Poor delineation of labrum and acetabular surface on arthrogram is a predictor of early failure of closed reduction in children aged six to 24 months with developmental dysplasia of the hip

Abstract

Purpose The objective of this study was to explore the predictors for failed reduction in children with developmental dysplasia of the hip (DDH) managed by arthrogram, closed reduction (CR) and spica cast immobilization. Methods We retrospectively reviewed the clinical data of patients with DDH treated by CR and cast immobilization (2015-2020), including age, sex, affected side, presence/absence of an ossific nucleus, International Hip Dysplasia Institute classification, the delineation of labrum and acetabular surface on arthrogram, inverted labrum, acetabular index (AI), hip abduction angle and medial dye pool (MDP) distance. Predictors that potentially predicted failure of CR were evaluated by logistic regression analysis, simple t-test, Fisher’s Exact Test and chi-square test. Results In total, 16 out of 187 hips failed to achieve initial CR (8.6%). Gender, age, preoperative AI and poor delineation of arthrogram were candidate predictors for failed CR in children aged six to 24 months with DDH; on the other hand, logistic regression analysis confirmed age and poor delineation of arthrogram significantly predicted failure of CR. Receive operating characteristic curve (ROC) showed MDP less than 6 mm and age higher than 14.5 months significantly increased the failure rate of CR in children aged six to 24 months with DDH. Conclusion Age and poor delineation of labrum and acetabular surface during arthrogram predicted failure of CR in children with DDH. In particular, age > 14.5 months and MDP distance ≥ 6 mm significantly increased the risk of CR failure. Level of evidence III

Hip arthrogram parameters predict radiographic outcomes of patients with developmental dysplasia of the hip treated by closed reduction

“…Many researchers have previously investigated the use of MDP in hip arthrogram. Yuan et al (26) investigated the clinical data of 173 patients (187 hips) with DDH treated with closed reduction and measured MDP to predict reduction failure. They showed that the risk of reduction failure was significantly increased when MDP was >6 mm.…”

Magnetic resonance imaging follow-up can screen for soft tissue changes and evaluate the short-term prognosis of patients with developmental dysplasia of the hip after closed reduction

“…By arthrography and MRI, Hattori [ 24 ] and Kim [ 26 ] found that obvious soft tissue insertion in the hip joint, widening of the medial contrast cistern, and LCC hypertrophy would increase the probability of CR failure, thus increasing the need for open surgery, even if surgical treatment cannot achieve a good prognosis. Yuan et al [ 27 ] found that poor delineation of the labrum and acetabular surface during arthrogram predicted failure of CR in children with DDH, and medial dye pool distance ≥6 mm significantly increased the risk of CR failure. However, the studies by Severin [ 12 ] and Aoki [ 28 ] have shown that the inverted labrum can be gradually shaped and returned to a normal shape after CR without affecting the final acetabular-head alignment.…”