I had a slipped capital femoral epiphysis at age 15, 3 pins were put in and about a year later the were removed, I am now 26 years old, I have severe hip pain all the time, I to have got use to the pain, along with the help of pain meds which I have been on for all this time.
The pain was bothersom but I was still able to work okay and live life okay, until latley when the hip got much worse, to make a long story short on june 12th 2006, just 9 days from today, I am having my total hip replacement on my left hip, i'm told that I will fee much better. However I am scared out of my mind, i'll let you know how it goes, if anyone out there has had the replacement let me know how it went.
To answer your question it was not a big deal to get my pins removed, just don't let the docotors shoot cortozone into your hips all the time, it can make them worse. I don't think you can keep the pins in and have a replacement.
Goodluck