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Background: The aim of this study was to develop and validate radiogenomic models to predict the MDM2 gene amplification status and differentiate between ALTs and lipomas on preoperative MR images. Methods: MR images were obtained in 257 patients diagnosed with ALTs (n = 65) or lipomas (n = 192) using histology and the MDM2 gene analysis as a reference standard. The protocols included T2-, T1-, and fat-suppressed contrast-enhanced T1-weighted sequences. Additionally, 50 patients were obtained from a different hospital for external testing. Radiomic features were selected using mRMR. Using repeated nested cross-validation, the machine-learning models were trained on radiomic features and demographic information. For comparison, the external test set was evaluated by three radiology residents and one attending radiologist. Results: A LASSO classifier trained on radiomic features from all sequences performed best, with an AUC of 0.88, 70% sensitivity, 81% specificity, and 76% accuracy. In comparison, the radiology residents achieved 60–70% accuracy, 55–80% sensitivity, and 63–77% specificity, while the attending radiologist achieved 90% accuracy, 96% sensitivity, and 87% specificity. Conclusion: A radiogenomic model combining features from multiple MR sequences showed the best performance in predicting the MDM2 gene amplification status. The model showed a higher accuracy compared to the radiology residents, though lower compared to the attending radiologist.

Objectives To develop and validate machine learning models to distinguish between benign and malignant bone lesions and compare the performance to radiologists. Methods In 880 patients (age 33.1 ± 19.4 years, 395 women) diagnosed with malignant (n = 213, 24.2%) or benign (n = 667, 75.8%) primary bone tumors, preoperative radiographs were obtained, and the diagnosis was established using histopathology. Data was split 70%/15%/15% for training, validation, and internal testing. Additionally, 96 patients from another institution were obtained for external testing. Machine learning models were developed and validated using radiomic features and demographic information. The performance of each model was evaluated on the test sets for accuracy, area under the curve (AUC) from receiver operating characteristics, sensitivity, and specificity. For comparison, the external test set was evaluated by two radiology residents and two radiologists who specialized in musculoskeletal tumor imaging. Results The best machine learning model was based on an artificial neural network (ANN) combining both radiomic and demographic information achieving 80% and 75% accuracy at 75% and 90% sensitivity with 0.79 and 0.90 AUC on the internal and external test set, respectively. In comparison, the radiology residents achieved 71% and 65% accuracy at 61% and 35% sensitivity while the radiologists specialized in musculoskeletal tumor imaging achieved an 84% and 83% accuracy at 90% and 81% sensitivity, respectively. Conclusions An ANN combining radiomic features and demographic information showed the best performance in distinguishing between benign and malignant bone lesions. The model showed lower accuracy compared to specialized radiologists, while accuracy was higher or similar compared to residents. Key Points • The developed machine learning model could differentiate benign from malignant bone tumors using radiography with an AUC of 0.90 on the external test set. • Machine learning models that used radiomic features or demographic information alone performed worse than those that used both radiomic features and demographic information as input, highlighting the importance of building comprehensive machine learning models. • An artificial neural network that combined both radiomic and demographic information achieved the best performance and its performance was compared to radiology readers on an external test set.

Objectives To evaluate the performance and reproducibility of MR imaging features in the diagnosis of joint invasion (JI) by malignant bone tumors. Methods MR images of patients with and without JI (n = 24 each), who underwent surgical resection at our institution, were read by three radiologists. Direct (intrasynovial tumor tissue (ITT), intraarticular destruction of cartilage/bone, invasion of capsular/ligamentous insertions) and indirect (tumor size, signal alterations of epiphyseal/transarticular bone (bone marrow replacement/edema-like), synovial contrast enhancement, joint effusion) signs of JI were assessed. Odds ratios, sensitivity, specificity, PPV, NPV, and reproducibilities (Cohen’s and Fleiss’ κ) were calculated for each feature. Moreover, the diagnostic performance of combinations of direct features was assessed. Results Forty-eight patients (28.7 ± 21.4 years, 26 men) were evaluated. All readers reliably assessed the presence of JI (sensitivity = 92–100 %; specificity = 88–100%, respectively). Best predictors for JI were direct visualization of ITT (OR = 186–229, p < 0.001) and destruction of intraarticular bone (69–324, p < 0.001). Direct visualization of ITT was also highly reliable in assessing JI (sensitivity, specificity, PPV, NPV = 92–100 %), with excellent reproducibility (κ = 0.83). Epiphyseal bone marrow replacement and synovial contrast enhancement were the most sensitive indirect signs, but lacked specificity (29–54%). By combining direct signs with high specificity, sensitivity was increased (96 %) and specificity (100 %) was maintained. Conclusion JI by malignant bone tumors can reliably be assessed on preoperative MR images with high sensitivity, specificity, and reproducibility. Particularly direct visualization of ITT, destruction of intraarticular bone, and a combination of highly specific direct signs were valuable, while indirect signs were less predictive and specific. Key Points • Direct visualization of intrasynovial tumor was the single most sensitive and specific (92–100%) MR imaging sign of joint invasion. • Indirect signs of joint invasion, such as joint effusion or synovial enhancement, were less sensitive and specific compared to direct signs. • A combination of the most specific direct signs of joint invasion showed best results with perfect specificity and PPV (both 100%) and excellent sensitivity and NPV (both 96 %).

Background An artificial intelligence model that assesses primary bone tumors on radiographs may assist in the diagnostic workflow. Purpose To develop a multitask deep learning (DL) model for simultaneous bounding box placement, segmentation, and classification of primary bone tumors on radiographs. Materials and Methods This retrospective study analyzed bone tumors on radiographs acquired prior to treatment and obtained from patient data from January 2000 to June 2020. Benign or malignant bone tumors were diagnosed in all patients by using the histopathologic findings as the reference standard. By using split-sample validation, 70% of the patients were assigned to the training set, 15% were assigned to the validation set, and 15% were assigned to the test set. The final performance was evaluated on an external test set by using geographic validation, with accuracy, sensitivity, specificity, and 95% CIs being used for classification, the intersection over union (IoU) being used for bounding box placements, and the Dice score being used for segmentations. Results Radiographs from 934 patients (mean age, 33 years ± 19 [standard deviation]; 419 women) were evaluated in the internal data set, which included 667 benign bone tumors and 267 malignant bone tumors. Six hundred fifty-four patients were in the training set, 140 were in the validation set, and 140 were in the test set. One hundred eleven patients were in the external test set. The multitask DL model achieved 80.2% (89 of 111; 95% CI: 72.8, 87.6) accuracy, 62.9% (22 of 35; 95% CI: 47, 79) sensitivity, and 88.2% (67 of 76; CI: 81, 96) specificity in the classification of bone tumors as malignant or benign. The model achieved an IoU of 0.52 ± 0.34 for bounding box placements and a mean Dice score of 0.60 ± 0.37 for segmentations. The model accuracy was higher than that of two radiologic residents (71.2% and 64.9%

Background: A pathological/inflamed cellular microenvironment state is an additional risk factor for any cancer type. The importance of a chronic inflammation state in most diffuse types of tumour has already been analysed, except for in Ewing’s sarcoma. It is a highly malignant blue round cell tumour, with 90% of cases occurring in patients aged between 5 and 25 years. Worldwide, 2.9 out of 1,000,000 children per year are affected by this malignancy. The aim of this retrospective study was to analyse the role of C-reactive protein (CRP) as a prognostic factor for Ewing’s sarcomas. Methods: This retrospective study at Klinikum rechts der Isar included 82 patients with a confirmed Ewing’s sarcoma diagnosis treated between 2004 and 2019. Preoperative CRP determination was assessed in mg/dL with a normal value established as below 0.5 mg/dL. Disease-free survival time was calculated as the time between the initial diagnosis and an event such as local recurrence or metastasis. Follow-up status was described as death of disease (DOD), no evidence of disease (NED) or alive with disease (AWD). The exclusion criteria of this study included insufficient laboratory values and a lack of information regarding the follow-up status or non-oncological resection. Results: Serum CRP levels were significantly different in patients with a poorer prognosis (DOD) and in patients who presented distant metastasis (p = 0.0016 and p = 0.009, respectively), whereas CRP levels were not significantly different in patients with local recurrence (p = 0.02). The optimal breakpoint that predicted prognosis was 0.5 mg/dL, with a sensitivity of 0.76 and a specificity of 0.74 (AUC 0.81). Univariate CRP analysis level >0.5 mg/dL revealed a hazard ratio of 9.5 (95% CI 3.5–25.5). Conclusions: In Ewing’s sarcoma cases, we consider a CRP pretreatment value >0.5 mg/dL as a sensitive prognostic risk factor indication for distant metastasis and poor prognosis. Further research with more data is required to determine more sensitive cutoff levels.

BACKGROUND Soft tissue sarcomas (STS) are a relatively rare group of malignant tumors. Currently, there is very little published clinical data, especially in the context of curative multimodal therapy with image-guided, conformal, intensity-modulated radiotherapy. METHODS Patients who received preoperative or postoperative intensity-modulated radiotherapy for STS of the extremities or trunk with curative intent were included in this single centre retrospective analysis. A Kaplan-Meier analysis was performed to evaluate survival endpoints. Multivariable proportional hazard models were used to investigate the association between survival endpoints and tumour-, patient-, and treatment-specific characteristics. RESULTS 86 patients were included in the analysis. The most common histological subtypes were undifferentiated pleomorphic high-grade sarcoma (UPS) (27) and liposarcoma (22). More than two third of the patients received preoperative radiation therapy (72%). During the follow-up period, 39 patients (45%) suffered from some type of relapse, mainly remote (31%). The two-years overall survival rate was 88%. The median DFS was 48 months and the median DMFS was 51 months. Male gender (HR 0.460 (0.217; 0.973)) and histology of liposarcomas compared to UPS proved to be significantly more favorable in terms of DFS (HR 0.327 (0.126; 0.852)). CONCLUSION Conformal, intensity-modulated radiotherapy is an effective treatment modality in the preoperative or postoperative management of STS. Especially for the prevention of distant metastases, the establishment of modern systemic therapies or multimodal therapy approaches is necessary.

Purpose Health care systems in most European countries were temporarily restructured to provide as much capacity as possible for the treatment of coronavirus disease 2019 (COVID-19) patients. Subsequently, all elective surgeries had to be cancelled and postponed for months. The aim of the present study was to assess the pretreatment health status before and after COVID-19-related cancellation and the psychosocial distress caused by the cancellation. Methods For this study, a questionnaire was developed collecting sociodemographic data and information on health status before and after the cancellation. To assess psychosocial distress, the validated depression module of the Patient Health Questionnaire (PHQ-9), was implemented. PHQ-9-Scores of 10 and above were considered to indicate moderate or severe depressive symptoms. In total, 119 patients whose elective orthopaedic surgery was postponed due to the COVID-19 pandemic were surveyed once at least 8 weeks after the cancellation. Results Seventy-seven patients (65%; 34 female, 43 male) completed the questionnaire and were included. The predominant procedures were total knee arthroplasty (TKA), hip arthroscopy and foot and ankle surgery. The mean pain level significantly increased from 5.5 ± 2.2 at the time of the initially scheduled surgery to 6.2 ± 2.5 at the time of the survey (p p = 0.029). An increased analgetic consumption was identified in 46% of all patients. A mean PHQ-9 score of 6.1 ± 4.9 was found after cancellation. PHQ-9 scores of 10 or above were found in 14% of patients, and 8% exhibited scores of 15 points or above. Significantly higher PHQ-9 scores were seen in female patients (p = 0.046). No significant differences in PHQ-9 scores were found among age groups, procedures or reasons for cancellation. Conclusion Cancellation of elective orthopaedic surgery resulted in pain levels that were significantly higher than when the surgery was scheduled, leading to increased analgesic use. Additionally, significant psychosocial distress due to the cancellation was identified in some patients, particularly middle-aged women. Despite these results, confidence in the national health care system and in the treating orthopaedic surgeons was not affected. Level of evidence Level III.

BACKGROUND/AIM Surgical resection for soft tissue sarcomas (STSs) is the gold standard for a curative oncologic therapy in combination with neoadjuvant or adjuvant radiation therapy (NRT/ART). The aim of this study was to determine prognostic factors influencing the survival of patients with STS undergoing NRT or ART considering various parameters in a retrospective, single-centre analysis over 15 years. PATIENTS AND METHODS We included 119 patients (male 59) and the median follow-up period was 69 months (4-197). The patients received NRT (n=64) or ART (n=55). We recorded the histopathologic subtype of STS, tumour grade, localization, tumour margins, complications, survival, local recurrence, and metastases. Survival analysis was performed using the Kaplan-Meier method. RESULTS The overall survival rate was 68.9% at 5 years. The localization (epifascial/subfascial), resection margin and type of radiation therapy (NRT/ART) had no significant impact on survival. Tumour grade, tumour size, local recurrence and metastases were significantly correlated with patient survival (p

Knochentumoren liegen nur sehr selten kindlichen Knieschmerzen zugrunde, sie sollten jedoch aufgrund der moglicherweise weitreichenden Konsequenzen von jedem Orthopaden erkannt werden. Aufgrund der Seltenheit aller Tumorentitaten des Knochens sollte die Diagnosefindung und Behandlung an einem spezialisierten Zentrum mit interdisziplinarer Expertise erfolgen. Bei anhaltenden Beschwerden, Ruhe- bzw. Nachtschmerzen, einhergehend mit Schwellung und Allgemeinsymptomen, wie B‑Symptomatik, sollte eine Tumorabklarung erfolgen. Ungefahr zwei Drittel aller kindlichen Knochentumoren sind gutartig, selten treten bosartige Tumoren auf, diese sind fast ausschlieslich Osteo- oder Ewing-Sarkome. In diesem Ubersichtsartikel stellen wir die haufigsten Knochentumoren am kindlichen Knie vor und weisen auf wichtige Aspekte der Diagnose und Behandlung hin. Dabei werden die oben genannten zwei wichtigsten malignen Entitaten im Detail dargestellt.

Ewing sarcoma is a highly malignant tumour predominantly found in children. The radiological signs of this malignancy can be mistaken for acute osteomyelitis. These entities require profoundly different treatments and result in completely different prognoses. The purpose of this study was to develop an artificial intelligence algorithm, which can determine imaging features in a common radiograph to distinguish osteomyelitis from Ewing sarcoma.A total of 182 radiographs from our Sarcoma Centre (118 healthy, 44 Ewing, 20 osteomyelitis) from 58 different paediatric (≤18 years) patients were collected. All localisations were taken into consideration. Cases of acute, acute on chronic osteomyelitis and intraosseous Ewing sarcoma were included. Chronic osteomyelitis, extra-skeletal Ewing sarcoma, malignant small cell tumour and soft tissue-based primitive neuroectodermal tumours were excluded. The algorithm development was split into two phases and two different classifiers were built and combined with a Transfer Learning approach to cope with the very limited amount of data. In phase 1, pathological findings were differentiated from healthy findings. In phase 2, osteomyelitis was distinguished from Ewing sarcoma. Data augmentation and median frequency balancing were implemented. A data split of 70%, 15%, 15% for training, validation and hold-out testing was applied, respectively.The algorithm achieved an accuracy of 94.4% on validation and 90.6% on test data in phase 1. In phase 2, an accuracy of 90.3% on validation and 86.7% on test data was achieved. Grad-CAM results revealed regions, which were significant for the algorithms decision making.Our AI algorithm can become a valuable support for any physician involved in treating musculoskeletal lesions to support the diagnostic process of detection and differentiation of osteomyelitis from Ewing sarcoma. Through a Transfer Learning approach, the algorithm was able to cope with very limited data. However, a systematic and structured data acquisition is necessary to further develop the algorithm and increase results to clinical relevance.

Background/aim Myxofibrosarcoma (MFS) is characterized by an infiltrative growth pattern. This study aimed to determine the correlation between overall survival (OS) and morphological features of MFS as well as examine the reproducibility of these findings on preoperative magnetic resonance imaging (MRI). Patients and methods Fifty-eight MFS patients underwent preoperative MR imaging with the following features analysed: i) tumour size, ii) localization, iii) margins, iv) morphology, v) signal characteristics, vi) contrast enhancement, vii) presence and extent of perilesional oedema, and viii) presence of the tail sign. Results Only circumscribed perilesional oedema was associated with a significantly better survival compared to diffuse oedema (p=0.010), which was found in the majority of cases. The tail sign was found in less than 50% of the cases. Cohen's kappa coefficients confirmed a relatively high interrater variability. Conclusion Perilesional diffuse oedema on MR imaging of MFS is significantly correlated with a poor overall survival. The interrater variability in interpretation of MR examinations varies from slight to substantial agreement. Preoperative MR imaging with detailed planning of the resection seem to be a logical approach to achieve negative resection margins and recurrence-free survival.

An amputation around, through or below the knee joint constitutes a "huge" change in a patient's life. In Orthopaedics, amputations are most frequently performed in cases with musculoskeletal tumours or failed total knee arthroplasty. A multidisciplinary team approach (surgeon, anaesthetist, pain specialists, orthotist, psychologist etc.) and patient-specific treatment regime from the outset as well as a meticulous surgical technique are of the outmost importance. Nowadays, prosthetic legs can be fitted for nearly any amputation level. The functional outcome of amputations below the knee is usually superior to amputations above or through the knee joint. Postoperative stump conditioning is paramount and the final prosthetic leg should not be fitted earlier than 4-6 months postoperatively. Problems with wound healing, muscle contractures and phantom limb pain represent common complications which might adversely affect patient outcomes.

Diese Kasuistik behandelt den Fall eines 16-jahrigen mannlichen Patienten mit einem paraossalen Low-grade-Osteosarkom mit fokaler Dedifferenzierung am distalen Femur. Vorgestellt werden Anamnese, Krankheitsverlauf und der diagnostische Prozess sowie das operative Vorgehen und die pathologische Aufarbeitung mit finaler Diagnosestellung. Relevante radiologische und pathologische Differenzialdiagnosen sowie Fallstrickdiagnosen werden ausfuhrlich erlautert und diskutiert. Zudem werden postoperative therapeutische Optionen aufgezeigt.

Purpose: In high-grade soft-tissue sarcomas (STS) the standard of care encompasses multimodal therapy regimens. While there is a growing body of evidence for prognostic pretreatment radiomic models, we hypothesized that temporal changes in radiomic features following neoadjuvant treatment ("delta-radio mics") may be able to predict the pathological complete response (pCR). Methods: MRI scans (T1-weighted with fat-saturation and contrast-enhancement (T1FSGd) and T2 weighted with fat-saturation (T2FS)) of patients with STS of the extremities and trunk treated with neoadjuvant therapy were gathered from two independent institutions (training: 103, external testing: 53 patients). pCR was defined as

Background Treatment decisions for multimodal therapy in soft tissue sarcoma (STS) patients greatly depend on the differentiation between low-grade and high-grade tumors. We developed MRI-based radiomics grading models for the differentiation between low-grade (G1) and high-grade (G2/G3) STS. Methods The study was registered at ClinicalTrials.gov (number NCT03798795 ). Contrast-enhanced T1-weighted fat saturated (T1FSGd), fat-saturated T2-weighted (T2FS) MRI sequences, and tumor grading following the French Federation of Cancer Centers Sarcoma Group obtained from pre-therapeutic biopsies were gathered from two independent retrospective patient cohorts. Volumes of interest were manually segmented. After preprocessing, 1394 radiomics features were extracted from each sequence. Features unstable in 21 independent multiple-segmentations were excluded. Least absolute shrinkage and selection operator models were developed using nested cross-validation on a training patient cohort (122 patients). The influence of ComBatHarmonization was assessed for correction of batch effects. Findings Three radiomic models based on T2FS, T1FSGd and a combined model achieved predictive performances with an area under the receiver operator characteristic curve (AUC) of 0.78, 0.69, and 0.76 on the independent validation set (103 patients), respectively. The T2FS-based model showed the best reproducibility. The radiomics model involving T1FSGd-based features achieved significant patient stratification. Combining the T2FS radiomic model into a nomogram with clinical staging improved prognostic performance and the clinical net benefit above clinical staging alone. Interpretation MRI-based radiomics tumor grading models effectively classify low-grade and high-grade soft tissue sarcomas. Fund The authors received support by the medical faculty of the Technical University of Munich and the German Cancer Consortium.

Durch Fortschritte in der Diagnostik und Therapie primar maligner Knochentumoren kann heute in den allermeisten Fallen ein Extremitatenerhalt erreicht werden. Mithilfe moderner modularer Tumorprothesen konnen hierbei alle grosen Gelenke und sogar ganze Extremitatenabschnitte wie das Femur, der Humerus oder die Tibia endoprothetisch ersetzt werden. In diesem Beitrag werden die jeweils individuellen Voraussetzungen und Herausforderungen bei Durchfuhrung eines endoprothetischen Totalersatzes an vorgenannten anatomischen Lokalisationen herausgearbeitet. Des Weiteren wird ein Uberblick uber das zu erwartende Outcome sowie Probleme und Komplikationsraten gegeben.

ZusammenfassungNeben der herausragenden Stellung im Bereich der Tumororthopädie erlangen Megaprothesen zunehmend Bedeutung für die Revisionsendoprothetik. Trotz der breiten Anwendung bleiben die berichteten Komplikations- und Versagensraten jedoch hoch. Die Analyse der Versagensursachen lässt grob eine Unterteilung in mechanische und nicht mechanische Versagensursachen zu, unter diesen nimmt einerseits das Weichteilversagen (Funktionsverlust) und die Lockerung, andererseits der Infekt eine herausragende Bedeutung ein. Dabei kann jedem Versagenstyp ein spezifisches Prothesenbauteil zugeordnet werden. Die technisch korrekt durchgeführte Operation vorausgesetzt, ist für das Weichteilversagen die muskuläre Anbindung an die Prothese, für die Lockerung die Verankerungstechnik über den Stem und für den Infekt die Oberflächenbeschaffenheit bzw. ggf. die Beschichtung der Prothese entscheidend. Bis heute haben sich einige vollwertige Systeme für den Ersatz des proximalen Femurs auf dem Markt etabliert, deren klinische Resultate in etwa vergleichbar sind. Im Detail sind deutliche Unterschiede hinsichtlich Verankerungstechniken, Modularität bzw. Modulverbindungen und Weichteilanbindung erkennbar, die spezifische Vor- und Nachteile mit sich bringen. In jedem Fall belegen die hohen Versagensraten ein großes Potenzial für zukünftige Entwicklungen. Innovative Verbesserungsvorschläge für jedes Bauteil sind durch Quervernetzungen zu bereits funktionierenden Systemen gut möglich. Zusammen mit neuen Erkenntnissen der Grundlagenforschung sollte es bei zukünftigen Systemen möglich sein, den Anteil der Prothesenversager deutlich zu reduzieren.

Background Small soft tissue masses are often falsely assumed to be benign and resected with failure to achieve tumor-free margins. Therefore, this study retrospectively investigated the distribution of histopathologic diagnosis to be encountered in small soft tissue tumors (≤ 5 cm) in a large series of a tertiary referral center. Methods Patients with a soft tissue mass (STM) with a maximum diameter of 5 cm presenting at our institution over a period of 10 years, who had undergone preoperative Magnetic resonance imaging and consequent biopsy or/and surgical resection, were included in this study. A final histopathological diagnosis was available in all cases. The maximum tumor diameter was determined on MR images by one radiologist. Moreover, tumor localization (head/neck, trunk, upper extremity, lower extremity, hand, foot) and depth (superficial / deep to fascia) were assessed. Results In total, histopathologic results and MR images of 1753 patients were reviewed. Eight hundred seventy patients (49.63%) showed a STM ≤ 5 cm and were therefore included in this study (46.79 +/− 18.08 years, 464 women). Mean maximum diameter of the assessed STMs was 2.88 cm. Of 870 analyzed lesions ≤ 5 cm, 170 (19.54%) were classified as superficial and 700 (80.46%) as deep. The malignancy rate of all lesions ≤ 5 cm was at 22.41% (superficial: 23.53% / deep: 22.14%). The malignancy rate dropped to 16.49% (20.79% / 15.32%) when assessing lesions ≤ 3 cm (p = 0.007) and to 15.0% (18.18% / 13.79%) when assessing lesions ≤ 2 cm (p = 0.006). Overall, lipoma was the most common benign lesion of superficial STMs (29.41%) and tenosynovial giant cell tumor was the most common benign lesion of deep STMs (23.29%). Undifferentiated pleomorphic sarcoma was the most common malignant diagnosis among both, superficial (5.29%) and deep (3.57%) STMs. Conclusions The rate of malignancy decreased significantly with tumor size in both, superficial and deep STMs. The distribution of entities was different between superficial and deep STMs, yet there was no significant difference found in the malignancy rate.

Background: Peri-prosthetic joint infection (PJI) is a major complication of knee arthroplasty that can cause long-term disability. In addition to its physical impact, there is a clear psychologica...

An amputation around, through or below the knee joint constitutes a "huge" change in a patient's life. In Orthopaedics, amputations are most frequently performed in cases with musculoskeletal tumours or failed total knee arthroplasty. A multidisciplinary team approach (surgeon, anaesthetist, pain specialists, orthotist, psychologist etc.) and patient-specific treatment regime from the outset as well as a meticulous surgical technique are of the outmost importance. Nowadays, prosthetic legs can be fitted for nearly any amputation level. The functional outcome of amputations below the knee is usually superior to amputations above or through the knee joint. Postoperative stump conditioning is paramount and the final prosthetic leg should not be fitted earlier than 4-6 months postoperatively. Problems with wound healing, muscle contractures and phantom limb pain represent common complications which might adversely affect patient outcomes.

To evaluate the diagnostic value of fiber tractography and diffusivity analysis generated from 3D diffusion-weighted (DW) sequences for preoperative assessment of benign peripheral nerve sheath tumors.MR imaging at 3 T was performed in 22 patients (mean age 41.9 ± 17.1y, 13 women) with histologically confirmed schwannomas (N = 18) and histologically confirmed neurofibromas (N = 11), including a 3D DW turbo spin echo sequence with fat suppression. Diffusion tensor parameters were computed and fiber tracks were determined. Evaluation was performed by two radiologists and one orthopedic surgeon blinded for final diagnosis. Mean diffusivity was computed to allow further assessment of tumor microstructure. Preoperative fascicle visualization was graded, fascicles were categorized regarding anatomical location and amount of fascicles surrounding the tumor. The agreement of imaging findings with intraoperative findings was assessed.On 78.3 % of the DTI images, the fascicle visualization was rated as good or very good. Tractography differences were observed in schwannomas and neurofibromas, showing schwannomas to be significantly more often located eccentrically to the nerve (94.8 %) than neurofibromas (0 %, P 0.01). Fascicles were significantly more often continuous (87.5 %) in schwannomas, while in neurofibromas, none of the tracks was graded to be continuous (0 %, P = 0.014). A substantial agreement between fiber tracking and surgical anatomy was found regarding the fascicle courses surrounding the tumor (κ = 0.78). Mean diffusivity of schwannomas (1.5 ± 0.2 × 10Preoperative diffusion tensor imaging allowed to accurately differentiate between schwannomas and neurofibromas and to describe their location in relation to the nerve fascicles for preoperative planning.

This case study deals with the case of a 16-year-old male patient with a low-grade parosteal osteosarcoma of the distal femur with focal differentiation. Case history, disease course, and surgery as well as the pathological workup with final diagnosis are presented. Relevant radiologic and pathologic differential diagnoses und diagnostic pitfalls are explained in detail and discussed. Additionally, postoperative treatment options are illustrated.

BACKGROUND/AIM: Chondrosarcomas (CS) of the chest wall are rare, but present an aggressive biological behavior compared to CS of the extremities. The aims of the present study were to determine factors associated with oncological outcomes as well as complications. PATIENTS AND METHODS: We retrospectively analyzed 53 patients (42 primary, 11 recurrent tumors). In total, 39 central CS, 10 peripheral CS, 3 dedifferentiated CS and 1 mesenchymal CS were included. The ribs were most commonly affected (68%). Overall survival and disease-free survival were estimated with Kaplan-Meier analyses and compared with log-rank test. RESULTS: Mean follow-up was 7 years. Negative margins were achieved in 87% of patients. Thirty patients (57%) remained continuously disease-free (NED), three (5%) NED after treatment of relapse, seven (13%) were alive with disease, twelve (23%) were dead with disease and one of other cause. The 10-year survival rate was 81% and 45% in primary and recurrent tumors, respectively. Survival was significantly affected by tumor stage (p

Survival rates of pediatric sarcoma patients stagnated during the last two decades, especially in adolescents and young adults (AYAs). Targeted therapies offer new options in refractory cases. Gene expression profiling provides a robust method to characterize the transcriptome of each patient's tumor and guide the choice of therapy. Twenty patients with refractory pediatric sarcomas (age 8-35 years) were assessed with array profiling: ten had Ewing sarcoma, five osteosarcoma, and five soft tissue sarcoma. Overexpressed genes and deregulated pathways were identified as actionable targets and an individualized combination of targeted therapies was recommended. Disease status, survival, adverse events (AEs), and quality of life (QOL) were assessed in patients receiving targeted therapy (TT) and compared to patients without targeted therapy (non TT). Actionable targets were identified in all analyzed biopsies. Targeted therapy was administered in nine patients, while eleven received no targeted therapy. No significant difference in risk factors between these two groups was detected. Overall survival (OS) and progression free survival (PFS) were significantly higher in the TT group (OS: P=0.0014, PFS: P=0.0011). Median OS was 8.83 versus 4.93 months and median PFS was 6.17 versus 1.6 months in TT versus non TT group, respectively. QOL did not differ at baseline as well as at four week intervals between the two groups. TT patients had less grade 1 AEs (P=0.009). The frequency of grade 2-4 AEs did not differ. Overall, expression based targeted therapy is a feasible and likely beneficial approach in patients with refractory pediatric sarcomas that warrants further study.

The two-stage revision protocol is the gold standard for controlling and treating low-grade prosthetic joint infections of total hip and total knee arthroplasty. The antibiotic pause for diagnostic reasons before reconstruction (stage two) is discussed in relation to the persistence of the infection and the development of resistant bacterial strains. Serological markers and a synovial analysis are commonly used to exclude the persistence of infection. Therefore, we asked (1) is the serological testing of C-reactive protein and leucocytes a valuable tool to predict a persistence of infection? and (2) what is the role of synovial aspiration of Plymethylmethacrylat (PMMA) spacers in hip and knee joints? One hundred twelve patients who were MSIS criteria-positive for a prosthetic joint infection were studied, including 45 total hip arthroplasties (THA) and 67 total knee artrhoplasties (TKA) patients. All patients were treated with a two-stage-protocol using a mobile PMMA spacer after a 14-day antibiotic-free interval, during which we measured serological markers (C-reactive protein and leucocytes) and performed synovial aspiration (white blood cell count, polymorphonuclear cell percentage, and microbiological culture) in these patients and compared the results with those of their long-term-follow-up (mean follow-up 27 months, range 24–36 months). Of the 112 patients, 89 patients (79.5%; 95% CI 72–86.9) exhibited infection control after a two-stage exchange, and we detected most methicillin-resistant, coagulase-negative Staphylococci (CoNS) in cases of a persistent infection. The mean sensitivity of serum C-reactive protein in the patients was 0.43 (range 0.23–0.64), and the mean specificity was 0.73 (range 0.64–0.82). For serum leucocytes, the mean sensitivity was 0.09 (range 0–0.29), and the mean specificity was 0.81 (range 0.7–0.92). The mean sensitivity for the WBC count in the synovial fluid (PMMA spacer aspiration) was 0.1 (range 0–0.29), and the mean specificity was 0.79 (range 0.68–0.92). For the PMN percentage, the mean sensitivity was 0.1 (range 0–0.29), and the mean specificity was 0.79 (range 0.68–0.92). No cut-off values could be established for C-reactive protein, leucocytes, WBC count and PMN percentage due to the low AUC. No reliable markers were identified for the long-term persistence of infection. C-reactive protein and leucocytes were often elevated, even when the infection was controlled. In addition, normalized serum markers did not exclude the persistence of infection during follow-up. The synovial analysis of the WBC count and PMN percentage did not predict the persistence of infection. However, microbiological synovial fluid analysis is often misleading due to false positive microbiological cultures, which results in overtreatment.

This case report presents an osteosclerotic bone lesion in a 49-year-old man with MDM2 amplification. The final diagnosis shows metastasis to the bones from stomach cancer. In primary bone tumours, the MDM2 amplifications observed have been described for many other tumour entities as well, and therefore do not exclude bone metastasis from a carcinoma.

Die Rekonstruktion ausgedehnter ossarer Defekte nach Tumor, Trauma oder Infekt ist schwierig und unterliegt zumeist den individuellen Praferenzen des jeweiligen Operateurs. Freie autologe Fibulagrafts stellen eine verlassliche biologische Behandlungsoption dar, wobei die Transplantation grundsatzlich mit (vaskularisiert) oder ohne gleichzeitigen Gefasanschluss (nichtvaskularisiert) erfolgen kann. Beide Varianten weisen jeweils individuelle Vor- und Nachteile auf. Vaskularisierte Fibulatransplantate sind insbesondere zur Uberbruckung ausgedehnter segmentaler Knochendefekte und bei Patienten mit adjuvanter Chemo- oder Strahlentherapie geeignet. Nichtvaskularisierte Fibulae – welche den Vorteil eines Regenerationspotenzials an der Entnahmestelle sowie eine deutlich kurzere Operationszeit bieten – konnen hingegen gunstig zur Rekonstruktion hemikortikaler Defekte oder segmentaler Defekte im ersatzstarken Lager eingesetzt werden.

Background Psychosocial distress can be frequently observed in patients with sarcoma, depicting a relevant clinical problem. However, prospective data collection on psychosocial distress in patients with rare tumors is often time-consuming. In this context, social media such as Facebook can serve as a potential platform to expand research. The aim of this study was to assess the feasibility of psychosocial distress screening in patients with osteosarcoma and Ewing's sarcoma via social media. Materials and methods For this study an online questionnaire including general information and self-assessment distress measurement tools for patients and parents was created. The link to the questionnaire was then posted on the main page of the two largest disease-specific Facebook communities on osteosarcoma and Ewing's sarcoma. Results Within 2 months, 28 patients and 58 parents of patients were enrolled. All patients with osteosarcoma and Ewing's sarcoma, as well as the majority of parental caregivers of such patients, showed relevant psychosocial distress levels. Conclusion Crowdsourcing via disease-specific patient communities on Facebook is feasible and provides great potential for acquisition of medical data of rare diseases.

Background Patients with sarcoma are particularly vulnerable to psychosocial distress. The aim of this study was to collect preliminary data on the prevalence of psychosocial distress in such patients during follow-up care and identify risk factors associated with higher psycho-oncological stress levels. Patients and methods The study retrospectively enrolled 202 patients with bone or soft-tissue sarcomas who underwent routine psychosocial distress screening during their follow-up care. All patients were screened using an electronic cancer-specific questionnaire. Results Females and patients who underwent radiotherapy were more distressed. Psychosocial distress levels were markedly higher in the early postoperative phase, but approximately one-third of patients showed high psychosocial distress levels even more than 2 years postoperatively. Conclusion The results underscore the importance of routine psychosocial distress screenings in patients with sarcoma, which should be performed throughout the follow-up period.

Background Soft-tissue sarcomas are rare entities that are divided into approximately 50 histological subtypes. Myxofibrosarcoma (MFS) represents approximately 20% of all soft-tissue sarcomas, especially in elderly patients in their sixth to eighth decades of life. The treatment for soft-tissue sarcomas varies from primary surgical resection to neoadjuvant or adjuvant radiotherapy or cytotoxic chemotherapy. The aim of this study was to evaluate the prognostic factors affecting survival of patients with MFS, taking into account gender, tumour grade, state of the resection margin, local recurrence, use of radiotherapy, presence of metastases and blood levels of haemoglobin and C-reactive protein in a retrospective, single-centre analysis with a minimum follow-up period of 60 months (range=60-156 months). Patients and methods The study included 34 patients (male/female=20/14). Tumour localization, tumour grade, tumour margins, local recurrence, the use of radiotherapy, the presence of metastasis, and the blood levels of haemoglobin and C-reactive protein preoperatively and during follow-up were evaluated. Results MFS constituted the most common high-grade sarcoma (G2/G3, 79.4%) in our cohort and was generally located in a lower limb (73.6%). Negative margins (R0) were detected in 67.6% of patients after surgical resection, and local recurrence occurred in 23.5% of all patients after a mean disease-free period of 19.4 months. Both parameters exerted no significant influence on survival. Radiotherapy was performed in a neoadjuvant or an adjuvant setting in 50% of patients (eight neoadjuvant, nine adjuvant). Metastasis occurred after a mean of 20.4 months in 38.2% of the patients. Higher C-reactive protein levels showed a trend towards being associated with worse survival, but the association was not significant (p=0.084); haemoglobin level had no influence on the survival rate (p=0.426). Tumour grade and metastasis were significant prognostic factors of survival (log-rank test p=0.041 and p=0.00007). Ten patients (29.4%) died due to MFS during our follow-up period. Conclusion The tumour grade and metastasis of MFS are independently associated with disease-specific survival, whereas negative surgical margins, local recurrence and blood levels of C-reactive protein and haemoglobin were not significant prognostic factors. The understanding of the molecular biological patterns that result in the metastasis of these tumours will help develop better treatment plans in the future.