Does epidural cause long term back aches?

i had an epidural for both my babies and i did suffer from back pain, but it was only for a few months after the delivery. in the first case, i had a back ache for about 6 months and in the second deliveyr i had a backachae for about 2 months. but it did not come back again. check this link which also says that even though some people suffer from back pain after an epidural, it is mostly caused due to other factors http://www.livestrong.com/article/262868-bad-long-term-side-effects-of-an-epidural/