By: 25 October 2011

Michael A. Mont, MD, et al.
In The Journal of Bone and Joint Surgery. September 15, 2010. Vol. 92-A. No. 12. Pp. 2165-2170.

Adults who have a painful hip from osteonecrosis of the femoral head often have the same problem in the other hip but it is “silent” or asymptomatic. In other words, there’s no pain. If it wasn’t for the telltale signs on X-ray, the affected individual wouldn’t even know there was a problem.

The first goal in treating symptomatic (painful, limiting) osteonecrosis of the femoral head is to save the bone. The second goal is to keep function while relieving pain. But what about that asymptomatic hip? Is treatment needed at all? What’s the natural history (i.e., what happens over time if it is NOT treated).

Some surgeons advocate what is referred to as careful neglect. This is a watch-wait-and-see approach. Some of the phrases used to defend this position include no sense in muddying up the waters or best to leave well enough alone. But there are just as many orthopaedic surgeons who say head it off at the pass. In other words, treat it early and prevent the problem from getting much worse.

The voice of reason and experience comes through loud and clear on this one: study patients who have this problem and see if there are any predictive factors of disease progression. Those patients who have significant risk factors for progression of disease without treatment should be treated early in the course of their disease development.

It is possible that the question of how (and when) it’s best to treat asymptomatic osteonecrosis of the femoral head has already been answered but lies buried in the medical literature. That’s why these surgeons reviewed all of the articles published on this topic up to the middle of 2008. This type of study is called a systematic review.

Information collected from the studies that were high enough quality to be part of the review included patient age, how long they were followed, location and size of the bone lesion, and use of certain medications (e.g., steroids) or excessive alcohol. They also looked at personal medical history of lupus, sickle cell disease, kidney disease, kidney transplantation, and human immunodeficiency virus (HIV).

By combining all the hips studied into one group, they found that 394 of the total 664 hips developed symptoms and eventual collapse. That’s a percentage rate of about 59 per cent (more than half, almost two-thirds). The destruction took place over a period of time from as little as two months and as long as 20 years.