Animal studies reported positive results with the use of AM to treat osteoarthritis, cartilage defects, and tendon and ligament injuries. Few studies involving human participants also revealed favorable results with regard to the use of AM for the treatment of plantar fasciitis and osteoarthritis; however, these studies are industry-sponsored and employed small sample sizes. The unique mixture of a collagen-rich extracellular matrix, bioactive growth factors, and pluripotent stem cells may allow AM to become an effective treatment for MSK injuries. Although initial animal and human studies show promising results, variabilities regarding models (animal and human), pathologies, placental tissues, and methods of preparation, preservation, and delivery used limit the ability for comparison, analysis, and drawing of definitive conclusions. Thus far, no studies have evaluated the use of currently available AM products for the treatment of injuries sustained by soccer players.
Despite the current popularity of AM as regenerative therapy in academic research and potential use in clinical treatment in sports medicine, physicians should remain aware of the limited evidence available. Other barriers to research and use AM as a regenerative therapy include regulatory classifications based on the concept of “minimal manipulation” in biologic therapies. Minimally manipulated placental allografts are less regulated, less costly to study, and more easily commercialized. These products are not required to undergo FDA phase I to III trials prior to premarket approval. In 2000, the FDA position on all AM products falls into 2 categories. The first position states that AM that contains allogenic stem cells mixed with another drug that is micronized and/or cryopreserved is more than “minimally manipulated” and therefore categorized as “biologic” and would be subject to phase I to III trials. Dehydrated and decellularized AM, however, may meet the concept of minimal manipulation and is only approved by the FDA as a wound covering. Thus, any application of AM for the treatment of sports medicine pathology is not currently FDA-approved, considered off-label, not covered by insurance, and subject to out-of-pocket pay.30,31
CONCLUSION
With improvements in technology and portability, US has become an effective imaging modality for point-of-care evaluation, diagnosis, and continuous monitoring of many MSK injuries. Additionally, as a dynamic imaging modality, US allows for increased accuracy and efficacy when combined with minimally invasive procedures, such as diagnostic and therapeutic guided injections and percutaneous tenotomy, in the clinical setting; thereby decreasing the overall healthcare costs. PRP is proven to be a safe treatment for several MSK conditions, such as lateral epicondylitis, patellar tendonitis, and plantar fasciitis. Although PRP has been included in the standard of care in some areas, this technique may be predominantly athlete driven. Conflicting evidence with regard to return-to-play timeframes following PRP treatment for muscular injuries and poor evidence in conditions, such as Achilles tendonitis, have led to inconsistent indications for use, dose, and timing of treatment. Although early evidence of MSC therapy is promising, high-level evidence for MSC therapy is insufficient, despite its increased use among athletes. Thus far, no data are available regarding the outcomes of the use of amniotic products for the treatment of injuries among athletes. Furthermore, the preparation of amniotic products has many regulatory concerns. The authors advocate for continuous high-level research on regenerative medicine therapies to establish clinical efficacy and safety data.