Abstract
Dear Editors,
I read the paper by Castaneda et al. about LCP with great interest. In the paper's introduction section, the authors state that “many of the concepts regarding the disease have not evolved in almost a century.” This is quite unfortunate indeed, and I fully agree with them. The study is well conducted, and the paper is well written. However, I would be less affirmative in stating that femoral varus osteotomy (FVO) achieves similar results to non-operative treatment in Herring B and C. Their findings may not necessarily support this conclusion.
The fact that both treatments lead to almost similar results, even slightly worse in the surgically treated group, do not mean that one should observe severely involved Perthes hips and never take them to surgery, be it pelvic or femoral. Important clinical and radiological information is necessary to support their statement and is missing from their paper. Although classification according to Caterall and/or Herring certainly has a prognostic implication, other factors play a major role in determining outcome and are certainly used for decision making by a vast majority of pediatric orthopedic surgeons around the globe. The Iowa hip score and the Stulberg classification were used in this study to determine the outcome at final follow-up, but no information is given to the reader concerning preoperative clinical and radiological differences (other than the Herring classification) between both groups, mainly those related to hip motion, hinge abduction, and the severity of femoral head extrusion or subluxation. Severity of involvement should not only be decided based on the height of the lateral pillar, as we all know. Two hips classified as Herring C may behave completely differently and lead to different outcomes following operative or non-operative treatments.
In fact, one could assume that cases where FVO was performed were clinically and radiographically initially more severe with obvious and progressive lack of containment compared to cases where non-operative management was decided upon and undertaken. From another angle, why did the physicians who chose to treat Herring C hips nonsurgically decide to do so, and why did those who operated on similar hips (based only on the classification) decide to do so? In my perspective, viewed from this angle, a similar outcome in both groups could rather be seen as being in favor of performing FVO in severely affected and subluxed hips, as it may improve the hip situation to a point where it becomes similar to those hips that do not need surgery.
This is an issue that I was just discussing with some colleagues who had the same impression after reading the manuscript, and I wanted to share it with you and the authors. I am sure that they have conducted and worked out this study so well that the information I am asking for can be easily made available, maybe as a basic criteria for further studies and publications on such a mysterious and controversial disease.
Once again, I would like to congratulate the authors for this long-term, well-conducted and well-written study, and I thank them in advance for their answer.
Sincerely,
Ismat Ghanem