How long does PRP injection take to work for a knee cartilage injury?

PRP is placed inside or around the knee according to the suspected source of pain. It is intended to support the local healing environment; it does not instantly restore a damaged cartilage surface. Soreness during the first part of recovery can make the knee feel worse before the response is clear.

The outlook varies with the size and location of the cartilage injury, other knee damage, swelling, alignment and activity demands. Clinicians may look for less swelling, improved range of motion, easier stairs and better tolerance of strengthening rather than relying on pain alone.

Use the activity and medication instructions supplied by the treating clinician. Avoid impact, deep loaded bending and twisting until your knee is ready. Physiotherapy may restore motion first, then build thigh and hip strength and gradually reintroduce impact. A symptom diary can show whether walking, stairs or exercise is improving between reviews.

Seek prompt advice for increasing redness, warmth, drainage, fever or severe pain after the injection. Urgent assessment is needed for a locked knee, sudden inability to bear weight, marked swelling or a new cold or discoloured foot. Arrange follow-up when symptoms remain unchanged or repeatedly flare with ordinary activity.

Where is the cartilage injury and what else is affecting my knee? Which activities are safe now? When should physiotherapy progress? What finding would show that another treatment needs consideration?