Six months ago, my doctor reconstructed my torn ACL using a piece of the tendon and bone from below my kneecap. I completed physical therapy and still feel like the knee isn’t going to hold me. My doctor says the surgery was a success and the knee is as “tight,” if not tighter, than before my injury. If that’s the case, why do I feel so unsteady on the leg?

There are several tests physicians use to check the integrity or strength of the repaired ligament. One of these is the pivot-shift test, in which the doctor applies pressure to the lower leg just below the knee. A “tight” joint will not shift or move with this test.

Your sense that the leg is not steady or stable enough to hold you may be caused by muscle weakness. When the replacement tissue for the torn ligament is taken from below the kneecap, the quadriceps muscle on the front of the thigh may lose strength. You may need some additional strengthening exercises. Contact your physical therapist for a follow-up evaluation.