Three years ago I had my left hip replaced. Everything went very well. Now I’ve got a problem with extra bone growing in the muscles around the joint. Does this happen very often?

You are describing a problem called heterotopic ossification (HO). Sometimes it’s called myositis ossificans. It can occur anywhere in the body but seems to affect the hips most often.

Trauma to the muscle tissue is a major risk factor for HO. Patients who have decreased hip motion before the total hip replacement (THR) are also more likely to develop HO.

It can happen in almost any patient after THR. Reported incidence ranges from 15 to 90 percent.