Prediction of osteoporotic hip fracture in postmenopausal women through patient-specific FE analyses and machine learning.

A great challenge in osteoporosis clinical assessment is identifying patients at higher risk of hip fracture. Bone Mineral Density (BMD) measured by Dual-Energy X-Ray Absorptiometry (DXA) is the current gold-standard, but its classification accuracy is limited to 65%. DXA-based Finite Element (FE) models have been developed to predict the mechanical failure of the bone. Yet, their contribution has been modest. In this study, supervised machine learning (ML) is applied in conjunction with clinical and computationally driven mechanical attributes. Through this multi-technique approach, we aimed to obtain a predictive model that outperforms BMD and other clinical data alone, as well as to identify the best-learned ML classifier within a group of suitable algorithms. A total number of 137 postmenopausal women (81.4 ± 6.95 years) were included in the study and separated into a fracture group (n = 89) and a control group (n = 48). A semi-automatic and patient-specific DXA-based FE model was used to generate mechanical attributes, describing the geometry, the impact force, bone structure and mechanical response of the bone after a sideways-fall. After preprocessing the whole dataset, 19 attributes were selected as predictors. Support Vector Machine (SVM) with radial basis function (RBF), Logistic Regression, Shallow Neural Networks and Random Forest were tested through a comprehensive validation procedure to compare their predictive performance. Clinical attributes were used alone in another experimental setup for the sake of comparison. SVM was confirmed to generate the best-learned algorithm for both experimental setups, including 19 attributes and only clinical attributes. The first, generated the best-learned model and outperformed BMD by 14pp. The results suggests that this approach could be easily integrated for effective prediction of hip fracture without interrupting the actual clinical workflow.

[Malignant hemangiopericytoma: a rare primary retroperitoneal tumor]. / Hemangiopericitoma maligno: un raro tumor retroperitoneal primario.

A case of malignant retroperitoneal hemangiopericytoma is described. The infrequency of the retroperitoneal mesenchymatous origin, specific anatomopathological criteria of malignity, constant hypervascularization as well as clinico-radiological, surgical and prognostic characteristics found in the literature are highlighted.

[Testicular and epididymal malacoplakia. Presentation of a case and review of the literature]. / Malacoplaquia testicular y epididimaria. Aportación de un caso y revisión de la literatura.

A case of testicular malacoplakia and epididymis in a 62 year old man is presented. A literature review is made (only 6 cases describing epididymal malacoplakia have been reported), commenting on the clinical, diagnostic, anatomopathological, pathogenic and therapeutic aspects of malacoplakia.

[Calcified kidney masses. Study of 23 cases]. / Masas renales calcificadas. Estudio de 23 casos.

We consider the presence of calcifications in a series of 107 renal masses by means of simple X-ray, echography and CAT, in which 23 cases (21.4%) were found. The most effective exploration for revealing them was CAT (in 13% of the cases, the only one). We found a relative higher frequency of calcification in the benign masses (31%) than in the neoplastic ones (17%). In the latter we found no differences in survival as compared with the non-calcified ones. No pattern of calcification proved characteristic of benignity or of neoplasia. The variety of malignant renal mass most often calcified was the papillary hypernephroma (57.1%).

[Fistulization in xanthogranulomatous pyelonephritis. Presentation of 6 clinical cases and review of the literature]. / Fistulización en la pielonefritis xantogranulomatosa. Presentación de 6 casos clínicos y revisión de la literatura.

Fistulization is an uncommon complication in Xanthogranulomatous Pyelonephritis, but harmful for the adjacent organs. Owing to their rare localization we present 6 cases with scrotal skin, bronchi, colon and spleen fistulization.