Watch Caitlin’s video of her experiences with hip replacement.

Ask Caitlin Ryan to name her favorite subject in school and she doesn’t hesitate – it’s dance.

“Right now we are doing hip hop. We’ve done world dance and ballet,” Caitlin says. “It’s amazing because I’ve never been able to really dance like there’s nothing wrong.”

Caitlin may be forgiven if dancing shoes hold more appeal than schoolbooks this year. Because while her classmates spent their summer vacations going to the swimming pool and the beach, Caitlin, age 11, was undergoing hip replacement surgery.

Caitlin is one of an estimated 300,000 children in the U.S. who have juvenile arthritis, or JA. At age 3, she was diagnosed with juvenile rheumatoid arthritis, or JRA, the most common form of arthritis among children. This autoimmune disease, which affects an estimated 50,000 children, causes the body to attack its own joints and organs. The symptoms ebb and flare, often without warning or explanation. Additionally, it dramatically affects physical mobility and may lead to blindness.

“When they first said it was arthritis I was a little bit relieved it wasn’t cancer,” says Caitlin’s mother, Colleen Ryan. “But the more I learned about it, the more devastating the diagnosis became because her [case] is one of the most severe. She has it in every joint.”

It’s not known what causes the condition, and there is no known cure. It goes into remission for some children but lasts into adulthood for many more.

Caitlin’s rheumatologist, Andreas Reiff, MD, Associate Professor of Clinical Rheumatology at the Children’s Hospital Los Angeles, says 80 to 85 percent of JRA patients respond well to medication and find relief.

Special Challenges

Dr. Reiff says these newer medications are so effective that the number of joint replacement surgeries his hospital has performed on pediatric patients has dropped dramatically. Since 2000, Children’s Hospital Los Angeles has only done eight to 10 joint replacement surgeries compared with the 15 to 18 the hospital did yearly until 1999.

That’s good news, because joint replacement poses special challenges for younger patients.

Their bones are smaller, so it’s often difficult for doctors to find replacement parts that are the right size. Components sometimes have to be custom designed and built for children.

Additionally, replacement joints wear out over time, meaning that most who have their joints replaced at young ages will likely need a second or even third surgery later in life. For each subsequent surgery, less of the patient’s natural bone remains, making it an increasingly difficult and complicated procedure.

What’s more, replacing joints destroys the growth plates in bones, which stalls a child’s development and sometimes limits height. 

The Only Option

Despite all these problems, experts say there are still cases, like Caitlin’s, when joint replacement remains the only option.

“There are still kids that don’t respond, can’t afford the treatments or don’t do well with the treatments and their arthritis progresses and they still need surgery,” says Mark Figgie, MD, chief of the surgical arthritis service at the Hospital for Special Surgery in New York.

From the age of 3, Caitlin tried medication after medication, but still endured hospital stays and arthritis flares that caused her to miss school. She went into an unexplained remission for a few months in 2008, then relapsed. Her pain was increasingly debilitating and between March 2008 and March 2009, measurements and X-rays taken by doctors showed her left leg shortened about an inch as her hip essentially crumbled and turned on itself.  

“Her hip bone was dying from the damage and all the prednisone over the years,” Colleen says.

The pain got so bad, Caitlin, a middle schooler, began taking Vicodin daily, just to get through her classes. She had terrible anxiety, couldn’t sleep and was having problems in school. She was seeing a pain management team, having acupuncture, getting herbal remedies and massage – all to no avail.

“It was a nightmare,” Colleen says, “I would have given anything to take the pain away from her.”

Caitlin’s parents and doctors tried to put surgery off as long as possible, but it soon became clear they had run out of options.

“I did not feel like there was any choice. As much as I wanted to wait and I wanted her to be older and you worry about how long the joint will last, there was no choice to let her continue living in chronic pain like that,” Colleen says.

Caitlin had her left hip replaced on August 11, 2009.

Night and Day Difference

“It’s night and day. I have a different daughter now,” Colleen says. “So much of the darkness we had last year, it was all pain,” she says.  “Every part of our lives got better.”

Caitlin’s doctors hope her new joints will last 10, 15, maybe even 20 years, but nobody knows for sure. For now though, they say her newly replaced hip is working very well.

“In general it sounds scary that this girl has one titanium hip,” Dr. Reiff says. “But on the other hand, this titanium hip allows her to be fully functional.”

Dr. Figgie estimates that nationwide, less than 1,000 juvenile arthritis patients a year require joint replacements. As a result, finding doctors who do the procedure and equipment suited for young children can be a challenge.

Dr. Figgie is in the process of putting together a multi-center study involving institutions that have experience with pediatric total joint replacements to gather data on patients and their surgeries.

“There’s a real interest in putting together registries for patients with juvenile inflammatory arthritis, and we’re trying to spearhead putting together more data on incidents and results of joint replacements in these patients,” he explains.

Colleen says that would be helpful for parents like her. “The information is not out there,” she says. “So it’s fortunate that there are not a lot of kids in this situation but frustrating for the ones that are.”

Before Caitlin was diagnosed with JRA at the age of 3, she was a tall child and doctors predicted she would grow to be about 5 feet 10 inches as an adult. Now her growth has slowed dramatically, to about one centimeter every two months. Her mother says Caitlin’s growth potential is likely limited long term due to a combination of joint inflammation, drug side effects and the hip replacement, which removed some of the growth potential at her hip growth plate.

But she is back on medications that for now have her arthritis under control. And this year she will lead her team, dubbed the Princess Parade, in the Orange County Arthritis Walk. It’s one of the top Arthritis Walk teams in the county and has raised more than $100,000 for the Arthritis Foundation. She is also the 2010 National Arthritis Walk Youth Honoree.

“I’m really excited about it. Especially with my new hip,” Caitlin says.

Facing the Future

More challenges likely lie ahead, however. Caitlin’s other hip, the right one, has started to hurt and her mom says that next summer she’ll likely need that hip replaced, too.

“We will do it sooner if she deteriorates quickly,” Colleen says. “We will not go back to the place we were before.”

For now, Caitlin is trying to enjoy just being a kid. That means indulging her love of shopping, the Jonas Brothers, the Twilight series and returning to the softball field.

“Before I had my hip replaced, they pulled me out of a lot of games and I had to have someone run for me,” she explains. “But I did a lot better after I got my hip replaced, and I was able to get back into it and not have a pinch runner,” she says. “So I’m starting again for the first time, and it feels really good.”

Looking ahead, she has dreams of being a fashion designer and holds out hope that one day, someone will find a cure for JRA.

“I’d tell other kids that have [JRA] to always keep your head up,” Caitlin says. “Someday they’re going to find a cure. So until then, keep your life going the way you want it to and you can find a way around obstacles in your life.”