Implant Deformation on Digital Preoperative Planning of Lower Extremities Fractures

Author(s):  
Esmitt Ramírez ◽  
Ernesto Coto

Preoperative planning is an essential step before performing any surgical procedure. Computer Aided Orthopedic Surgery (CAOS) systems are extensively used for the planning of surgeries for fractures of lower extremities. These systems are input an X-Ray image of the fracture and the planning can be digitally overlaid onto the image. In many cases, when an implant is added to the planning, it does not fit perfectly in the patient’s anatomy and therefore it is bended to be adjusted to the bone. This paper presents a new method for the deformation of implants in CAOS systems, based on the Moving Least Squares (MLS) method. Several improvements over the original MLS are introduced to achieve results visually similar to the real procedure and make the deformation process easier and simpler for the surgeon. Over 100 clinical surgeries have been already planned successfully using a CAOS system that employs the proposed technique.

2001 ◽  
Vol 6 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Qingmao Hu ◽  
Ulrich Langlotz ◽  
Jeff Lawrence ◽  
Frank Langlotz ◽  
Lutz-Peter Nolte

PLoS ONE ◽  
2018 ◽  
Vol 13 (6) ◽  
pp. e0199136
Author(s):  
Kenan Niu ◽  
Jasper Homminga ◽  
Victor I. Sluiter ◽  
André Sprengers ◽  
Nico Verdonschot

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1986
Author(s):  
Andreas Koenig ◽  
Julius Schmidtke ◽  
Leonie Schmohl ◽  
Sibylle Schneider-Feyrer ◽  
Martin Rosentritt ◽  
...  

The performance of dental resin-based composites (RBCs) heavily depends on the characteristic properties of the individual filler fraction. As specific information regarding the properties of the filler fraction is often missing, the current study aims to characterize the filler fractions of several contemporary computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs from a material science point of view. The filler fractions of seven commercially available CAD/CAM RBCs featuring different translucency variants were analysed using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), Micro-X-ray Computed Tomography (µXCT), Thermogravimetric Analysis (TG) and X-ray Diffractometry (XRD). All CAD/CAM RBCs investigated included midifill hybrid type filler fractions, and the size of the individual particles was clearly larger than the individual specifications of the manufacturer. The fillers in Shofu Block HC featured a sphericity of ≈0.8, while it was <0.7 in all other RBCs. All RBCs featured only X-ray amorphous phases. However, in Lava Ultimate, zircon crystals with low crystallinity were detected. In some CAD/CAM RBCs, inhomogeneities (X-ray opaque fillers or pores) with a size <80 µm were identified, but the effects were minor in relation to the total volume (<0.01 vol.%). The characteristic parameters of the filler fraction in RBCs are essential for the interpretation of the individual material’s mechanical and optical properties.


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