Background. Surgical treatment of malignant pelvic bone tumors can be very challenging. The objective of this retrospective study was to evaluate the oncological as well as the clinical and functional outcome after limb salvage surgery and biological reconstruction.Methods. The files of 27 patients with malignant pelvic bone tumors, who underwent surgical resection at our department between 2000 and 2011, were retrospectively analyzed (9 Ewing's sarcoma, 8 chondrosarcoma, 4 osteosarcoma, 1 synovial sarcoma, 1 malignant fibrous histiocytoma, and 4 carcinoma metastases).Results. After internal hemipelvectomy reconstruction was performed by hip transposition (), using autologous nonvascularised fibular graft () or autologous iliac crest bone graft (). In one patient a proximal femor prothetis and in three patients a total hip prosthesis was implanted at the time of resection. The median follow-up was 33 months. Two- and five-year disease-specific survival rates of all patients were 86.1% and 57.7%, respectively. The mean functional MSTS score was 16.5 (~55%) for all patients.Conclusion. On the basis of the oncological as well as the clinical and functional outcome, biological reconstruction after internal hemipelvectomy seems to be a reliable technique for treating patients with a malignant pelvic bone tumor.

Studienziel: Achsfehlstellungen der unteren Extremitäten gelten als prädisponierende Faktoren für degenerative Erkrankungen. Als Korrekturoption besteht die Möglichkeit der Osteotomie. Dieser Eingriff gilt jedoch als komplex und beinhaltet eine spezielle Nachbehandlung. Im Kindesalter besteht bei noch vorhandenem Restwachstum die elegante Möglichkeit der Wachstumslenkung. Neben den Blount-Klammern und der definitiven Epiphyseodese steht mit der eight-Plate eine alternative Technik im Sinne einer temporären Epiphyseodese zur Verfügung. Wir untersuchten den Effekt dieser Platte auf die Achskorrektur bei Kindern verschiedener Altersstufen und Diagnosen. Methode: Seit 04/2006 wurde in unserem Hause bei 22 Patienten mit Achsfehlstellungen der unteren Extremitäten unterschiedlicher Genese die eight-Plate zur kniegelenksnahen Achskorrektur eingesetzt (42 eight-Plates). Gegenstand dieser Nachuntersuchung sind die bisher ausbehandelten 13 Patienten (26 eight-Plates). Der Beobachtungszeitraum erstreckte sich bis zum gewünschten Korrekturergebnis und der erfolgten Materialentfernung. Eine spezielle Nachbehandlung war nicht erforderlich. Ergebnisse: Bei allen Patienten wurde eine Verbesserung der mechanischen Beinachse erzielt. Das Durchschnittsalter bei Implantation betrug 9,4 Jahre (2,3–13,7 Jahre). Die durchschnittliche Liegedauer betrug 10,7 Monate (6–34 Monate). Es traten keine Materiallockerungen, ‐brüche, ‐dislokationen, Wundinfekte oder weitere Komplikationen auf. Bei 2 Patienten konnte die gewünschte Zielkorrektur aufgrund des geringen verbliebenen Wachstumspotenzials nicht erreicht werden, weshalb ein zusätzlicher Eingriff zur Achskorrektur erfolgte. Die durchschnittliche Korrektur im Gesamtkollektiv betrug in Bezug auf die mechanische Achsabweichung (MAD) 22 mm (6–43 mm) und in Bezug auf die Winkelkorrektur des mechanischen lateralen distalen Femurwinkels (mLDFW) 10,6 ° (5–27 °). Der mechanische mediale proximale Tibiawinkel (mMPTW) veränderte sich um 8,0 ° (3–15 °). Schlussfolgerung: Nach unseren ersten Erfahrungen stellt die eight-Plate ein sicheres und zuverlässiges Verfahren zur wachstumsparallelen kniegelenksnahen Achskorrektur im Kindesalter dar. Die Technik ist einfach zu erlernen, die Komplikationsrate im Vergleich zur Klammertechnik niedrig. Eine besondere Nachbehandlung ist nicht erforderlich, das operative Trauma ist gering. Derzeit liegen jedoch noch keine Daten über den weiteren Langzeitverlauf nach Materialentfernung bis zum Wachstumsabschluss vor. Offen ist darüber hinaus auch die Definition des optimalen Zeitpunkts zur Materialentfernung. Aim: Angular deformities of the lower extremity are considered as prearthrotic factors. Osteotomy is regarded as a way of corrective treatment. But this intervention is considered as complex and requires a special after-treatment. During childhood and with remaining growth, guided growth offers an elegant solution for this problem. Resulting in a temporary hemiepiphyseodesis, the eight-Plate offers an alternative technique besides the Blount staples and the definitive epiphyseodesis. We evaluated the effect of this device on the correction of angular deformities in children with different diagnoses and at different ages. Method: Since 04/2006 22 patients with angular deformities of the lower extremities due to different diagnoses were treated at our department with the eight-Plate (42 eight-Plates). In this study we evaluated the outcome of 13 patients (26 eight-Plates) until the completed angular correction and removal of the eight-Plate. A special treatment after plate removal was not applied. Results: All patients improved their mechanical leg axis. The average age at implantation was 9.4 years (2.3–13.7 years). The average time until plate removal was 10.7 months (6–34 months). No hardware failures, extrusions, growth arrests, wound infections or other complications were observed. Two patients did not achieve the desired axis correction because of insufficient remaining growth potential. An additional surgical intervention was realised. The average correction of the study group regarding the mechanical axis deviation (MAD) was 22 mm (6–43 mm) and 10.6 ° (5–27 °) regarding the angular correction of the mechanical lateral distal femoral angle (mLDFW). The mechanical medial proximal tibial angle (mMPTW) changed by 8.0 ° (3–15 °). Conclusion: In our opinion the eight-Plate seems to be a safe and reliable device for guided growth of angular deformities around the knee. The technique is easy to learn and the complication rate low compared to the staple technique. A special after-treatment is not needed and there is only minor operative trauma. At present there are only few data on long-term follow-up after plate removal until skeletal maturity. The definition of the ideal point in time for plate removal is still open.

Background: The use of cold atmospheric plasma (CAP) in oncology has been intensively investigated over the past 15 years as it inhibits the growth of many tumor cells. It is known that reactive oxidative species (ROS) produced in CAP are responsible for this effect. However, to translate the use of CAP into medical practice, it is essential to know how CAP treatment affects non-malignant cells. Thus, the current in vitro study deals with the effect of CAP on human bone cancer cells and human osteoblasts. Here, identical CAP treatment regimens were applied to the malignant and non-malignant bone cells and their impact was compared. Methods: Two different human bone cancer cell types, U2-OS (osteosarcoma) and A673 (Ewing’s sarcoma), and non-malignant primary osteoblasts (HOB) were used. The CAP treatment was performed with the clinically approved kINPen MED. After CAP treatment, growth kinetics and a viability assay were performed. For detecting apoptosis, a caspase-3/7 assay and a TUNEL assay were used. Accumulated ROS was measured in cell culture medium and intracellular. To investigate the influence of CAP on cell motility, a scratch assay was carried out. Results: The CAP treatment showed strong inhibition of cell growth and viability in bone cancer cells. Apoptotic processes were enhanced in the malignant cells. Osteoblasts showed a higher potential for ROS resistance in comparison to malignant cells. There was no difference in cell motility between benign and malignant cells following CAP treatment. Conclusions: Osteoblasts show better tolerance to CAP treatment, indicated by less affected viability compared to CAP-treated bone cancer cells. This points toward the selective effect of CAP on sarcoma cells and represents a further step toward the clinical application of CAP.

This paper deals with bilateral vascularized fibular grafts (BVFG) as a method for reconstruction of metadiaphyseal defects of the femur and tibia in young patients suffering from malignant bone tumors of the lower limb. This reconstructional technique was used in 11 patients undergoing metadiaphyseal resection of lower limb malignant bone tumors. All patients with Ewing’s sarcoma and osteosarcoma had multimodal treatment according to the EURO-E.W.I.N.G 99 or COSS-96 protocol. Median FU was 63 months. None of the patients experienced local recurrence during FU. 2 patients died due to distant disease during FU. Full weight- bearing was permitted after a mean of 8 months. The median MSTS score was 87%. Complications occurred in five patients. None of the complications led to failure of the biological reconstruction or to amputation. Biological reconstruction of osseous defects is always desirable when possible and aims at a permanent solution. Good functional and durable results can be obtained by using BVFG for the reconstruction of metadiaphyseal defects of the femur and tibia. Radiotherapy in the multimodal setting increases the risk for graft or fixation failure.

Although Ewing’s sarcoma (ES) is a rare, but very aggressive tumor disease affecting the musculoskeletal system, especially in children, it is very aggressive and difficult to treat. Although medical advances and the establishment of chemotherapy represent a turning point in the treatment of ES, resistance to chemotherapy, and its side effects, continue to be problems. New treatment methods such as the application of cold physical plasma (CPP) are considered potential supporting tools since CPP is an exogenous source of reactive oxygen and nitrogen species, which have similar mechanisms of action in the tumor cells as chemotherapy. This study aims to investigate the synergistic effects of CPP and commonly used cytostatic chemotherapeutics on ES cells. The chemotherapy drugs doxorubicin and vincristine, the most commonly used in the treatment of ES, were applied to two different ES cell lines (RD-ES and A673) and their IC₂₀ and IC₅₀ were determined. In addition, individual chemotherapeutics in combination with CPP were applied to the ES cells and the effects on cell growth, cell viability, and apoptosis processes were examined. A single CPP treatment resulted in the dose-dependent growth inhibition of ES cells. The combination of different cytostatics and CPP led to significant growth inhibition, a reduction in cell viability, and higher rates of apoptosis compared to cells not additionally exposed to CPP. The combination of CPP treatment and the application of cytostatic drugs to ES cells showed promising results, significantly enhancing the cytotoxic effects of chemotherapeutic agents. These preclinical in vitro data indicate that the use of CPP can enhance the efficacy of common cytostatic chemotherapeutics, and thus support the translation of CPP as an anti-tumor therapy in clinical routine.