There is a great profusion of medical information available for free on the Internet, and a lot of it is good. Yet even good information may not be completely useful to the reader who may not know if it is trust worthy. By contrast, there is also a lot of information of medical information available for sale that is produced by well known authors and organizations, though not always for free.

This volume aims to be both free and accurate.

To ensure medical accuracy, all of the material was reviewed by the section editors, who are of course content experts of great renown. In addition, each chapter was reviewed by an expert who was not involved in the creation of the material. These reviewers were asked to read the chapter with one overriding goal in mind: to detect errors. The reviewers were then asked to " certify " the chapter as a reasonable presentation of the topic without any glaring mistakes in content. We are grateful to our reviewers, listed below:

• Fractures of the Growth Plate was reviewed by JonSchoenecker MD PhD.
• Fractures of the Upper Extremities was reviewed by AnthonyRiccio MD.
• Fractures of the Lower Extremities was reviewed by YingLi MD.
• Non-Accidental Trauma / Child Abuse was reviewed by MartyHerman MD.
• Musculoskeletal Infections was reviewed by JuliaSanders MD.
• Lower Limb Deformity was reviewed by Ray Liu MD.
• Foot Deformities was reviewed by B. David Horn MD.
• Clubfoot was reviewed by Vincent Mosca MD.
• Developmental Dysplasia of the Hip was reviewed by SalilUpasani MD.
• Legg-Calve-Perthes Disease was reviewed by Rob MurphyMD.
• Slipped Capital Femoral Epiphysis was reviewed by MichelleS. Caird MD.
• Adolescent Idiopathic Scoliosis was reviewed by MichaelGlotzbecker MD.
• Early Onset Scoliosis was reviewed by Lindsay Andras MD.
• Scheuermann’s kyphosis was reviewed by Jeff Sawyer MD.
• Down Syndrome was reviewed by Ken Illingworth MD.
• Osteogenesis Imperfecta was reviewed by Paul Sponseller MDMBA.
• Muscular Dystrophy was reviewed by Judson KarlenMD.
• Spina Bifida was reviewed by Colyn Watkins MD.
• Cerebral Palsy was reviewed by Keith Baldwin MD MPHMPST.
• Spinal Muscular Atrophy was reviewed by Brian Synder MDPhD.

The material was also reviewed by the following students from the Perelman School of Medicine at the University of Pennsylvania:

Joshua T. Bram Ariana T. Meltzer-Bruhn Olivia G. Cohen William Cohen Benjamin F. Frost Lindsay Grossman Jacob C. Harris William H. Huffman Lori Jia

David E. Jimenez Mitchell A. Johnson Nicolas Pascual-Leone Mariia Alibekova Long Christian A. Rodriguez Margaret K. Tamburro Thaddeus K. Woodard Siddharth Yarlagadda Kelly C. Zochowski

(And yet a necessary disclaimer)

Peer review notwithstanding, this being 21st century America, we must include the following Disclaimer, similar to those found in works produced by well known authors and organizations.

This material was prepared for educational purposes only. We therefore disclaim any and all liability for any damages resulting to any individual which may arise out of the use of the material presented here. We similarly disclaim responsibility for any errors or omissions or for results obtained from the use of information contained here.

This material is not intended to represent the only, nor necessarily best, method or procedure appropriate for the medical situations discussed, but rather is intended to present an approach which may be helpful to others who face similar situations. We cannot can take any responsibility for the consequences following the application of any of the information presented here.

The information provided here cannot substitute for the advice of a medical professional. Even if a given statement is completely true in the abstract, it may not apply to a given patient.

The information we offer is provided "as is" and without warranty of any kind.