Yes your tendons tighten up to give you less range of motion, so that you do not rub the bones together. It is the bodys way of handling the pain by compensating. You will also notice that you will start putting weight on the other leg for longer and then kicking the hip out and then comes the limp. The next 6 months you will probably see alot of regression of muscles because of the arthritis, it is just what happens when you cant walk. I was having issues just standing in one place, leaning over on the other side. You will know when it is time, just plan ahead for the surgery finacially and with appointments. I do not regret waiting until I could not take it any more, but I am so thrilled that I got the surgery. I feel like I have a life again, I walk without pain, I am biking with the kids, I have so much ROM, and no pain at night. I feel normal.
I am still working on stretching my tight tendons out, but I am now at nearly normal range of motion and I am nearly 3 months (August 11th). Best of luck with you and your decisions.