In February 2014, a 46-year-old woman was in a car accident and sustained multiple fractures of her left leg, which included open fractures and bone loss.
Fractured bones included the tibia, talus, and calcaneus, and overall bone loss in the lower leg was extensive. Shortly after arriving at Duke University Hospital, her lower leg was stabilized with an external fixator, which held the alignment in a reasonable place.
The patient underwent conventional surgical repair, but could not support her weight based on the position of bones that remained in the leg after initial treatment. Trauma surgeons assessed the patient and concluded that the leg would not be reconstructible by conventional surgical methods.
The patient, a mother of 2 young children, asked whether there was any other viable alternative; she had an active life and taught at an elementary school, so she wanted to avoid amputation.
What new technology could be offered to the patient to save her limb?
Answer: A 3-dimensional (3D)-printed bone implant.
Duke orthopaedic surgeon Samuel Adams, MD, had learned about a company called 4WEB at a medical conference and thought that a 3D-printed bone implant might work in this particular case, enhancing quality of life and sparing the limb.
The patient was willing to undergo this process and procedure, and Adams obtained one-time-use approval from procurement purchasing for the Food and Drug Administration–approved implant. (The implant, which is still considered to be a new technology, must demonstrate clinical benefit and cost effectiveness before insurer reimbursement will be offered.)
Adams worked with the company to create a custom template for the missing bone and ascertain where cuts should be made to fit the titanium implant for optimal placement. He said that limb salvage is a primary reason for using the implants, and he has since used other preprinted implants.
Using CT scan measurements from the patient’s leg, a computer-generated “titanium cage” was printed to replace the missing bone. The cage allowed the patient’s bone to maintain structural integrity. The open architecture of the implant allowed for up to 75% of the implant to be filled with graft material to maximize bone incorporation. Graft material used in the cage was allograft and some of the patient's own bone.
The new internal structure was fixed with an intramedullary nail—a rod that went through the foot into the shinbone to provide stability to the injured region. The rod could not have been placed without the implant because there was not enough bone to support it, Adams said.
Four months after her accident, the patient underwent surgery to have the implant placed in her leg. Six weeks later, she was no longer restricted to a wheelchair and was gradually bearing more weight on her leg. By November 2014, she was back to work as an elementary schoolteacher wearing a shoe with an ankle support. As of January 2015, she has been brace free.