Computational analysis of MRIs predicts osteosarcoma chemoresponsiveness.

Aim: This study aimed to improve osteosarcoma chemoresponsiveness prediction by optimization of computational analysis of MRIs. Patients & methods: Our retrospective predictive model involved osteosarcoma patients with MRI scans performed before OsteoSa MAP neoadjuvant cytotoxic chemotherapy. Results: We found that several monofractal and multifractal algorithms were able to classify tumors according to their chemoresponsiveness. The predictive clues were defined as morphological complexity, homogeneity and fractality. The monofractal feature CV for Λ'(G) provided the best predictive association (area under the ROC curve = 0.88; p <0.001), followed by   Y-axis intersection of the regression line  for â€Šbox fractal dimension, r²â€Š for  FDM and tumor circularity. Conclusion: This is the first full-scale study to indicate that computational analysis of pretreatment MRIs could provide imaging biomarkers for the classification of osteosarcoma according to their chemoresponsiveness.

[Contribution of novel anticoagulants fondaparinux and dabigatran to venous thromboembolism prevention].

The data that episodes and sequels of venous thromboembolism (VTE) are recorded in a significant percentage of patients receiving standard anticoagulants as VTE prophylaxis (unfractionated, low-molecular-weight heparin and vitamin K inhibitors) as well as the fact that these drugs have significant limitations and that they may cause serious side-effects in some patients indicate the need for the introduction of new anticoagulant drugs. Fondaparinux, a selective inhibitor of Factor Xa, administered following major orthopedic surgeries having a high risk for the development of VTE, is more efficient than enoxaparin sodium used in European and North-American approved doses. The increased incidence of major bleeding (excluding fatal) due to fondaparinux could be perhaps lowered by dosage reduction in patients with a mildly decreased creatinine clearance. Dabigatran, a peroral direct thrombin inhibitor, administered for VIE prophylaxis in elective hip and knee surgery, showed in to date studies the efficacv comparable (if dabiqatran is given in both dosage regimes of 150 mg and 220 mg daily) or superior (if dabigatran is given at a dose of 220 mg daily) to enoxaparin administered in European-approved doses, while North American-approved doses of enoxaparin were superior than dabigatran in VTE reduction. No significant differences in bleeding rates were determined in any of the study groups. We consider that the introduction of new anticoagulants, including fondaparinux and dabigatran, will contribute to the establishment of a better safety profile and efficacy, and will also enable adequate therapy individualization for each patient depending on his/hers clinical characteristics. The introduction of novel peroral anticoagulants will, inter alia, significantly contribute to improvement in the quality of life, release the patient from numerous limitations in nutrition, interreaction, frequent laboratory monitoring, and also significantly improve therapeutic predictability.

[Contemporary approach to primary prophylaxis of venous thromboembolism regarding the impact of risk factors on anticoagulation therapy duration].

Adequate thromboprophylaxis primarily requires timely detection of reversible and irreversible risk factors of venous thromboembolism (VTE) and their categorization. It is important to note that the highest percentage ofVTE episodes occur in non-surgical (medical) patients and that VTE develops in a large number of surgical patients upon hospital discharge; this emphasizes the need for adequate VTE prevention in inflammatory diseases, acute medical illness and other medical diseases as well as for prolonging and optimizing the anticoagulant regimen after surgical intervention in the primary VTE prophylaxis. As almost completely unrecognized and neglected major risk factors of VTE in clinical practice, we particularly point out the chronic obstructive pulmonary disease (COPD) and heart failure, especially in NYHA functional class III and IV patients with significantly reduced left heart ventricle. It is necessary to raise clinicians' awareness of a potential danger from wrongly and one-sidedly interpreted dyspnea and coughing signs in patients with COPD as typical symptoms of basic respiratory disease as well as from ascribing the signs of disease aggravation in heart failure patients exclusively to cardial status worsening, neglecting the possibility of having unrecognized and untreated pulmonary embolism at issue. Contemporary way of life enhances the development of new VTE risk factors such as traveler's thrombosis, in particular during long-haul flights as well as in individuals sitting at a computer for prolonged periods (e-thrombosis). Determining and recognizing VTE risk factors, especially those formerly neglected nonsurgical ones and simultaneous presence of multiple risk factors within a given period is required for defining an adequate anticoagulant regimen in primary VTE prophylaxis for surgical and non-surgical (medical) patients.

[Chiari pelvic osteotomy in treatment of hip dysplasia].

Chiari pelvic osteotomy is a surgical procedure having been performed for almost sixty years in patients with the insufficient coverage of the femoral head. It is most frequently used in young patients with dysplastic acetabular sockets as a part of developmental hip dysplasia. Even though performance of the Chiari osteotomy is associated with positive therapeutical results, above all, its main goal is to delay inevitable degenerative changes. Original surgical technique has been modified and improved over time. Nevertheless, the basic idea has remained unchanged--increasing of the femoral head coverage by medial displacement of the distal partof the pelvis along with capsular interpositioning. Given the complexity of operation, the complication percentage is rather low. Chiari pelvic osteotomy has lost its actuality and importance during this past six decades. The role of Chiari pelvic osteotomy has been considerably taken over by other more efficient and more lasting surgical procedures. Nonetheless, Chiari pelvic osteotomy is still present in modern orthopedic practice, above all as,salvage" osteotomy.

Acute patellar dislocation in adolescents: operative versus nonoperative treatment.

PURPOSE: The purpose of this prospective non-randomised study was to compare the efficacy of two opposed methods, operative and conservative. Our hypothesis was that if the method was selected correctly, on an individual basis, the results should be approximately equal. METHODS: The study included 37 adolescents aged between 12 and 16 years, with a mean follow up of 6.1 years. The presence of a significant loose body, confirmed by precise imaging, was the key for selecting operative or arthroscopic treatment. In both groups of patients, we evaluated functional knee scores and the incidence of residual patellofemoral disorders. RESULTS: We confirmed our hypothesis using the t-test to compare functional results and a test for comparison of proportions for incidence of residual disorders. There was no statistically significant difference (p=0.091) between operatively and conservatively treated groups with regard to functional results. The same statistical outcome emerged when comparing incidences of re-dislocation (p=0.854), or other major patellar instabilities (p=0.856), between the groups. CONCLUSIONS: The results obtained should not promote a non-operative method on the basis of lower risk, but do support an individual approach based on precise diagnosis and defined criteria.

[Review of thirty patients with bone chondroblastoma].

BACKGROUND/AIM: To analyse the results of the treatment of the patients with the diagnosis of chondroblastoma, to confirm the possible malignancy and to recommend the best and the safest method of the treatment. METHODS: We reviewed the cases of 30 patients with chondroblastoma who were treated between 1975 and 2004. Data were obtained using complete medical documentation, physical examinations, radiographic findings, and the available additional diagnostic procedures. RESULTS: We found that the proximal part of the tibia, proximal part of the humerus, and distal part of the femur were the most common sites of the tumor in 63% of the cases. The higher prevalence of chondroblastoma in male patients was found, especially in the second decade of life. The patients were treated with different surgical procedures after histologically confirmed chondroblastoma. In 1 of the patients, radiation therapy was performed because the lesion recurred, after which the malignant transformation of chondroblastoma occured. We found two more malignant chondroblastomas, one of which had been diagnosed as a primary tumor. Seven patients had a local recurrence, one of them had a second recurrence and the malignant transformation of chondroblastoma. The only solution was a below-knee amputation. CONCLUSION: Chondroblastoma of bone is a rare lesion with the high local recurrence rate. We emphasized the need for an adequate and rapid diagnosis, including histological verification. The treatment was strictly surgical. The basic goal of the treatment was to avoid tumor penetration into articular cavity and/or local soft tissues. Malignant chondroblastoma of bone should be treated with radical surgical resection, avoiding any adjuvant therapy.