If hip or knee replacement is planned or being considered, discuss any proposed injection into that joint with your surgical team before booking it. The injection type and timing can affect the plan. A short-term attempt to reduce pain should not create an avoidable conflict with surgery or leave two teams working from different information.
This question is different from whether PRP helps a particular painful joint. It is about fitting an elective procedure into a wider treatment pathway. Do not assume an injection is safe close to surgery because it uses your own blood, or that evidence about corticosteroid injections automatically proves the same risk for PRP.
Tell both teams before a date is agreed
Give the injection clinician the joint, proposed operation, surgeon's details and any likely surgery date. Tell the surgical team exactly what injection is being considered and where it would be given. If you do not know the product, ask before either team makes a decision.
Include previous injections, approximate dates and what was injected. A record saying 'knee injection' may omit important information. If another clinic performed it, ask for the procedure record rather than relying on memory of a brand name or the colour of a syringe.
Discuss a diagnosis-led assessment with The London PRP Clinic. Make the planned operation clear in the first enquiry. Confirm whether an injection assessment is appropriate at all while the surgical plan is being settled.
What does the steroid evidence say?
AAOS OrthoInfo advises delaying replacement surgery in a joint for at least three months after a cortisone injection in that joint to minimise infection risk. This is a specific patient-facing recommendation about cortisone and joint replacement, not a universal rule for every injection and every type of surgery.
The AAOS clinical guideline on periprosthetic joint infection describes limited evidence for a time-dependent association between injections before arthroplasty and infection. It also notes uncertainty about the exact interval and limitations in the underlying studies. That distinction matters: an observed association and a practical surgical recommendation should not be turned into a precise prediction of an individual's risk.
Do not calculate a surgery date yourself from a general article. The surgeon needs to consider the exact procedure, injected product, joint, dates and your health, alongside the team's current policy.
What if the proposed injection is PRP?
PRP is prepared from a sample of your blood and is not a corticosteroid. However, that difference does not establish that there is no infection risk, no effect on the operative pathway or no need to tell the surgeon. An injection still involves entering tissue or a joint, and the evidence relevant to timing may be incomplete.
Ask whether there is evidence for PRP in your diagnosis and whether the likely benefit would change the decision to proceed with replacement. A promise to 'avoid surgery' is not an appropriate substitute for discussing advanced joint disease and the surgical opinion you have already received.
The steroid timing recommendation should not be relabelled as a proven PRP rule. Equally, absence of a precise PRP interval should not be sold as proof that an injection can be done immediately before surgery. The teams should agree the plan rather than asking you to bridge the uncertainty alone.
Clarify what problem the injection is meant to solve
Explain your priorities: sleep, walking, work, travel or managing symptoms while a decision is made. Ask what alternatives are appropriate while waiting and whether an injection is likely to provide enough useful benefit to justify its cost and any change to timing.
Pain can arise from more than one structure. If the diagnosis or source of pain is uncertain, ask whether further examination or a specific investigation would help before adding another procedure. A new injection should not replace review of a changing clinical picture.
Make the dates and responsibilities visible
Ask for a written account of what has been agreed, including who has reviewed the timing and whether the operation date needs confirmation. If surgery moves, or another injection is proposed, tell both teams again. An earlier discussion may no longer cover the changed plan.
Ask what happens if the surgeon recommends waiting and how an unused treatment booking would be handled. Confirm assessment, procedure and cancellation fees before paying. Do not purchase a course on the assumption that the operation will be postponed or avoided.
Contact The London PRP Clinic to discuss the assessment route. Bring imaging reports, the surgical letter and previous injection records. A useful review may support an injection, a non-injection plan or a return to the surgical team; it should not promise one answer in advance.
When symptoms need a different route
A hot, markedly swollen joint, fever, feeling seriously unwell or a sudden major loss of function needs prompt medical assessment rather than a routine injection appointment. If you already have a replacement joint and develop new pain, tell the service: evaluation of a prosthetic joint is a different pathway from treating ordinary arthritis in a native joint.
Evidence and scope
General adult information, not surgical clearance or a personal waiting interval. Sources checked 6 November 2026. The AAOS guideline below was published in 2019; its evidence limitations are retained here. The OrthoInfo advice concerns corticosteroid injection, not proof of PRP timing safety.
AAOS OrthoInfo: cortisone shots and future joint replacement.
AAOS: diagnosis and prevention of periprosthetic joint infection guideline.