3D Extremity Imaging in Orthopaedic Practice

Reading Time: 3 minutes read

3D extremity CT imaging has changed the way I treat and evaluate patients.

By Dr. Bryan D. Den Hartog, M.D., orthopedic surgeon Twin Cities Orthopedics.

Twin Cities Orthopedics recently installed the CARESTREAM OnSight 3D Extremity System at our clinic in Woodbury, Minnesota. At the American Academy of Orthopaedic Surgeons (AAOS) annual meeting this year, I had the opportunity to share my experience of being an early adopter of this technology with my peers.

Like many orthopaedic surgeons who specialize in foot and ankle, I have several diagnostic challenges:

The anatomy of the foot is complex with lots of fine detail.

Common deformities, such as pes planus and pes cavus, have several components that need weight-bearing views to evaluate joints.

We do a lot of redo surgery and need to understand where pain is coming from: Has the fusion or fracture healed? Is there residual deformity? Can we see broken or loose hardware?

Traditional CT systems have limitations that compound these diagnostic challenges. They are expensive, inconvenient, and expose additional sensitive patient anatomy to radiation.
3D extremity CT imaging has changed the way I treat and evaluate patients. Eight months post-install, the CARESTREAM OnSight 3D Extremity System gives me what I need to make good clinical decisions in a timely fashion:

    • High resolution 3D images available in the clinic during one patient visit
    • Dynamic weight-bearing images
    • Joint fusion evaluation
    • Ability to see around metal
    • Four times less radiation exposure
  • At a cost 35 – 35 % less than a traditional multi-slice CT

Advantages of weight-bearing images

Weight bearing is a great advantage. It becomes an important pre-op and post-operative assessment tool. Weight-bearing images more accurately identify ligamentous laxity, loss of cartilage space, and the degree of deformity to give me greater confidence in my care recommendations. Specifically in fusion healing or “trabecularization”, the OnSight 3D Extremity Imaging System allows me to:

    • Evaluate the extent of trabecular bone bridging
    • Improve the visualization around hardware with metal artifact reduction software
    • Visualize complex fractures, foot and ankle joints, and overlapping bone structures
  • View joints under natural load, thanks to weight-bearing capability

With this system, I can see the degree of fusion across the area of interest and determine how much surface area is connected by trabeculae. The image detail and quality are much better than traditional CT systems. These images give me greater confidence when determining when patients can go back to work and resume normal activities. That’s good for my patients and good for the growth of Twin Cities Orthopedics. You can watch a video of my full AAOS presentation here.

And read the blog by Dr. Lew Schon on “Extremity Reconstruction’s Game Changer:  Weight-Bearing CT Imaging”.

Feel free to leave any questions you have about my experience as an early adopter of the CARESTREAM OnSight 3D Extremity System in the comments. #extremityimaging #twincitiesorthopaedics #orthopaedics

C:\Users\19019997\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Word\DenHartog.jpgDr. Bryan D. Den Hartog, M.D. is an orthopedic surgeon with Twin Cities Orthopedics. He has 27 years of practice in foot and ankle care with a focus on sports, trauma, and reconstruction.


  • reply

    Ryan Callahan

    We are considering utilizing this machine in our practice. What application is there for the 2-D use in obtaining weight bearing AP foot, lateral, sesamoid, Saltzman views, etc?

    • reply

      Hi, here is the response from Dr. Den Hartog. And please let me know if you would like someone from Carestream to contact you to give you more information. Thank you for reading Everything Rad! “The OnSight 3D Extremity System does provide a method to acquire a specific set of 2D images. The Lateral Foot view is easily acquired; it is the same view used for scouts & the same patient position used for CBCT (Cone Beam CT) scanning. The tube angles & detector positions required for the other views specified are not easily achieved, however the ability to scroll through a CBCT volume in the different planes provides excellent visualization of the sesamoid bone. Similarly, tibiocalcaneal alignment could be evaluated based on the slices from the CBCT volume. In ImageView v1.1, a Capture slice can be made of the most helpful slices, this could be used to make the measurements currently done with the Saltzman image.”


This site uses Akismet to reduce spam. Learn how your comment data is processed.