Abduction Orthosis in Treatment of Primary Acetabular Dysplasia: Results of Three Years Follow-up

Abstract

Background: Acetabular dysplasia (AD) may appear after six months old despite normal previous physical and ultrasonographic examination, and management remains unclear. The purpose of current study was to evaluate success of abduction orthosis in treatment of primary AD patients. Methods: Patients presented with AD between 2010-2017 were retrospectively reviewed. AD patients, who had stable hip joints on previous phsycial examination and Graf type1 on ultrasonography when younger than six months, were included study. AD was diagnosed according to the age-related acetabular index(AI) values. Abduction orthoses were applied full-time for five months plus part-time for three months. AI was re-measured at sixth months, at the end of first and third year. AI change was compared between dysplastic and nondysplastic hips. Results: We evaluated 60 hips of 39 patients with AD treated with abduction orthosis at median age of 6 months. The mean AI was 31,4(29-35)°±2,1° in dysplastic hips. AI decreased to 26,5°±2,2°, 24,5°±2°, 21°±2,1° at sixth months, first and third years after treatment; respectively. The mean AI of nondysplastic hips was 25,3°(22-28)±2,1°; and decreased to 22,6°±2,4°, 21,1°±2°, 17,9°±1,8° at sixth months, first and third years follow-ups, respectively. At the end of the first 6 months, dysplastic hips had significantly better improvement in AI(4,9±2,1°) compared to non-dysplastic hips(2,7°±0,8°)(P<0.001). There was no significantly difference in AI impovement after six months. Conclusion: Primary acetabular dysplasia should not be ignored despite normal previous physical and ultrasonographic examination. Abduction orthosis may be used safely in treatment of children with primary AD older than six months.