Platelet-rich plasma (PRP) injection into the lateral ankle ligaments for treatment of acute lateral ankle sprains significantly expedites athletes’ return to sport, according to data presented at the AAOS Annual Meeting in New Orleans. Study patients treated with PRP returned to sport an average of 11 days sooner, compared to patients treated with saline injection.

Although most ankle sprains heal with conservative treatment, many patients continue to be symptomatic and chronic ankle instability may develop, according to study presenter Michael C. Stanton, MD. This can be particularly devastating in high-level athletes. The use of orthobiologics such as PRP injections, which may lead to an earlier return to sport, are therefore becoming increasingly popular.

Prospective, blinded study
Between July 2010 and March 2013, Dr. Stanton and his fellow researchers prospectively identified patients who had sustained a first-time ankle injury within 7 days of their visit to his clinic. The 37 athletes who met the inclusion criteria were between ages 18 and 45 and desired to return to sport. Patients with fracture or osteochondral injury, prior history of an ankle injury, malalignment of the foot or ankle, or known coagulopathy were excluded.

Patients were randomized to a PRP treatment group (n= 26) or placebo group (n= 11), based on a 2:1 randomization for both grade II and III ankle sprains. Patient demographics were as follows:

• PRP: 20 males, 6 females; mean age = 23 years; grade II = 20; grade III = 6
• placebo: 8 males, 3 females; mean age = 21 years; grade II = 8; grade III = 3

“We designed our study to establish a protocol for using PRP in a blinded fashion for treatment of acute grade II and grade III lateral ankle sprains. Patients were blinded to the treatment method, as were all physical therapists and athletic trainers working with the patients,” Dr. Stanton explained. “Our primary outcome was a patient-reported return-to-sport time following either an injection of PRP or saline.”

All patients underwent a peripheral blood draw. Blood samples from the PRP group were centrifuged and the PRP isolate was then injected into the patients’ anterior talofibular ligament and calcaneofibular ligament. Patients in the placebo group were injected with 5 mL of saline. Afterward, all patients were offered a brace, physical therapy, and allowed to weight bear as tolerated.

Results
Patients in both groups completed the Foot and Ankle Ability Measure (FAAM) and Short Form 36 (SF-36) validated outcome measures at initial visit, and 10 to 20 days, 6 to 8 weeks, and 6 to 12 months after injection. Return to sport time was recorded by the patient.

Overall, 28 patients (PRP = 19; placebo = 9) reported return-to-sport times. The mean time for return to sport was 16.5 days (range: 1–44 days) in the PRP group and 26.3 days (range: 9–63 days) in the placebo group (P = 0.02). Subgroup analysis of grade II and grade III sprains revealed no significant differences between the PRP and placebo groups with respect to return–to-sport time. In addition, the differences in FAAM and SF-36 outcome measures between the two groups did not reach statistical significance at any follow-up.

“At this point in the study,” Dr. Stanton concluded, “our results show a statistically significant shorter return-to-sport time in the PRP group as compared to the saline group. Our study supports the use of PRP as a treatment modality for acute lateral ankle sprains in athletes when an expedited return to sport is desired, such as with an in-season injury.”

Dr. Stanton’s coauthors of “Earlier Return to Sport after Lateral Ankle Ligament Injury Treated with Platelet-Rich Plasma” are Russell LaFrance, MD; Brian D. Giordano, MD; Ilya Voloshin, MD; John P. Goldblatt, MD; and Michael D. Maloney, MD.

Disclosure information: Dr. Giordano—Arthrex, Inc.; Dr. Voloshin—Acumed, LLC; Zimmer; Arthrex, Inc; Arthrocare; American Shoulder and Elbow Surgeons; Arthroscopy Association of North America. Dr. Maloney—Arthrex, Inc; Telephus. Drs. Stanton, LaFrance, and Goldblatt —no conflicts.

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

Bottom Line

• Although conservative treatment is effective most of the time, many patients with ankle sprains continue to have symptoms and chronic ankle stability develops.
• This prospective, blinded study involved 37 patients with first-time ankle injuries (acute grade II and grade III lateral ankle sprains) who received either platelet-rich plasma (PRP) or saline injection.
• Patients in the PRP group had a mean return-to-sport time 10 days shorter than those in the saline group (16.5 days vs. 26.3 days), but no significant difference in FAAM and SF-36 outcome measures.