Persistent or uncontrolled hypothyroidism can cause joint afflictions. However bilateral knee joint stiffness can be due to osteoarthritis, rheumatoid arthritis, bursitis or tendonitis. Hence it is important to consult an orthopedic specialist. To start with both the knees need to be X-rayed, and RA factor and antinuclear antibody (ANA) levels detected in blood. If nothing is detected then MRI may be done. Take care!
"Could this be related to the problem in finding the correct dose?"
- Possibly, it depends on the individual, other health issues.
Hypo thyroid will magnify other health problems, so the cause can be more than one.
Regulating thyroid only by TSH is most common, but not the best. You need to see T4 and T3, by geting what is called the Free T3 and Free T4 test. Low T3 levels (even low but in range) are most contributing to muscle and joint pain associated with hypothyroid.
So this is also worth looking at. It can make a difference. For further questions go to the thyroid disorder forum here.
To simplify things, if someone is experiencing symptoms caused by low thyroid, there will be other symptoms as well, not just one. The list is huge, but most people are familiar with some of their individual thyroid symptoms after a while.