Platelet-rich plasma (PRP) has been reported to be an effective treatment for knee osteoarthritis (OA). The application in ankle OA has rarely been investigated. The aim was to evaluate the efficacy and safety of a single intraarticular injection of PRP for the treatment of patients with ankle OA.

Methods: In a prospective study, patients with symptomatic ankle OA for at least 6 months were recruited. Patients received a single injection of 3-ml of PRP into symptomatic ankles. The primary outcome was the change from baseline in the visual analog scale (VAS) pain score (0-10cm) at 6 months. Secondary outcomes included the Ankle Osteoarthritis Scale (AOS) score, American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot score, single leg stance test (SLS), use of rescue analgesics and patient satisfaction. Adverse events were recorded during the study.

Patients were followed at 1, 3 and 6 months postinjection .

Inclusion Criteria:

• Age of at least twenty years
• Ankle pain lasted for at least 6 months, despite conservative treatment or inability to tolerate the side effects of medications
• Ankle radiographs taken within 6 months (reviewed by the senior author) were equivalent to grade 1-4 osteoarthritis by the Kellgren Lawrence grading system
• Average ankle pain of > 3cm on a 10-cm visual analog scale (VAS)
• Radiological evidence of bilateral ankle osteoarthritis was accepted if VAS pain in the contralateral ankle was < 3 cm
• Normal activity level, not bedridden or confined to a wheelchair, able to walk 30 meters without the aid of a walker, crutches or cane
• No use of physical therapy or changes in shoes or orthotic devices during the study

Exclusion Criteria:

• Pregnancy or lactation in women
• Lower leg trauma in a location other than within the ankle
• Previous surgery involving the spine, hip or knee
• The presence of an active infection of the ankle
• Surgery involving the affected ankle within the previous 12 months
• Intraarticular steroid or hyaluronate injection in the ankle within the previous 6 months
• Treatment with anticoagulants or immunosuppressives
• History of rheumatoid arthritis, gout, or other inflammatory arthropathy
• The presence of visual or vestibular impairments
• Poor health status (such as a neoplasm, diabetes mellitus, or paresis) that would interfere with the assessments