By Kenneth L. Cameron, PhD, MPH, ATCOctober 18, 2012
WEST POINT, N.Y. (Oct. 18, 2012) -- The John A. Feagin Jr. Sports Medicine Fellowship program here received a $750, 000 grant to continue research in preventive medicine; specifically preventing Anterior Cruciate Ligament, or ACL, injuries through the use of biomarker research.
In their initial study, the research team including, Lt. Col. Steven Svoboda MD, Lt. Col. Brett D. Owens, Dr. Travis Harvey, Dr. Patrick Tarwater, Dr. William Brechue, and Dr. Kenneth Cameron, co-authored a research paper pertaining to "The Association Between Serum Biomarkers of Cartilage Turnover and Subsequent Anterior Cruciate Ligament Rupture." Their work was recognized by the American Orthopaedic Society for Sports Medicine with the 2012 O'Donoghue Sports Injury Research Award.
"If we can identify people predisposed to ACL tears, one day we may be able to prevent injuries before they occur," said Svoboda, director, John A. Feagin Jr. Sports Medicine Fellowship, and the head physician for the Army football team.
Individuals who tear their ACL are seven to eight times more likely to develop post-traumatic osteoarthritis in their knee following injury. Those who injure their ACL are also substantially more likely to experience osteoarthritis at a much younger age than the general population. One study reported that 51 percent of female soccer players who had torn their ACL developed osteoarthritis in their knee by the age of 31.
Svoboda recognized that a significant challenge in treating patients at risk for post-traumatic osteoarthritis is the ability to identify the initiation and progression of this debilitating condition earlier in its clinical course.
According to Svoboda, "we currently rely on standard x-rays to diagnose osteoarthritis following ACL injury; however, the condition does not generally show up on x-ray until the disease is in its advanced stages. As a result, a significant window to intervene and potentially alter the clinical course of post-traumatic osteoarthritis is lost."
To address this problem, Svoboda initiated a series of studies, funded by a research grant from the Orthopaedic Research and Education Foundation, to examine changes in four biomarkers of cartilage turnover and metabolism following ACL injury.
Biomarkers are substances that can be collected and measured in blood and urine. The advantage of most emerging biomarkers for osteoarthirtis is that they may be less costly than other methods (e.g., magnetic resonance imaging), and they show potential as being sensitive to early molecular changes in disease.
Additionally, biomarker levels may change with joint injury, indicating an alteration in joint metabolism and possibly the initiation of post-traumatic osteoarthritis.
In their initial study, the research team, examined changes in several biomarkers over time, from pre-injury to the post-injury state, in a group of ACL injured patients and a group of uninjured control patients matched for gender, age, height, and weight. They found that the change over time in three of the four biomarkers studied was significantly different for the ACL injured patients when compared to the control subjects.
According to Cameron, "this suggests that cartilage turnover and metabolism was altered following injury in the ACL injured cases when compared to the uninjured matched controls."
The results of this study were presented at the 2011 American Orthopaedic Society for Sports Medicine, or AOSSM, annual meeting where the research team received the best scientific poster award for the meeting.
During their initial study the research team observed notable differences between the ACL injured cases and the uninjured control subjects at baseline, prior to ACL injury.
According to Svoboda, "we expected that the two groups (Control and Injury) would be similar at baseline (i.e. pre-injury) but would be divergent at follow-up (post-injury). Surprisingly, we found that the cases and controls differed both in their pre-injury state, as well as, in the change in biomarker levels over time."
To assess the magnitude of the association between pre-injury biomarker levels and the subsequent likelihood of ACL injury the research team conducted additional analyses and the findings of this work were presented at the 2012 AOSSM annual meeting where the research team received the O'Donoghue Sports Injury Research Award, which is the society's highest award for clinical research.
"The results of the study suggest that pre-injury concentrations for three of the four biomarkers studied may also be predictive of subsequent ACL injury risk," Svoboda explained.
This may be due to pre-injury differences in movement patterns (biomechanics) or genetics, but further prospective research is needed to answer these questions.
Leveraging these award winning preliminary studies, the research team at Keller Army Hospital recently received a research grant from the Congressionally Directed Medical Research Program's Peer Reviewed Orthopaedic Research Program to continue their work. The grant will provide approximately $750,000 over a three year period to prospectively study changes in the four original biomarkers studied, as well as additional biomarkers that may be important in identifying acute changes in cartilage metabolism following ACL injury.
Svoboda and the research team hope that their research will someday allow orthopaedic surgeons to identify individuals who are at high risk for post-traumatic osteoarthritis much earlier following ACL injury so that effective interventions can be developed and implemented to mitigate the impact of this disease on physical function and quality of life.