A clinical study of hip arthrography combined with MRI to assess acetabular development after early treatment of DDH in children
A clinical study of hip arthrography combined with MRI to assess acetabular development after early treatment of DDH in children
Background： Developmental dysplasia of the hip (DDH) is one of the most common skeletal muscle diseases in children. Even after successful early conservative treatment, there is a high risk of residual acetabular dysplasia (RAD) in the affected hip, which may require secondary surgery. The current study suggests several prediction indexes for clinical reference, but if the hip with the poorer future outcome can be identified at an earlier stage by several prediction indexes, and thus a second surgery can be performed earlier, the greater the developmental potential left for the child.Purpose： The purpose of this study was to find a more stable and accurate early RAD prediction model by hip arthrography combined with MRI and a combination of multiple indexes for the prediction of RAD after early treatment.
Patients and Methods： From December 2020 to December 2021,13 children who met the inclusion criteria were included, with a total of 21 hips ( 8 cases of bilateral DDH ). According to the exclusion criteria, the remaining 15 hips were statistically analyzed. The acetabular cartilaginous angle (ACA) and femoral head coverage (FHC) were measured on the initial closed reduction arthrography X-ray, and the cartilaginous acetabular index (CAI) and cartilaginous center-edge angle (CCE) were measured on the MRI after the initial closed reduction. The AI in the 1-year follow-up X-ray was compared with the corresponding normal AI range in Chinese children and divided into satisfactory and unsatisfactory groups. ICC was used to assess intra-observer and inter-observer consistency for the same index. Independent samples t-test and χ 2 test were used to compare the two groups for measurement and count data, respectively, and differences were considered statistically significant at P < 0.05. The receiver operating characteristic ( ROC ) curve was drawn to evaluate the diagnostic efficacy of CAI, CCE, ACA, FHC, and different combinations of each index on prognosis, and the area under the curve ( AUC ) was calculated.
Results： The ROC curve of each early prediction index showed that the AUC values of CAI and CCE were between 0.5 and 0.7 when using a single cartilaginous index to evaluate short-term prognosis, which was at a low level; The AUC values of ACA and FHC were between 0.7 and 0.9, which was in medium level. The combination of multiple indexes can improve the diagnostic efficacy, and in the analysis of the combination of both indexes, CAI combined with ACA had the highest AUC value of 0.893, which was at a medium level. When the three indexes were combined, the CAI+CCE+ACA combination had the highest AUC value of 0.946, achieving a high level. The maximum AUC value of 0.982 was obtained when all four indexes were combined, achieving a high level of diagnostic efficacy.
Conclusion： The combination of multiple indexes and multiple imaging examinations can form a comprehensive and systematic prediction model, which can significantly improve the accuracy of single index prediction, and our validated "ACA+FHC+CAI+CCE" is a reliable prediction model. The model can predict early acetabular developmental outcomes after closed reduction and provide guidance for possible secondary orthopedic surgery
