A pilot study of observing "docking" in patients with developmental dislocation of the hip after closed reduction by serial MRI
10.3760/cma.j.cn121113-20201231-00765
- VernacularTitle:系列MRI观察发育性髋脱位闭合复位后"靠港"现象的研究
- Author:
Xianghong MENG
;
Jianping YANG
;
Zhi WANG
;
Zhe FU
;
Zhongli ZHANG
- From:
Chinese Journal of Orthopaedics
2021;41(4):219-226
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To utilize MRI and plain films to observe the changes of soft tissue structures in patients with developmental dysplasia of the hip (DDH) after closed reduction, and explore the concentric reduction rate, the "docking" rate and the femoral head necrosis rate after reduction.Methods:Retrospective analysis of unilateral completely dislocated DDH patients with closed reduction and spica casting in our hospital from October 2012 to July 2018. MRI was performed on the day of closed reduction and every 2-3 months after operation. Pelvic plain films were performed before operation and follow-up. The labro-chondral complex (LCC) of the hip was divided into 4 types on MRI images, and the reliability and repeatability of LCC classification were evaluated by intra-class correlation coefficient. Trend chi-square test or Fisher exact probability method was used to analyze the variation of thickening rate of ligamentum teres, transverse ligaments and pulvinar during MRI follow-up, and the difference of cartilaginous acetabular head index was evaluated by analysis of variance of repeated measurements or Mann-Whitney U test. The concentric reduction rate of the femoral head after performing closed reduction, the "docking" rate of the femoral headwhen the cast was changed for the last time were analyzed, and the necrosis rate of the femoral head were followed up for 18 months or more after reduction.Results:A total of 63 DDH patients (63 hips) with closed reduction were included. Intra-class correlation coefficient of LCC classification was 0.84 between observers (95%CI: 0.74-0.91) and 0.94 within observers (95%CI: 0.90-0.97) . Most LCC classifications were type 4 on the day of CR (93.7%, 59/63) , and return to normal (type 1 classifications) at the second follow-up (50.9%, 28/55). ligamentum teres, transverse ligaments and pulvinar were hypertrophic (94.5%-100%) on the day of CR, and decreased to 10.9%-12.7% at the second follow-up, which had statistically differences ( χ2=88.6; χ2=86.4; χ2=97.9, P<0.05). The cartilaginous acetabular head index was 68.1±12.1 on the day of CR, and increased to 84.4±7.0 at the second follow-up, which had statistically difference ( Z=-3.15, P=0.002). 58.7% femoral heads were "docking", 8.6% femoral head had necrosis. Conclusion:The abnormal soft tissue structures in the hip joint mostly recovered gradually after closed reduction, and 60% femoral heads could be docked, the short-term risk of the femoral head necrosis was low.
