Collaborative effort leads to improvements in knee repair
Osteochondral allografts (OCAs), tissue surgically transplanted from one person to another, are key components in alleviating osteoarthritis (OA), particularly in the knee. The problem is the limited window of time between being taken from donor cadavers and when they can be implanted effectively and viably in the recipient’s joint. Researchers at the University of Missouri College of Engineering, School of Veterinary Medicine and School of Medicine recently developed a way to crack that window open much wider.
Ferris Pfeiffer, an assistant professor of bioengineering, was the corresponding author, and James L. Cook, a professor of veterinary medicine and surgery in the MU College of Veterinary Medicine, director of the MU Comparative Orthopaedic Laboratory and the William and Kathryn Allen Distinguished Professor in Orthopaedic Surgery, was the lead author on a recent paper published by The American Journal of Sports Medicine called “Importance of Donor Chondrocyte Viability for Osteochondral Allografts.”
The paper outlines how their team doubled the window from donor removal to recipient transplant for OCAs, making them potentially more accessible and cost effective for patients, particularly younger patients who could have a more natural fix than frequently-used metal or plastic replacements.
“Donor tissue needs at least 70 percent of living chondrocytes [healthy cartilage cells] in order for the transplant to take place,” said Pfieffer, who also is an assistant professor in the department of orthopadeic surgery in the MU School of Medicine and head of biomechanics and bioengineering at the MU Comparative Orthopaedic Laboratory. “The current storage protocol allows only 28 days from the time a donor is identified to the time the surgery is completed. During this 28 days, the donor tissue must be tested for diseases and matched to a recipient. Time constraints translated to 80 percent of donor tissue being discarded, which is very costly.”
The bone and cartilage removed from a donor under this new process is stored in a liquid medium made up of antibiotics and other nutrients which allow cells to stay viable for longer.
The method was tested on adult female dogs with OA, with the recipients of the transplanted cartilage illustrating normal chondrocyte levels, indicating the knee was healing naturally as the allografts began to merge with the remaining natural bone and cartilage in the knee.
The research was funded in part by Mizzou Advantage’s “One Health, One Medicine” program, and The American Journal of Sports Medicine had interest because of the research’s ties to ACL tears in young athletes.
“Studies have shown that individuals who have had an ACL tear have an 80 percent chance of developing OA. Most of the time, OA onset in these individuals is happening before the age of 50,” Pfeiffer said.
“Our new storage protocol allows the donor tissue to remain viable for 70 days, allowing the healthcare team more time to find a match and for more patients to receive treatment.”