Effect of age on radiographic outcomes of patients aged 6-24 months with developmental dysplasia of the hip treated by closed reduction

Severity of hip dysplasia as the major factor affecting outcome of closed reduction in children with hip dysplasia

The objective of this study was to analyze a multicenter cohort of children with developmental dysplasia of the hip (DDH) who underwent treatment with closed reduction. We sought to report the effects that severity of hip dysplasia and age have on the development of femoral head avascular necrosis (AVN) and the need for additional procedures. All patients with DDH and minimum 2 years of follow-up who underwent closed reduction were identified. The following variables were recorded: sex, laterality of hip involvement, age, acetabular index (AI), and International Hip Dysplasia Institute (IHDI) grade. The effects of patient age and pre-procedure IHDI grade on the rate of AVN and need for additional procedures after the closed reduction were analyzed using an alpha of 0.05. Seventy-eight total hips were included in the final analysis. The average patient age was 12 months. AVN of the femoral head was reported in 24 hips (30.8%) and 32 hips (41.0%) required additional surgery. Higher pre-op IHDI grade was associated with higher risk of developing Bucholz-Ogden grades II-IV AVN of the femoral head ( P = 0.025) and requiring additional surgery ( P = 0.033) regardless of patient age. There were no statistically significant differences for the effect of age on the measured outcomes ( P  > 0.05). These findings suggest that severity of dislocation (IHDI grade) is a significant risk factor for the development of AVN and need for additional procedure.

Routine ultrasound screening for hip dysplasia in children with clubfoot is not supported

PURPOSE

Despite the existence of guidelines for screening for developmental dysplasia of the hip (DDH), there remains controversy regarding the need for routine ultrasound screening for DDH in patients with clubfoot due to an unclear correlation between the two conditions. The purpose of this study is to determine whether ultrasound screening for DDH in this population improved the diagnostic accuracy of DDH over standard assessment for patient risk factors and physical exam.

METHODS

This is a retrospective cross-sectional review of infants diagnosed with idiopathic clubfoot who underwent hip ultrasounds to assess for DDH as identified by keyword search in an institutional radiological database at a tertiary care paediatric hospital. Patient demographics, risk factors for DDH, physical exam findings, and ultrasound results were recorded.

RESULTS

Of the 120 patients who met the inclusion criteria between 2003 and 2018, 8 had hip dysplasia confirmed on ultrasound (6.7%). All these patients either had known risk factors for hip dysplasia or had an abnormal physical exam finding suggestive of hip instability or dislocation as performed by an orthopaedic surgeon on their initial consultation.

CONCLUSION

A detailed history to determine risk factors and a thorough physical exam are adequate to determine the need for hip ultrasound in infants with idiopathic clubfoot. Routine ultrasound screening of all patients with clubfoot is likely unnecessary and may pose a significant burden on the health care system.

Avascular necrosis predictive factors after closed reduction in patients with developmental dysplasia of the hip

Background

Developmental dysplasia of the hip (DDH) is a common pediatric orthopedic condition. Closed reduction (CR) is the conservative treatment approach with high success rates for DDH. However, avascular necrosis (AVN) is a severe potential complication after this procedure. This study retrospectively assessed the potential risk factors for AVN occurrence after CR and Spica cast immobilization.

Materials and Methods

In a retrospective observational study, 71 patients (89 hips) with DDH aged 6-24 months old undergoing CR were enrolled. All patients were followed up for 3 years, and their demographic data, initial Tönnis grade, pre-reduction procedures, abduction angle in the Spica cast, and the AVN presence (based on Bucholz and Ogden classification [3rd-4th class]) were documented.

Results

Of 71 patients (89 hips) with a mean age of 12.5 ± 3.9 months, 13 patients (18 hips) developed AVN. The mean age of patients in the AVN and non-AVN groups was 14.3 ± 4.9 and 12.2 ± 3 months (P = 0.07); also, the mean abduction angle in patients with and without AVN was 51.86 ± 3.66 and 58.46 ± 3.91 (P < 0.001) in univariate analysis. The distribution of initial Tönnis grade, and previous conservative procedures, adductor tenotomies during the CR were comparable between the two groups (P > 0.05). We found age 12 months and 54° in abduction angle as the best cutoff values for differentiating AVN patients from non-AVN and the risk of experiencing AVN for patients older than 12 months was odds ratio (OR) =4.22 (P = 0.06) and patients with abduction angle greater than 54 was OR = 34.88 (P < 0.001).

Conclusion

In this study, older age at the time of intervention and larger abduction angle in the hip Spica cast were two predictors of experiencing AVN in DDH patients after undergoing CR treatment approach. Performing CR at a younger age and keeping the abduction angle lower than 54° in the hip Spica cast could help to have the best possible prognosis.

Level of Evidence

IV, retrospective, observational, cross-sectional study.

Anteroposterior pelvic radiograph is not sufficient to confirm hip reduction after conservative treatment of developmental dysplasia of the hip

The purpose of this study was to investigate whether an anteroposterior pelvic radiograph alone is sufficient to confirm hip reduction after conservative treatment or whether MRI could be alternatively performed. A total of 133 children (145 hips) were enrolled. All children were examined by anteroposterior pelvic radiographs and MRI. Three experts interpreted anteroposterior pelvic radiographs and then verified these results on MRI. For patients with inconsistent results between anteroposterior pelvic radiographs and MRI, the continuity of Shenton's line and Calve's line was recorded, and the medial clear space of bilateral hips was measured for unilateral cases. There was complete agreement between the three experts in the interpretation of anteroposterior pelvic radiographs of 111 (76.55%) hips; there was disagreement in the remaining 34 hips, with two experts diagnosing satisfactory reduction in 13 hips and dislocation in 21 hips. Assuming that the judgment of two or more doctors on anteroposterior pelvic radiographs was taken as the final result, 17 hips (11.72%) were misjudged. There was no statistically significant difference between the actual in-position group and the actual dislocation group in terms of the continuity of Shenton's line ( P  = 0.62) and Calve's line ( P  = 0.10) and the medial clear space of bilateral hips ( P  = 0.08). In children less than 1 year of age with developmental dysplasia of the hip treated conservatively, the use of anteroposterior pelvic radiographs alone to judge hip reduction might result in misdiagnosis and missed diagnosis. MRI could be alternatively used to detect hip reduction after conservative treatment, especially when the doctor was not familiar with ultrasound in the presence of plaster.

Residual Acetabular Dysplasia in the Reduced Hip

BACKGROUND

Residual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA).

DISCUSSION

Age at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4-5 years of age, and common surgical indications include acetabular index (AI) > 25°-30°, lateral center-edge angle (LCEA) < 8°-10°, and a broken Shenton's line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center-edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results.

CONCLUSION

RAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.

The incidence of avascular necrosis following a cohort of treated developmental dysplasia of the hip in a single tertiary centre

PURPOSE

Avascular necrosis (AVN) may occur following treatment for developmental dysplasia of the hip (DDH). The primary aim of this study was to identify the incidence of AVN in a cohort of patients treated for DDH. Secondary aims were to classify AVN using available classification systems, analyze the correlation between the systems and investigate their relationship with the age at diagnosis of DDH.

METHODS

An 11-year retrospective study was carried out at a single tertiary centre, using data from the clinical portal (patient records database) and IMPAX (system used to store plain radiographic images). Clinical details (patient demographics and outcomes) and plain radiographic images were used to identify cases of DDH and categorize cases of AVN using available classification systems: Tonnis and Kuhlmann, Kalamchi and McEwen, Bucholz and Ogden and Salter. Severin was used to assess final clinical outcome.

RESULTS

In total, 405 (522 hips) cases of DDH were identified, of which 213 resolved without treatment, 93 were treated conservatively and 99 surgically. Only treated cases were included in the analysis (n = 192). AVN (45/99; 45.5%) was found to occur only postoperatively. A positive correlation was present between age at presentation and severity of AVN as classified according to Salter's criteria (chi-squared p value < 0.01).

CONCLUSION

AVN incidence was 23.4% (45/192) and only occurred in surgically treated patients. Older age at diagnosis was associated with a higher incidence of AVN, as defined according to Salter's criteria. The classification systems appeared to show no correlation amongst each other (p-value < 0.01).

LEVEL OF EVIDENCE

III - Retrospective cohort study.

Timing for closed reduction procedure for developmental dysplasia of the hip and its failure analysis

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 different 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.