Corticosteroids and avascular necrosis of the femoral head

We agree with Allan Knight that avascular necrosis was reported long before corticosteroids were introduced and that it remains to some extent a disorder of unknown origin. There are cases of “idiopathic” avascular necrosis for which no precipitating or predisposing factor can be found. However, a multitude of clinical studies confirm that corticosteroids represent a risk factor for the development of this condition. In a previous study from our institution 63% of the cases of avascular necrosis were induced by steroid use.1 At present, corticosteroids remain the single most common etiological factor for avascular necrosis seen in our centre.

Only 3 of the 15 patients in our series had other risk factors for avascular necrosis.2 We included these patients in our article to illustrate the point that of the many patients who receive a short course of corticosteroid medication only a small percentage develop avascular necrosis. It is clear that some other predisposing condition or concomitant risk factor is responsible for the development of avascular necrosis.

We agree that short courses of corticosteroid therapy are widely used for life-threatening conditions. However, we do not feel that such treatment is appropriate in self-limiting conditions where it is of dubious benefit (e.g., in cases of poison ivy).

Our goal is not to “embolden lawyers” or increase the number of lawsuits. Rather, we are attempting to alert physicians to what we feel is strong presumptive evidence that some association exists between short-course steroid therapy and the development of avascular necrosis. There is much more to learn regarding this condition, and our series does not provide conclusive proof that there is a cause–effect relationship between the two. However, avascular necrosis is a crippling condition in young adults and the distressing number of cases that we have seen, and continue to see, following the use of steroid medication stimulated this report.