How effective is PRP injection for knee osteoarthritis?

Knee osteoarthritis involves changes in the joint surfaces and surrounding tissues. PRP is made from your own blood and injected into the knee with the aim of influencing pain and local inflammation. Any benefit is measured by practical changes such as walking, stairs, sleep and exercise tolerance, not by a claim that the joint has been rebuilt. Stiffness, alignment, muscle strength, body weight, activity demands and the extent of joint change can all affect the experience. The treatment is therefore a shared decision rather than a guaranteed outcome. See the [Knee Osteoarthritis](/conditions/knee-osteoarthritis/) overview for condition context.

Start with an assessment of pain pattern, movement, strength and function. A clinician may combine activity modification, physiotherapy, strengthening, mobility work and weight-management support where appropriate. If PRP is discussed, ask which symptom it is intended to target, how improvement will be reviewed and what other options remain. Plan for a gradual return to exercise after the procedure and follow the specific aftercare advice given. The [PRP Injection](/treatments/non-surgical-orthopedics/prp-injection/) page explains the treatment in broader terms.

Get prompt medical review for a newly hot and red knee, fever, sudden inability to bear weight, a major injury, a locked joint or rapidly increasing swelling. After an injection, worsening pain with redness, drainage or fever should be reported to the treating service without delay.

What features of my osteoarthritis make PRP reasonable? Which functional change will we track? How does it fit with exercise therapy and other treatments? What symptoms would mean the diagnosis or plan needs review?