Avascular necrosis following closed reduction for treatment of developmental dysplasia of the hip: A systematic review

et al. 2020

Preprint

Background It remains controversial whether the older age to perform closed reduction (CR) procedure for developmental dysplasia of the hip (DDH), the higher incidence of complications. The aim of this study is to evaluate the midterm outcome of CR for DDH among difference age groups, and to analyze and identify risk factors for the failure of this procedure. Methods Clinical data of 107 DDH patients, who received CR, were retrospectively reviewed. Data were divided into three groups according to initial treatment age (Group I: younger than 12 months; Group II: 12 months to less or equal to18 months; Group III: older than 18 months). The presence of avascular necrosis (AVN), residual acetabular dysplasia (RAD), re-dislocation, and further surgeries (FS) were observed. The risk factors were identified for those outcomes aforementioned using univariable logistic regression models. For identified risk factor age, pre-op acetabular index (AI) and post-op AI, their prediction of CR failure were evaluated by receiver operating characteristics curve (ROC).Results A total of 107 patients (156 hips) undergoing CR procedure were evaluated with a median age at initial reduction of 13.0±5.4 months (range, 4 to 28 mo). Mean follow-up time in this study was 6.7±0.8 years (range, 3-8 years). The incidence of AVN, RAD and re-dislocation was 15.4% (24/156), 17.3% (27/156) and 14.7% (23/156) respectively. For AVN, RAD and re-dislocation, the significant risk factors are pre-op IHDI IV (p=0.033), age≥18 months (p=0.012), and pre-op IHDI IV (p=0.004) and walking (p=0.011), respectively. The areas under the ROC curve of each type of failures were 0.841 (post-op AI), 0.688 (pre-op AI) and 0.650 (age).Conclusions Severe DDH patients older than 18 months with CR procedure may result in a high risk of RAD complication. Re-dislocation is significantly associated with pre-op IHDI IV and walking. Patients, who are older than 12.5 months or have a pre-op AI of 38.7° or a post-op AI of 26.4°, are also more likely to fail of CR procedure.

Section: Discussionsupporting

confidence: 90%

Timing for Closed Reduction Procedure for Developmental Dysplasia of the Hip and its Failure Analysis

et al. 2020

Preprint

“…Earlier studies have reported that various possible factors related to the AVN, including the age at the onset of treatment [32] , genders [33] , the utilization of prereduction traction [34] , the severity of hip dislocation at treatment [35] , laterality (unilateral/bilateral DDH) [36] , absence of proximal femoral ossi c nucleus [37] , failed Pavlik harness treatment [38] , or adductor tenotomy [39] . However, either of these underlying factors was disputed, especially in recent evidence-based studies [40] . Whilst these variations may be a consequence of natural variation due to the relatively small case numbers, different cases selection or the diversities in therapeutic regimes.…”

Section: Discussionmentioning

confidence: 99%

Efficacy of closed reduction for developmental dysplasia of the hip: midterm outcomes and risk factors associated with treatment failure and avascular necrosis

et al. 2020

Preprint

Abstract Background: The purpose of this study was to evaluate the efficacy after closed reduction (CR) in the treatment of developmental dysplasia of the hip (DDH) and investigate risk factors associated with CR failure and avascular necrosis (AVN) occurrence in the follow-ups.Primary and secondary outcome measures: The study retrospectively included 110 patients and 138 hips with DDH diagnosis between February 2012 and November 2015 in our single tertiary medical institution and underwent closed reduction. The failure rate of CR and the underlying risk factors were evaluated. meanwhile, the incidence of AVN and the related risk factors among the successful CR cases were assessed.Results: The overall failure rate of DDH treated by CR in present study was 31.16% (43/138). Risk factors for the CR failure was older age at the time of CR (≥18.35 month), large medical interval before CR (≥35.35 millimeters), and severer dislocation of the affected hip (IDHI grade III and IV). The incidence of AVN was 8.33% (6/72) in the patients with successful CR at last follow-up. No significant risk factors had been established in present study that associated with the AVN occurrence.Conclusions: For the treatment of DDH with CR, patients with younger age might achieve better outcomes, early diagnosis and early treatment might be the key point in the DDH treatment.

“…The incidence of AVN varies widely (0 ~ 92.4%), mainly due to the lack of uni ed diagnostic criteria and some different understandings. Bradley et al [24] conducted a retrospective study on AVN incidence after CR, and it was 10% among 441 DDH children (538 hips) on an average follow-up time of 7.6 years.…”

Section: Discussionmentioning

confidence: 99%

Contact pressure distribution of the hip joint during closed reduction of developmental dysplasia of the hip: A Patient-Specific Finite Element Analysis

Sui

et al. 2020

Preprint

Background Developmental dysplasia of the hip (DDH) is the most common deformity of the lower extremity in children, and the etiology remains unclear. The biomechanical change during closed reduction (CR) focused on cartilage contact pressure (CCP) has not been studied. Thereby, we try to provide insight into biomechanical factors potentially responsible for CR treatment success and complications by using finite element analysis (FEA) for the first time. Methods Finite element models of one patient with DDH were established based on the data of MRI scan on which cartilage contact pressure was measured. During CR, CCP between the femoral head and acetabulum in different abduction and flexion angles were tested to estimate the efficacy and potential risk factors of avascular necrosis (AVN) following CR. Results A 3D reconstruction by the FEA method was performed on a sixteen-month-old girl with DDH on the right side. The acetabulum of the involved side showed a long, narrow, and "plate-shaped" deformity, whereas the femoral head was smaller and irregular compared with the contralateral side. With increased abduction angle, the stress of the posterior acetabulum increased significantly, and the stress on the lateral part of the femoral head increased as well. The changes of CCP in the superior acetabulum were not apparent during CR. There were no detectable differences in terms of pressure on the femoral head. Conclusions Severe dislocation (IHDI grade III and IV) in children showed a high mismatch between the femoral head and acetabulum. Increased abduction angle corresponded with high contact pressure, which might relate to avascular necrosis, whereas increased flexion angle was not. Enhanced pressure on the lateral part of the femoral head might increase the risk of AVN.