“…Thirty-nine studies [1, 4, 6-8, 11, 13, 14, 16, 18-20, 23, 27, 29, 30, 34, 38, 40, 41, 45, 53, 54, 56, 61, 64, 67, 69, 72, 74, 77, 79, 81, 83-85, 89, 94, 96] [54], older than 6 months [5], between 6 and 18 months old [95], younger than 18 months [43], and younger than 24 months [87]; an anterior approach for patients 12 months or older [57,69]; and no operative treatment at all before 9 months of age [7].…”