Treatment of sports injuries has improved through sophisticated rehabilitation programs, novel operative techniques, and advances in biomechanical research during the past two decades. Despite considerable progress, treatments remain limited due to poor healing capacity for anterior or posterior cruciate ligament rupture, central meniscal tear, cartilage lesions, and delayed bone fracture. New biological approaches seek to treat these injuries with growth factors to stimulate and hasten the healing process. Gene therapy using the transfer of defined genes such as those encoding growth factors represents a promising way to deliver therapeutic proteins to the injured tissue. Tissue engineering, which may eventually be combined with gene therapy, offers the potential to create tissues or scaffolds for regeneration of defects occurring from trauma.