Most patients find that their greatest improvement comes in the first three months after surgery. Gains in joint motion and strength help increase function. Walking speed and distance improve as well.
Sometimes patients improve more than they realize. Tests that measure their function and physical performance show better results than what they self-report.
Experts aren't sure why there is such a difference between actual and perceived results. It may be that different aspects of physical function are measured from one test to another. It's possible the tests used to measure recovery don't include the types of skill patients are hoping for.
Patients aren't always told what to expect during rehab and recovery. This could influence how outcomes are viewed. Studies show that maximum function after total knee replacement is reached right around the six to seven month mark. This can vary from patient to patient depending on general health and pre-operative status.
Those patients who have better function before surgery tend to end up with the best outcomes after surgery. Patients with the lowest pre-operative function make greater gains at first compared to less impaired patients. But their final results aren't as good.
It may be helpful to talk with your surgeon and/or your physical therapist. Find out what are realistic goals for your situation. You may be right on target but don't know it. Or there may be some additional steps you can take in the rehab process to get the maximum results you desire.