WESTON, Fla. -

Doctors are now using imaging to customize knee replacement for patients.

Judy Mirman loves playing fetch with her dog, but knee problems began to rob her of that joy.

"I was afraid to walk in areas that weren't flat. I thought it was just going to collapse," said Mirman. "You just don't want to do anything. Your life changes, and when it changes that drastically, you have to do something about it."

Mirman decided to consider knee replacement surgery.

"Knee replacement traditionally has been that you shave the ends of the bone free of the diseased cartilage," said Dr. Preetesh Patel with the Cleveland Clinic Florida.

The surgery is often done with off-the-shelf instruments, but now doctors are using imaging to model a knee specifically designed and custom fit for each patient.

"Through that modeling process, we're able to create instruments that fit directly onto the patient's bone during the surgery that allows us to make the cuts in the bone specifically and customized for that patient," said Patel, "so, it's really a custom fit knee replacement."

The process takes the guesswork out of surgery, and allows for a better outcome.

"By the time the patient gets to the operating room, we know the size of the implants, we know exactly what alignment it should be put in, and we know exactly what rotation to place those components," said Patel.

Mirman was walking without pain a few weeks after surgery.

"I have a strength in my leg I'd forgotten. It's wonderful. It's a whole new feeling," said Mirman.

A traditional knee replacement can last up to 15 years but doctors believe improve techniques, like imaging, can double that time frame.

The custom fit procedure can only be done for patients who have not already had a knee replacement surgery.