Anterior cruciate ligament (ACL) repair in the knee healed faster and stronger in canines whose surgery included an experimental collagen- and platelet-rich gel material, according to a recent study funded in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

A research team headed by Martha M. Murray, M.D., of Children's Hospital of Boston showed that animals treated using this plasma scaffolding had significantly greater filling at the injury site at both 3 and 6 weeks than control animals. Strength tests showed treated animals had significantly greater increase in strength after 6 weeks (40 percent increase in strength vs. 14 percent increase in strength). The study team included members from Beth Israel Deaconess Hospital in Boston and Vanderbilt University Medical Center in Nashville.

The results are especially promising, since they point to a better type of ACL repair than the current "gold standard," ACL reconstruction, where a ligament or tendon graft is put in place of the ACL. Physicians believe that preserving the patient's own ACL (if it becomes possible) would likely better protect the mechanics of the knee. ACL reconstruction often yields less than perfect results.

Why are researchers looking at biological scaffolding materials for ACL repair? Such material is essential for the ligament to heal at all, because the ACL does not have the ability to heal the way other tissues do. Most types of tissue in the body can repair themselves, but the ACL cannot form a stable bridge between the torn ends of the tissue, which is needed as a framework for other cells to invade and reinforce over time. The collagen/platelet-rich plasma scaffold developed and tested by this research helps to provide this important framework.

The research team recommends that future studies more closely resemble clinical situations, such as a complete ligament tear and increased lag time between injury and treatment. They also suggest studies that focus on longer term aspects of this type of treatment; the technique's effectiveness for different extents of ACL injuries; and testing the technique's effectiveness for meniscus and cartilage damage.

Additional funding for the study came from the Vanderbilt University Medical Center Discovery Grant Program, the National Football League Medical Charities Program, the Orthopaedic Research and Education Foundation, and the Orthopaedic Foundation of the Children's Hospital of Boston.

The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services' National Institutes of Health, is to support research into the causes, treatment and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about NIAMS, call the information clearinghouse at (301) 495-4484 or (877) 22-NIAMS (free call) or visit the NIAMS Web site at

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Murray MM, et al. Use of a collagen-platelet rich plasma scaffold to stimulate healing of a central defect in the canine ACL. J Orthop Res 2006;24:820-830.

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