A Single Intraarticular Injection of Platelet-Rich Plasma on Pain and Physical Function in Patients With Ankle OA

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