How accurate are these simulations?
To begin with: these simulations do not include soft tissue simulations. Only the rigid shapes are taken into account. To understand the value of the simulations it is important to understand the difference between the absolute range of motion and the relative range of motion.
The absolute range of motion values (e.g. 122 degrees of flexion) are an overestimation of the real physical range of motion. There’s a labrum and capsule that limit the actual range of motion, so it’s very likely that the patient will have 10 or 20 degrees less range of motion that what’s calculated and visualized.
The relative range of motion is what brings the value: we have shown in a cadaveric experiment that a change of bone morphology in the same joint can be captured with an accuracy of 5 degrees (with the soft tissues in between). Within a single patient (pre and post-operatively for example) one can capture these differences at that resolution. This concept also applies inter-patient: Based on a study we know that on average patients will have a bony range of motion of 120 degrees of flexion. If a patient only reaches 110 degrees then this patient has less bony range of motion than the average patient (and most likely also in absolute terms, but you don’t know this for sure).
Since femoral neck osteoplasty (or trimming of the acetabular rim, for that matter) is a bony procedure, it’s this relative value that’s interesting; potentially more so than the range of motion in absolute terms.
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?