Untreated Acetabular Dysplasia of the Hip in the Navajo: A 34 Year Case Series Followup.Schwend, Richard M. MD*; Pratt, William B. MD**; Fultz, Jeffrey DC, PT, OCS CHES†Author Information From the *Department of Orthopaedic Surgery, Children's Hospital, State University of New York at Buffalo, Buffalo, NY; **Gallup Indian Medical Center, Gallup, NM; †Chinle Comprehensive Health Care Facility, Chinle, AZ. Reprint Requests to Richard M. Schwend, MD, Department of Orthopaedic Surgery, Children's Hospital, State University of New York at Buffalo, 219 Bryant Street, Buffalo, NY 14222. Clinical Orthopaedics and Related Research (1976-2007): July 1999 - Volume 364 - Issue - pp 108-116 Buy Abstract Patients born in the Many Farms District of the Navajo Indian Reservation from 1955 to 1961 were studied. Five hundred forty-eight of the 628 infants born (87%) received clinical examinations and pelvic radiographs at some time during the first 4 years of their lives. Eighteen (3.3%) of the 548 infants examined had acetabular dysplasia. Because of traditional cultural beliefs, none of these children received medical treatment. Followup evaluations and radiographs were obtained in these 18 patients during early adolescence. In 10 of the original 18 patients followup evaluations and radiographs were obtained at an average age of 35 years. None of the dysplastic hips progressed to frank dislocation. The mean center edge angle improved from 7° when the patients were 1 year of age, to 29° when the patients were 12 years of age, to 30° when the patients were 35 years of age. Despite overall improvement of hip measurements with maturity, eight hips in five of the 10 patients who were in their fourth decade of life and who were available for examination, had radiographic evidence of residual abnormalities. The hips in patients with subluxation during infancy were less likely to be normal as adults. The results of this 34-year followup study of untreated developmental hip dysplasia showed marked radiographic improvement in all patients during childhood; however, subtle abnormalities persisted in the radiographs of 40% of the hips. © 1999 Lippincott Williams & Wilkins, Inc.