Wei Fan1, Xue-Jiao Li2, Hong Gao2, Xin Yi2, Qiao-Jian Liu2. 1. Department of Ultrasound, Kunming Children's Hospital, Kunming, 650228, China. fwss2000@163.com. 2. Department of Ultrasound, Kunming Children's Hospital, Kunming, 650228, China.
Abstract
PURPOSE: To investigate the relationship of femoral head coverage (FHC) with Graf's classification for diagnosis of developmental dysplasia of the hip (DDH) and its role in evaluating hip stability. METHODS: A total of 4222 hips were screened ultrasonographically with Graf's and Harcke's methods. The stability of hips was analyzed using the difference between FHCs at neutral and flexion positions (FHC-D). RESULTS: (1) For the non-dislocated hips, the mean value of FHC at the neutral position was 59.4%, which was significantly greater than 55.0% of FHC at the flexion position (p < 0.001). (2) FHC at the neutral position corresponding to Graf I, IIa/b, IIc, D, III, and IV was 63.0 ± 4.7%, 57.0 ± 5.2%, 49.5 ± 5.5%, 37.7 ± 3.7%, 30.2 ± 12.7%, and 7.4 ± 11.9%, respectively, and that at the flexion position was 59.0 ± 4.4%, 50.7 ± 9.4%, 35.2 ± 5.2%, 30.8 ± 1.3%, 23.4 ± 10.7%, and 4.7 ± 9.9%, respectively, showing a statistically significant difference between the two positions. (3) The AUC of FHC-D in evaluating the stability of hips was 0.972. When the threshold was 8.5%, the sensitivity, specificity, and accuracy of FHC-D in detecting hip instability were 89.0%, 93.0%, and 93.9%, respectively. CONCLUSIONS: FHC can be used as a reference indicator for DDH classification. FHC at different positions corresponds to different reference values, and FHC-D can be used as a quantitative indicator for assessment of hip stability.
PURPOSE: To investigate the relationship of femoral head coverage (FHC) with Graf's classification for diagnosis of developmental dysplasia of the hip (DDH) and its role in evaluating hip stability. METHODS: A total of 4222 hips were screened ultrasonographically with Graf's and Harcke's methods. The stability of hips was analyzed using the difference between FHCs at neutral and flexion positions (FHC-D). RESULTS: (1) For the non-dislocated hips, the mean value of FHC at the neutral position was 59.4%, which was significantly greater than 55.0% of FHC at the flexion position (p < 0.001). (2) FHC at the neutral position corresponding to Graf I, IIa/b, IIc, D, III, and IV was 63.0 ± 4.7%, 57.0 ± 5.2%, 49.5 ± 5.5%, 37.7 ± 3.7%, 30.2 ± 12.7%, and 7.4 ± 11.9%, respectively, and that at the flexion position was 59.0 ± 4.4%, 50.7 ± 9.4%, 35.2 ± 5.2%, 30.8 ± 1.3%, 23.4 ± 10.7%, and 4.7 ± 9.9%, respectively, showing a statistically significant difference between the two positions. (3) The AUC of FHC-D in evaluating the stability of hips was 0.972. When the threshold was 8.5%, the sensitivity, specificity, and accuracy of FHC-D in detecting hip instability were 89.0%, 93.0%, and 93.9%, respectively. CONCLUSIONS:FHC can be used as a reference indicator for DDH classification. FHC at different positions corresponds to different reference values, and FHC-D can be used as a quantitative indicator for assessment of hip stability.
Entities:
Keywords:
Developmental dysplasia of the hip; Femoral head coverage; Hip stability; Ultrasonography