Impact of topography and added TiN-coating on adult human dermal fibroblasts after seeding on titanium surface in-vitro.

Complications of transcutaneous osseointegrated prosthetic systems (TOPS) focus on the metal-cutaneous interface at the stoma. Besides pain due to scare tissue as well as undefined neuropathic disorders, there is high evidence that the stoma presents the main risk causing hypergranulation and ascending infection. To restore the cutaneous barrier function in this functional area, soft-tissue on- or in-growth providing a vital and mechanically stable bio-artificial conjunction is considered a promising approach. In this study we assessed viability and proliferation of adult human dermal fibroblasts (HDFa) on modifications of a standard prosthetic titanium surface. Un-coated (TiAl6V4) as well as a titanium-nitrite (TiN) coated additive manufactured porous three-dimensional surface structures (EPORE®) were seeded with HDFa and compared to plain TiAl6V4 and polystyrene surfaces as control. Cell viability and proliferation were assessed at 24 h and 7 days after seeding with a fluorescence-based live-dead assay. Adhesion and cell morphology were analyzed by scanning electron microscopy at the respective measurements. Both EPORE® surface specifications revealed a homogenous cell distribution with flat and spread cell morphology forming filopodia at both measurements. Proliferation and trend to confluence was seen on un-coated EPORE® surfaces with ongoing incubation but appeared substantially lower on the TiN-coated EPORE® specification. While cell viability on both EPORE® specifications was comparable to plain TiAL6V4 and polystyrene controls, cell proliferation and confluence were less pronounced when compared to controls. The EPORE® topography allows for fibroblast adhesion and viability in both standard TiAl6V4 and - to a minor degree - TiN-coated specifications as a proof of principle.

[Conventional epiphyseal chondrosarcoma of childhood and adolescence: a case report]. / Konventionelles epiphysäres Chondrosarkom des Kindes- und Jugendalters: ein Fallbericht.

INTRODUCTION: Conventional chondrosarcoma is the second most common primary malignant bone tumor and usually occurs at older adult ages. It is rare in childhood and adolescence. CASE HISTORY: This case report presents the treatment course of a 13-year-old boy with a symptomatic chondrogenic tumor of the right distal femur. Histopathologically, an epiphyseal intermediate-grade chondrosarcoma (G2) was diagnosed. DISCUSSION: Based on the following case, potential radiological and histopathological differential diagnoses, such as chondroblastoma or chondroblastic osteosarcoma, are discussed against the background of current standards in orthopedic oncology.

Surgical Outcome and Oncological Survival of Osteofibrous Dysplasia-Like and Classic Adamantinomas: An International Multicenter Study of 318 Cases.

BACKGROUND: Osteofibrous dysplasia-like adamantinoma (OFD-AD) and classic adamantinoma (AD) are rare, neoplastic diseases with only limited data supporting current treatment protocols. We believe that our retrospective multicenter cohort study is the largest analysis of patients with adamantinoma to date. The primary purpose of this study was to describe the disease characteristics and evaluate the oncological outcomes. The secondary purpose was to identify risk factors for local recurrence after surgical treatment and propose treatment guidelines. METHODS: Three hundred and eighteen confirmed cases of OFD-AD and AD for which primary treatment was carried out between 1985 and 2015 were submitted by 22 tertiary bone tumor centers. Proposed clinical risk factors for local recurrence such as size, type, and margins were analyzed using univariable and multivariate Cox regression analysis. RESULTS: Of the 318 cases, 128 were OFD-AD and 190 were AD. The mean age at diagnosis was 17 years (median, 14.5 years) for OFD-AD and 32 years (median, 28 years) for AD; 53% of the patients were female. The mean tumor size in the OFD-AD and AD groups combined was 7.8 cm, measured histologically. Sixteen percent of the patients sustained a pathological fracture prior to treatment. Local recurrence was recorded in 22% of the OFD-AD cases and 24% of the AD cases. None of the recurrences in the OFD-AD group progressed to AD. Metastatic disease was found in 18% of the AD cases and fatal disease, in 11% of the AD cases. No metastatic or fatal disease was reported in the OFD-AD group. Multivariate Cox regression analysis demonstrated that uncontaminated resection margins (hazard ratio [HR] = 0.164, 95% confidence interval [CI] = 0.092 to 0.290, p < 0.001), pathological fracture (HR = 1.968, 95% CI = 1.076 to 3.600, p = 0.028), and sex (female versus male: HR = 0.535, 95% CI = 0.300 to 0.952, p = 0.033) impacted the risk of local recurrence. CONCLUSIONS: OFD-AD and AD are parts of a disease spectrum but should be regarded as different entities. Our results support reclassification of OFD-AD into the intermediate locally aggressive category, based on the local recurrence rate of 22% and absence of metastases. In our study, metastatic disease was restricted to the AD group (an 18% rate). We advocate wide resection with uncontaminated margins including bone and involved periosteum for both OFD-AD and AD. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

[Complication management following resection and reconstruction of the upper limbs and shoulder girdle]. / Komplikationsmanagement nach Tumorresektion und Defektrekonstruktion an der oberen Extremität und am Schultergürtel.

BACKGROUND: Sarcomas of the upper limbs commonly affect the proximal humerus or scapula. Complications after tumor resection and reconstruction are rare but cannot be neglected, particularly after tumor endoprosthetic reconstructions. MATERIALS AND METHODS: The most common complications after resection of sarcomas of the upper limbs and shoulder girdle are described, and current knowledge regarding complication management is presented. Additionally, a selective literature search was performed, incorporating personal experiences. RESULTS: Wound healing disorders and infections after tumor resection without specific reconstruction (clavicle resection, scapulectomy) usually respond well to conservative or surgical treatment. However, periprosthetic infections after reconstruction using a megaendoprosthesis constitute a severe and frequent complication, with an incidence of 5-10%. Two-stage implant replacement still represents the gold standard, although in selected cases, one-stage revision with retention of the prosthetic stem appears warranted. Secondary amputation as a result of periprosthetic infection is rare compared to the situation with infections of the lower limb. Mechanical complications necessitating surgical revision are mostly limited to joint dislocation after inverse total shoulder replacement (TSR). (Sub)luxation in anatomic TSR can be tolerated provided there is no tendency toward perforation of the skin in a asymptomatic patient. Biological reconstructions are most often indicated for reconstruction of intercalary defects of the humerus, and revision is necessitated most frequently by mechanical complications. Despite multiple surgical revisions, stable reconstructions and limb salvage can usually be achieved in the upper limb.

[Treatment concepts for complications after resection and defect reconstruction of pelvic tumours]. / Behandlungskonzepte von Komplikationen nach Resektion und Defektrekonstruktion pelviner Tumoren.

BACKGROUND: Partial pelvic resection, internal hemipelvectomy or sacrectomy as a result of bone sarcoma is still challenging. No matter what kind of reconstruction is used, there is still a much higher rate of complications in pelvic surgery compared to sarcoma surgery of the long bones. OBJECTIVES: We describe the most common complications in pelvic sarcoma surgery and specific complications related to the reconstruction method. Handling strategies for these complications are specified. METHODS: We performed a literature search and report our own experiences in the troubleshooting of pelvic surgery-related complications to gain an up-to-date overview of the state-of-the-art in management strategies. RESULTS: Prospective randomized trials or meta-analyses on this topic are lacking. The literature search depicted that, besides local recurrence, deep infection after reconstruction is the most serious complication. An early revision with radical debridement has to be performed in order to save the reconstruction. In the case of a deep infection, the removal of all implants with a total loss of the reconstruction is often unavoidable. Therefore, an individualized risk-benefit analysis prior to surgery with respect to the type of reconstruction, or no reconstruction at all (hip transposition), together with the patient is advisable. CONCLUSIONS: Complications-especially infections-after hemipelvectomy or sacrectomy are common. In the case of infection, in some cases, an early revision is the only chance to prevent a reconstruction from explantation.

What is the Likelihood That Tumor Endoprostheses Will Experience a Second Complication After First Revision in Patients With Primary Malignant Bone Tumors And What Are Potential Risk Factors?

BACKGROUND: Endoprosthetic reconstruction of massive bone defects has become the reconstruction method of choice after limb-sparing resection of primary malignant tumors of the long bones. Given the improved survival rates of patients with extremity bone sarcomas, an increasing number of patients survive but have prosthetic complications over time. Several studies have reported on the outcome of first endoprosthetic complications. However, no comprehensive data, to our knowledge, are available on the likelihood of an additional complication and the associated risk factors, despite the impact of this issue on the affected patients. QUESTIONS/PURPOSES: (1) What are the types and timing of complications and the implant survivorship free from revision after the first complication? (2) Does survivorship free from repeat revision for a second complication differ by anatomic sites? (3) Is the type of first complication associated with the risk or the type of a second complication? (4) Are patient-, tumor-, and treatment-related factors associated with a higher likelihood of repeat revision? METHODS: Between 1993 and 2015, 817 patients underwent megaprosthetic reconstruction after resection of a tumor in the long bones with a single design of a megaprosthetic system. No other prosthetic system was used during the study period. Of those, 75% (616 of 817) had a bone sarcoma. Seventeen patients (3%) had a follow-up of less than 6 months, 4.5% (27 of 599) died with the implant intact before 6 months and 43% (260 of 599 patients) underwent revision. Forty-three percent of patients (260 of 599) experienced a first prosthetic complication during the follow-up period. Ten percent of patients (26 of 260) underwent amputation after the first complication and were excluded from further analysis. Second complications were classified using the classification of Henderson et al. to categorize surgical results. Briefly, this system categorizes complications as wound dehiscence (Type 1); aseptic loosening (Type 2); implant fractures or breakage and periprosthetic fracture (Type 3); infection (Type 4); and tumor progression (Type 5). Implant survival curves were calculated with the Kaplan-Meier method and compared using the log-rank test. Hazard ratios (HR) were estimated with their respective 95% CIs in multivariate Cox regression models. RESULTS: A second complication occurred in 49% of patients (115 of 234) after a median of 17 months (interquartile range [IQR] 5 to 48) after the surgery for the first complication. The time to complication did not differ between the first (median 16 months; IQR 5 to 57) and second complication (median 17 months; IQR 5 to 48; p = 0.976). The implant survivorship free from revision surgery for a second complication was 69% (95% CI 63 to 76) at 2 years and 46% (95% CI 38 to 53) at 5 years. The most common mode of second complication was infection 39% (45 of 115), followed by structural complications with 35% (40 of 115). Total bone and total knee reconstructions had a reduced survivorship free from revision surgery for a second complication at 5 years (HR 2.072 [95% CI 1.066 to 3.856]; p = 0.031) compared with single joint replacements. With the numbers we had, we could not show a difference between the survivorship free of revision for a second complication based on the type of the first complication (HR 0.74 [95% CI 0.215 to 2.546]; p = 0.535). We did not detect an association between total reconstruction length, patient BMI, and patient age and survivorship free from revision for a second complication. Patients had a higher risk of second complications after postoperative radiotherapy (HR 1.849 [95% CI 1.092 to 3.132]; p = 0.022) but not after preoperative radiotherapy (HR 1.174 [95% CI 0.505 to 2.728]; p = 0.709). Patients with diabetes at the time of initial surgery had a reduced survivorship free from revision for a second complication (HR 4.868 [95% CI 1.497 to 15.823]; p = 0.009). CONCLUSIONS: Patients who undergo revision to treat a first megaprosthetic complication must be counseled regarding the high risk of future complications. With second complications occurring relatively soon after the first revision, regular orthopaedic follow-up visits are advised. Preoperative rather than postoperative radiotherapy should be performed when possible. Future studies should evaluate the effectiveness of different approaches in treating complications considering implant survivorship free of revision for a second complication. LEVEL OF EVIDENCE: Level III, therapeutic study.

[Resection margins in soft tissue sarcomas]. / Resektionsgrenzen bei Weichteilsarkomen.

BACKGROUND: Soft tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that arise from the mesenchymal tissue. STS can form anywhere in the human body, with the extremities being preferred sites of predilection. TREATMENT: A fundamental pillar of treatment is the surgical resection of soft tissue sarcomas. The goal is always an R0 resection with a safety margin. There is no consensus in the literature about the desired tumor-free resection margin. The decisive factors for these resection margins are histopathology, presence of anatomical barriers (capsule, tendon, fascia, cartilage, periosteum) and possibilities of (neo-) adjuvant therapy. DISCUSSION: References in the literature support the role of resection margins as a predictor of local recurrence. Regarding the role of resection margins in overall survival, available data is divergent. There are known prognostic factors that influence overall survival, such as histological subtype, tumor size, tumor grading, and presence of metastases. So far, several studies have attempted to quantify the margins of resection, but no consensus has been reached, and debates are ongoing. When analyzing all the results of the data in the literature, it seems appropriate to aim for a negative resection margin >1 mm including an anatomical border structure, if possible.

[Differentiated treatment strategies for bone metastases of the extremities]. / Differenzierte Therapiestrategien bei Knochenmetastasen der Extremitäten.

BACKGROUND: Bone metastases are the most common malignant bone tumours and most commonly occur in the spine, pelvis, proximal femur and proximal humerus. Prostate and breast cancer most often metastasize to the bone. DIAGNOSTICS: In patients with a history of tumours and local unspecific pain in the back and extremities, further diagnostic examinations should be performed. For the initial diagnosis a conventional radiograph of the whole bone in two planes is sufficient. For further diagnostics, the imaging may be supplemented with CT, MRI, scintigraphy and a PET-CT (PET-MRI) if the findings are not inconspicuous on the x­ray. An indication for biopsy exists if the tumor cannot be classified, especially in solitary findings with or without previous tumor anamnesis. THERAPY: Surgical indications for bone metastases are a pathological fracture, an impending fracture, a solitary late metastasis, radiation-resistant osteolysis and therapy-resistant pain. In solitary metastases, the prognosis for patients can be significantly improved by a wide (R0 resection) depending on the primary tumour. For multiple metastases the restoration of mobility and improvement of the quality of life are in the foreground. Depending on the life expectancy and other factors, such as the location of the metastases osteosynthesis, implantations of dual head prothesis, total joint arthroplasty and tumor endoprostheses can be performed.

[Hemipelvectomy for pelvic sarcomas]. / Hemipelvektomie bei Sarkomen des Beckens.

BACKGROUND: Hemipelvectomy is an important technique for the treatment of pelvic sarcomas. OBJECTIVES: Presentation of the technical overview, as well as surgical and oncological outcomes of sarcoma patients treated with pelvic tumor resections and treatment recommendations. METHODS: Retrospective analysis of 160 patients treated by pelvic tumor resection for chondrosarcoma between 1977 and 2014. RESULTS: Chondrosarcoma was the most common diagnosis leading to pelvic tumor resection in this collective (38%). The mean patient age at operation was 49 years. 44 patients were treated for G1, 83 patients for G2 and 33 patients for G3 or dedifferentiated chondrosarcoma. The mean tumor diameter was ≥10 cm in 76.1% of cases. Limb salvaging operations were possible in 82.5% of patients. The most common reconstruction technique was hip transposition (38.7%). Clear resection margins were achieved in 86.9% (R0). Local recurrence was observed in 22.5%. Distant pulmonal metastasis was diagnosed in 25% of patients. Grading-specific survival was 81.8% for G1, 59% for G2 and 24.2% for G3 or dedifferentiated chondrosarcoma with a mean survival of 84.4, 89 and 69.4 months respectively. CONCLUSIONS: Pelvic tumor resection with clear margins is the most important known positive predictive local factor affecting overall outcomes, in addition to uncontrollable factors such as grading and tumor size. Defect reconstruction depends on multiple factors such as patient age and adjuvant therapy. The stage of the disease has the greatest impact on overall survival rates and should be considered when contemplating pelvic tumor resections in sarcoma patients.

[Current results of tumour endoprosthetics in adolescents and adults]. / Aktuelle Ergebnisse der Tumorendoprothetik bei Jugendlichen und Erwachsenen.

BACKGROUND: The majority of osteoarticular defects after tumor resection in adolescent and adult patients are reconstructed using megaendoprosthetic implants. However, even infant and pre-teen children undergo reconstruction of defects using so-called growing prostheses with an increasing frequency. OBJECTIVES: Presentation of current techniques, outcomes and the most common complications of megaendoprosthetic reconstruction following tumour resection. METHODS: Selective literature review and discussion of current concepts and knowledge in megaendoprosthetic reconstruction against personal experience and treatment strategies. RESULTS: Megaendoprosthetic reconstructions achieve good functional results and long-term limb salvage (ca. 90% of cases) in adolescent and adult patients. Still, periprosthetic infection and mechanical failure of joint components are among the most common complications observed. In infant and pre-teen children treated by reconstruction using a growing prosthesis, mandatory maintenance operations-in the process of elongating the implant-must also be considered when assessing complication risks. CONCLUSIONS: Megaendoprosthetic reconstructions of osteoarticular defects are a standard procedure in adolescent and adult patients. Despite a substantial complication rate, limb salvage is achieved in a majority of patients. When using growing prostheses in younger children, one needs to be aware of additional servicing procedures that occur independently of those arising from complications.

[Endoprostheses for stump formation after hip disarticulation]. / Endoprothesen zur Stumpfbildung nach Hüftexartikulation.

BACKGROUND: Hip disarticulation is a psychologically and physically demanding procedure. However, it remains a therapeutical option whenever limb salvage proves impossible due to sarcoma, severe implant-associated infections or trauma. The stump lengthening procedure (SLP) is a surgical technique that allows partial salvage of the thigh through endoprosthetic proximal femur replacement after hip disarticulation, depending on the amount of viable soft tissue coverage. This leads to a more appealing visual appearance, facilitates prosthetic fitting and significantly improves limb function. OBJECTIVES: Description of indications for SLP, surgical technique, presentation of clinical and functional outcomes. METHODS: Review of applying literature and presentation of outcomes of our own SLP collective. RESULTS: The risk of local recurrence does not increase after SLP compared to hip disarticulation. While the majority of patients can be fitted with an exoprosthesis, a walking aid is usually necessary for ambulation. Exoprostheses are usually worn throughout the entire day, and patients manage distances of a mean of 2000 metres, even if reconstruction lengths are less than 10 cm. Patients aged 50 years or older tend to wear their exoprosthesis for shorter periods of daywear and achieve significantly poorer functional scores. Postoperative complications are common at a rate of 52%. Periprosthetic infection (21%) and soft tissue perforation of the implant with subsequent implant-associated infection (14%) were the most severe complications observed. CONCLUSIONS: The stump lengthening procedure poses a feasible alternative to classic hip disarticulation in patients with multiple prior operations and/or advanced stages of disease. It leads to satisfactory cosmetic and functional results without jeopardizing local tumor control. Stump perforation presents as the most common complication. Apart from improving the ability to sit down comfortably, both patients treated with a curative and palliative intent manage to ambulate using exoprostheses. With increasing age at the time of operation, walking aids are necessary for ambulation.

Ultra-short stem anchorage in the proximal tibial epiphysis after intercalary tumor resections: analysis of reconstruction survival in four patients at a mean follow-up of 56 months.

INTRODUCTION: Tumors localized in the proximal tibial meta-diaphysis often lead to osteoarticular resections. MATERIALS AND METHODS: In this study, we retrospectively reviewed four patients who underwent intercalary tumor resection and reconstruction using an ultra-short stem in the proximal tibial epiphysis, a procedure that to our knowledge has not been reported in literature so far. RESULTS: At the time of operation, the mean patient age was 26.2 years. Three patients were male and one was female. Patients were diagnosed with osteosarcoma in two cases, Ewing's sarcoma and malignant fibrous histiocytoma of bone in one case each. In all cases, wide tumor resections were achieved (osteotomy 3-3.5 cm below the tibia plateau joint surface, mean resection length of tibial bone 18 cm) at a mean time of operation of 198.8 min. Two superficial wound-healing disorders occurred, leading to one surgical revision in each case. One local tumor recurrence occurred 12 months after operation in a patient who discontinued his adjuvant chemotherapy. This patient died of disease, 31 months after operation. Three patients are alive with no evidence of disease at a mean follow-up of 56 months. Walking is not impaired and light sports activities have been reported in all cases. The mean MSTS score is 28/30. CONCLUSIONS: Therefore, we report this reconstruction technique to be considered for special indications where the functional outcome can be improved by preservation of the knee joint in tumors of the proximal meta-diaphyseal tibial region.

[Quality in Revision Arthroplasty: A Comparison between Claims Data Analysis and External Quality Assurance]. / Ergebnisqualität in der Revisionsendoprothetik: Eine Analyse von Routinedaten mit dem Vergleich zur externen Qualitätssicherung.

BACKGROUND: External quality assurance for revisions of total knee arthroplasty (TKA) and total hip arthroplasty (THA) are carried out through the AQUA institute in Germany. Data are collected by the providers and are analyzed based on predefined quality indicators from the hospital stay in which the revision was performed. The present study explores the possibility to add routine data analysis to the existing external quality assurance (EQS). Differences between methods are displayed. The study aims to quantify the benefit of an additional analysis that allows patients to be followed up beyond the hospitalization itself. MATERIAL AND METHODS: All persons insured in an AOK sickness fund formed the population for analysis. Revisions were identified using the same algorithm as the existing external quality assurance. Adverse events were defined according to the AQUA indicators for the years 2008 to 2011.The hospital stay in which the revision took place and a follow-up of 30 days were included. For re-operation and dislocation we also defined a 365 days interval for additional follow-up. The results were compared to the external quality control reports. RESULTS: Almost all indicators showed higher events in claims data analysis than in external quality control. Major differences are seen for dislocation (EQS SD: 1.87 vs. claims data [cd] SD: 2.06 %, cd+30 d: 2.91 %, cd+365 d: 7.27 %) and reoperation (hip revision: EQS SD: 5.88 % vs. claims data SD: 8.79 % cd+30 d: 9.82 %, cd+365 d: 15.0 %/knee revision: EQS SD: 3.21 % vs. claims data SD: 4.07 %, cd+30 d: 4.6 %, cd+365 d: 15.43 %). Claims data could show additional adverse events for all indicators after the initial hospital stay, rising to 77 % of all events. CONCLUSIONS: The number of adverse events differs between the existing external quality control and our claims data analysis. Claims data give the opportunity to complement existing methods of quality control though a longer follow-up, when many complications become evident.

Selective arterial Embolisation of Aneurysmal Bone Cysts of the Sacrum: a promising Alternative to Surgery.

PURPOSE: The sacrum is a rare but unfavourable location for Aneurysmal Bone Cysts (ABCs), surgical procedures aiming to achieve local tumour control can be mutilating. Aim of this study was to evaluate whether selective arterial embolisation (AE) of ABC of the sacrum is an effective treatment and might be an alternative to surgical treatment options. MATERIALS AND METHODS: Between 2007 and 2011 six patients (mean age 13.7 years, range 8 - 18 years) with an ABC of the sacrum were treated by AE. Follow-up was performed by MRI-scans as well as clinical examination (mean 36.5 months, range 14 - 56 months). RESULTS: No treatment related complications have been observed. AE resulted in devascularisation of ABC and led to local tumour control in all patients. A partial consolidation was noticed in three patients. Pain relief was achieved in five of six patients, neurological deficits dissolved. In two patients more than one embolization was necessary. In one of these patients due to exacerbation of pain a surgical decompression was performed. CONCLUSION: AE of sacral ABCs can serve as an effective and safe treatment option. Thus it might be an alternative to potentially harmful surgical procedures. In case of ongoing tumour growth or pain recurrence AE can be repeated. In case of treatment failure surgical interventions are still possible. KEY POINTS: • transarterial embolisation enables local tumour control in sacral ABCs. • transarterial embolisation of sacral ABCs is a safe procedure. • in case of tumour progression repetitive embolisations are possible and effective.

[Osteosarcoma and chondrosarcoma of the pelvis and lower extremities]. / Osteo- und Chondrosarkome des Beckens und der unteren Extremitäten.

A wide tumor resection is essential in the therapy of primary malignant bone tumors to minimize the risk of local recurrence and ensure long-term survival. While chondrosarcoma is mainly treated surgically, osteosarcoma therapy consists of both chemotherapy and surgical resection of the tumor. While endoprosthetic replacement after hemipelvectomy tends to be associated with high infection rates and has been superseded by hip transposition and composite osteosynthetic replacements, the use of megaendoprosthetic tumor prostheses is the most common reconstruction technique when the extremities are affected. Biological reconstruction or ablative procedures are reserved for special indications. Overall, the reconstruction techniques presented in this article manage to ensure limb salvage in most patients. Functional outcome, however, greatly depends on the tumor size and site as well as postoperative residual soft tissue coverage.

Development of curative therapies for Ewing sarcomas by interdisciplinary cooperative groups in Europe.

Curative therapies for Ewing sarcoma have been developed within cooperative groups. Consecutive clinical trials have systematically assessed the impact and timing of local therapy and the activity of cytotoxic drugs and their combinations. They have led to an increase of long-term disease-free survival to around 70% in patients with localized disease. Translational research in ES remains an area in which interdisciplinary and international cooperation is essential for future progress. This article reviews current state-of-the art therapy, with a focus on trials performed in Europe, and summarizes novel strategies to further advance both the cure rates and quality of survival.

[Interdisciplinary diagnostic and treatment of bone sarcomas of the extremities and trunk]. / Die interdisziplinäre Diagnostik und Therapie von Knochensarkomen der Extremitäten und des Rumpfes.

Contrary to the relatively common benign bone tumours and tumour-like lesions, bone sarcomas are rare malignancies with an incidence of 0.8 new cases per 100 000 persons per year. The most common primary malignant bone tumour is osteosarcoma, followed by chondrosarcoma and Ewing sarcoma. Osteosarcomas and Ewing sarcomas occur predominantly in children, adolescents and young adults, while chondrosarcomas primarily affect older patients. Most of the tumours are located in the extremities and the pelvis and in about 90% of the cases the surgical treatment can be performed by means of a limb-sparing wide resection. An endoprosthetic or biological reconstruction of the resulting defect, depending on several patient- und tumour-related factors, is usually necessary. Apart from the surgical treatment, patients with osteosarcoma and Ewing sarcoma require a pre- and postoperative chemotherapy, while Ewing sarcoma patients often undergo radiation therapy as well. Regular follow-up examinations are required after the completion of treatment for the early detection and management of local and/or systemic recurrences as well as treatment-related complications. An extensive experience in the clinical and imaging features as well as the interdisciplinary treatment of these tumours is necessary for optimal patient care. Without it mistakes are often made, which can have grave consequences on the patients' prognosis and functional outcome. The centralised treatment of these patients in specialised sarcoma centres is therefore recommended.