In his presentation on “Platelet-rich Plasma (PRP) in Rotator Cuff Surgery: Good, Bad and Inconsequential,” at the 2012 annual meeting of the Arthroscopy Association of North America (AANA), Stephen C. Weber, MD, of Sacramento Knee & Sports Medicine, reviewed the available studies on PRP and rotator cuff repair and stated that so far the evidence does not demonstrate efficacy.
Among the investigations he reviewed was his own prospective, randomized, double-blinded study of patients undergoing rotator cuff repair, which found that the use of a platelet-rich plasma (PRP) fibrin matrix during surgery did not significantly improve clinical outcomes nor did it have a beneficial effect on perioperative morbidity or structural integrity. The results of the Level I study were initially reported at the 2011 AANA annual meeting.
Numerous anecdotal reports of favorable results from the use of PRP to treat injured athletes have increased awareness of the treatment among the public. Yet, Dr. Weber noted, little, if any, conclusive evidence exists to prove that PRP actually achieves the effects claimed for it.
Furthermore, he said, although PRP has been described as “safe,” largely because it is the product of the patient’s own body and because few reports show any deleterious effects, the use of PRP must be viewed as experimental at this time. “It is not without risk,” Dr. Weber said.
Infection is theoretically possible despite the protocol for sterile preparation. PRP is expensive, and insurance companies, which view it as an investigational product, generally will not reimburse for its use. It is not indicated for use in pregnant women, and recent reports of carcinogenesis associated with bone morphogenetic protein give cause for caution and scrutiny with the use of any growth factors, including those found in PRP.
For his study, 60 consecutive patients were randomized to either receive a platelet-rich fibrin matrix (PRFM) product, prepared using a commercially available system and the patient’s own blood, or nothing. “PRFM has the seeming appeal of creating a product with structural integrity that allows for gradual elution of the growth factors,” Dr. Weber said.
Pre- and postoperative range of motion (ROM), UCLA scores, and simple shoulder test (SST) results were recorded. Surgery was performed by two fellowship-trained surgeons using an arthroscopic, single-row technique (Fig. 1).
Based on a power analysis, a sample size of 30 patients in each group was needed to identify a 20 percent difference in perioperative pain scores, Dr. Weber said. Visual analog pain scores (VAS) were obtained upon the patient’s arrival in the recovery room and 1 hour postoperatively. SST and ROM measurements were taken at 3, 6, 9, and 12 weeks postoperative. Postoperative MRI scans were interpreted by the surgeon and by an independent, blinded fellowship-trained surgeon. Final evaluations were made at 1 year, and all patients were followed for at least 1 year.
Neither group had any complications such as infection, stiffness, or bleeding. Mean surgical time was longer for PRFM group (83.28 ± 17.13 minutes) than for the control group (73.28 ± 17.18 minutes) (P < 0.03).
Parenteral narcotic use was not significantly different between the groups.VAS scores for the PRFM group were actually slightly higher, both upon entry into the recovery room and at 1 hour postoperative, Dr. Weber said, but the differences were not statistically significant.
“Despite the promise of the basic science, we were unable to demonstrate improvement in perioperative pain management, functional recovery, or structural integrity with the use of PRFM,” he said. Instead, the preoperative size of the tear was the most important variable in postoperative integrity of the rotator cuff.
The variability factor
Dr. Weber said that one of the major difficulties in working with and assessing PRFM is the variability of the PRFM created by each manufacturer’s system, variability from patient to patient, and even variability in an individual patient from day to day. Patients have widely differing levels of growth factors in PRP prepared in similar fashion.
“This is consistent with our own inability to obtain a product with reasonable structural integrity using the same centrifuge protocols in different patients,” he said. Noting that PRP has been used for a variety of different problems, he said, “The biologic goals of resolving tendinopathy and improving structural integrity of repairs are very different, and it may be unreasonable to expect one product to do both well.
“Given the cost and risks associated with the use of PRFM, it is difficult to recommend its use at this time,” he concluded. “The reason for the failure of PRFM to fulfill its promise is unclear. Perhaps the biggest problem is the lack of data on how best to use PRP products clinically.”
Coauthors with Dr. Weber (DePuy, Sport Medicine and Arthroscopy Review, Journal of Shoulder and Elbow Surgery, Techniques in Shoulder and Elbow Surgery, Archives of Orthopaedic and Trauma Surgery,) are Jeffrey I. Kauffman, MD (Ferring Pharmaceuticals, Bristol-Myers Squibb, Stryker, Smith & Nephew, Zimmer); Carol Parise, PhD (no data available); Stephen Katz, MD (Genzyme, GlaxoSmithKlein); and Sophia J. Weber (no data available).
Terry Stanton is senior science writer for AAOS Now. He can be reached at email@example.com
- Despite the widespread publicity and use of PRP in clinical practice, scientific evidence has not demonstrated its efficacy.
- PRP is expensive and its use is not risk-free.
- This prospective, randomized study found no benefit from PRP in rotator cuff repair.
- More knowledge is needed about timing of application and dosing with PRP.