How effective is PRP injection for patellar tendinitis?

Patellar tendinitis, also called patellar tendinopathy, affects the tendon connecting the kneecap to the shinbone. PRP is prepared from your blood and placed near the affected tendon. The proposed aim is to support a more suitable local healing response and make loading more tolerable. It does not immediately restore tendon capacity, and pain relief alone does not prove that the tendon is ready for jumping. A clinician should also check whether the pain comes from the tendon rather than the kneecap joint, a bursa or another structure. The [Patellar Tendinitis](/conditions/patellar-tendinitis/) guide gives additional condition background.

A useful plan usually increases tendon load in stages: comfortable isometric work, controlled strengthening, faster movements and eventually jumping or sport drills when strength and symptoms allow. Avoid sudden spikes in running or jumping while the tendon is irritable. If PRP is chosen, ask how long heavy activity should pause and when the loading programme restarts. Use pain, next-day stiffness and function to guide progression with your physiotherapist. Details about preparation and aftercare are covered in the [PRP Injection](/treatments/non-surgical-orthopedics/prp-injection/) guide.

Seek prompt assessment after a sudden snap, a new gap in the tendon, inability to straighten the knee, marked swelling or difficulty taking weight. Following an injection, report increasing warmth, redness, drainage, fever or rapidly worsening pain to the treating service.

Is the patellar tendon definitely the pain source? What loading stage am I at now? What change would justify PRP, and how will we measure it? When can I safely resume jumping or sport?