I had an ACL repair two years ago. My doctor says the knee is "good to go." But it feels unsteady to me like it's going to give way at any time. How can this be?

It's not uncommon for tests to show a stable knee while the patient has symptoms of pain, swelling, and giving way. The opposite can happen, too. The patient may feel great and start playing sports again while the doctor is finding evidence of instability.

Why the difference? Scientists aren't sure. It may be the ligament is fine, but other parts of the knee aren't working normally yet. There are receptors that sense the joint's position and movement. Perhaps these have been damaged and aren't "firing" properly yet.

Some studies suggest the muscles aren't coordinated normally after injury and surgery. This is called motor control. You may need a rehab program to address these specific issues now that the ligament is stable. Talk to your doctor about your concerns and ask about returning to rehab for a short time.