Last reviewed: September 29, 2026

Yes. A past PRP injection does not rule out a knee replacement. As with other knee injections, the question is timing.

No study has looked at PRP on its own. The best evidence comes from a large insurance database study that grouped PRP with other injections that contain no cortisone, and even with simply drawing fluid from the knee. Together, these were linked to more infection in the new joint when given within three months of surgery, and the risk was highest within the first month. Studies of knee injections in general point the same way. In one, the higher risk lasted up to about six months.

The authors suggested that the needle itself, not only what is injected, may play a part. That idea has not been proven.

The evidence has limits. It comes from records, not trials, so it shows a link rather than proof of cause.

In general:

  • Tell your surgeon about any PRP or other injection in that knee, and when it was given.
  • If surgery is already scheduled, ask before getting another injection in that knee.
  • The longer the gap between an injection and surgery, the lower the risk appears to be.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

  • Shahzad H, et al. Does a Simple Needle Stick From a Preoperative Knee Aspiration or Non-Steroidal Injection Influence Total Knee Arthroplasty Infection Risk? A Retrospective Database Analysis. J Arthroplasty. 2025. https://doi.org/10.1016/j.arth.2025.05.095
  • Avila A, et al. Intra-Articular Injection Receipt Within 3 Months Prior to Primary Total Knee Arthroplasty Is Associated With Increased Periprosthetic Joint Infection Risk. Knee Surg Sports Traumatol Arthrosc. 2022. https://doi.org/10.1007/s00167-022-06942-3
  • Bedard NA, et al. The John N. Insall Award: Do Intraarticular Injections Increase the Risk of Infection After TKA? Clin Orthop Relat Res. 2017. https://doi.org/10.1007/s11999-016-4757-8

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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