For several years, virtual reality has been a crucial part of preoperative planning for shoulder replacement. Creating 3D models with sophisticated software, we have been able to develop precise arthroplasty procedures that preserve more of the patient’s natural anatomy.
Earlier this year at UT Southwestern, we took that technology a step further by performing the first augmented reality shoulder replacement in Texas.
Appreciating that achievement might just be a matter of recognizing the difference between virtual reality and augmented reality because they’re not the same. Virtual reality (VR) platforms replace or recreate the real world; augmented reality (AR) platforms overlay data on the real world in real time.
It was the latter technology we used in the OR in April 2021, not only making shoulder replacement history but also opening the gateway to a new gold standard in surgical approach for this arthroplasty procedure.
UT Southwestern is one of just 15 surgical centers in the world using this next-generation arthroplasty technique, which was approved by the Food and Drug Administration (FDA) in July 2020.
‘Limitless potential’: Watch the AR technology in action and see what Dr. Khazzam sees as he performs a shoulder surgery while wearing the AR headset in the operating room.
Creating the surgical plan, virtually
The process begins by using software to generate a 3D model of the patient’s preoperative shoulder CT scan that we can manipulate in the virtual space. With this model, we can examine the patient's anatomy, plan incision points, mark the points for the anchor pins, and adjust the prosthetic device as needed.
Also using the model, we can conduct a virtual “dry run,” implanting the shoulder in the software environment so we can determine what works best for that patient's anatomy and pathology. Ultimately, this virtual dry run becomes our surgical plan for the operating room.
The software also allows us to run a virtual model of the patient's arm and shoulder through range of motion exercises to further refine the procedure. By estimating the range of motion each surgical touch provides, we can maximize patient function and potentially optimize their recovery.
Essentially, we can perform the entire surgery and estimate post-surgical mobility and function in virtual reality before we even touch the patient in the OR. What's more, we can show patients what we'll do prior to surgery, which helps them feel more informed and engaged in their care.
“It's almost like what people see when playing Pokémon Go – you see the real world, with a cartoon-like overlay of the surgical plan. Rather than an immersive VR experience, it's a supplement to reality.”
Bringing AR into the OR
During the actual surgery, the orthopaedic surgeon wears an AR headset that allows the surgeon to visualize the virtual 3D surgical plan overlay over the patient’s anatomy in real time, providing an intricately personalized procedure with the highest level of precision.
The headset makes it possible to see, navigate, and manipulate the entire surgical plan during the procedure. The surgeon can scroll through it and zoom in or out while comparing it in real time to the patient's anatomy.
It's almost like what people see when playing Pokémon Go – you see the real world, with a cartoon-like overlay of the surgical plan. Rather than an immersive VR experience, it's a supplement to reality.
Being able to reference the surgical plan during surgery adds another layer of checks and balances to already highly precise shoulder replacement procedures. Combined with the decades of orthopedic surgical experience of our team, this technology allows us to deliver safe, effective, and precise surgeries using one robust toolkit.
What’s next for ‘extended reality technologies’
Because this technology is in its infancy, the potential long-term benefits regarding post-surgical pain and recovery times haven’t been studied yet.
However, we do know that better planning leads to better surgeries. Research shows that 3D modeling can result in highly accurate restoration of the patient's anatomy and precise positioning of the implant.
In the future, we will conduct clinical studies of device survivorship and outcomes. For now, we are performing this procedure for every patient who has had CT imaging that is properly formatted to suit the software – we've been doing imaging in this manner for all recent UT Southwestern patients interested in shoulder replacement.
We anticipate that the technology will also expand educational opportunities for future orthopaedic surgeons. Versions of AR surgical software allow for clinical "spectators" to see the procedure virtually through the surgeon's eyes.
This is the first iteration of AR surgical technology. We anticipate future improvements will only enhance the accuracy of placing the implants, cutting the bone, and determining the trajectory of the screws in the hardware. Augmented reality certainly feels like a game-changing advancement for shoulder repair and replacement surgery.
About the Author
Michael Khazzam, M.D., is an Associate Professor of Orthopaedic Surgery at UT Southwestern. He specializes in evaluating and treating atraumatic and traumatic shoulder injuries. These include all forms of shoulder pain and injury, from shoulder arthritis and degenerative problems to rotator cuff tears, shoulder dislocations and instability, and complex shoulder disorders. A member of UTSW’s Sports Medicine and Shoulder Service team, he also routinely takes care of common sport-related problems such as golf shoulder injury, tennis shoulder injury, and bench press shoulder injury.
