Until recently, capturing weight-bearing CT images of the lower extremities was impossible. Most CT scanners required patients to lie down, and equipment that compressed the foot to simulate the forces of standing was a poor substitute for the real thing. If a clinician wanted information about the biomechanics of a patient’s joints, they were forced to use x-Ray, missing the fine-grain anatomic information provided by CT.
However, a 2012 Finnish study demonstrated the clinical viability of weight bearing CT for the first time, thanks to a prototype portable cone-beam CT scanner (CBCT). The prototype design allows the gantry arm to be tilted horizontal and lowered to the floor, letting patients stand during the procedure.
Several studies have since investigated the utility of weight-bearing CT for specific applications, finding the modality useful for biomechanical evaluation and preoperative planning. Adding 3D into the mix provides even more value, according to Bob Baravarian, MD, Chief of Podiatric Surgery at UCLA Medical Center.
“I can remember one time when I performed a replacement on a healthy, active patient with an arthritic ankle. I ordered 3D CT scans in preparation for the surgery, and found to my surprise that he had a completely hollow distal tibia and talus: absolutely no bones in the regions,” wrote Baravarian in blog post for the University Foot & Ankle Institute. “If I operated on this patient 5 years ago, I would have found myself in the operating room with a disaster on my hands. This case taught me that the planning phase is no longer an option—it’s actually the most important phase of treatment.”
Carestream and CurveBeam will work together to support the Weight-Bearing CT International Study Group, who recently met during the American Academy of Orthopedic Surgeons (AAOS) 2017 Annual Meeting. Several members presented research and discussed creating standardized protocols for measurement and analysis.
“Significant clinical research has already demonstrated weight-bearing CT has the potential to be the new standard of care for an initial diagnosis,” said Vinti Singh, Marketing Manager for CurveBeam. “However, much work remains to be done to increase awareness among orthopedic specialists."