Patellar tendinitis — often called jumper's knee — is one of those injuries that earns its reputation for persistence. The pain settles just below the kneecap, shows up reliably at the start of activity, and tends to linger long after rest.

If you've been told your knee pain is related to "mucoid degeneration" of the patellar tendon, you've probably already noticed the gap between the MRI report and the advice that follows it. The report describes something precise — a tendon whose collagen structure has been replaced, in patches, by a gel-like mucoid substance, usually alongside disorganized fibers and increased signal on imaging.

Patellar enthesopathy, better known to most people as jumper's knee, tends to follow a frustrating pattern. You rest, the pain fades, you return to running or jumping, and within a few weeks the ache at the bottom of the kneecap is back.

You strained your quadriceps, your patellar tendon, or the whole extensor chain that straightens your knee, and the advice you got was some version of "rest a few weeks, ice it, do some physio, see how it feels." That advice isn't wrong.

If your knee pain sits right at the bottom of the kneecap, flares after jumping or squatting, and never fully settles no matter how much you stretch or rest, you've probably already heard the standard advice: ice it, rest it, strengthen the quad, maybe try eccentric squats.