Previous advances in orthopaedics have centered largely on surgical techniques. But biologics—including platelet-rich-plasma (PRP), bone marrow aspirate (BMA), and stem cells—are emerging as therapies due to their regenerative properties. An overview of the use of these techniques in the treatment of the rotator cuff, meniscus, cartilage, and osteoarthritis appears in the February Journal of the AAOS (JAAOS). To learn more, AAOS Now spoke with principal author Adam W. Anz, MD.

AAOS Now: Biologics have been used for some time in medicine. What is their role in orthopaedics?

Dr. Anz: In my opinion, biologics represent the next frontier in orthopaedics. During the past 30 years, particularly in sports medicine, the focus has been on the use of the arthroscope, which revolutionized how we performed treatments. I believe biologics will revolutionize the next 30 years.

We’re still figuring out exactly what all these different biologics are and how we are going to use them—things like PRP, BMA, and adult stem cells that can be derived from fat or blood. We’re still learning about them and feeling our way, as well as dealing with regulatory constraints. Biologics are going to change what we do and how we do it—it’s very exciting.

From a sports medicine standpoint, biologics will play an important role in treating rotator cuff, meniscal, and cartilage injuries. We’ll also be using biologics to enhance bone and wound healing. Right now, for example, PRP is a growth factor therapy that can be used to augment healing after a partial tear of a tendon. BMA can isolate platelets, and mesenchymal stem cells derived from a patient’s own bone marrow can be used to help manage symptoms of knee arthritis.

Stem cells—cells that are one generation matured from germ layer cells—have four capabilities that make them unique (Fig. 1). First, they can reproduce. Second, they can differentiate, meaning that they can become different types of cells such as cartilage, bone, or fat cells. Stem cells can also mobilize in situations of angiogenesis, and finally, they can release growth factors and other cell signaling molecules. These capabilities make stem cells fascinating because they are needed to best repair tissues or heal different injuries.

AAOS Now: Are each of these technologies equally important?

Dr. Anz: I don’t think any one of them is more important or warrants more study than the others. PRP, BMA, and stem cells are like arrows in a quiver. In some instances, PRP will be the right arrow to use; in a different situation, BMA might be more appropriate.

From a regulatory standpoint, PRP and BMA are the arrows we can use right now. The FDA has made it clear that it is going to take a tough stance on stem cells, no matter what the harvest site—and rightfully so. It will be exciting, however, once we can use them.

AAOS Now: How close are these biologic technologies to becoming a reality for the general orthopaedist?

Dr. Anz: PRP and BMA are already available to the general orthopaedist. However, there is no standard preparation for PRP, and different preparations have different concentrations of platelets. That’s frustrating because it makes it extremely difficult to study PRP and prove its worth. Unfortunately, the lack of data represents a major hurdle for widespread adoption.

The acceptance of a PRP classification system is another hurdle. Although work toward such a system has begun, the many different PRP preparation techniques can be confusing for the general orthopaedist.

BMA is not widely used because it can be expensive. In addition, although BMA can be harvested in the clinic using a local anesthetic like lidocaine, the procedure involves a learning curve. As a result, most patients are brought to the operating room.

Just as the general orthopaedists need to become comfortable using these techniques, the orthopaedic research community needs to provide the data that clearly outline the time and indications for their use. For example, we need clinical trials comparing PRP to BMA in the treatment of knee arthritis. This is something my institution is working on.

AAOS Now: What do orthopaedic surgeons need to keep in mind with respect to biologics?

Dr. Anz: I encourage orthopaedic surgeons to give researchers time to put together the studies that will prove the value of biologic technologies. Be patient. I’m convinced that biologic studies are worthwhile because they will result in better treatments for conditions—like cartilage injuries—that have frustrated orthopaedic surgeons for years. Every day, the general orthopaedist struggles to treat cartilage injuries, because we don’t have a great solution for it. Those are the conditions that researchers who work with biologics are targeting

Dr. Anz’s coauthors of “Application of Biologics in the Treatment of the Rotator Cuff, Meniscus, Cartilage, and Osteoarthritis” are Joshua G. Hackel, MD; Erik C. Nilssen, MD; and James R. Andrews, MD. A link to the article can be found here.

Disclosure information: Dr. Anz—Arthrex, Ceterix Orthopaedics, MicroAire Surgical Instruments LLC, Celling Biosciences; Dr. Nilssen—Arthrex, ETEX, Medartis, ASE Medical, Tenex, CorMatrix, ETEX, FUSE Medical; Dr. Andrews—Biomet Sports Medicine, Bauerfeind, Theralase, MiMedx, Physiotherapy Associates, Patient Connection, Connective Orthopaedics, FastHealth Corp.; Dr. Hackel—no conflicts.

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org