Efficacy and Safety of a Single Intra-articular Injection of Platelet-rich Plasma on Pain and Physical Function in Patients With Ankle Osteoarthritis—A Prospective Study

Ankle osteoarthritis (OA) can cause disabling symptoms, and some patients prefer to be treated with minimally invasive procedures. The aim was to evaluate the efficacy and safety of a single intraarticular injection of platelet-rich plasma (PRP) for patients with ankle OA. In a prospective study done in a university-affiliated tertiary care medical center, 44 patients with symptomatic ankle OA for at least 6 months were recruited. Patients received a single injection of PRP (3 mL) into symptomatic ankles. The primary outcome was the change from baseline in the visual analog scale (VAS) pain (0-10 cm) at 6 months. Secondary outcomes included the Ankle Osteoarthritis Scale (AOS) score, American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle score, single-leg stance test (SLS), rescue analgesics consumption and patient satisfaction. Thirty-nine participants (88.64%) completed the study. Significantly improvement in the VAS and AOS was noted at 1-, 3-, and 6-month follow-ups (p < .001). The mean VAS pain decreased significantly from 4.1 ± 1.7 at baseline to 2.2 ± 1.9, 1.7 ± 1.5, and 1.8 ± 1.6 at 1, 3, and 6 months (p < .001). The mean total AOS score reduced by 1.5, 2.2, and 2.1 from baseline respectively postinjection (p < .001). The mean AOFAS hindfoot-ankle score improved from 80.3 points at baseline to 87.2, 91.6, and 89.7 points at 1, 3, and 6 months (p < .001). SLS tests improved significantly (p < .001) at each follow-up. Acetaminophen consumption dropped significantly (p < .001) and no serious adverse events occurred. The study showed promise for a single intraarticular injection of PRP in the treatment of ankle OA.