Residual axial plane deformities after hip reconstruction for developmental dysplasia of the hip after walking age

Abstract

Children with developmental dysplasia of the hip after walking age can be treated with one-stage combined operations. In these procedures, complex deformity corrections at both frontal and axial planes are performed in the guidance of intraoperative stability tests. The reports about the results of these procedures focus on frontal plane assessments but neglect to assess axial plane corrections. We aimed to find out whether hips with unilateral developmental dysplasia of the hip, treated by one-stage combined procedures after walking age and which had good frontal plane containment at the last follow-up, had any axial plane deformities. Twenty-one patients were included in this study according to our described criteria. Mean age at the operation time was 38.04 months (range: 20-86 months), mean follow-up time was 55.54 months (range: 24-117 months) and mean age at latest follow-up was 93.46 months (range: 52-150 months). Femoral anteversions, acetabular anteversions and acetabular sector angles were measured bilaterally in the computed tomography examination. Operated hip measurements were compared with the contralateral hips. One-way variance analysis was used for statistical analysis. Femoral anteversion, acetabular anteversion and posterior acetabular sector angle values of the operated hips were found to be statistically lower than those of the contralateral hips. Our findings suggest that using the intraoperative stability test alone for planning osteotomies may lead to unsuitable femoral head coverage in axial plane although successful frontal plane containment can be obtained. We believe that strict preoperative planning that can be accomplished by a preoperative computed tomography examination should be performed in order to decide innominate osteotomy type and correction amounts.