Had CMC fusion surgery on my right thumb due to an injury about 30 years ago...it took about 18 months to get full motion back, but like I said, it was due to an injury...hopefully techniques have improved since then. After fusion surgery, that joint is no longer able to move, so the other joints have to make up for it by moving more. Rehab to make the others stretch took a while. I do have full movement now, and only a couple of scars to brag about.