How do I explain my absence from work on a resume?

Here’s the situation. I had to take time off for a health issue. Because of the difficulty in finding insurance to pay for the procedure I was off a fair amount of time. I was out a total of 15 months before being OK’d to go back to work, now I’m looking and haven’t found a good way to explain it. I did study for two additional certifications (Network+ and Security+) and I’m healthy enough to do what I was doing before. How do I let potential employers know why without them worrying that my past health issue could become a liability?

FYI, I have arthritis and had hip resurfacing surgery. I can take care of things without a problem, unless my future job expects me to be carting 8 or 10 PCs uphill or something.