Blood Test Predicts ACL Tear Probability

Can a blood biomarker predict the likelihood of an ACL injury? It can, according to a discovery by Lt. Col. Steven Svoboda, an orthopedic surgeon at West Point’s Keller Army Community Hospital. Svoboda is also head physician for the Army football team. According to an August 11 article in Stars and Stripes by Seth Robson, Svoboda and his research team came upon their finding while they were studying four “biomarkers” to see if they were associated with ACL injuries.

Svoboda looked at blood taken from 90 cadets entering West Point, half of whom tore their ACLs while at the academy. Robson quotes Svoboda as saying, “We expected to see post-injury differences in biomarkers but were astonished that the biomarkers showed measurable differences months or years prior to injury.” Svoboda presented his findings last month at the 2012 annual meeting of the American Orthopaedic Society for Sports Medicine.

The research team found that cadets with elevated levels of three of the four biomarkers were more likely than others to tear their ACLs, while those who had elevated levels of one of them—a biomarker derived from collagen in joints—were 19 times more likely to sustain an injury than cadets with normal levels.

“If we can identify people predisposed to ACL tears, one day we may be able to prevent injuries before they occur, ” Svoboda said. The academy takes blood samples from cadets when they enter West Point. Researchers now plan to analyze the samples taken from each cadet who injures an ACL during the next three years, estimated to be about 100 cadets, and compare the levels of biomarkers in their blood with others who do not injure their knees.

Svoboda believes that his research has implications for the study of post-traumatic arthritis because about half of those who tear an ACL go on to develop osteoarthritis. “The real scourge for the military is a much higher incidence of arthritis even of service members in their upper 20s and early 30s, ” he said. “The rates are clearly higher than in the civilian population.”

Robson noted that a study published last year in the journal Arthritis and Rheumatism reported that military doctors diagnosed 108, 266 cases of osteoarthritis in 1998-2008. Arthritis rates were 26% higher in service members ages 20 to 24 than in the general population. Troops over age 40 were more than twice as likely to develop the ailment as civilians, according to the study.