scholarly journals Patient-specific reconstruction utilizing computer assisted 3D modelling for partial bone flap defect in hybrid cranioplasty

2016 ◽  
Author(s):  
Low Peh Hueh ◽  
Johari Yap Abdullah ◽  
Abdul Manaf Abdullah ◽  
Suzana Yahya ◽  
Zamzuri Idris ◽  
...  
Keyword(s):  
3D Modelling ◽  
Bone Flap ◽  
Patient Specific ◽  
Computer Assisted

Patient-Specific Reconstruction Utilizing Computer Assisted Three-Dimensional Modelling for Partial Bone Flap Defect in Hybrid Cranioplasty

2019 ◽  
Vol 30 (8) ◽  
pp. e720-e723 ◽  
Author(s):  
Peh Hueh Low ◽  
Johari Yap Abdullah ◽  
Abdul Manaf Abdullah ◽  
Suzana Yahya ◽  
Zamzuri Idris ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bone Flap ◽  
Patient Specific ◽  
Computer Assisted

Cervical 1-2 Posterior Instrumented Fusion Utilizing Computer-Assisted Navigation With Harvest of Rib Strut Autograft: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Timothy J Yee ◽  
Michael J Strong ◽  
Matthew S Willsey ◽  
Mark E Oppenlander
Keyword(s):  
Surface Area ◽  
Odontoid Process ◽  
Odontoid Fracture ◽  
Patient Specific ◽  
Computer Assisted ◽  
Type Ii ◽  
Instrumented Fusion ◽  
Assisted Navigation ◽  
Patient Consent ◽  
Posterior Instrumented Fusion

Abstract Nonunion of a type II odontoid fracture after the placement of an anterior odontoid screw can occur despite careful patient selection. Countervailing factors to successful fusion include the vascular watershed zone between the odontoid process and body of C2 as well as the relatively low surface area available for fusion. Patient-specific factors include osteoporosis, advanced age, and poor fracture fragment apposition. Cervical 1-2 posterior instrumented fusion is indicated for symptomatic nonunion. The technique leverages the larger posterolateral surface area for fusion and does not rely on bony growth in a watershed zone. Although loss of up to half of cervical rotation is expected after C1-2 arthrodesis, this may be better tolerated in the elderly, who may have lower physical demands than younger patients. In this video, we discuss the case of a 75-yr-old woman presenting with intractable mechanical cervicalgia 7 mo after sustaining a type II odontoid fracture and undergoing anterior odontoid screw placement at an outside institution. Cervical radiography and computed tomography exhibited haloing around the screw and nonunion across the fracture. We demonstrate C1-2 posterior instrumented fusion with Goel-Harms technique (C1 lateral mass and C2 pedicle screws), utilizing computer-assisted navigation, and modified Sonntag technique with rib strut autograft.  Posterior C1-2-instrumented fusion with rib strut autograft is an essential technique in the spine surgeon's armamentarium for the management of C1-2 instability, which can be a sequela of type II dens fracture. Detailed video demonstration has not been published to date.  Appropriate patient consent was obtained.

Computer assisted evaluation of plate osteosynthesis of diaphyseal femur fracture considering interfragmentary movement: a finite element study

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Claudia Wittkowske ◽  
Stefan Raith ◽  
Maximilian Eder ◽  
Alexander Volf ◽  
Jan S. Kirschke ◽  
...  
Keyword(s):  
Finite Element ◽  
Plate Osteosynthesis ◽  
Computation Time ◽  
Fe Analysis ◽  
Patient Specific ◽  
Osteoporotic Bone ◽  
Computer Assisted ◽  
Efficient Computation ◽  
User Input ◽  
Patient Specific Modeling

AbstractA semi-automated workflow for evaluation of diaphyseal fracture treatment of the femur has been developed and implemented. The aim was to investigate the influence of locking compression plating with diverse fracture-specific screw configurations on interfragmentary movements (IFMs) with the use of finite element (FE) analysis. Computed tomography (CT) data of a 22-year-old non-osteoporotic female were used for patient specific modeling of the inhomogeneous material properties of bone. Hounsfield units (HU) were exported and assigned to elements of a FE mesh and converted to mechanical properties such as the Young’s modulus followed by a linear FE analysis performed in a semi-automated fashion. IFM on the near and far cortex was evaluated. A positive correlation between bridging length and IFM was observed. Optimal healing conditions with IFMs between 0.5 mm and 1 mm were found in a constellation with a medium bridging length of 80 mm with three unoccupied screw holes around the fracture gap. Usage of monocortical screws instead of bicortical ones had negligible influence on the evaluated parameters when modeling non-osteoporotic bone. Minimal user input, automation of the procedure and an efficient computation time ensured quick delivery of results which will be essential in a future clinical application.

scholarly journals 3D MODELLING AND RAPID PROTOTYPING FOR CARDIOVASCULAR SURGICAL PLANNING – TWO CASE STUDIES

2016 ◽  
Vol XLI-B5 ◽  
pp. 887-893 ◽  
Author(s):  
E. Nocerino ◽  
F. Remondino ◽  
F. Uccheddu ◽  
M. Gallo ◽  
G. Gerosa
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Case Studies ◽  
Surgical Planning ◽  
Heart Diseases ◽  
Coronary Vessels ◽  
3D Modelling ◽  
Patient Specific ◽  
Surface Model ◽  
Medical Imagery

In the last years, cardiovascular diagnosis, surgical planning and intervention have taken advantages from 3D modelling and rapid prototyping techniques. The starting data for the whole process is represented by medical imagery, in particular, but not exclusively, computed tomography (CT) or multi-slice CT (MCT) and magnetic resonance imaging (MRI). On the medical imagery, regions of interest, i.e. heart chambers, valves, aorta, coronary vessels, etc., are segmented and converted into 3D models, which can be finally converted in physical replicas through 3D printing procedure. In this work, an overview on modern approaches for automatic and semiautomatic segmentation of medical imagery for 3D surface model generation is provided. The issue of accuracy check of surface models is also addressed, together with the critical aspects of converting digital models into physical replicas through 3D printing techniques. A patient-specific 3D modelling and printing procedure (Figure 1), for surgical planning in case of complex heart diseases was developed. The procedure was applied to two case studies, for which MCT scans of the chest are available. In the article, a detailed description on the implemented patient-specific modelling procedure is provided, along with a general discussion on the potentiality and future developments of personalized 3D modelling and printing for surgical planning and surgeons practice.

scholarly journals Patient-specific template and electromagnetic navigation assisted bilateral periacetabular osteotomy for staged correction of bilateral injury-induced hip dysplasia: a case report

2021 ◽  
Author(s):  
Peter Brumat ◽  
Rene Mihalič ◽  
Črt Benulič ◽  
Anže Kristan ◽  
Rihard Trebše
Keyword(s):  
Case Report ◽  
Hip Dysplasia ◽  
Periacetabular Osteotomy ◽  
Patient Specific ◽  
Computer Assisted ◽  
Electromagnetic Navigation ◽  
Assisted Navigation ◽  
High Surgical Risk ◽  
Unique Method ◽  
Post Traumatic

ABSTRACT Periacetabular osteotomy (PAO) for pelvic fracture sequelae presents a challenge in hip preservation surgery due to a combination of complex conditions involving post-traumatic altered anatomy and technically demanding procedure, with high surgical risk involved. To address these challenging conditions and evade potential devastating complications, a combination of patient-specific template (PST) and electromagnetic navigation (EMN) guidance can be used to increase the safety of the procedure and the accuracy of the acetabular reorientation. Herein we report our experience utilizing a combined PST- and EMN-assisted bilateral PAO for staged correction of bilateral severe, injury-induced hip dysplasia. The presented case report describes a unique method of successful surgical treatment of severe, bilateral injury-induced hip dysplasia with combined 3-D printing technology (PST) and intra-operative electromagnetic computer-assisted navigation (EMN) aided technically demanding surgical procedure (PAO), which emphasizes the benefits of PST and EMN use in hip preservation surgery in patients with complex pathoanatomic circumstances.

scholarly journals Unicompartmental Knee Resurfacing: Enlarged Tibio-Femoral Contact Area and Reduced Contact Stress Using Novel Patient-Derived Geometries

2010 ◽  
Vol 4 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Nick Steklov ◽  
John Slamin ◽  
Sudesh Srivastav ◽  
Darryl D’Lima
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Polyethylene Wear ◽  
Femoral Condyle ◽  
Implant Design ◽  
Heel Strike ◽  
Patient Specific ◽  
Computer Assisted ◽  
Average Curvature ◽  
Standard Deviations

Advances in imaging technology and computer-assisted design (CAD) have recently enabled the introduction of patient-specific knee implant designs that hold the potential to improve functional performance on the basis of patient-specific geometries, namely a patient-specific sagittal and coronal curvature, as well as enhanced bone preservation. The objective of this study was to investigate the use of a novel implant design utilizing a patient specific sagittal J-curve on the femoral component combined with a novel constant, patient-derived femoral coronal curvature and to assess tibio-femoral contact area and contact stress on a femur matched curved tibial polyethylene insert. Mean contact area and standard deviations were 81±5, 96±5 and 74±4 mm2 for the heel strike, toe off and mid-stance positions, respectively. Mean contact stress and standard deviations were 23.83±1.39, 23.27±1.14 and 20.78±0.54 MPa for the heel strike, toe off and mid-stance positions, respectively. Standard deviations of the measurements were small, not exceeding 6-7% confirming the consistency of loading conditions across different flexion angles. The results were comparable to those reported for standard, off-the-shelf fixed-bearing implants with paired femoral and tibial geometries. These data show that a constant coronal curvature can be applied to a patient-specific implant by measuring coronal curvatures across the femoral condyle in each patient and by deriving an average curvature. This novel approach combines unique benefits of patient-specific geometry with proven design concepts for minimizing polyethylene wear.

scholarly journals Comparison of the Accuracy and Clinical Parameters of Patient-Specific and Conventionally Bended Plates for Mandibular Reconstruction

2021 ◽  
Vol 11 ◽  
Author(s):  
Henriette L. Möllmann ◽  
Laura Apeltrath ◽  
Nadia Karnatz ◽  
Max Wilkat ◽  
Erik Riedel ◽  
...  
Keyword(s):  
Computer Assisted Surgery ◽  
Reference Points ◽  
Mandibular Reconstruction ◽  
Patient Specific ◽  
Computer Assisted ◽  
Advantages And Disadvantages ◽  
Patient Specific Implants ◽  
Operative Complications ◽  
The Difference ◽  
And Training

ObjectivesThis retrospective study compared two mandibular reconstruction procedures—conventional reconstruction plates (CR) and patient-specific implants (PSI)—and evaluated their accuracy of reconstruction and clinical outcome.MethodsOverall, 94 patients had undergone mandibular reconstruction with CR (n = 48) and PSI (n = 46). Six detectable and replicable anatomical reference points, identified via computer tomography, were used for defining the mandibular dimensions. The accuracy of reconstruction was assessed using pre- and postoperative differences.ResultsIn the CR group, the largest difference was at the lateral point of the condyle mandibulae (D2) -1.56 mm (SD = 3.8). In the PSI group, the largest difference between preoperative and postoperative measurement was shown at the processus coronoid (D5) with +1.86 mm (SD = 6.0). Significant differences within the groups in pre- and postoperative measurements were identified at the gonion (D6) [t(56) = -2.217; p = .031 <.05]. In the CR group, the difference was 1.5 (SD = 3.9) and in the PSI group -1.04 (SD = 4.9). CR did not demonstrate a higher risk of plate fractures and post-operative complications compared to PSI.ConclusionFor reconstructing mandibular defects, CR and PSI are eligible. In each case, the advantages and disadvantages of these approaches must be assessed. The functional and esthetic outcome of mandibular reconstruction significantly improves with the experience of the surgeon in conducting microvascular grafts and familiarity with computer-assisted surgery. Interoperator variability can be reduced, and training of younger surgeons involved in planning can be reaching better outcomes in the future.

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