I did a quick Google search and it does seem that lupus, especially when treated with prednisone, seems to have a higher incidence of spontaneous tendon ruptures. Are you on prednisone? For a while? It's not a common occurrence, but it definitely happens!
Here is one article synopsis, and you can read the full thing if you want to...
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1237870
Another article popped up in my search about 2 women with SLE in their 40's who had ruptured Achilles tendons and both had been on prednisone at the time, both had a delay in diagnosis, but both had surgery to repair it. Have you seen a top notch specialist about your achilles tendon rupture to be sure it can't be fixed? Seems like an especially important tendon to have working to me!
In your shoes, I would probably get the surgery. Especially if the doctors are recommending it (get a second opinion if you want extra reassurance/information). It may not bother you much now, but it sounds like it will get worse over time and there could come a time when it is too late to fix.
Here is one article synopsis, and you can read the full thing if you want to...
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1237870
Another article popped up in my search about 2 women with SLE in their 40's who had ruptured Achilles tendons and both had been on prednisone at the time, both had a delay in diagnosis, but both had surgery to repair it. Have you seen a top notch specialist about your achilles tendon rupture to be sure it can't be fixed? Seems like an especially important tendon to have working to me!
In your shoes, I would probably get the surgery. Especially if the doctors are recommending it (get a second opinion if you want extra reassurance/information). It may not bother you much now, but it sounds like it will get worse over time and there could come a time when it is too late to fix.