Key Insights On Platelet-Rich Plasma For Soft Tissue Repair
Achilles tendinosis or chronic tendinopathy is one of the most studied tendon injuries in regard to the use of PRP. A randomized control trial by de Vos and colleagues evaluated the effectiveness of injecting 4 mL of PRP into degenerated areas in the Achilles tendon using Doppler ultrasound guidance in comparison to a placebo saline injection.18 The authors found that both groups had similar improvement based on the Victorian Institute of Sports Assessment-Achilles (VISA-A) score and a similar rate of return to sports. However, the authors elected to inject both groups prior to the start of physical therapy.
Conservative treatment with physical therapy, especially eccentric exercises, is known to treat chronic Achilles tendinopathy effectively.19 So one might argue that the effect of PRP or the placebo would have been masked because most patients will likely respond favorably with the use of eccentric therapy.
Gaweda and co-workers evaluated the effectiveness of PRP on non-insertional Achilles tendinopathy.20 Fourteen patients (total of 15 tendons) had a 3 mL PRP injection under the guidance of ultrasound into the degenerated portion of the Achilles tendon. The study authors emphasized protected weightbearing for six weeks. Six patients received a repeat injection.
Patients were allowed to begin normal daily activities between six and 12 weeks after the injection, although sporting activities were discouraged at this time. Researchers evaluated patients with the American Orthopedic Foot and Ankle Society (AOFAS) scoring scale and the VISA-A scale. Both the AOFAS and the VISA-A scores improved significantly from 24 to 96 and from 55 to 96 at 18 months respectively. The authors also noted a decrease in fusiform thickening, peritendinous thickening, hypoechoic foci and intrasubstance tears.
A Closer Look At The Author’s Experience With PRP
I have treated 25 patients with Achilles tendinosis with PRP injections. All patients failed conservative treatment including immobilization and physical therapy. The PRP injection was an attempt to avoid formal surgical debridement of the Achilles tendon.
The patients received a 5- to 7-mL PRP injection in addition to undergoing a gastrocnemius recession. I performed the procedure with patients under a general anesthetic as a same-day operative procedure. I injected both within the tendon and between the tendon and paratenon.
The postoperative protocol involved two weeks of weightbearing in a protective cast boot as tolerated. Patients wore the boot for 24 hours per day during the first two weeks. At the two-week follow-up, the patients advanced into shoes as tolerated and continued to sleep in a night splint for the next four weeks. At six weeks post-op, I re-evaluated the patients.
The patients subjectively rated their improvement as 75 percent (16 of 25 patients), 50 percent (six patients) or 25 percent improvement (three patients). Patients who noted 75 percent improvement were allowed to advance activities as tolerated. For patients who noted 50 percent improvement, I performed another PRP injection. For those who had 25 percent improvement, I considered PRP unsuccessful and gave these patients the option of open Achilles debridement.
Sixteen of the 25 patients had 75 percent improvement or better, and returned to normal activities. Three patients had less than 25 percent improvement with PRP and all three went on to formal debridement. The remaining six patients had 50 percent improvement.
All patients with 50 percent improvement received a second PRP injection six to nine weeks after the initial surgery. I performed the second injection as an outpatient procedure with the patients under sedation. The patients wore a walking boot for seven days and were allowed to advance into shoes at that point.