Braden Fleming’s group recently published two studies related to ACL injury and repair.  In a systematic review of the literature, they evaluated the association between oral contraceptive pill (OCP) use and ACL injuries. Because young women are particularly vulnerable to anterior cruciate ligament (ACL) injuries, investigation of hormonal factors involved may help to mitigate risks.  “Limited Evidence Suggests a Protective Association Between Oral Contraceptive Pill Use and Anterior Cruciate Ligament Injuries in Females: A Systematic Review,” published in Sport Health, suggests OCP use may reduce the risk of ACL injury, but the studies examined were limited by small sample sizes, heterogeneity, and methodological concerns. Kathleen Samuelson ‘16 ScM (Biotechnology) ‘17 was the lead author, and collaborators included Ethan Balk from the School of Public Health and Erika Sevetson from Health and Information Services.

The study “Magnetic resonance measurements of tissue quantity and quality using T2* relaxometry predict temporal changes in the biomechanical properties of the healing ACL“ sought to establish a mathematical model to predict the structural properties of the healing anterior cruciate ligament (ACL) over a 24-week healing period following ACL repair in Yucatan minipigs. Because of its non-invasive nature, magnetic resonance (MR) imaging is an attractive method to probe the relationship between MR signal properties and the structural properties of the native ACL or ACL graft in vivo. MR T2* relaxation time was used as an indication of tissue “quality” because it is related to collagen fibril organization, water content, and local inhomogeneities. Their model, which accounted for both the short and long T2 * relaxation times over the healing period, were in close agreement to the measured values suggesting that they may be applied in future studies to estimate the structural properties of ACL repairs in vivo. Postdoctoral researcher Jillian Beveridge was the first author of the study. Edward Walsh from the Department of Neuroscience and Jason Machan from the Rhode Island Hospital Biostatistics Core also contributed to this work.

Fleming also contributed to the article, “Synovial inflammation plays a greater role in post-traumatic osteoarthritis compared to idiopathic osteoarthritis in the Hartley guinea pig knee“ published in BioMed Central Musculoskeletal Disorders.