Radiation to Prevent Abnormal Bone Growth after Total Hip Replacement

Radiation treatment is used for more than just cancer. It also helps prevent a condition called heterotopic ossification( HO). HO is an overgrowth of bone that is not malignant. It's also known as myositis ossificans.

Some patients receiving a total hip replacement are at risk for HO. Preventing this problem is a goal after surgery. The best way to do this is with radiation. Using the lowest dose while still preventing HO is the focus of this study.

Patients were divided into two groups. One group got 500 cGy (centigray) while the other group had 1,000 cGy. Radiation can cause hardening of the tissues. It can also keep the bone from growing around the new implant. So researchers are looking for the lowest dose that works while still preventing HO. The results of this study show that 500 cGy is effective in preventing HO without causing other problems from the use of radiation.

But does everyone having a hip replacement need radiation? No, just patients at increased risk for HO. This includes patients who've had HO before and patients who have other bone problems such as ankylosing spondylitis or bone spurs in the spine. Past studies suggest that the type of surgery and the way the implant is put in can make a difference, too.

Is 500 cGy the lowest dose needed to prevent HO? Researchers don't know yet. This is the first study to try the use of 500 cGy. Bone growth around the implant wasn't a problem with this dose. A larger study is needed to confirm these results before trying an even lower dose.



References: Douglas E. Padgett, MD, et al. The Efficacy of 500 CentiGray Radiation in the
Prevention of Heterotopic Ossification after Total Hip Arthroplasty: A Prospective, Randomized, Pilot Study. In The Journal of Arthroplasty. September 2003. Vol. 18. No. 6. Pp. 677-686.