Animal evidence for hyaluronic acid efficacy in knee trauma injuries. Review of animal-model studies

IntroductionIntra-articular injections of hyaluronic acid (HA) could have potential interest in therapy of acute knee trauma injuries, but few results are available in humans.ObjectiveWe reviewed the literature for animal studies of intra-articular HA injections after knee trauma injury to determine the interest of human clinical research into and/or use of such injections for knee trauma.MethodsSystematic literature search on MEDLINE for studies involving animal models of osteoarthritis created by acute knee trauma injury, with HA injections beginning during the 2 weeks after injury.ResultsThe search revealed 14 studies with a high methodological quality: 7 related to meniscus injury, 3 ACL injury, 1 combined ACL–meniscus injury and 3 cartilage injury. The animal models were rabbits in 10 studies. Four studies demonstrated positive effects and 3 moderate effects of intra-articular HA injection for meniscus injury; 1 positive effects and 2 no effect for ACL injury; 1 positive effects for combined ACL–meniscus injury; and 2 moderate effects and 1 no effect for cartilage injury.ConclusionsWith a high strength of recommendation, intra-articular HA injections in animal models with meniscus injury improved the healing process and/or had a protective role in articular cartilage, a slightly protective role in ACL injury animal models and low or no effect on healing in articular cartilage injury animal models.