Virtual Surgical Planning, 3D-Printing and Customized Bone Allograft for Acute Correction of Severe Genu Varum in Children
, Leonardo Frizziero 1,*, Gian Maria Santi 1, Alfredo Liverani 1, Dante Dallari 3, Leonardo Vivarelli 3, Giovanni Luigi Di Gennaro 2, Diego Antonioli 2, Grazia Chiara Menozzi 1,2, Alessandro Depaoli 2, Gino Rocca 2 and Giovanni Trisolino 2,*Round 1
Reviewer 1 Report
The manuscript attempts to present a case report about virtual surgical planning (VSP), 3D printing, and customized bone allograft for acute correction of severe genu varum in children. The paper is very interesting with explanations of the importance and details of the VSP in Infantile Tibia Vara (ITV or Blount disease) treatment. No doubt, in this pediatric case the 3D digital reconstruction of the anatomical region of the patient was analyzed from different points of view for able to plan, simulate the level of correction, design patient-specific implants and predict the final outcome. It was very important that no significant deformations or mechanical problems of the cutting guides were observed after the proximal elevation osteotomy and the dome osteotomy on both sides of the knees. The present study underlines the role of this innovative step-by-step process, using an in-hospital low-cost 3D-printing Point-of-Care (POC), and matching the precisely shaped graft to the patient unique anatomy. Besides this, the authors described several advantages and disadvantages of these procedures too. The experience of the authors with this pediatric case can offer new studies for other scientists in the future.
I would like to suggest just minor corrections from my side and the most important details I have underlined in the comments. Please, find the attached document describing a few of these minor issues noted in the manuscript.
Comments for author File: 
Comments.pdf
Author Response
We thanks the reviewer for the comments.
Please see the attachment for our response.
Author Response File: Author Response.pdf
Reviewer 2 Report
It's a very interesting paper. the 3D planning is a good and sure method to prepare the correct osteotomy to reduction of the deformity. Moreover, I prefer Hexapod external fixator assisted by computer to reduced such deformities but I appreciate this study
Author Response
We thank the reviewer for this comment.
Currently there is initial evidence that double elevating osteotomies are the best choice of treatment for late presenting ITV. Concerning the method of correction, acute correction by osteotomies or gradual correction by external fixator are both suitable options for treating severe ITV in children. Advantages of gradual correction include higher versatility and potential better outcomes, expecially when limb lenghtening must be combined with the correction. Disadvantages include the risk of pin side infections and overall poor compliance to the external fixator, especially in children. Additionally, computer aided correction by hexapod, is more accurate than traditional external fixators, but requires a steep learning curve and it is far more expensive. Both advantages and disadvantages must be considered in the choice of treatment, along with the experience and preference of the surgeon. We added a final consideration about these aspects in the "Discussion".
