Personalized medicine in upper extremity traumatology

Question 1

For what can 3D applications / computer assisted surgery (CAS) be used in regard to upper extremity traumas?

Answer 1

• Understanding morphological specifics fracture (pattern)
• Aid in reconstruction fracture
• Aid in correction posttraumatic deformity/complications (malunion/nonunion)

Question 2

What is the current 3D workflow for e.g. upper extremity trauma?

Answer 2

• Image acquisition CT-MRI
• Image reconstruction
• Design and reverse engineering
• Manufacturing

Question 3

What is the problem with the current 3D workflow?

Answer 3

That there are a lot of factors to take into account.

Question 4

What does the segmentation of CT images imply?

Answer 4

• Define region of interest
• Select this region by selection of voxels
• Translate this selection to a 3D model

Question 5

What are complications of distal radiusfractures?

Answer 5

Functional limitations:
- Screw penetration
- Tendon injury
- Malposition plate
- Secondary dislocation
- Posttraumatic arthritis

Union-related:
- Nonunion
- Malunion

Instability (DRUJ, SL)

Deep infections

Neuropraxia:
- N. medianus
- N. radialis superficialis

Question 6

Question 7

For the radial reconstruction, three templates are made so that the best possible plate can be used for the surgery. What three templates are designed?

Answer 7

• First the osteosynthesis plate is chosen and a 3D printed digital correction is made of the fracture. The plate should be shaped to best fit the 3D printed model.
• Another scan is made of the 3D printed model with the plate attached, which results in a digital model where we can extract the screw insert points.
• These screw insertion points are then translated to the position before the digital osteotomy and a digital model of the drill and saw template is designed in CAD software.
• The second template is digitally designed for an exact cutting guide to reconconstruct the step down malunion of the styloid process and the carpal articulate surface,
• The third template is designed to assist in shaping the autograft bone piece harvested from the iliac crest.

Question 8

What are minimal important changes (MICs)?

Answer 8

Smallest changes in an outcome measurement that a patient would perceive as important.

Question 9

Is there evidence about the cost-effectiveness of 3D models during surgery?

Answer 9

No, more research is mandatory.

Question 10

Where is the treatment of a proximal humerus fracture dependent on?

Answer 10

• Bone quality (osteoporosis, communition)
• Vascularization
• Quality rotator cuff
• Comorbidity / condition patient
• Surgeons expertise
• Rehabilitation goal of the patient
• Patient shared decision making

Question 11

What are complications of a proximal humerus fracture?

Answer 11

• Mechanical complaint
• Deep infection
• Union-related (non-union, AVN, malunion)
• Neuropraxia

Question 12