The Use of Biologic Agents in Athletes with Knee Injuries.

Biologic agents are gaining popularity in the management of bony and soft tissue conditions about the knee. They are becoming the mainstay of nonoperative therapy in the high-demand athletic population. The most well-studied agents include platelet-rich plasma (PRP) and stem cells-both of which have shown promise in the treatment of various conditions. Animal and clinical studies have demonstrated improved outcomes following PRP treatment in early osteoarthritis of the knee, as well as in chronic patellar tendinopathy. Early clinical evidence also lends support for PRP in the augmentation of anterior cruciate ligament (ACL) reconstruction. Research investigating the role of biologic agents in collateral ligament and meniscal injuries is ongoing. Studies assessing the utility of stem cells have shown encouraging results in the setting of osteoarthritis. Unfortunately, strict regulations by the FDA continue to restrict their application in clinical practice. A major limitation in the interpretation of current data is the significant variability in the harvesting and preparation of both PRP and stem cells. As the volume and quality of evidence continue to grow, biologic agents are poised to become an integral component of comprehensive patient care throughout all orthopedic specialties.