Scientists from ExplantLab have identified a genotype that is associated with joint replacement failure in some patients. Based on these findings, the scientists developed a machine-learning algorithm called Orthotype, which uses a patient’s genotype and other factors to accurately predict the outcome of joint replacement surgery.
More than five million joint replacements are performed globally each year. Although most patients are satisfied with the results of their surgery, a significant number of joint replacements fail early, following adverse immune responses.
One of the most popular implant materials used in joint replacements is cobalt chrome (CoCr). When small particles from CoCr joints are released into the blood, it can lead to an immune response that results in pain and joint failure in some patients.
“Essentially, the immune system attacks the implant in a process similar to how a patient rejects an organ transplant,” explained David Langton, PhD, director of ExplantLab. “How quickly this happens is variable and unpredictable, but it appears to be dependent on the type of material, the amount of wear debris released, and other patient-specific factors.”
One of those patient-specific factors is their genes. The HLA genes play a central role in immune function, and Langton and his colleagues determined that patients with certain HLA genotypes are likely to develop responses to CoCr-containing implants. Their results were published in Communications Medicine.
Taking the research one step further, ExplantLab, working with bioengineers, medical staff, and patients from collaborating institutions, developed a machine-learning algorithm called Orthotype, which uses a patient’s genotype to provide a risk profile of that patient developing hypersensitivity to CoCr. Orthotype was developed and validated from the results from 606 patients implanted with metal hip replacements and resurfacings, each of whom had been followed for a mean duration of ten years.
This could herald a new era where it will become routine for patients to undergo genetic testing prior to receiving medical implants. Orthotype will identify patients more likely to have a reaction to a joint replacement made of CoCr components, helping surgeons select an implant based on the manufactured material most suited to the individual patient.
“This represents a significant advance in orthopedic care for patients,” said Langton, “with potentially significant financial repercussions for global healthcare systems, through the avoidance of repeat surgery.”
As populations around the world grow older and heavier, joint replacements are more common than ever. The number of joint replacement surgeries carried out globally is forecast to double over the next two decades.
