Using Free Navigation Reference Points and Prefabricated Bone Plates for Zygoma Fracture Model Surgeries

The Impact of 3D Technology in Optimizing Midface Fracture Treatment-Focus on the Zygomatic Bone

PURPOSE

In the context of the ongoing development and expanding availability of 3-dimensional (3D) printing, there is increasing interest in designing simplified workflows that would encourage more medical practitioners to include 3D printing in their current practice. The purpose of this study is to present our experience regarding the use of 3D printing in the preoperative planning and management of acute midface trauma, an area less explored by existing studies.

METHODS

We performed a retrospective case series study including admitted patients who underwent surgical repair of midface fractures, in which 3D-printed stereolithic models were used preoperatively for shaping the osteosynthesis material. We recorded standard information about the patients, imaging method used, and type of midface fracture. We also logged the details and durations of each main step in the preoperative 3D printing workflow and documented the durations and outcomes of each surgical procedure.

RESULTS

We identified 29 cases of midface fractures that benefited of a preoperative stereolithic model. From the 2 main methods of obtaining the virtual model, mirroring and virtual fracture reduction, the longest duration was recorded in a case in which the later method was used. The longest stereolithic model printing time was found in a complex midface fracture case. All the prebent osteosynthesis material was used intraoperatively and fitted the reduced fracture sites, also serving as an intraoperative guide for correct fracture reduction. The particularities, benefits, as well as the possible challenges associated with the application of 3D printing in acute trauma cases are discussed.

CONCLUSIONS

Our 3D printing protocol was applicable and rendered favorable outcomes in the acute midface trauma setting. Proper understanding of the steps involved in achieving the stereolithic model is key for the adaptation of 3D printing to the current management of acute midface trauma.

A personalized preoperative modeling system for internal fixation plates in long bone fracture surgery-A straightforward way from CT images to plate model

BACKGROUND

Long bone fractures are a type of physical damage with high incidence rates that have serious impacts on the normal lives of humans.

AIMS

How to obtain a preoperative internal fixation plate model before cutting muscle has become a critical issue.

MATERIALS AND METHODS

In this paper, we present a new personalized modeling system for internal fixation plates in long bone fracture surgery. This system can achieve straight semi-automatic processing from CT images to 3D models. First, broken bones are separated in CT images. Second, the axes of long broken bones are extracted using 3D models. Third, the vertices on the broken bone cross-sections are segmented. Fourth, rough alignment and fine registration are implemented.

RESULTS

An internal fixation plate is reconstructed for a long bone fracture.

DISCUSSION

Three validations indicate that this method framework is reasonable and feasible.

CONCLUSION

This system can provide technical support for the personalized, minimally invasive and accurate operation on long bone fractures.

COMPARATIVE ANALYSIS FOR THREE FIXTURES OF PAUWELLS-II BY THE BIOMECHANICAL FINITE ELEMENT METHOD

Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for [Formula: see text](3LS) is the least; Internal-fixator stress (MPa) for [Formula: see text]; Integral stress (MPa) for [Formula: see text]; displacement of femoral head (mm) for a[Formula: see text](DHS+LS) = 0.735; displacement of femoral shaft (mm) for [Formula: see text]; and displacement of fixators for [Formula: see text]. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.

Application of computer-assisted surgery techniques in the management of zygomatic complex fractures

Patients suffering from zygomatic complex fractures always present facial deformity and dysfunctions, and thereafter develop psychological and physiological problems. It is really hard to get an ideal prognosis for the zygomatic complex fractures because of the complicated anatomical structures. Computer-assisted surgery techniques, as the new emerging auxiliary methods, can optimize the surgical protocol, predict operation outcomes, and improve the accuracy and quality of the operation. Meanwhile the postoperative complications can be reduced effectively. This review aims to provide a comprehensive overview of the application of computer-assisted surgery techniques in the management of zygomatic complex fractures.