Establishing a central zone in scaphoid surgery: a computational approach.

PURPOSE: Scaphoid fractures are commonly fixed with headless cannulated screws positioned centrally in the scaphoid. Judgement of central placement of the screw may be difficult. We generated a central zone using computer analysis of 3D reconstructions of computed tomography (CT) images. As long as the screw axis is completely contained within this central zone, the screw would be considered as centrally placed. METHODS: Thirty cases of 3D CT reconstructions of normal scaphoids in a computerised operation planning and simulation system (Vxwork software) were obtained. The central zone was established after some distance shrinkage of the original scaphoid surface reconstruction model using the function "erode" in the software. The shape of the central zone was evaluated, and the width of the central zone in the proximal pole, waist portion and distal pole was measured. We also established the long axis of the scaphoid to see whether it stays in the central zone. RESULTS: All central zones could be divided into distal, waist and proximal portions according to the corresponding irregular shape of the scaphoid. As the geometry of the central zone was so irregular and its width very narrow, it was possible to completely contain the screw axis either in the proximal portion alone, waist alone or distal central zone alone. CONCLUSIONS: Establishing the central zone of scaphoid 3D CT images provided a baseline for discussion of central placement of a scaphoid screw. The geometry of the scaphoid central zone determined that the screw could hardly be inserted through entire scaphoid central area during surgery.

Sensory recovery following decellularized nerve allograft transplantation for digital nerve repair.

This study reported preliminary clinical experience of using decelluarised nerve allograft material for repair of digital nerve defect in five hand injury patients. From October 2009 to July 2010, five patients with traumatic nerve defect were treated with nerve repair using AxoGen® nerve allograft (AxoGen Inc, Alachua, FL) in California Hospital Medical Center. All patients were followed at least for 12 months, and sensory recovery and signs of infection or rejection were documented by a hand therapist. Average two-point discrimination was 6 mm, and average Semmes-Weinstein Monofilaments test was 4.31. No wound infections or signs of rejections were observed at wound site. All patients reported sensory improvement during the follow-up period after operation. It is believed that decellularised nerve allografts may provide a readily available option for repair of segmental nerve defect.

Calcificaciones mamarias: descripción y clasificación según la 5ª edición BI-RADS / Breast calcifications: description and classification according to BI-RADS 5th edition

Abstract. Breast calcifications are frequent findings in mammography. Most of them have a benign origin, such as in the case of the response to inflammatory disease of the ducts or coarse calcifications in benign nodules. Many of these calcifications show a characteristic benign appearance, and they do not need to be magnified or monitored. However, other calcifications can show a grouped pattern, have a suspicious appearance, and transform into an in situ ductal carcinoma or a high risk breast lesion. It is important to know the morphological and distribution patterns of these calcifications in order to make right decisions for each case. In the 5th edition of the BI-RADS atlas, 2013, categories and levels of suspicion for some patterns were modified. The objective of this article is to update descriptors and categories of BI-RADS micro-calcifications, pointing out their most important features and malignancy risk linked to each descriptor.

Resumen. Las calcificaciones mamarias son un hallazgo frecuente en mamografía. La mayoría de ellas tienen un origen benigno, como puede ser la respuesta a patología inflamatoria de los conductos o calcificaciones gruesas en nódulos benignos. Muchas de estas calcificaciones presentan un aspecto benigno característico y no requieren ser magnificadas o controladas. Otras calcificaciones sin embargo pueden presentarse agrupadas, tener un aspecto sospechoso y originarse en un carcinoma ductal in situ o una lesión de alto riesgo. Es relevante conocer los patrones morfológicos y de distribución de estas calcificaciones a fin de tomar la conducta adecuada para cada caso. En la 5.ª edición del atlas BI-RADS, 2013, las categorías y grados de sospecha de algunos patrones fueron modificados. El objetivo del presente artículo es realizar una actualización de los descriptores y las categorías BI-RADS de las microcalcificaciones, señalando sus características más importantes y el riesgo de malignidad asociado a cada descriptor.