Of the many people who receive artificial hips, approximately 10 percent will require replacement surgery within 10 to 15 years. This is due to a condition called osteolysis, in which the adjacent bone deteriorates, causing the implant to loosen. Soon, however, it may be possible to determine who will develop the condition, via a urine test.
Led by Dr. D. Rick Sumner, a team from Chicago's Rush University Medical Center analyzed urine samples that were collected from 26 patients 24 hours before hip replacement surgery, and then annually for several years afterwards. A total of 16 of these people developed osteolysis, while the other 10 did not.
It was found that even up to six years before they were diagnosed with osteolysis, the patients who developed the condition showed higher-than-average levels of two biomarkers – one was a connective tissue protein called alpha CTX, which is involved in the body's resorption of bone, while the other was the immune response protein interleukin 6, which is involved in inflammation.
"We are hopeful that early biomarkers for implant loosening will alert surgeons to be especially vigilant in their follow-up of at-risk patients and may eventually lead to treatments delaying or avoiding the need for revision surgery," says Sumner. "Perhaps even more intriguing is that the two biomarkers we identified also differed before surgery among patients who eventually developed peri-implant osteolysis and those who did not, supporting the concept that other researchers have proposed of genetic risk factors for loosening."
A paper on the research was recently published in the Journal of Orthopaedic Research.
Sources: Rush University, Wiley