma-mediated surface activation.

PURPOSE: The effect of cold low-pressure plasma treatment on neovascularization of a dermis substitute was evaluated in a mouse model. MATERIAL AND METHODS: Collagen-elastin matrices (Matriderm(®)) were used as scaffolds. Low-pressure argon/hydrogene plasma-treated scaffolds were transplanted into the dorsal skinfold chambers of balb/c mice (group 1, n=10). Untreated scaffolds served as controls (group 2, n=10). Intravital fluorescence microscopy was performed within the border zone of the scaffolds on days 1, 5 and 10. Functional vessel density (FVD), vessel diameter, intervascular distance, microvascular permeability, and leukocyte-endothelium interaction were analyzed. RESULTS: An increase of FVD associated with a reduction of the intervascular distance was observed. Statistical analysis revealed that the functional vessel density in the border zone of the scaffolds was significantly enhanced in the plasma-treated group compared to controls. For group 1, an increase of FVD from 282±8 cm/cm(2) on days 5 to 315±8 cm/cm(2) on day 10 was observed. Whereas values of 254±7 cm/cm(2) on day 5 and 275±13 cm/cm(2) on day 10 have resulted in group 2 (mean±S.E.M., Student's t-test, p<0.05). CONCLUSION: The surface treatment by cold low-pressure plasma intensifies the angiogenesis and accelerates the neovascularization of collagen-elastin matrix.

Limb salvage in malignant tumors.

Limb-sparing resection and reconstruction has become the treatment of choice in extremity malignancies, as amputation does not provide better long-term survival rates or functional advantages. R0 resection, the removal of the tumor in sano, remains the prerequisite and most important oncologic parameter to avoid local recurrence. Successful treatment requires the combination of surgical eradication and the patient's specific functional and aesthetic rehabilitation. Our clinical rationale resulting from more than 2000 cases will be demonstrated. The problematic aspects of different tumor entities and the locoregional clearance of lymphatic pathways will be discussed. Differential diagnosis and multimodality treatment in high-volume tumor centers is likely to achieve superior oncologic statistics. Long-term survivors after microsurgical reconstructions and possible secondary malignancies will be addressed.

Merkel cell carcinoma metastasis and dermatofibrosarcoma protuberans presenting as a collision tumour: a case report and review of the literature.

INTRODUCTION: Merkel cell carcinoma and dermatofibrosarcoma protuberans are two very rare neoplasms. The simultaneous occurrence of two different tumour entities at the same anatomical site, collision tumours, is a rare phenomenon. CASE PRESENTATION: We present a rare case of a 74-year-old woman with a previous history of a recurrent dermatofibrosarcoma protuberans presenting with a metastatic Merkel cell carcinoma. Further investigation revealed a collision tumour of a metastatic lesion of the Merkel cell carcinoma within a tumour relapse of a dermatofibrosarcoma protuberans. CONCLUSION: Synchronous occurrence of two different tumour entities is extremely rare and has not been described for Merkel cell carcinoma and dermatofibrosarcoma. Merkel cell carcinoma, a tumour of the elderly or immunocompromised patients, leads to early metastasis and can be expected to be the limiting factor for prognoses.

In vivo analysis of tissue response to plasma-treated collagen-I-coated titanium alloys.

PURPOSE: The aim of this study was to evaluate the in vivo tissue response to low-pressure plasma-pretreated collagen-I-coated titanium implant in a middle-term mouse model. METHODS: Plasma-treated collagen-coated titanium implants were transplanted into the dorsal skinfold chambers of BALB/c mice. Untreated, regular titanium implant material served as control. The neovascularization (functional vessel density) of the implant border zone and of the surrounding muscle tissue was analysed by intravital fluorescence microscopy. Additional histological analysis was performed to observe the inflammatory reaction. RESULTS: Statistical analysis revealed that the vessel density in the border zone of the implants was significantly enhanced in the plasma-treated collagen-I-coated group compared to controls. The histological examination of the two groups confirmed that the inflammatory response to the collagen-coated titanium implants was reduced compared to controls. CONCLUSION: Plasma pretreatment and collagen I coating of titanium implant material leads to an enhanced tissue vascularization and a reduced inflammatory response.

[Surface modification of metal implant materials by low-pressure plasma treatment]. / Oberflächenmodifikation metallischer Implantatmaterialien durch Niederdruckplasmabehandlung / Surface modification of metal implant materials by low-pressure plasma treatment.

BACKGROUND: Plasma treatment leads to a significant change of surface free energy of medical implant materials. These changes strongly influence protein and cell adhesion on the material surface. The aim of the study was to quantify the plasma-induced surface changes and to analyse whether the change of treatment parameters, such as pressure, gas mixture, energy and treatment time, influences the surface free energy of the implant materials. To improve the biocompatibility of the surfaces, polyamino acid coating experiments were performed. MATERIALS AND METHODS: Three different metal implant materials (X2CrNiMo18-15-3, Ti6Al4V, Ti6Al7Nb) were treated with a double-inductively coupled low-pressure plasma. The influence of treatment parameter variation on the surface free energy was evaluated by drop shape analysis. The plasma treated and non-treated materials were incubated in collagen I solution. Afterwards, the coatings were analysed by electron microscopy in terms of structure and adhesion. RESULTS: Drop shape analysis revealed that plasma treatment leads to a significant increase of surface free energy in all groups. Long plasma treatment times and low treatment pressures lead to a significant (p<0.05) extension of the detectable surface free energy increase. Coating experiments showed that only on plasma-treated samples solid and adherent collagen layers could be achieved.