MRI Predictors of Residual Dysplasia in Developmental Dysplasia of the Hip Following Open and Closed Reduction

Abstract

Background: Following open or closed reduction for children with developmental dysplasia of the hip, there remains a significant risk of residual acetabular dysplasia which can compromise the long-term health of the hip joint. The purpose of this study was to use postoperative in-spica magnetic resonance imaging (MRI) data to determine factors predictive of residual acetabular dysplasia at short-term follow-up. Methods: We retrospectively reviewed 63 hips in 48 patients which underwent closed or open reduction and spica casting for developmental dysplasia of the hip. MRI performed in-spica at ∼3-week follow-up were used to assess 11 validated metrics and 2 subjective factors. Acetabular index (AI) was measured on anteroposterior pelvic radiographs at 2-year postoperative followup. Binary logistic regression was then used to identify variables predictive of residual dysplasia, defined as an AI greater than the 90th percentile for age based on historic normative data. Results: Average age at surgical reduction was 9.3 ± 3.2 months. 58.7% (37/63) of reductions were open. A total of 43 (68.3%) hips demonstrated residual acetabular dysplasia at 2 years postoperatively based on normative values. In those with persistent dysplasia, patients were on average older at the time of reduction (10.0 mo ± 3.2 vs. 8.0 mo ± 2.8, P = 0.010) and more likely female (88.4% vs. 60.0%, P = 0.010). Patients with residual dysplasia were more likely to have mild subluxation on postoperative MRI (40.0% vs. 10.5%, P = 0.022). Hips with a cartilaginous acetabular index (CAI) of > 23 degrees were 7.6 times more likely to develop residual dysplasia. Type of reduction (ie, closed vs. open) did not appear to influence the rate of residual dysplasia (P = 0.682). Conclusion:In this series, the rate of residual dysplasia after surgical reduction was higher than most previous reports, with no appreciable difference between closed and open reductions. Older age, female sex, and a higher CAI were associated with a greater risk of persistent radiographic dysplasia. In particular, hips with a CAI > 23 degrees were 7.6 times more likely to be dysplastic at 2-year follow-up.

Cartilaginous predictors of residual acetabular dysplasia (RAD) in developmental dysplasia of the hip following closed or open reduction: A systematic review and meta-analysis

“…And 4 of them were not available for full text, 17 studies did not match the subject, and 9 studies could not extract the 2 × 2 contingency table. Finally, 9 studies were included for qualitative synthesis ( 18 , 27 – 34 ) and 6 studies for quantitative synthesis ( 18 , 28 , 29 , 31 , 33 , 34 ). The search process and results are shown in Figure 2 .…”

“…The information from the 6 quantitatively synthesized studies is shown in Table 2 . Among them, there were 4 studies in the CAI group ( 18 , 28 , 31 , 34 ) and 4 studies in the CCE group ( 18 , 28 , 29 , 33 ).…”

“…First of all, CAI and CCE can be measured by MRI or arthrography, which are two different imaging methods. Secondly, from the perspective of the anatomical structure of the acetabulum, some studies have only measured the angle of the cartilage part, that is, CAI and CCE ( 18 , 29 , 31 , 34 ); other studies on the measurement of the angle include both the cartilage part and the labrum part, named L-AI and L-CEA ( 28 , 33 ) ( Figure 1 ). Although the two methods have different angles, they belong to the same type of measurement in principle, so we merge them into the same group and redefine them as the CAI group and CCE group.…”

Developmental retardation of femoral head size and femoral head ossification in mild and severe developmental dysplasia of the hip in infants: a preliminary cross-sectional study based on ultrasound images

“…Our results showed that US is a useful and easy method for screening and early diagnosis of DDH. However, to evaluate the therapeutic effect following open and closed reduction, magnetic resonance imaging (MRI) is typically performed to confirm the concentric reduction and predict prognosis (24,29). At this point, for severe DDH that needs reduction, the US results of femoral head size and femoral head ossification may be reproduced by MRI images.…”

What’s New in Pediatric Orthopaedics

“…A retrospective review found that the risk of residual acetabular dysplasia was higher in older patients, female patients, and patients with elevated cartilaginous acetabular indices on MRI 25 . A study of 108 infants with hip dysplasia found that elevated acetabular indices on radiographs before treatment were associated with residual acetabular dysplasia after Pavlik harness treatment 26 .…”