What they all said. I've had both knees replaced. When I had to have the second one done in November 2010, I was partway through 24/7 nursing/rehab of a post-spinal surgery, 100-lb Bernese Mtn. Dog.
Unfortunately, that knee replacement surgery almost cost me my life: I threw a clot (right outside lower leg) on the table, lost a unit (maybe two?) of blood--and had been unable to donate my own, and developed a Baker's cyst in the popliteal region of the right knee so that even the Continuous Passive Motion machine hurt my knee!
Fortunately (?), we had moved our bed downstairs so that DDog and I were just a few feet from one another. DH helped both of us for the time he had off work, and then I was right back to 24/7 care for DDog.
My quilts fell by the wayside, my crocheting too; I didn't know how to knit yet (learned in May 2011). No one said a thing, not at Christmas 2010 and not even at Christmas 2011, when I was still thrown for a big loss by the unexpected death of DDog due to an opportunistic infection.
People will be understanding of your situation; they were of mine. The quilts that have been delayed are important ones: nephew's graduation quilt; niece's marriage quilt that I had hoped to finish before her 1st anniversary (September 2011); sister's quilt in a Celtic-inspired design; MIL's quilt from late FIL's shirts (MIL herself is in fragile health). But I couldn't stand up to do the cutting.
Now I can, but now I have a rescue dog who needs intensive care. The quilts have come back to the top of the list, together with the knitting/crochet projects, to the point where I've had to develop a spreadsheet to make sure none of them get short-changed or forgotten!
And, like others have said, if anyone gives you static, consider the possibility that he/she isn't "knit-worthy." That'll make your list shorter, too.