Lead Sponsor: Washington University School of Medicine

Collaborators: Mayo Clinic, University of Iowa, Boston Children's Hospital, University of Colorado, Denver, Children's Hospital of Eastern Ontario, University of Wisconsin, Madison, University of Texas Southwestern Medical Center, CHU de Quebec-Universite Laval, William Beaumont Hospitals, Ottawa Hospital Research Institute, San Antonio Military Medical Center, Twin Cities Orthopedics, Regents of the University of Michigan

Lead Sponsor: Texas Scottish Rite Hospital for Children

Collaborators: Children's Hospital Los Angeles, Mayo Clinic, Children's Hospital of Philadelphia, University of California, San Francisco, Columbia University, Children's Healthcare of Atlanta, Montefiore Medical Center, Oregon Health and Science University, Boston Children's Hospital, Children's Hospital Medical Center, Cincinnati, Universitätsklinikum Hamburg-Eppendorf, Kaiser Permanente, Johns Hopkins University, Children's National Research Institute, Children's Hospital Colorado, Alberta Children's Hospital, Rady Children's Hospital, San Diego, Connecticut Children's Medical Center, Ann & Robert H Lurie Children's Hospital of Chicago, Baylor College of Medicine, Seattle Children's Hospital, Nationwide Children's Hospital, British Columbia Children's Hospital, University of Oklahoma, NYU Langone Health, Uppsala University, Oslo University Hospital, Shriners Hospitals for Children, Alfred I. duPont Hospital for Children, Le Bonheur Children's Hospital, University of Sao Paulo General Hospital, Children's of Alabama, Gillette Children's Specialty Healthcare, Kasturba Medical College, OrthoCarolina Research Institute, Inc., Seoul National University Childrens Hospital, University Hospital Southampton NHS Foundation Trust, Hospital Infantil Universitario Niño Jesús, Madrid, Spain, San Jorge Children's Hospital (Puerto Rico), University College Dublin, Tianjin Children's Hospital, University Hospital Schleswig-Holstein, University of Haifa, Medical University of Lodz

Intervention / Treatment: PROCEDURE: Multiple Epiphyseal Drilling, PROCEDURE: Osteotomy + Long Term Non-Weight Bearing, PROCEDURE: Osteotomy + Short Term Non-Weight Bearing, PROCEDURE: Nonoperative Observation