Legg-Calvé-Perthes Disease is a loss of blood and subsequent death of bone tissue. Children are affected (boys more than girls). It affects the head of the femur (thigh bone) where the growth plate is located. This condition can result in hip deformity.
The author of this review article, reminds us that treatment early in the process gives the best results. But sometimes knowing what stage the disease is in can be difficult. By the time X-rays show a collapse of the lateral pillar, it may be too late for optimal treatment.
The lateral pillar refers to the outer one-third of the femoral head. Loss of height and a change in bone density cause the bone to collapse. Collapse of the lateral pillar is never seen on X-ray early in this disease.
Using the lateral pillar as a way to determine treatment and predict the results can only be done after the fact. And by then, it may be too late to save the shape of the hip.
The author concludes that the lateral pillar classification of Legg-Calvé-Perthes Disease cannot be relied upon to help direct treatment.
We still need some kind of scanning technique to identify the problem early and influence treatment choices. This may not be possible until imaging technology advances beyond what it is now.