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Background: Proximal femur replacements in patients with sarcoma are associated with high rates of infection. This study is the largest one comparing infection rates with titanium versus silver-coated megaprostheses in sarcoma patients.Methods: Infection rates were assessed in 99 patients with proximal femur sarcoma who underwent placement of a titanium (n = 35) or silver-coated (n = 64) megaprosthesis. Treatments administered for infection were also analyzed.Results: Infections occurred in 14.3% of patients in the titanium group, in comparison with 9.4% of those in the silver group, when the development of infection was the primary end point. The 5- and 10-year event-free survival rates for the prosthesis relative to the parameter of infection were 90% in the silver group and 83% in the titanium group. The overall infection rates were 10.9% in the silver group and 20% in the titanium group. Two patients each in the silver and titanium groups ultimately had to undergo amputation. The need for two-stage prosthesis exchanges (57.1% in the titanium group) declined to 14.3% in the silver group.Conclusion: Using a silver-coated proximal femoral replacement nearly halved the overall infection rate. When infections occurred, it was usually possible to avoid two-stage prosthesis exchanges in the silver group. [ABSTRACT FROM AUTHOR]

Introduction: The minimally invasive direct anterior approach (DAA) is an established approach for primary total hip arthroplasty (THA). The complication rates in hip revision arthroplasty are much higher in comparison with primary THA. A right positioning of the implants and a soft tissue, especially the abductors spearing approach, is important to get good functional results and low complication rates. The aim of this study was to show the clinical and radiological outcome of isolated revision hip arthroplasty of the cup by using the DAA.Materials and Methods: Aseptic cup revisions were carried out in 48 patients using the DAA. A decision to exchange the stem was made intraoperatively in seven cases. Complications, radiological and functional outcome were assessed. All of the data were collected retrospectively. The mean follow-up period was 65 months.Results: In most of the cases the standard DAA was used. A proximal extension was nescessary in 15 patients (31%). The mean cup inclination angle after revision was 44° (min. 25°, max. 62°). Six implants (12.5%) were located outside of the Lewinnek safe zone. The centers of rotation of the revision implants were a mean of 0.6 cm superior (min. 0, max. 2.2 cm) and 0.5 cm lateral (min. 0.2 cm, max 1.2 cm) in comparison with the center of rotation in the healthy hip on the contralateral side. Harris Hip Score improved significantly from 50 to 91 (P = 0.03). Complications noted consisted of two periprosthetic infections (4.2%), one aseptic cup loosening (2.1%), two hematomas requiring revision (4.2%), and one case each of femoral nerve injury, lower-leg venous thrombosis, and pneumonia. No dislocations were observed and there were no cases of heterotopic ossification based on the Brooker classification. No persistent damage of the nervus cutaneus femoris lateralis was found at the follow-up examinations.Conclusions: The DAA represents a feasible option in hip revision arthroplasty. Anatomic reconstruction of the cup is reproducibly possible. Good medium-term results can also be achieved. Particularly in relation to dislocation, the complication rates are low. Due to the learning curve, the DAA should only be used in hip revision arthroplasty by those with sufficient experience in primary THA. Adequate data regarding stem revisions through the DAA are not available at the moment. [ABSTRACT FROM AUTHOR]

Local treatment is a crucial element in the standard of care for Ewing sarcoma (EWS). While systemic treatment is improved in randomised clinical trials, local treatment modalities are discussed controversially. We analysed the association between local therapy and event-free survival (EFS), overall survival (OS), and local recurrence (LR) in prospectively collected data of patients with localised EWS. We analysed data from the international Ewing 2008 study registered between 2009 and 2019 in 117 centres. After induction chemotherapy, patients received surgery, radiotherapy, or a combination thereof. We performed Cox regression, conducted propensity score-weighted sensitivity analysis, and performed subgroup analyses. Hazard ratios (HRs) and 95% confidence intervals are reported. We included 863 patients with localised EWS (surgery alone: 331, combination therapy: 358, definitive radiotherapy: 174). In patients treated with combination therapy compared to surgery alone, EFS HR was 0.84 (0.57–1.24; p = 0.38), OS HR was 0.84 (0.57–1.23; p = 0.41), and LR HR was 0.58 (0.26–1.31; p = 0.19). Hazards of any event were increased in patients treated with definitive radiotherapy compared to surgery only, HR 1.53 (1.02–2.31; p = 0.04). Patients with poor responses to chemotherapy benefitted from combination therapy over definitive surgery with an EFS HR 0.49 (0.27–0.89; p = 0.02). Patients with pelvic tumours benefitted from combination therapy over surgery only regarding LR, HR 0.12 (0.02–0.72; p = 0.02). Patients with poor responses to chemotherapy benefitted from radiotherapy added to surgery. In the whole group, radiotherapy alone as opposed to surgery alone increased the hazards of any event. • Local therapy modalities in patients with localised Ewing sarcoma were analysed. • Definitive radiotherapy compared to surgery alone increased hazards of any event. • No difference between combination therapy and surgery only regarding EFS, OS, LR. • Patients with poor responses to chemotherapy benefitted from combination therapy. • Patients with pelvic tumours benefitted from combination therapy regarding LR. [ABSTRACT FROM AUTHOR]

Periprosthetic infection remains one of the most serious complications following megaendoprostheses. Despite a large number of preventive measures that have been introduced in recent years, it has not been possible to further reduce the rate of periprosthetic infection. With regard to metallic modification of implants, silver in particular has been regarded as highly promising, since silver particles combine a high degree of antimicrobial activity with a low level of human toxicity. This review provides an overview of the history of the use of silver as an antimicrobial agent, its mechanism of action, and its clinical application in the field of megaendoprosthetics. The benefits of silver-coated prostheses could not be confirmed until now. However, a large number of retrospective studies suggest that the rate of periprosthetic infections could be reduced by using silver-coated megaprostheses. [ABSTRACT FROM AUTHOR]

Introduction: Besides CRP in serum, white cell counts and cultures of synovial fluid are routinely used to detect periprosthetic joint infections. But the sensitivities of these parameters do vary from 12 to 100 %. In two stage revision arthroplasty before the second stage surgeons have to decide if reimplantation is justified. Therefore, we investigated the value of cultures and white cell count from the synovial fluid with a polymethyl methacrylate spacer in place and CRP in serum before reimplantation to detect persistent infection in a standardized setting.Methods: 115 patients with a two-stage revision hip or knee arthroplasty were included in this study. All patients had an antibiotic loaded polymethylmethacrylate spacer. Retrospectively synovial cultures, white blood count in synovial fluid and CRP in serum were assessed before reimplantation.Results: The sensitivity of the synovial cultures was 5 % (95 % CI 0.13-24.87), with a specificity of 99 % (95 % CI 94.27-99.97). For white blood count in synovial fluid the sensitivity was 31.3 %, specificity was 39.1 %. Sensitivity for CRP in serum was 42.10 %, specificity was 84.21 %.Conclusion: Cultures from synovial fluid and white blood count in synovial fluid and CRP seem to be uncertain parameters to exclude persistent infection. We do not recommend joint aspiration before reimplantation anymore. Further research is necessary to find other markers to confirm or exclude persistent infection. [ABSTRACT FROM AUTHOR]

Purpose: Active shoulder function after segmental tumour resection of the proximal humerus and endoprosthetic reconstruction is regularly compromised, while the overall arm function allows a satisfying use in daily activities. The main functional problem remains the loss of huge parts of the shoulder girdle musculature and its bony attachment. In revision arthroplasty inverse shoulder implants can improve the active range of motion significantly in comparison to anatomical shaped prostheses. The aim of this study was to investigate if these promising experiences are transferable to reconstructions after tumour resection of the proximal humerus by using a modular inverse tumour prosthesis. Methods: In this study we observed the functional and oncological results of 18 inverse proximal humerus endoprosthetic replacements (IPHP) with the MUTARS system (Implantcast®) after resection of benign (1x giant cell) and malignant (11x primary bone sarcoma, 5x bone metastasis of carcinoma) bone tumours. Mean age at operation was 42 years. The mean postoperative follow-up was 33 months (range ten to 120). Results: Resection margins were wide in 13 and marginal in five patients. Mean reconstruction length was 15.1 cm (range 6-25 cm). Mean operation time was 191 minutes. The axillary nerve was mostly preserved in 78 % ( n = 14). At latest follow-up the patients presented a medium MSTS-score of 24.6/30. The mean active arm abduction in the shoulder joint was 78° and 88° active arm elevation for patients with intact axillary nerve function, but significantly reduced for the four patients with compromised deltoid function. One patient needed a surgical revision due to a deep implant infection. Conclusions: The IPHP offers a significant improvement of active shoulder function in patients in whom the axillary nerve can be preserved in comparison to anatomically-shaped implants. However, for patients without any deltoid function there is no benefit regarding an improved active range of motion using an IPHP. [ABSTRACT FROM AUTHOR]

Disseminated or relapsed Ewing sarcoma (EwS) has remained fatal in the majority of patients. A promising approach to preventing relapse after conventional therapy is to establish tumor antigen-specific immune control. Efficient and specific T cell memory against the tumor depends on the expansion of rare T cells with native specificity against target antigens overexpressed by the tumor. Candidate antigens in EwS include six-transmembrane epithelial antigen of the prostate-1 (STEAP1), and the human cancer/testis antigens X-antigen family member 1 (XAGE1) and preferentially expressed antigen in melanoma (PRAME). Here, we screened normal donors and EwS patients for the presence of circulating T cells reactive with overlapping peptide libraries of these antigens by IFN-γ Elispot analysis. The majority of 22 healthy donors lacked detectable memory T cell responses against STEAP1, XAGE1 and PRAME. Moreover, ex vivo detection of T cells specific for these antigens in both blood and bone marrow were limited to a minority of EwS patients and required nonspecific T cell prestimulation. Cytotoxic T cells specific for the tumor-associated antigens were efficiently and reliably generated by in vitro priming using professional antigen-presenting cells and optimized cytokine stimulation; however, these T cells failed to interact with native antigen processed by target cells and with EwS cells expressing the antigen. We conclude that EwS-associated antigens fail to induce efficient T cell receptor (TCR)-mediated antitumor immune responses even under optimized conditions. Strategies based on TCR engineering could provide a more effective means to manipulating T cell immunity toward targeted elimination of tumor cells. [ABSTRACT FROM AUTHOR]

Background: Up until now, reconstructions after partial supraacetabular pelvic resection have been done with the use of megaprostheses or allo-/autografs, including screws. The literature states complications in up to 100%. Therefore, the university hospital of Muenster has successfully established a reconstruction using poly-axial screws and titanium rods in combination with a Palacos® shroud. The aim of this study was to gather data on primary stability of five different types of reconstruction. Methods: Using a biomechanical model Load (N), displacement (mm) and stiffness (N/mm) were recorded in load cycles from 100N up to 1050N. Findings: The data shows that reconstructions with poly-axial screws, titanium rods and Palacos® can bear a load of up to 1050N without structural damages. The same is valid with an additional bone graft and for a full metal prosthesis. Referring to reconstructions with just bone graft or without graft and Palacos® the load-bearing capacity is significantly worse. Additionally, structural damages were recorded in those reconstructions from 700N onwards. Interpretation: Due to the biomechanical results and the save and easy handling, reconstructions with poly-axial screws, titanium rods and Palacos® (and, if necessary, bone graft) can be recommended achieving high primary stability for pelvic ring reconstruction after partial supraacetabular pelvic resection. [ABSTRACT FROM AUTHOR]

Abstract: A new method for the analysis of 1-hydroxy-2-imidazol-1-yl-phosphonoethyl phosphoric acid (zoledronic acid) in urine and blood samples has been developed. It consists of a derivatisation of the bisphosphonate with trimethylsilyl diazomethane under multiple methylester formation. The formed derivative can, in contrast to the non-derivatised analyte, easily be separated by reversed phase liquid chromatography due to its reduced polarity. Detection is performed by electrospray tandem mass spectrometry. For calibration purposes, a deuterated internal standard has been synthesised in a three-step synthesis starting with d4-imidazole. For human urine, the limit of detection (LOD) is 1.2x10−7 mol/L, limit of quantification (LOQ) is 3.75×10−7 mol/L in the MRM mode. For human blood plasma, a LOD of 1×10−7 mol/L and a LOQ of 2.5×10−7 mol/L were determined. The linear dynamic range comprised 3.5 decades starting at the limit of quantification. The method was successfully applied for the analysis of spiked urine and blood plasma samples as well as samples from two osteoporosis patients. [Copyright &y& Elsevier]

Background: Osteosarcoma may arise as a secondary malignancy following rhabdomyosarcoma (RMS). We utilized the Cooperative Osteosarcoma Study Group (COSS) database to better understand this association., Patients and Methods: The COSS database (1980-05/2023) was searched for patients whose osteosarcoma was preceded by RMS. Eligible patients were analyzed for patient-, tumor-, and treatment-related variables as well as outcomes., Results: The search revealed 28 eligible osteosarcomas (27 high-grade central, one periosteal; male:female = 16:12; median age RMS 2.1 [range: 0.9-10.0] years, osteosarcoma 13.5 [7.2-29.0] years). Genetic tumor-predisposition syndromes were documented in 12 patients. One patient had had a distinct malignancy prior to RMS, two intermittently, seven following osteosarcoma. Local RMS treatment had included radiotherapy in 20/26 cases (two unknown). Secondary osteosarcoma sites were extremity 13, trunk seven, head and neck eight; 15 osteosarcomas were radiation-associated. There was only one case of primary osteosarcoma metastases. Osteosarcoma treatment included chemotherapy (27), surgery (26), or radiotherapy (2). A macroscopically complete remission of all osteosarcoma sites was achieved in 24 cases. Median follow-up was 5.8 (range: 0.5-18.4) years after osteosarcoma and 8.1 (1.0-15.4) years for 14 survivors. Actuarial 5-year overall and event-free survival were 66% (standard error 9%) and 45% (10%), respectively. Five of 14 deaths were caused by further malignancies., Conclusion: This series offers a benchmark for patients who develop a secondary osteosarcoma after RMS. Affected patients are generally still in the pediatric age. The results obtained strongly argue for genetic predisposition testing in RMS and against therapeutic leniency in comparable situations., (© 2024 The Author(s). Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

This study aimed to retrospectively analyze the follow-up results of cases in which the adjacent joint was preserved using a custom-made uncemented short-stem design (hollow stem) with optional external flanches in tumor endoprosthetic replacement due to bone sarcomas in 13 patients (with an average age of 9.6 years) between 2017 and 2023. Reconstructions were proximal femur ( n = 6), intercalary femur ( n = 4), intercalary tibia ( n = 2), and proximal humerus ( n = 1) tumor prostheses. The hollow body was used distally in 10 of the megaprotheses, proximally in 1, and both proximally and distally in 2 of them. The average distance from the joints was 6 cm in stems with flanches and 11.8 cm in stems without flanches. No aseptic loosening or deep infection was observed during an average follow-up of 34 months. Except for one case with a tibial intercalary prosthesis that needed a revision, all cases were well osteointegrated and all lower extremity cases could bear full weight without pain. In cases where the remaining bone stock after bone resection is insufficient for a standard stem implantation, reconstruction with a patient-specific short hollow-stem design appears to be a good alternative to protect healthy joints with high prosthesis survival and low revision rates in the short-term follow-up.

Aims: Custom-made partial pelvis replacements (PPRs) are increasingly used in the reconstruction of large acetabular defects and have mainly been designed using a triflange approach, requiring extensive soft-tissue dissection. The monoflange design, where primary intramedullary fixation within the ilium combined with a monoflange for rotational stability, was anticipated to overcome this obstacle. The aim of this study was to evaluate the design with regard to functional outcome, complications, and acetabular reconstruction., Methods: Between 2014 and 2023, 79 patients with a mean follow-up of 33 months (SD 22; 9 to 103) were included. Functional outcome was measured using the Harris Hip Score and EuroQol five-dimension questionnaire (EQ-5D). PPR revisions were defined as an endpoint, and subgroups were analyzed to determine risk factors., Results: Implantation was possible in all cases with a 2D centre of rotation deviation of 10 mm (SD 5.8; 1 to 29). PPR revision was necessary in eight (10%) patients. HHS increased significantly from 33 to 72 postoperatively, with a mean increase of 39 points (p < 0.001). Postoperative EQ-5D score was 0.7 (SD 0.3; -0.3 to 1). Risk factor analysis showed significant revision rates for septic indications (p ≤ 0.001) as well as femoral defect size (p = 0.001)., Conclusion: Since large acetabular defects are being treated surgically more often, custom-made PPR should be integrated as an option in treatment algorithms. Monoflange PPR, with primary iliac fixation, offers a viable treatment option for Paprosky III defects with promising functional results, while requiring less soft-tissue exposure and allowing immediate full weightbearing., Competing Interests: C. Gebert, M. Wessling, and L. M. Jeys act as academic consultants for Implantcast, unrelated to this study. C. Gebert and M. Wessling act as academic consultants for Heraeus Medical, unrelated to this study. C. Gebert has received royalties, payment for expert testimony, and support for attending meetings and/or travel from Implantcast, all unrelated to this study. M. Wessling has received royalties, speaker honoraria, payment for expert testimony, and support for attending meetings and/or travel from Implantcast, all unrelated to this study. J. Hardes has received financial support from Implantcast for scientific projects unrelated to this study. Y. Hanusrichter has received speaker honoraria from Curasan and Implantcast, unrelated to this study. L. M. Jeys has received speaker honoraria from Zimmer Biomet, Stryker, and Implantcast, as well as payment for expert testimony from Implantcast, all of which are unrelated to this study., (© 2024 Hanusrichter et al.)

Osteosarcoma and Ewing sarcoma are bone tumors mostly diagnosed in children, adolescents, and young adults. Despite multimodal therapy, morbidity is high and survival rates remain low, especially in the metastatic disease setting. Trials investigating targeted therapies and immunotherapies have not been groundbreaking. Better understanding of biological subgroups, the role of the tumor immune microenvironment, factors that promote metastasis, and clinical biomarkers of prognosis and drug response are required to make progress. A prerequisite to achieve desired success is a thorough, systematic, and clinically linked biological analysis of patient samples, but disease rarity and tissue processing challenges such as logistics and infrastructure have contributed to a lack of relevant samples for clinical care and research. There is a need for a Europe-wide framework to be implemented for the adequate and minimal sampling, processing, storage, and analysis of patient samples. Two international panels of scientists, clinicians, and patient and parent advocates have formed the Fight Osteosarcoma Through European Research consortium and the Euro Ewing Consortium. The consortia shared their expertise and institutional practices to formulate new guidelines. We report new reference standards for adequate and minimally required sampling (time points, diagnostic samples, and liquid biopsy tubes), handling, and biobanking to enable advanced biological studies in bone sarcoma. We describe standards for analysis and annotation to drive collaboration and data harmonization with practical, legal, and ethical considerations. This position paper provides comprehensive guidelines that should become the new standards of care that will accelerate scientific progress, promote collaboration, and improve outcomes., (©2024 The Authors; Published by the American Association for Cancer Research.)

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting., Competing Interests: A. Puri is a member of the editorial board of The Bone & Joint Journal. P. Ruggieri reports consulting fees from Exactech and Stryker, unrelated to this study. M. T. Houdek reports consulting fees from Link Orthopedics, unrelated to this study. E. Botello reports consulting fees, payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events, and support for attending meetings and/or travel from Zimmer Biomet, all of which are unrelated to this study. G. V. Morris reports consulting fees, payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events, and support for attending meetings and/or travel from Implantcast, all of which are unrelated to this study., (© 2024 Jeys et al.)

While the usual etiology of slipped capital femoral epiphysis (SCFE) is idiopathic, there are many other factors that increase the predisposition to slippage. Chemotherapy can be one of them. In this article, we report a rare case of acute SCFE after tumor prosthesis implantation in a patient who received chemotherapy. A 10-year-old girl with osteosarcoma of the right distal femur underwent (neo-) adjuvant chemotherapy, wide tumor resection, and reconstruction using a growing tumor prosthesis and a short non-cemented femoral stem. Half a year after implantation, she developed aseptic loosening. Revision surgery was performed using a hydroxyapatite (HA)-coated cementless femoral stem. Postoperative plain radiographs revealed SCFE that was treated by closed reduction and screw fixation. The patient recovered without complications, and unaffected hip showed no radiographic signs of slippage on follow-up. The forces of implanting a tumor prosthesis, particularly with a non-cemented stem, can increase the risk of an acute SCFE. The controversy over prophylactic pinning of the uninvolved hip in chemotherapy-associated SCFE is unresolved. Pinning can be considered only in the presence of abnormal prodromal radiological findings.

Introduction: Most tumour-related pathological fractures occur in patients with bone metastases. However, in mostly younger patients, a pathological fracture can be due to both a benign or a malignant bone tumour. Making the correct diagnosis from among these two differential diagnoses is enormously important. If the tumour is malignant, treating the fracture inevitably leads to tumour cell contamination and can significantly worsen the oncological situation. The aim of this review article is firstly to provide the reader with diagnostic assistance in the case of suspected pathological fractures, and secondly to focus on the treatment of pathological fractures occurring with benign bone tumours., Methods: This is a non-systematic review of the diagnosis and treatment of pathological fractures in benign bone tumours or tumour-like lesions, based on an electronic PubMed database search. We also present our own procedures, in particular for ruling out a malignant bone tumour., Results and Discussion: Whenever a fracture occurs in the absence of sufficient traumatic force, the possibility of a pathological fracture should always be considered. As well as taking a general history for a possible primary tumour, it is particularly important to ask the patient whether they had any pain before the fracture occurred. If the findings from clinical examination or conventional radiological imaging give rise to suspicion of a pathological fracture, an MRI of the affected skeletal section with contrast medium should be carried out before commencing any fracture treatment. A CT scan is also helpful for accurately assessing bone destruction. If a malignant or locally aggressive benign bone tumour such as giant cell tumour (GCT) or aneurysmal bone cyst (ABC) cannot be definitively ruled out through imaging, a biopsy is essential. The bone biopsy must always be carried out on the assumption that the histological work-up will reveal a malignant bone tumour; it must therefore be performed according to strict oncological criteria. If the radiological diagnosis is unambiguous, e. g., a juvenile bone cyst (JBC) or a non-ossifying fibroma (NOF), conservative treatment of the fracture can be considered, depending on the location. In the presence of a locally aggressive benign bone tumour such as a GCT or ABC, curettage of the tumour must be carried out as well as treating the fracture. With GCT in particular, neoadjuvant therapy with denosumab prior to curettage and osteosynthesis or en bloc resection of the tumour should be considered, depending on the extent of the tumour., Conclusion: Pathological fractures, especially in younger patients, should not be overlooked. Only after a malignant or benign locally aggressive bone tumour has been definitively ruled out should fracture treatment be performed. In the presence of a locally aggressive bone tumour, as well as treating the fracture, it is usually necessary to perform curettage of the tumour - also en bloc resection, where applicable, in the case of a GCT. Depending on the location, benign, non-aggressive tumours can be treated conservatively if necessary., Competing Interests: J. Hardes und A. Streitbürger weisen auf folgende Beziehung hin: Forschungsunterstützung durch die Firma Implantcast, Buxtehude. D. Spodeck, W.Guder,M.Nottrott, L.Podleska,und M.Dudda geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Introduction: Due to substantial advances in all medical disciplines, interdisciplinary cooperation is of major relevance in modern medicine. Given the rarity of benign and malignant bone tumours, diagnosis and therapy of these lesions is especially challenging. Focusing on typical cases, it is the aim of this article to illustrate the necessity of interdisciplinary cooperation., Methods: The scope of this article is to highlight the particular significance of interdisciplinarity in the diagnosis of bone tumours. To this end, we illustrate the interdisciplinary approach in typical clinical cases., Results and Discussion: The article demonstrates that a combined clinico-radiological approach is essential in the diagnosis of leave-me-alone lesions, and it underlines the essential role of an interdisciplinary correlation of clinical context, radiology and pathology in the interpretation of bone tumour biopsies. It documents the experience that all clinical aspects and diagnostic findings need to be synoptically integrated in a joint interdisciplinary tumour board to eventually find the correct diagnosis., Conclusion: It is generally accepted that the diagnosis of a bone tumour can often not be made by the pathologist alone but essentially requires interdisciplinary cooperation., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Megaendoprosthesis offer a viable treatment in complex revision arthroplasty cases with good functional outcome. In the context of a neoplastic indication, the diagnosis-related group (DRG) I95A is usually assigned with a relative weight of 4.906 (2021). In contrast, in revision arthroplasty, the appropriate DRG is assigned, depending on the joint replacement. The additional costs compared to the invoiced DRG are to be compensated by agreeing on hospital-specific individual fees. These complex revision arthroplasties set high technical and operative demands and are mainly performed in specialised departments. We conducted a cost-benefit analysis of the use of the megaendoprosthesis in revision cases in a specialised orthopaedic clinic, as a single centre study. The question we sought to answer was: Is cost recovery possible in the modified German DRG system (aG-DRG)?A retrospective single centre analysis of treatment costs was performed. From 2018 to 2020, 113 patients treated with a megaendoprosthesis reconstruction in a referral centre due to extensive bone loss after aseptic or septic revision of a hip or knee prosthesis were included in the study. Relevant case-related cost drivers of the aG-DRG matrix (including staff and material costs of the operating theatre area and the ward) were taken into account. The actual costs were determined according to the specifications of the calculation manual published by the German institute for the remuneration system in hospitals (InEK). For each case, the contribution margin was calculated by relating the hospital's internal costs to the corresponding cost pool of the aG-DRG matrix.According to the DRG system 2021, 17 different DRGs were used for billing - in 70% based on a patient clinical complexity level (PCCL) ≥ 4. Compared with the InEK calculation, there is a deficit of -2,901 € per case in the examined parameters. The costs of physicians show a shortfall in both the operating theatre and on the ward. Implant costs, which were supposed to be compensated by hospital-specific additional charges, show a hospital-specific shortage of -2,181 €. When analysing the risk factors for cost recovery, only these showed a significant difference.Implantation of the megaendoprosthesis in revision arthroplasty is often the last option to preserve limb function. At present, despite a high degree of specialisation and process optimisation, this treatment cannot be provided cost-effectively even in tertiary care. The politically desired specialised department structure requires sufficient reimbursement for complex cases. The economic outcome of each treatment case is often unpredictable, however the surgeon is confronted with these cases and is expected to treat them. The high standard deviation indicates large differences in the cost/revenue situation of each individual case. Our results show for the first time a realistic cost analysis for megaprosthesis in revision arthroplasty and underline the importance of an adequate hospital-specific charge, individually agreed by the funding units. The calculation should include not only the implant costs, but also the increased staff costs (increased, complex planning effort, quality management, surgery time, etc.)., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Background: The classic type of epithelioid sarcoma (ES) is a rare, aggressive soft tissue neoplasm that most commonly affects the distal upper extremities of young patients. This study aimed to assess clinical features and provide a long-term report of the oncological outcome., Methods: We retrospectively analyzed our clinical database for patients with ES of the distal upper extremities., Results: Twenty-three patients with ES of the distal upper extremity were treated surgically between January 1990 and August 2018. ES affected most commonly the palmar side of young patients. The most common site affected by a sarcoma was the wrist in 47.8% of cases, followed by metacarpals and fingers with 34.8% and 17.4%, respectively. Most of the patients were treated according to the protocols of interdisciplinary tumor boards with multimodal therapy. A local recurrence was observed in 7 patients (30.4%). The 5 - and 10-year recurrence-free survival was 80.4% (95% confidence interval [CI]: 68.6-76.8) and 60.9% (95% CI: 53.5-68.3), respectively. The 5- and 10-years disease-specific survival was 89.9% (95% CI: 87-92.8) and 61.9% (95% CI: 56.5-67.3), respectively. Five patients (21.7%) had metastasis in regional lymph nodes., Conclusion: The classic type of ES represents a group of high-grade sarcomas, which affect the dominantly distal upper extremity. Specific clinical, diagnostic, and oncological characteristics make it difficult to diagnose and therapy. Wide tumor resection as a part of multimodal therapy remains a more viable and common treatment option for patients with ES on distal extremities. High rates of lymph node metastasis are typical for ES.

As survival rates associated with the multimodal treatment of malignant bone cancer (osteosarcoma and Ewing's sarcoma) are satisfactory, health-related quality of life and the return to activity and sports by the affected patients have attracted increasing attention in recent years. Nowadays, limbs can be salvaged for most patients using modular endoprostheses. Such patients are typically adolescents and young adults who have high activity levels and thereby high demands for multimodal cancer treatment. This study aimed to evaluate the activity levels and sporting proficiencies that can be attained after modular endoprosthetic treatment of bone sarcomas as well as the extent to which physiotherapeutic and sports interventions influence functional outcome and activity levels.This non-systematic review of the literature focused on the return to activity and sports after modular endoprosthetic treatment of lower extremities bone sarcomas in adolescents and young adults. The electronic database PubMed was screened for relevant publications on this issue. A treatment algorithm for return to activity and sports in tumor orthopaedics is proposed.The objective activity level (gait cycles per day and gait intensities) in patients treated for bone sarcomas is reduced in short- and long-term follow-ups compared with healthy controls and patients with other cancers (leukaemia). Although a negative impact is observed in terms of motor performance, it shows improvement over time. Functional assessment at 12 postoperative months is sensible as neoadjuvant chemotherapy is completed by then. In long-term follow-up, patients with bone sarcomas can achieve high sports activity levels, i.e., type of sport, frequency/week and UCLA score, after modular endoprosthetic reconstruction. The maximum level is attained at 5 years postoperatively. Nevertheless, there is a shift from high- and intermediate- to low-impact sports. Only 20% of the patients participate in school sports regularly without limitations. The localisation of bone sarcoma, but not the rate of postoperative complications, influences the postoperative activity level. Individualised sports-related interventions during and after multimodal treatment can improve the short-term activity levels; moreover, "serious games" can improve motor performance and postural control. There is no evidence that intense activity levels leads to early loosening of the endoprosthesis. There is insufficient valid data on activity and sports after modular endoprosthetic treatment of bone sarcomas of the upper extremities.High preoperative activity levels of young patients with bone sarcomas must be considered in tumour orthopaedics. Limitations on sports activities have a significant negative impact on the quality of life and mental health of such patients. Therefore, tumour orthopaedic treatment has to focus on preserving an improvement in these factors. The overall existing evidence concerning this issue is weak. Additional studies to evaluate the ability to return to specific sports activities are desirable, as well as prospective interventional studies., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Purpose: Radiation therapy (RT) is an integral part of Ewing sarcoma (EwS) therapy. The Ewing 2008 protocol recommended RT doses ranging from 45 to 54 Gy. However, some patients received other doses of RT. We analyzed the effect of different RT doses on event-free survival (EFS) and overall survival (OS) in patients with EwS., Methods and Materials: The Ewing 2008 database included 528 RT-admitted patients with nonmetastatic EwS. Recommended multimodal therapy consisted of multiagent chemotherapy and local treatment consisting of surgery (S&RT group) and/or RT (RT group). EFS and OS were analyzed with uni- and multivariable Cox regression models including known prognostic factors such as age, sex, tumor volume, surgical margins, and histologic response., Results: S&RT was performed in 332 patients (62.9%), and 145 patients (27.5%) received definitive RT. Standard dose ≤ 53 Gy (d1) was admitted in 57.8%, high dose of 54 to 58 Gy (d2) in 35.5%, and very high dose ≥ 59 Gy (d3) in 6.6% of patients. In the RT group, RT dose was d1 in 11.7%, d2 in 44.1%, and d3 in 44.1% of patients. Three-year EFS in the S&RT group was 76.6% for d1, 73.7% for d2, and 68.2% for d3 ( P  = .42) and in the RT group 52.9%, 62.5%, and 70.3% ( P  = .63), respectively. Multivariable Cox regression revealed age ≥ 15 years (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.63-4.38) and nonradical margins (HR, 1.76; 95% CI, 1.05-2.93) for the S&RT group (sex, P  = .96; histologic response, P  = .07; tumor volume, P  = .50; dose, P  = .10) and large tumor volume (HR, 2.20; 95% CI, 1.21-4.0) for the RT group as independent factors (dose, P  = .15; age, P  = .08; sex, P  = .40)., Conclusions: In the combined local therapy modality group, treatment with higher RT dose had an effect on EFS, whereas higher dose of radiation when treated with definitive RT was associated with an increased OS. Indications for selection biases for dosage were found. Upcoming trials will assess the value of different RT doses in a randomized manner to control for potential selection bias., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Tenosynovial giant cell tumour (TGCT) is a rare, locally aggressive, mesenchymal tumor arising from the joints, bursa and tendon sheaths. TGCT comprises a nodular- and a diffuse-type, with the former exhibiting mostly indolent course and the latter a locally aggressive behavior. Although usually not life-threatening, TGCT may cause chronic pain and adversely impact function and quality of life (QoL). CSFR1 inhibitors are effective with benefit on symptoms and QoL but are not available in most countries. The degree of uncertainty in selecting the most appropriate therapy and the lack of guidelines on the clinical management of TGCT make the adoption of new treatments inconsistent across the world, with suboptimal outcomes for patients. A global consensus meeting was organized in June 2022, involving experts from several disciplines and patient representatives from SPAGN to define the best evidence-based practice for the optimal approach to TGCT and generate the recommendations presented herein., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Aims: The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants., Methods: A consecutive series of 45 (2014 to 2019) PPRs for Paprosky III defects at rTHA were analyzed comparing the preoperative planning CT scans used to manufacture the implants with postoperative CT scans and radiographs. The anteversion (AV), inclination (IC), deviation from the preoperatively planned implant position, and deviation of the centre of rotation (COR) were explored. Early postoperative complications were recorded, and factors for malpositioning were sought. The mean follow-up was 30 months (SD 19; 6 to 74), with four patients lost to follow-up., Results: Mean CT defined discrepancy (Δ) between planned and achieved AV and IC was 4.5° (SD 3°; 0° to 12°) and 4° (SD 3.5°; 1° to 12°), respectively. Malpositioning (Δ > 10°) occurred in five hips (10.6%). Native COR reconstruction was planned in 42 cases (93%), and the mean 3D deviation vector was 15.5 mm (SD 8.5; 4 to 35). There was no significant influence in malpositioning found for femoral stem retention, surgical approach, or fixation method., Conclusion: At short-term follow-up, we found that PPR offers a viable solution for rTHA in cases with massive acetabular bone loss, as highly accurate positioning can be accomplished with meticulous planning, achieving anatomical reconstruction. Accuracy of achieved placement contributed to reduced complications with no injury to vital structures by screw fixation.Cite this article: Bone Joint J  2022;104-B(10):1110-1117.

Purpose: Ewing 2008R3 was conducted in 12 countries and evaluated the effect of treosulfan and melphalan high-dose chemotherapy (TreoMel-HDT) followed by reinfusion of autologous hematopoietic stem cells on event-free survival (EFS) and overall survival in high-risk Ewing sarcoma (EWS)., Methods: Phase III, open-label, prospective, multicenter, randomized controlled clinical trial. Eligible patients had disseminated EWS with metastases to bone and/or other sites, excluding patients with only pulmonary metastases. Patients received six cycles of vincristine, ifosfamide, doxorubicin, and etoposide induction and eight cycles of vincristine, actinomycin D, and cyclophosphamide consolidation therapy. Patients were randomly assigned to receive additional TreoMel-HDT or no further treatment (control). The random assignment was stratified by number of bone metastases (1, 2-5, and > 5). The one-sided adaptive-inverse-normal-4-stage-design was changed after the first interim analysis via Müller-Schäfer method., Results: Between 2009 and 2018, 109 patients were randomly assigned, and 55 received TreoMel-HDT. With a median follow-up of 3.3 years, there was no significant difference in EFS between TreoMel-HDT and control in the adaptive design (hazard ratio [HR] 0.85; 95% CI, 0.55 to 1.32, intention-to-treat). Three-year EFS was 20.9% (95% CI, 11.5 to 37.9) in TreoMel-HDT and 19.2% (95% CI, 10.8 to 34.4) in control patients. The results were similar in the per-protocol collective. Males treated with TreoMel-HDT had better EFS compared with controls: median 1.0 years (95% CI, 0.8 to 2.2) versus 0.6 years (95% CI, 0.5 to 0.9); P = .035; HR 0.52 (0.28 to 0.97). Patients age < 14 years benefited from TreoMel-HDT with a 3-years EFS of 39.3% (95% CI, 20.4 to 75.8%) versus 9% (95% CI, 2.4 to 34); P = .016; HR 0.40 (0.19 to 0.87). These effects were similar in the per-protocol collective. This observation is supported by comparable results from the nonrandomized trial EE99R3., Conclusion: In patients with very high-risk EWS, additional TreoMel-HDT was of no benefit for the entire cohort of patients. TreoMel-HDT may be of benefit for children age < 14 years.

The recent WHO classification of Bone Tumours (2020) has introduced several changes. Conceptionally, small round cell sarcomas are now summarized in a distinct chapter, acknowledging their occurrence in both, bone and soft tissue. In the light of new molecular findings some diagnostic categories, such as fibrohistiocytic tumors, have been abandoned, and a few new entities have been added to the classification. Finally, systematic changes were made with regard to the terminology employed in the classification of chondrogenic tumours, and modifications have been made with respect to the biological potential of some lesions. This article summarizes the major changes made, underscoring the elementary role of an interdisciplinary approach in the diagnosis and management of bone lesions., (© 2022. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: Leiomyosarcoma (LMS) most frequently metastasizes to the lung. Metastatic LMS is considered incurable. Selected patients may benefit from pulmonary metastasectomy (PM) within multimodal therapy. This study analyzed the prognostic relevance of clinicopathologic factors in these patients., Methods: Patients with metastatic LMS to the lung treated in our center from 2004 to 2020 were included in this single-center retrospective study. Overall survival (OS), progression-free survival (PFS), and prognostic factors were analyzed., Results: The study had 64 patients (33 males, 52%) with metastatic LMS to the lung. The 5-year OS was 55% after the diagnosis of pulmonary metastases. Age older than 60 years at the primary tumor diagnosis, primary tumor larger than 70 mm, and five or more lung metastases were associated with poorer OS. Of the 64 patients, 44 underwent PM. The postoperative mortality rate was 0%. The patients selected for PM were younger and had smaller primary tumors, fewer metastases, and metastases that more often were metachronous. Metastasis grade (G1 vs. G2/3) and size (20-mm cutoff) were significant prognostic factors for OS (p = 0.05) and PFS (p = 0.028) after PM, respectively. The 44 patients who underwent PM had a survival benefit compared with the patients who were selected but did not undergo PM (n = 6) and the patients who were not selected for PM (n = 14). Three patients (7%) were alive and free of disease at the last follow-up visit respectively 5.5, 9, and 12 years after PM., Conclusions: For patients with leiomyosarcoma, PM is safe. Despite aggressive multimodal treatment, most patients will experience recurrence and eventually die of their disease. However, a small subgroup of patients could potentially be cured after PM., (© 2022. The Author(s).)

Purpose/objectives: Multimodality treatments together with local proton therapy (PT) are commonly used in unresectable primary bone malignancies in order to provide better tumor control rate while maintaining good feasibility. The aim of this study is to provide data on outcome of PT for the challenging cohort of pelvic and lumbar bone tumors., Methods and Materials: This retrospective study includes all patients with primary bone malignancy of the pelvis and lumbar spine receiving PT in our institution between May 2013 and December 2019 enrolled in the prospective registries KiProReg and ProReg collecting information on demographics, treatment, tumor characteristics, toxicities, and outcome., Results: Eighty-one patients were enrolled with a median age of 19.7 years (1.3-85.8). The median follow-up time was 27.5 months (1.2-83.2). The majority of patients was male (64.2%), ECOG status of 0-1 (75.2%), underwent only biopsy (50.6%), received chemotherapy (69.1%) and was assigned for definite PT (70.4%). The predominant tumor characteristics were as follows: Ewing's sarcoma histology (58%), negative nodal involvement (97.5%) and no metastasis at diagnosis (81.5%). Median maximal diameter of tumor was 8 cm (1.4-20). LC, EFS and OS rate were 76.5, 60, and 88.1% at two years and 72.9, 45.7, and 68.9% at three years, respectively. Age over 20 years was a significant negative factor for LC, EFS, and OS. Metastatic disease at initial diagnosis affected OS and ECOG status of 2-4 affected EFS only. Regarding 17 relapsed cases (21%), isolated distant relapse was the most common failure (46.9%) followed by local failure (40.6%). Eleven out of 14 evaluable patients relapsed within high-dose region of radiotherapy. Acute grade 3-4 toxicity was found in 41 patients (50.6%) and all toxicities were manageable. Late grade 3 toxicity was reported in 7 patients (10.4%) without any of grade 4. Most common higher grade acute and late side effects concerned hematologic and musculoskeletal toxicity., Conclusion: Proton therapy resulted in good oncological outcomes when being part of the multimodality treatment for pelvic and lumbar primary bone malignancies. However, distant metastases and local failures within the high-dose region of radiotherapy are still a common issue. Acute and late toxicities of combined therapy were acceptable., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Worawongsakul, Steinmeier, Lin, Bauer, Hardes, Hecker-Nolting, Dirksen and Timmermann.)

Introduction: Intercalary endoprosthetic reconstructions have been reserved for patients with a limited life expectancy due to reports of high rates of early mechanical and reconstruction failure., Materials and Methods: In this study, we retrospectively analyzed 28 patients who underwent intercalary endoprosthetic reconstruction of the femur (n = 17) or tibia (n = 11) regarding reconstruction survival and causes of complications and reconstruction failure., Results: A total of 56 stems were implanted in this collective, 67.9% of which were implanted using cementation. Eight different stem designs were implanted. The mean patient age at the time of operation was 42.3 years. The mean bone defect needing reconstruction measured 18.5 cm. Resection margins were clear in 96.4% of patients. Of twenty-six complications, five were not implant-associated. We observed infection in 10.7% (n = 3) and traumatic periprosthetic fracture in 3.6% (n = 1) of cases. The most frequent complication was aseptic stem loosening (ASL) (53.8%; n = 14) occurring in eight patients (28.6%). The metaphyseal and meta-diaphyseal regions of femur and tibia were most susceptible to ASL with a rate of 39.1% and 31.3% respectively. No ASLs occurred in epiphyseal or diaphyseal location. Overall reconstruction survival was 43.9% and 64.3% including patients who died of disease with their implant intact. Overall limb survival was 72.7%., Conclusions: Proper planning of segmental reconstructions including stem design with regard to unique anatomical and biomechanical properties is mandatory to address the high rates of ASL in metaphyseal and metadiaphyseal stem sites. With continued efforts of improving stem design in these implantation sites and decreasing rates of mechanical failure, indications for segmental megaendoprostheses may also extend to younger patients with the localized disease for their advantages of early weight bearing and a lack of donor-site morbidity., (© 2020. The Author(s).)

Pathological tumor-associated fractures are overall rare. They can occur in every age group and every bone. Although tumor-related fractures only form a small proportion of bone fractures, the early recognition of the cause of the fracture and treatment according to oncological guidelines are of enormous importance for affected patients. False treatment is frequently associated with far-reaching negative consequences with respect to the course of the disease. The great challenge is not the expeditious surgical treatment but much more the adequate diagnostics and the incorporation of local fracture treatment into an interdisciplinary overall oncological concept., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: The distal humerus is a rare location of bone tumors. Because of the complexity of the elbow joint, poor soft-tissue coverage, and proximity of nerves and vessels, resection and endoprosthetic reconstruction are demanding., Methods: This retrospective study evaluated the clinical results after distal humeral resection and megaprosthetic reconstruction in 12 patients with an average age of 46 years. All patient files were reviewed for clinical information, and postoperative function and patients' contentment were assessed using the Musculoskeletal Tumor Society score., Results: The predominant diagnoses were bone and soft-tissue sarcoma (n = 6), giant cell tumor (n = 2), and renal cell carcinoma metastasis (n = 2). Local recurrence was the reason for secondary amputation in all cases (n = 3). The prosthetic survival rate after surgery was 82% at 2 years and 64% at 5 years. Reconstruction failure was mainly caused by aseptic loosening of the humeral stem, occurring in 27% (n = 3), followed by aseptic loosening of the ulnar stem in 9% (n = 1) and periprosthetic infection in 9% (n = 1). The mean Musculoskeletal Tumor Society score was 24 points (range, 20-30 points). An extension lag of more than 10° was noted in 6 patients (55%)., Conclusion: Our results suggest that limb salvage with a distal humeral replacement can achieve good functional results in most patients, although the complication rate with special emphasis on the loosening rate of the humeral stem is high. However, limb salvage was not achieved in 27% of patients because of local recurrence., (Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Purpose: Proximal tibia replacements are commonly associated with post-operative complications and poor functional results due to an insufficiency of the extensor mechanism., Methods: This study evaluated the clinical results with a special emphasis of the extensor mechanism reconstruction with a reattachment tube and complications after intra-articular resection of the proximal tibia and reconstruction with a tumour endoprosthesis (MUTARS®) in 98 patients (median age 18 years) with malignant bone tumours or giant cell tumours., Results: Kaplan-Meier analysis showed that the limb survival rates were 94.9, 90.5 and 74.5% at one, two and ten years, respectively. Periprosthetic infection was the most common reason for secondary amputation (eight patients). The cumulative incidence rates of prosthetic failure (Henderson II-IV) were 18% at two years and 29% at five years post-operatively. An active extension deficit of more than 10° was noted in six patients only., Conclusions: These results suggest that limb salvage with tumour prostheses after intra-articular resection can achieve good functional results with an active extension of the knee in the majority of patients. While mechanical complications can be treated successfully with revision surgery, periprosthetic infection continues to be the main reason for secondary amputation.

Background: We designed the EURAMOS-1 trial to investigate whether intensified postoperative chemotherapy for patients whose tumour showed a poor response to preoperative chemotherapy (≥10% viable tumour) improved event-free survival in patients with high-grade osteosarcoma., Methods: EURAMOS-1 was an open-label, international, phase 3 randomised, controlled trial. Consenting patients with newly diagnosed, resectable, high-grade osteosarcoma aged 40 years or younger were eligible for randomisation. Patients were randomly assigned (1:1) to receive either postoperative cisplatin, doxorubicin, and methotrexate (MAP) or MAP plus ifosfamide and etoposide (MAPIE) using concealed permuted blocks with three stratification factors: trial group; location of tumour (proximal femur or proximal humerus vs other limb vs axial skeleton); and presence of metastases (no vs yes or possible). The MAP regimen consisted of cisplatin 120 mg/m 2 , doxorubicin 37·5 mg/m 2 per day on days 1 and 2 (on weeks 1 and 6) followed 3 weeks later by high-dose methotrexate 12 g/m 2 over 4 h. The MAPIE regimen consisted of MAP as a base regimen, with the addition of high-dose ifosfamide (14 g/m 2 ) at 2·8 g/m 2 per day with equidose mesna uroprotection, followed by etoposide 100 mg/m 2 per day over 1 h on days 1-5. The primary outcome measure was event-free survival measured in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00134030., Findings: Between April 14, 2005, and June 30, 2011, 2260 patients were registered from 325 sites in 17 countries. 618 patients with poor response were randomly assigned; 310 to receive MAP and 308 to receive MAPIE. Median follow-up was 62·1 months (IQR 46·6-76·6); 62·3 months (IQR 46·9-77·1) for the MAP group and 61·1 months (IQR 46·5-75·3) for the MAPIE group. 307 event-free survival events were reported (153 in the MAP group vs 154 in the MAPIE group). 193 deaths were reported (101 in the MAP group vs 92 in the MAPIE group). Event-free survival did not differ between treatment groups (hazard ratio [HR] 0·98 [95% CI 0·78-1·23]); hazards were non-proportional (p=0·0003). The most common grade 3-4 adverse events were neutropenia (268 [89%] patients in MAP vs 268 [90%] in MAPIE), thrombocytopenia (231 [78% in MAP vs 248 [83%] in MAPIE), and febrile neutropenia without documented infection (149 [50%] in MAP vs 217 [73%] in MAPIE). MAPIE was associated with more frequent grade 4 non-haematological toxicity than MAP (35 [12%] of 301 in the MAP group vs 71 [24%] of 298 in the MAPIE group). Two patients died during postoperative therapy, one from infection (although their absolute neutrophil count was normal), which was definitely related to their MAP treatment (specifically doxorubicin and cisplatin), and one from left ventricular systolic dysfunction, which was probably related to MAPIE treatment (specifically doxorubicin). One suspected unexpected serious adverse reaction was reported in the MAP group: bone marrow infarction due to methotrexate., Interpretation: EURAMOS-1 results do not support the addition of ifosfamide and etoposide to postoperative chemotherapy in patients with poorly responding osteosarcoma because its administration was associated with increased toxicity without improving event-free survival. The results define standard of care for this population. New strategies are required to improve outcomes in this setting., Funding: UK Medical Research Council, National Cancer Institute, European Science Foundation, St Anna Kinderkrebsforschung, Fonds National de la Recherche Scientifique, Fonds voor Wetenschappelijk Onderzoek-Vlaanderen, Parents Organization, Danish Medical Research Council, Academy of Finland, Deutsche Forschungsgemeinschaft, Deutsche Krebshilfe, Federal Ministry of Education and Research, Semmelweis Foundation, ZonMw (Council for Medical Research), Research Council of Norway, Scandinavian Sarcoma Group, Swiss Paediatric Oncology Group, Cancer Research UK, National Institute for Health Research, University College London Hospitals, and Biomedical Research Centre., (Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Massive bone loss of the femur condyles in revision arthroplasty often requires modular-hinged revision implants to restore a stable joint situation. In the present series, the outcome after knee revision surgery using a single modular-hinged revision implant in patients with severe bone defects (>Engh III) is investigated., Methods: Sixty patients with severe bone defects (≥Engh III) after failed primary and revision knee arthroplasty were included. Medium follow-up was 47 (range 10-84) months after knee revision surgery. Medium patient age was 70 (range 33-87) years at the time of surgery. An average of 2.3 prior knee operations per patient was performed. 70 % of the patients required the knee revision implant after two-stage revision because of a deep implant infection., Results: Estimated 5 year extremity survival was 95 and 65 % implant survival. Reasons for implant revision in decreasing order were reinfection (30 %), aseptic loosening (13 %), and periprosthetic fracture (9.8 %). The average active range of motion in the knee joint was 88° (range 40°-115°) for flexion. An extension deficit of a mean of -6° was (range -50-5° hyper-extension) observed. Patient age influenced the functional results significantly in terms of reduced walking distances and decreased modified WOMAC score., Conclusion: In consideration of this complex study, population acceptable functional results can be achieved using a modular knee revision endoprosthesis. In younger patients (<60 years), satisfying results in terms of walking ability and overall satisfactory can be expected. The outcome in older multimorbid patients is worse. Yet, operation in these patients can be feasible to restore enough mobility for daily household activities.

Background: Little is known about the metastatic potential of low-grade chondrosarcoma. This study was designed to evaluate the rate of metastasis to identify possible risk factors., Methods: The files of 225 patients with newly diagnosed, grade I chondrosarcoma of bone treated between 1975 and 2012 were retrospectively analyzed. Median follow-up was 80 months for survivors (range 24-445 months). Nonparametric analyses were performed with the Mann-Whitney U test. Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank test., Results: Fourteen patients developed metastases after a median of 49 months. Metastasis-free survival probability (MFS) was 95 % at 5 years and 92 % at 10 years. Post-metastasis survival probability amounted to 27 % after 5 years. Tumor size at diagnosis (P = 0.698) and surgical margin width (P = 0.514) had no influence on MFS. Patients who developed local recurrences had a significantly lower 10-year MFS than patients without recurrences (69 % vs. 99 %, P < 0.001). Patients with grade I recurrences had a significantly poorer MFS than patients without recurrences (P = 0.013) but a significantly higher MFS than patients with grade II recurrences (P = 0.006). Patients with thoracic wall tumors had a significantly lower 10-year MFS of 66 % compared with patients with tumors of the upper (100 %, P < 0.001) and lower extremity (93 %, P = 0.033)., Conclusions: The biological behavior of low-grade chondrosarcoma appears to be more consistent with the WHO definition of rarely metastasizing bone tumors, rather than the one of locally aggressive neoplasms. Thoracic wall tumors and the development of local recurrences were associated with a higher metastasis rate in this study.

In long-term survivors, oncologic surgeons are regularly faced with the problem of revising stem breakage of first generation Kotz modular femoral and tibial reconstruction system (KMFTR) prostheses. To avoid a whole prosthesis-exchange, we invented an adapter which allows connecting original KMFTR devices to new modular universal tumor and revision system (MUTARS) components. The adapter was used in 10 patients after a mean time span of 16.6 years after primary implantation of KMFTR prostheses. Reasons for revision included femoral stem breakage in five cases, breakage of tibial component in three cases and periprosthetic fracture in two cases (one femoral, one tibial). The femoral stem (three cases), the tibial stem (two cases) or the tibial plateau and body (two cases) were exchanged to MUTARS and connected to the remaining KMFTR parts. Three cases were converted to a total femur. Postoperative complications included one cone-dislocation and one aseptic loosening. In all patients, the pre-incidence function could be restored. The mean Musculoskeletal Tumor Society score was 81.7% of normal function. The presented adapter enables restoration of the long-term extremity function with relatively minor revision.

Modular tumor prostheses are well established today for the reconstruction of osseous defects after resection of malignant bone tumors. Almost every joint and even total bones (e.g., total femur or humerus) can be replaced with promising functional results, dramatically reducing the need for ablative procedures. Although the complication rate with the use of modern modular endoprostheses is constantly decreasing, the need for revision surgery is still significantly higher than in primary joint arthroplasty. In this review we present the modular endoprosthesis system developed in our institution, summarize the postoperative management, and discuss the indications, limits, and complications as well as the functional results.

In this study, a case of fibromyxoma of the proximal femur in a 59-year old woman is reported. The classification of this rare bone tumour is still a matter of debate and some investigators have suggested that these lesions represent a degenerative form of fibrous dysplasia. Some authors make a further distinction between fibromyxoma and myxoma of bone. In a review of 23 cases of fibromyxoma and five cases of myxoma, no differences in clinical, radiographic and biologic behaviour between fibromyxoma and myxoma were found. Apart from the age at diagnosis, the most important difference between fibromyxoma and myxoma was the degree of myxoid matrix. Therefore, we suggest that extragnathic myxoma is a regressive variant of extragnathic fibromyxoma and should be termed as the same entity. In contrast to monostotic fibrous dysplasia fibromyxoma / myxoma often causes pain and presents as a Lodwick IC lesion with a soft tissue mass. Therefore, fibromyxoma / myxoma should be distinguished from fibrous dysplasia because of its different clinical and radiographic features.

The authors report the case of a 65-year-old man who presented with an expansive osteolytic lesion in the right acromion, mimicking cystic fibrous dysplasia. Magnetic resonance imaging showed a lesion with intermediate-signal intensity on T1-weighted images and a high-signal intensity on fat suppressed T2-weighted images. The biopsy led to the diagnosis of chondroblastoma. This tumour is rare in flat bones, and may mimic other benign or malignant lesions. It is therefore essential to perform a biopsy in order to obtain a definite diagnosis. The acromion was excised, and replaced with an iliac crest graft.