Are the simulations based on a fixed center of rotation for the hip?
No. The femoral head is not completely spherical. The software calculates an optimal initial center of rotation for an individual hip. This center of rotation then is allowed to translate during the simulation of rotation. This translation is calculated as a ‘least effort’ direction: what translation is the least likely to put pressure on the bony surface?
The maximum allowed translation is 3 mm for all patients. In reality some patients may have 2 mm of translation in their joint, and others 4 mm. Literature shows that 3 mm is a reasonable average. In cadaveric experiments, we have shown that this assumption leads to accurate range of motion simulations.
CT image related questions
- Rejection due to lack of knee images
- Why does Clinical Graphics reject imaging with short femurs?
- Why is imaging of both hips required for a report of one joint side?
- What type of CT image reconstruction is preferred (continuous or overlap)?
- Does Clinical Graphics include pelvic tilt in its simulations?
- What are the dimensions of the field of view reconstruction for CT scans?
MRI image related questions
- Does Clinical Graphics take soft tissue into account?
- Does Clinical Graphics include pelvic tilt in its simulations?
- Rejection due to lack of knee images
- Why does Clinical Graphics reject imaging with short femurs?
- Can I use intra-articular gadolinium for MRI scans?
- Why is there a surcharge for processing MRI image data?
PDF report general questions
Report delivery time related questions
Range of motion simulation related questions
- How did Clinical Graphics determine the range of motion target end points?
- I see a big cam, but there’s no intersection zone visualized?
- Does Clinical Graphics include pelvic tilt in its simulations?
- Are the simulations based on a fixed center of rotation for the hip?
- How accurate are these simulations?