Biomarker Can Make Diagnosing Knee Injury Easier, Less Costly

A recently discovered biomarker could help physicians diagnose painful meniscal tears, according to a new study.

A team of researchers led by Gaetano Scuderi, MD, of Stanford University School of Medicine, has confirmed that a particular protein complex appears in patients with painful meniscal tears. The finding, published in The Journal of Bone and Joint Surgery, could be used to prevent needless surgery and to save billions of dollars in medical-imaging costs.

Patients are generally advised to elevate and apply ice to the knee, and to take a break from physical activity that could aggravate the injury. These measures might not be enough, however, so patients can undergo a minimally invasive procedure, arthroscopic surgery, to trim away or repair the meniscus.

In the study, Scuderi and colleagues found that the biomarker appeared in the knee fluid of 30 patients who had suffered a painful meniscal tear. It was not present in the knees of 10 asymptomatic patients. The biomarker, a fibronectin-aggrecan complex, holds out the promise of allowing orthopaedists to quickly and accurately diagnose whether the source of a patient’s discomfort is a meniscal tear, as opposed to another type of injury or abnormality, simply by taking a sample of knee fluid. It could thus obviate the need for expensive medical scans and help to prevent surgery that does not address the true cause of a patient’s pain.

“The challenge is not identifying molecular markers of cartilage degeneration, dozens of which are now known,” said co-author Raymond Golish, MD, PhD, who recently completed a fellowship in spine surgery at Stanford. “The difficulty is in finding markers that correlate with painful injuries, as opposed to age-related degeneration that is painless. This study is a big step in that direction.”

Scuderi and his colleagues undertook the prospective study to validate their findings from an earlier study in which they first noted the presence of the protein complex in patients with torn menisci and knee pain.

The researchers are now running experiments to confirm that the biomarker does not show up in other types of knee injuries, such as ACL tears unaccompanied by meniscal tears. They also are studying whether the protein complex, which is implicated in knee inflammation, could serve as a therapeutic target. “We could envision several things, such as blocking the fibronectin and aggrecan protein fragments from coming together to form a complex, or interfering with the activation of white blood cells at the site,” Scuderi said.

Source: Stanford University School of Medicine