Computer-assisted surgery in orbital reconstruction and facial trauma Flashcards
What is facial trauma?
- Injury of the viscerocranium (facial bones)
- Is injury to dentition, hard tissue, or soft tissue
- Has four urgent indications for surgery
- Is elective most of the time
- Has large functional and esthetic consequences
What the Le Fort fractures?
– look up image –
Le Fort I level – > a separation of the hard palate from the upper maxilla due to a transverse fracture running through the maxilla and pterygoid plates at a level just above the floor of the nose
- LeFort II –> transect the nasal bones, medial-anterior orbital walls, orbital floor, inferior orbital rims and finally transversely fracture the posterior maxilla and pterygoid plates
- LeFort III fractures result in craniofacial disjunction - separates the maxilla from the skull base
Data collection in computer-assisted surgery
bony structures –> CT, MRI
What ate the four urgent indications for surgery in facial trauma?
- airway
- blood loss
- (detail) eye (eg. compartment syndrome)
- (detail) tooth/ dental (ie. longtime to replace)
What is CAS?
CAS = Computer Assistent Surgery
orbital blow-out fracture
- isolated fracture of the orbital floor or medial wall
- globe usually not ruptured
Goals in orbital reconstruction
- Restore globe position * Restore orbital volume * Recover function
Obstacles of orbital surgery
- key hole surgery –> limited overview
What are the differences in steps between the conventional workflow and the CAS workflow?
Conventional: (1) Diagnosis, (2) Planning, (3) Surgery, (4) Evaluation
CAS: during 1-4 aid from –> (a) Virtual planning, (b) PSI, (c) navigation, (d) Intra-op imaging)
What are different imaging techniques that can be utilised during (diagnostic) imaging?
- Light (photography)
- Sound (ultrasound)
- Magnetism (MRI)
- X-ray (CT)
- Radioactivity
What are the differences between CT, x-ray, MRI?
- advantages and disadvantages in comparison
x-ray
- radioactive beams
- black/white images –> absorb different amounts due to density of material
+ quick
+ painless
- radioactivity
CT = Computer Tomography
- 360°-degree view of body structures
+ more detailed that x-ray
- more expensive
MRI = Magnetic Resonance Imaging
- combination of strong magnet with radio waves
- viewed in slices
+ no radiation
What is advanced in advances diagnostics compared to 8standard) diagnostics?
- additional diagnostic information
- enhanced diagnostic information
- combining diagnostic information
- segmentation and mirroring
Steps in Virtual surgical planning
- (repeated) virtual simulation to find optimal approach
- based on –> continuation of advances diagnosis
a. segmentation
b. mirroring
c. simulation anatomy before trauma
d. virtual implant positioning
e. different implant sizes
f. virtual trimming implant
- virtual simulation of surgery
- set goals for surgeon
- intraoperative feedback
What is ACOR?
Advanced Concepts in Orbital Reconstruction –> Validation of advanced technology
Conclusions:
* There are different CAS components to bring planning to surgery
* Intraoperative feedback leads to an improved implant position
* Navigation with markers provides the best accuracy and reproducibility
What can CAS due to improve preparation and surgery?
- 3D anatomical models and planned models
- PSIs
- Splints
- pre-bending
- form as drilling-guide
- visualisation (VR, AR)
indicate registration points
