Bone maturation of MRI residual developmental dysplasia of the hip with discrepancy between osseous and cartilaginous acetabular indexWalbron, Paula; Müller, Florencea; Mainard-Simard, Laurenceb; Luc, Amandinec; Journeau, PierreaJournal of Pediatric Orthopaedics B: September 2019 - Volume 28 - Issue 5 - p 419–423 doi: 10.1097/BPB.0000000000000581 PELVIS & HIP Buy Abstract Author InformationAuthors Article MetricsMetrics Quality of spontaneous amelioration of residual developmental dysplasia of the hip (DDH) is nowadays not possible to predict. Normal age-related values of the osseous acetabular index (OAI), cartilaginous acetabular index and labral acetabular index have been established on MRI. In this study, MRI of dysplastic hips has been evaluated, and further osseous acetabular maturation was followed-up over time on pelvic radiography to find a correlation between MRI findings and radiological evolution. This is a retrospective single-centre study. Children with DDH who had a pelvic MRI between February 2007 and June 2014 were included. AI was measured for osseous (OAI), cartilaginous (cartilaginous acetabular index) and labral (labral acetabular index) values on MRI. OAI was thereafter recorded on each available radiograph during follow-up. A total of 20 hips were included. The mean age at MRI diagnosis was 3.55 years. Two types of DDH were observed: harmonious dysplasia, associated with an osseous and cartilaginous defect (group A, n = 14), and divergent dysplasia, associated with an osseous defect but with sufficient cartilaginous coverage (group B, n = 6). The mean age at final radiological follow-up was 7.6 and 8.3 years (P = 0.7408), respectively. In group A, four (28.6%) children older than 6 years had an OAI of less than 18°, whereas only two (33.3%) children older than 6 years had an OAI less than 18° in group B (P = 0.0117). This study shows that, in one-third of cases, divergent dysplasia leads to a spontaneous recovery. MRI should be used early to accurately diagnose and follow-up DDH cases and allow surgeons to justify the required surgical treatment. Level of Evidence: IV. Departments of aPaediatric Orthopaedic Surgery bPaediatric Radiology, Hôpital d’Enfants cClinical Research, ESPRI-BioBase, CHU de Nancy, Vandoeuvre les Nancy, France Correspondence to Pierre Journeau, MD, Department of Paediatric Orthopaedic Surgery, CHU de Nancy, Hôpital d’Enfants, rue du Morvan, 54500 Vandoeuvre les Nancy, France Tel: + 33 383 154 715; fax: + 33 383 157 691; e-mail: email@example.com Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.