Virtual registration of comminuted bone fracture and preoperative assessment of reconstructed bone model using the Procrustes algorithm based on CT dataset.

A research work was undergone in a virtual bone reduction process for reconstruction of the comminuted pelvic bone fracture using a CT scan dataset of patients. This includes segmentation, 3D model optimization and bone registration technique. The accuracy of the reconstructed bone model was validated using Finite Element Method. Analysed and applied various segmentation techniques to segregate the injured bone structure. The ICP (Iterative Closest Point), Procrustes algorithm and Canny edge detection algorithm were applied to understand the bone registration process for surgery in detail. The average RMS error, mean absolute distance, mean absolute deviation, and mean signed distance of the reconstructed bone model using proposed algorithms involving 10 patient datasets in a group were found to be 1.77, 1.48, 1.51 and -0.31 mm respectively. The calculated RMS error value proved minimal error in semi-automatic registration than other existing automatic registration techniques. Therefore, the proposed approach is suitable for virtual bone reduction for comminuted pelvic bone fracture. This method could also be implemented for various other bone fracture reconstruction requirements.

Invasive, gangrenous mucormycosis of arm: A fatal opportunistic infection in a highly immunocompromised host.

Opportunistic fungal infections occur predominantly in immunocompromised (IC) patients. Mucormycosis has the highest mortality among fungal infections. The organism is ubiquitous in its presence. The infection is commonly acquired by inhalation of fungal spores or by inoculation by direct trauma. Rhinocerebral and pulmonary mucormycosis present commonly with high mortality rates. Cutaneous mucormycosis (CM) is rarely reported and usually presents in two forms, superficial and disseminated. The superficial infection occurs commonly in immunocompetent hosts, and it can sometimes turn angioinvasive and become a fatal and very aggressive disseminated disease, especially in IC hosts. Coexistant risk factors increase the mortality rate. We report a case of posttraumatic, highly lethal, angioinvasive, and gangrenous type of CM of the arm in an IC patient. Diabetic ketoacidosis and cirrhosis due to chronic alcoholic liver disease were the risk factors.