Managing Developmental Dysplasia of the Hip

Splinting for the non-operative management of developmental dysplasia of the hip (DDH) in children under six months of age

BACKGROUND

Developmental dysplasia of the hip (DDH) describes the abnormal development of a hip in childhood, ranging from complete dislocation of the hip joint to subtle immaturity of a hip that is enlocated and stable within the socket. DDH occurs in around 10 per 1000 live births, though only one per 1000 are completely dislocated. There is variation in treatment pathways for DDH, which differs between hospitals and even between clinicians within the same hospital. The variation is related to the severity of dysplasia that is believed to require treatment, and the techniques used to treat dysplasia.

OBJECTIVES

To determine the effectiveness of splinting and the optimal treatment strategy for the non-operative management of DDH in babies under six months of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, seven other electronic databases, and two trials registers up to November 2021. We also checked reference lists, contacted study authors, and handsearched relevant meetings abstracts.

SELECTION CRITERIA

Randomised controlled trials (RCTs), including quasi-RCTs, as well as non-RCTs and cohort studies conducted after 1980 were included. Participants were babies with all severities of DDH who were under six months of age. Interventions included dynamic splints, static splints or double nappies (diapers), compared to no splinting or delayed splinting.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and performed risk of bias and GRADE assessments. The primary outcomes were: measurement of acetabular index at years one, two and five, as determined by radiographs (angle): the need for operative intervention to achieve reduction and to address dysplasia; and complications. We also investigated other outcomes highlighted by parents as important, including the bond between parent and child and the ability of mothers to breastfeed.

MAIN RESULTS

We included six RCTs or quasi-RCTs (576 babies). These were supported by 16 non-RCTs (8237 babies). Five studies had non-commercial funding, three studies stated 'no funding' and 14 studies did not state funding source. The RCTs were generally at unclear risk of bias, although we judged three RCTs to be at high risk of bias for incomplete outcome data. The non-RCTs were of moderate and critical risk of bias. We did not undertake meta-analysis due to methodological and clinical differences between studies; instead, we have summarised the results narratively. Dynamic splinting versus delayed or no splinting Four RCTs and nine non-RCTs compared immediate dynamic splinting and delayed dynamic splinting or no splinting. Of the RCTs, two considered stable hips and one considered unstable (dislocatable) hips and one jointly considered unstable and stable hips. No studies considered only dislocated hips. Two RCTs (265 babies, very low-certainty evidence) reported acetabular index at one year amongst stable or dislocatable hips. Both studies found there may be no evidence of a difference in splinting stable hips at first diagnosis compared to a strategy of active surveillance: one reported a mean difference (MD) of 0.10 (95% confidence interval (CI) -0.74 to 0.94), and the other an MD of 0.20 (95% CI -1.65 to 2.05). Two RCTs of stable hips (181 babies, very low-certainty evidence) reported there may be no evidence of a difference between groups for acetabular index at two years: one study reported an MD of -1.90 (95% CI -4.76 to 0.96), and another study reported an MD of -0.10 (95% CI -1.93 to 1.73), but did not take into account hips from the same child. No study reported data at five years. Four RCTs (434 babies, very low-certainty evidence) reported the need for surgical intervention. Three studies reported that no surgical interventions occurred. In the remaining study, two babies in the dynamic splinting group developed instability and were subsequently treated surgically. This study did not explicitly state if this treatment was to achieve concentric reduction or address residual dysplasia. Three RCTs (390 babies, very low-certainty evidence) reported no complications (avascular necrosis and femoral nerve palsy). Dynamic splinting versus static splinting One RCT and five non-RCTs compared dynamic versus static splinting. The RCT (118 hips) reported no occurrences of avascular necrosis (very low-certainty evidence) and did not report radiological outcomes or need for operative intervention. One quasi-RCT compared double nappies versus delayed or no splinting but reported no outcomes of interest. Other comparisons No RCTs compared static splinting versus delayed or no splinting or staged weaning versus immediate removal.

AUTHORS' CONCLUSIONS

There is a paucity of RCT evidence for splinting for the non-operative management of DDH: we included only six RCTs with 576 babies. Moreover, there was considerable heterogeneity between the studies, precluding meta-analysis. We judged the RCT evidence for all primary outcomes as being of very low certainty, meaning we are very uncertain about the true effects. Results from individual studies provide limited evidence of intervention effects on different severities of DDH. Amongst stable dysplastic hips, there was no evidence to suggest that treatment at any stage expedited the development of the acetabulum. For dislocatable hips, a delay in treatment onset to six weeks does not appear to result in any evidence of a difference in the development of the acetabulum at one year or increased risk of surgery. However, delayed splinting may reduce the number of babies requiring treatment with a harness. No RCTs compared static splinting with delayed or no splinting, staged weaning versus immediate removal or double nappies versus delayed or no splinting. There were few operative interventions or complications amongst the RCTs and the non-randomised studies. There's no apparent signal to indicate a higher frequency of either outcome in either intervention group. Given the frequency of this disease, and the fact that many countries undertake mandatory DDH screening, there is a clear need to develop an evidence-based pathway for treatment. Particular uncertainties requiring future research are the effectiveness of splinting amongst stable dysplastic hips, the optimal timing for the onset of splinting, the optimal type of splint to use and the need for 'weaning of splints'. Only once a robust pathway for treatment is established, can we properly assess the cost-effectiveness of screening interventions for DDH.

A Preliminary Cadaveric MRI Study of Fetal Hip Development

Purpose

The earlier the detection of the hip joint is discovered, the better the final result. The purpose of this study aimed to investigate the fetal hip development using magnetic resonance imaging (MRI), so as to alert clinicians to possible abnormal development during intrauterine life.

Method

Measurements of 34 cadaver fetuses (68 hips) were obtained regarding acetabular width and depth, anterior bony acetabular index (ABAI), anterior cartilaginous acetabular index (ACAI), posterior bony acetabular index (PBAI), and posterior cartilaginous acetabular index (PCAI). The standard values of each acetabular measurement index were obtained, and the gestational age-measurement index change trend chart was drawn to comprehensively analyze the normal development law of the fetal hip joint.

Results

With the development of fetuses, the width and depth of acetabular increase linearly, and the slope of acetabular width was larger than that of depth. In addition, two change points during the 24th and 34th weeks of gestation were detected with regard to width. ABAI and PBAI also decreased. ABAI demonstrated an approximately linear trend, while PBAI shows a non-linear trend. During the 36th week, the change point in PBAI was observed. ACAI and PCAI exhibited slow increases, indicating a non-linear trend. During the 21st and 36th weeks of gestation, the change points regarding ACAI were observed. During the 22nd week of gestation, the change point for PCAI was observed.

Conclusion

Plots of the parameters obtained via MRI examinations of cadaver fetuses across gestational age comprehensively illustrated the fetal hip development. This developmental information about the hip joint has the potential to guide clinicians in the early detection of abnormal hip joint development during intrauterine life.

Developmental dysplasia of the hip screening programme in Chile

PURPOSE

Developmental dysplasia of the hip (DDH) encompasses a wide pathological spectrum, from mild acetabular dysplasia to complete congenital hip dislocation at birth. Screening policies have been implemented in an effort to effectively identify and treat patients with DDH. Since 2009 there has been a national DDH programme in Chile. The current study evaluates the results of the programme in patients born between 2010 and 2015.

METHODS

Records of patients hospitalized from 1st January 2010 to 31st December 2019 were retrieved from national databases. Those born from 1st January 2010 to 31st December 2015 who underwent a procedure for DDH under general anaesthesia during their first five years of life were selected. Sex, first surgical procedure and age at first surgical procedure were analyzed. The incidence of DDH that required major surgical treatment was calculated.

RESULTS

A total of 961 children born from 1st January 2010 to 31st December 2015 underwent a procedure for DDH during their first five years of life. The number of major procedures was significantly lower than the number of minor procedures (269 vs 692). The incidence of major procedures was 0.18 per 1000 live births. Girls underwent a higher number of procedures than boys (831 vs 130), whereas 39.2% of the boys and 26.2% of the girls had major procedures. The mean age at the time of the first procedure was 15.35 months (sd 10.09; range 0.03 to 55.92 months).

CONCLUSION

The present study suggests that the Chilean National DDH Screening Program is an appropriate programme with substantial benefits with respect to public health.

LEVEL OF EVIDENCE

II.

Variables influencing the pelvic radiological evaluation in children with developmental dysplasia of the hip managed by closed reduction: a multicentre investigation

PURPOSE

This study aims to evaluate (1) the probability to achieve normal pelvic radiographs in children with developmental dysplasia of the hip (DDH) treated by closed reduction and (2) the amount of time needed to achieve normal pelvic radiographs and to assess what factors influence both probability and time to achieve normal radiographic parameters following CR and spica cast immobilization for DDH.

METHODS

We retrospectively reviewed 436 patients (393 girls, 43 boys; 507 hips) with DDH treated by closed reduction (CR). Tönnis grade, AVN, acetabular index (AI), centre-edge angle (CEA), and Severin radiographic grade were evaluated on plain radiographs. Criteria to rate pelvis radiographs as normal were established. Cox regression was used to evaluate the factors influencing the probability and the time to achieve normal radiographs.

RESULTS

According to our criteria, 167 hips (32.9%) achieved normal radiographic parameters during follow-up. The overall amount of time to achieve normal pelvis radiographs was 36.1 ± 15.5 months. Patients older than 24 months of age at the time of CR needed longer time to achieve normal radiographic parameters (55.2 ± 28 months) compared with other age groups. Cox regression analysis suggested the overall cumulative probability of recovery increased by 46% at five years following CR, then it tended to plateau with an annual increase less than 5%. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN were risk factors for reduced probability of achieving normal radiographic parameters.

CONCLUSIONS

The cumulative probability of achieving normal pelvis radiographs increases linearly during the first five years following CR, then it tends to plateau. Age older than 24 months and Tönnis grade III and IV are associated with longer time to achieve normal radiographic parameters. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN are risk factors for reduced probability of achieving normal radiographic parameters in children with DDH treated by closed means.

Traction does not decrease failure of reduction and femoral head avascular necrosis in patients aged 6-24 months with developmental dysplasia of the hip treated by closed reduction: a review of 385 patients and meta-analysis

This study aimed to investigate the effects of preliminary traction on the rate of failure of reduction and the incidence of femoral head avascular necrosis (AVN) in patients with late-detected developmental dysplasia of the hip treated by closed reduction. A total of 385 patients (440 hips) treated by closed reduction satisfied the inclusion criteria. Patients were divided in two groups according to treatment modality: a traction group (276 patients) and a no-traction group (109 patients). Tönnis grade, rate of failure reduction, AVN rate, acetabular index, center-edge angle of Wiberg, and Severin's radiographic grade were assessed on plain radiographs, and the results were compared between the two groups of patients. In addition, a meta-analysis was performed based on the existing comparative studies to further evaluate the effect of traction on the incidence of AVN. Tönnis grade in the traction group was significantly higher than in the no-traction group (P = 0.021). The overall rate of failure reduction was 8.2%; no significant difference was found between the traction (9.2%) and no-traction groups (5.6%) (P = 0.203). The rates of failure reduction were similar in all Tönnis grades, regardless of treatment modality (P > 0.05). The rate of AVN in the traction group (14%) was similar to that of the no-traction group (14.5%; P = 0.881). Moreover, the rates of AVN were similar in all Tönnis grades, regardless of treatment modality (P > 0.05). The meta-analysis did not identify any significant difference in the AVN rate whether preliminary traction was used or not (odds ratio = 0.76, P = 0.32). At the last follow-up visit, the two groups of patients had comparable acetabular indices, center-edge angles, and Severin's radiographic grades (P > 0.05). In conclusion, preliminary traction does not decrease the failure of reduction and the incidence of AVN in developmental dysplasia of the hip treated by closed reduction between 6 and 24 months of age.

Evaluation of errors in measurements of infantile hip radiograph using digitally reconstructed radiograph from three-dimensional MRI

Purpose

Plain hip radiograph is commonly used for the diagnosis of infantile acetabular dysplasia. Many infants are unable to maintain adequate position during radiography. Besides, the infantile hip is much smaller and has a higher cartilage component in the acetabulum and proximal femur compared with the adult hip. In this study, we developed a digitally reconstructed radiograph synthesized from magnetic resonance imaging (MRI) and investigated errors of hip radiographic measurements in different pelvic positions.

Patients and methods

MRI of both hips was performed in 10 patients (mean age 3.9 years). Three-dimensional (3D) bone models were created from MRI data. We tilted 3D pelvic bone models between 10° anteversion and retroversion and through 10° rotation on the affected and contralateral sides using 3D axes. Following this, we created digitally reconstructed radiographs in each pelvic position and calculated the acetabular index (AI), center-edge angle (CEA), migration percentage (MP), and teardrop distance (TDD).

Results

AI tended to increase with pelvic retroversion and did not change with pelvic rotation. CEA tended to decrease with pelvic retroversion and rotation on the contralateral side. MP increased with pelvic retroversion and rotation on the contralateral side. TDD did not change significantly with pelvic tilt and rotation.

Conclusions

Radiographic measurements of hip in infants were highly influenced by pelvic movement. AI was influenced by pelvic tilt; CEA and MP were influenced by both pelvic tilt and rotation. We need to keep in mind that infantile hip radiographs could have about ±5° errors in AI and CEA.

Postoperative redislocation of the hip in a patient with congenital insensitivity to pain with anhidrosis: A case report and review of literature

Pelvic osteotomy is commonly used to adjust acetabula dysplasia for congenital dislocation of the hip, whereas congenital insensitivity to pain with anhidrosis (CIPA) is a rare hereditary disease that often has the characteristics of joint development deformity and easy fracture. This article reports the case involving a CIPA patient who was surgically treated by Chiari pelvic osteotomy and proximal femoral rotation osteotomy for congenital dislocation of the left hip joint and was provided long-term follow-up for redislocation and bilateral femoral head absorption.

Developmental dysplasia of the hip: why are we still operating on them? A plea for institutional newborn clinical screening

INTRODUCTION

Developmental dysplasia of the hip (DDH) is a common orthopaedic condition at birth. Non-surgical management with the Pavlik harness can effectively treat DDH in the newborn by providing an early clinical diagnosis, but open surgeries continue to be performed. We aimed to elucidate the reasons for this.

METHODS

A retrospective review was performed of all open surgeries related to DDH from 2006 to 2016. Patients were either born at our institution (Group 1) or outside of it (Group 2). All Group 1 newborns were routinely screened for DDH at birth.

RESULTS

27 patients (Group 1: n = 5, Group 2: n = 22) presented at age 25 ± 19 months. Left-sided DDH (n = 21, 77.8%) and female infants (n = 22, 81.5%) were more common. The mean age at surgery was 40 ± 31 months. The most commonly performed procedure was soft tissue release open reduction with acetabuloplasty (n = 20, 74.1%). Gender, site, median age at presentation and at surgery, and prevalence of risk factors were similar for both groups. Both groups were mostly made up of late presenters (> 3 months; p = 0.34). A few patients had undergone prior treatment (p = 0.64). Newborn screening was the only significantly different variable between the groups (p < 0.01).

CONCLUSION

Lack of institutionalised newborn clinical screening appears to be the root cause of late presentation of DDH leading to open surgery for its management. We recommend quality institutionalised newborn clinical screening to reduce the number of late presentations.

Evaluation of surgical outcome in advanced age patients with developmental hip dysplasia

BACKGROUND

This study aimed at determining the efficacy of the surgical treatment conducted on children with delayed presentation developmental dysplasia of the hip (DDH). The objective was to provide a good comparison of functional and radiographic outcomes and to determine various surgical treatment options.

METHOD

In this study, we evaluated the results of 38 hips of 27 patients aged 4 years onset which had been operated due to DDH. Radiographic outcomes were evaluated by using acetabular index, CE angle, Tonnis and the Severin classification system. Clinical evaluation was made by using IOWA hip scores. Degenerative changes were evaluated according to Boyer and avascular necrosis according to Kalamchi-MacEwen criteria.

RESULTS

The mean age of the patients at the operation time was 10 years 3 months (range: 4 years 3 months-30 years). While the mean acetabular index was 37.97 preoperatively, in the last follow-up it was 19.92. Thirty-six hips (94%) had an excellent and good outcomes, and two hips (%6) had a fair outcome with respect to the Severin criteria. The mean hip score with respect to IOWA was 93.736 (range: 75-98) and the rate of excellent and good outcomes was 98%.

CONCLUSION

For the treatment of patients with DDH of late onset, a one-staged operative procedure is recommended. This method is applied successfully and enables us to achieve good clinical and radiographic results.

Acetabular index is the best predictor of late residual acetabular dysplasia after closed reduction in developmental dysplasia of the hip

PURPOSE

Our objective was to find the best predictor of late residual acetabular dysplasia in developmental dysplasia of the hip (DDH) after closed reduction (CR) and discuss the indications for secondary surgery.

METHODS

We retrospectively reviewed the records of 89 patients with DDH (mean age 16.1 ± 4.6 months; 99 hips) who were treated by CR. Hips were divided into three groups according to final outcomes: satisfactory, unsatisfactory and operation. The changes in the acetabular index (AI), centre-edge angle of Wiberg (CEA), Reimer's index (RI) and centre-head distance discrepancy (CHDD) over time among groups were compared. The power of predictors for late residual acetabular dysplasia of AI, CEA, RI and CHDD at different time points was analysed by logistic regression analysis. Receiver operating characteristics (ROC) curve analysis was used to determine cutoff values and corresponding sensitivity, specificity and diagnostic accuracy for these parameters.

RESULTS

Both AI and CEA improved in all groups of patients following CR. In the satisfactory group, AI progressively decreased until seven to eight years, while CEA increased until nine to ten years (P < 0.05). In the unsatisfactory group, AI and CEA ceased to improve three and two years after CR, respectively (P < 0.05). CEA and RI were significantly better in the satisfactory group compared with the unsatisfactory group at all time points (P < 0.05). Following CR, both RI and CHDD remained stable over time in all groups. Final outcome following CR could be predicted by AI, CEA and RI at all time points (P < 0.01). Cutoff values of AI, CEA and RI were 28.4°, 13.9° and 34.5%, respectively, at one year and 25°, 20° and 27%, respectively, at two to four years post-CR. A total of 80-88% of hips had an unsatisfactory outcome if AI > 28.4° and >25 at one and two to four years following CR, respectively. However, if CEA was less than or RI was larger than the cutoff values at each time point, only 40-60% of hips had an unsatisfactory outcome. Mean sensitivity (0.889), specificity (0.933) and diagnostic accuracy (92.1%) of AI to predict an unsatisfactory outcome were significantly better compared with CEA (0.731; 0.904; 78.2%) and RI (0.8; 0.655; 70.8%) (P < 0.05).

CONCLUSIONS

Satisfactory and unsatisfactory hips show different patterns of acetabular development after reduction. AI, CEA and RI are all predictors of final radiographic outcomes in DDH treated by CR, although AI showed the best results. AI continues to improve until seven years after CR in hips with satisfactory outcomes, while it ceases to improve three to four years after CR in hips with unsatisfactory outcomes. According to our results, surgery is indicated if AI >28° 1 year following CR or AI >25° two to four years after CR. CEA and RI should be used as a secondary index to aid in the selection of patients requiring surgery.