Invasive surgery and long recovery times for orthopedic surgery are becoming a thing of the past. After years of extensive surgeries and painful recovery times, surgeons are now looking towards new nonsurgical management of orthopedic issues. The current nonsurgical treatment that everybody is talking about is platelet-rich plasma, or PRP.
PRP is an autologous derivative of blood, which singles out high concentrations of platelets and is loaded with many growth factors and cytokines. While it is clear from the buzz that PRP can be useful for orthopedics, there is some debate as to the best use of PRP in the orthopedic world.
PRP has been used to treat osteoarthritis, to repair fractures, and in ACL reconstruction. By first examining what PRP is made of, we can then examine how effective it is in treating these orthopedic issues.
PRP: What it is
First let’s look at what PRP is made of.
The most significant growth factors and cytokines in PRP are: platelet-derived growth factor (PDGF), transforming growth factor beta (TGF- B), fibroblast growth factor (FGF), insulin-like growth factor 1 (IGF-1), connective tissue growth factor (CTGF), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF). If you are not a doctor these things may sound like gibberish to you. So, to put things more simply, these growth factors and cytokines are essential for hemostasis, construction of new connective tissue, revascularization, cellular recruitment, and inflammation reduction after an injury.
Other components of PRP include fibrin, fibronectin, vitronectin, and thrombospondin; all of which are extremely important to the healing process. In addition, the optimal platelet concentration used in the PRP formula is between 3 and 5 times that of normal blood. Any more than that can have the opposite effect and slow the healing process.
PRP: Why and how it’s used
Now that we know the basic components of a PRP treatment we can focus on the purpose of this new technology as it relates to orthopedics.
According to the AAOS “the proposed function of PRP is to promote tissue healing by increasing extracellular matrix deposition, reducing pro-apoptotic signals, and minimizing joint inflammation”. The draw towards this kind of orthopedic injury treatment is obvious; it is easy to get your hands on, safe, adaptable, and can be used by athletes.
Although there are obvious benefits to this treatment, like less recovery time and no surgery, as with any new treatment there is a lack of long-term clinical justification. The PRP treatment is so new that there is a lack of uniform preparation, delivery, and dosing of the treatment. Because there are different ways that PRP can be prepared the final concentration of platelets can vary greatly. This means that the regenerative potential of the treatment also will be widely varied. Furthermore, there is no clinical consensus on the best way to prepare and deliver the treatment, which has caused much discussion on the true benefits of the treatment.
Osteoarthritis and PRP
Over 27 million people in the United States are affected by osteoarthritis. The condition accounts for over 50% of all non-steroidal, anti inflammatory drug prescriptions, and in 2011 was the second most expensive orthopedic condition seen in hospitals, totaling a staggering $15 billion dollars! Thus, it should come as no surprise that people began to look for other ways to treat such a widespread disease.
After many studies, examined intra-articular PRP injections, as a treatment of osteoarthritis, there were varied outcomes. One study demonstrated that short-term clinical trials could not conclude that intra-articular PRP injections were a good alternative for combating osteoarthritis. However, another demonstrated that these PRP injections could benefit adult and younger patients with mild-to-moderate knee osteoarthritis. In conjunction, this study also stated that more long-term research was needed to determine the benefits of PRP. Thus, the benefits of PRP for osteoarthritis are slightly inconclusive.
Fracture repair and PRP
As with any other new treatment, PRP injections were first tested in the lab before brought to clinical trial. In these preclinical trials PRP did show some osteogenic (bone regeneration) properties in some in vitro studies. However, a clinical study conducted with 76 patients there was no bone healing found when using PRP lumbar fusion. Furthermore, the presence of thrombin in the PRP formula was shown to actually decrease bone formation.
It can be concluded then that: the efficacy for bone formation due to PRP is inconclusive and needs more research.
ACL reconstruction and PRP
The very nature of an ACL tear dictates that the injury will have poor vascularity, and due to its intra-articular location it will be subject to synovial fluid proteases. In simpler terms, this means the environment for injury healing is extremely hostile.
Thus, many studies have been done using MRI to determine if PRP augmentation can aid in the healing process. Data from the Multicenter Orthopaedic Outcomes Network (MOON) determined that the use of PRP in ACL allograft reconstruction made no difference in patient-reported outcomes after a 2-year follow up. The results were the same with those who did receive PRP treatment and those who did not. However, there was some success shown in a study that applied PRP directly to the patellar and tibial bone plug harvest sites after ACL surgery. Studies showed that direct PRP application to the patellar and tibial sites led to better knee function and decreased patellar tendon gap following ACL reconstruction.
As an alternative to the more expensive orthopedic treatments, PRP or platelet-rich plasma has shown some promise. It has been mildly effective in treating osteoarthritis and ACL reconstruction healing, but showed less promise in fracture repair. However, in all cases it can be concluded that PRP as a widespread treatment needs more testing and desperately requires uniformity in development and delivery.