The new imaging equipment is based on Nobel Prize winning French technology, first developed for the spine and recently FDA approved for use in the hip and knee.
Called “weight bearing 3D imaging,” the technology allows radiologists to get images of patients from the front and side simultaneously while scanning the patient in a standing or even sitting position. Traditionally, such patients received several scans while laying down.
“What we try to accomplish in surgery is to restore a patient’s alignment in a functional position while they are standing upright,” says Robert Barrack, MD, chief of service for Washington University Orthopedics at Barnes-Jewish Hospital. “This is a revolutionary advance in how we image patients before and after surgical procedures.”
Surgeons such as Dr. Barrack rely heavily on such images before and after surgeries in which a hip implant is placed since they are changing the alignment of a patient’s body. Traditionally, this would mean several x-rays that would literally be spliced together to assess the alignment of the entire lower extremity or in the case of spine surgery, the entire body. This alternative creates a custom 3D image surgeons can rotate from various angles through a 30-second scan of the patient as they stand – a critical component according to physicians.
“We’ve found the alignment of the hip components change dramatically when a patient sits or stands up,” says Dr. Barrack. “Standing puts the hips under load and sitting places the hip in a position where it is more prone to dislocate, so if you’re interested in something like wear or dislocations, scanning a patient in while sitting or standing represents a major advance over traditional x-ray imaging. The associated advanced computer software allows accurate measurement of the alignment of the implants and the skeleton before and after surgery.”
In addition, radiation exposure from the 3D scan is “low-dose” and is five to 10 times less than traditional x-rays. This is important for patients who may need multiple images, particularly those that are still growing or are women of child-bearing age.
For more information about Washington University Orthopedics at Barnes-Jewish, call 314-867-3627 (TOP-DOCS) or visit www.barnesjewish.org/orthopedics.