Hip Surveillance and Management of Hip Displacement in Children with Cerebral Palsy: Clinical and Ethical Dilemmas

Hip Displacement After Triradiate Closure in Ambulatory Cerebral Palsy: Who Needs Continued Surveillance?

BACKGROUND

Hip surveillance in cerebral palsy (CP) is an accepted practice with evidence-based guidelines implemented. For the skeletally immature with open triradiate cartilage (TRC), recommendations for radiographic surveillance stemmed from population-based studies. For nonambulatory CP, progression of hip displacement after skeletal maturity has been reported; less is known for ambulatory CP. We aimed to determine the prevalence and risk factors associated with progressive hip displacement after TRC closure, a proxy for skeletal maturity, for ambulatory CP.

METHODS

This is a retrospective cohort study of patients with ambulatory CP (Gross Motor Function Classification System I-III), with unilateral or bilateral involvement, hypertonic motor type, regular hip surveillance (≥3 radiographs after age 10 yr, 1 before TRC closure, ≥1 after age 16 yr), and 2-year follow-up post-TRC closure. The primary outcome was migration percentage (MP). Other variables included previous preventative/reconstructive surgery, topographic pattern, sex, scoliosis, epilepsy, and ventriculoperitoneal shunt. An "unsuccessful hip" was defined by MP ≥30%, MP progression ≥10%, and/or requiring reconstructive surgery after TRC closure. Statistical analyses included chi-square and multivariate Cox regression. Kaplan-Meier survivorship curves were also determined. Receiver operating characteristic analysis was used to determine the MP threshold for progression to an "unsuccessful hip" after TRC closure.

RESULTS

Seventy-six patients (39.5% female) met the inclusion criteria, mean follow-up 4.7±2.1 years after TRC closure. Sixteen (21.1%) patients had an unsuccessful hip outcome. By chi-square analysis, diplegia ( P =0.002) and epilepsy ( P =0.04) were risk factors for an unsuccessful hip. By multivariate analysis, only first MP after TRC closure ( P <0.001) was a significant risk factor for progression to an unsuccessful hip; MP ≥28% being the determined threshold (receiver operating characteristic curve analysis, area under curve: 0.845, P <0.02).

CONCLUSIONS

The risk of MP progression after skeletal maturity is relatively high (21%), similar to nonambulatory CP. Annual hip surveillance radiographs after TRC closure should continue for Gross Motor Function Classification System I-III with an MP ≥28% after TRC closure, especially for bilateral CP and epilepsy.

LEVEL OF EVIDENCE

III.

Incidence of hip problems in developmental central hypotonia: A scoping review

AIM

To describe what is known about hip problems in individuals with developmental central hypotonia.

METHOD

Searches were conducted in five databases to October 2023. Down syndrome was excluded from this analysis of less well-known genetic diagnoses. At least two reviewers independently screened titles, abstracts, read full-text articles, and extracted data.

RESULTS

Of 89 full-text articles, 79 met inclusion criteria. Studies included 544 individuals aged 1 month to 63 years with Kabuki, 49, XXXXY, Prader-Willi, PURA, Koolen de Vries, Emanuel, TRPM3, Wolf-Hirschhorn, and other rare syndromes. Most diagnoses may be associated with a combination of differences in hip structure or stability that are evident at birth, or develop in early infancy, with increasing hip dysplasia and subluxation over time. Joint or ligamentous laxity was most reported along with hypotonia and hypermobility as risk factors. Limited data were identified about conservative or surgical intervention and outcomes in these populations.

INTERPRETATION

Children with significant hypotonia, with or without a confirmed genetic diagnosis, are at increased risk of hip problems that may be missed with standard neonatal screening. Ultrasound is recommended between 6 weeks and 6 months, and annual orthopaedic review with regular radiographs for older children and adults with significant and persistent hypotonia.

Femoral neck-shaft angle changes based on the severity of neurologic impairment in children with cerebral palsy and spinal muscular atrophy

Introduction

The neck-shaft angle and head-shaft angle in children with varying levels of neurological disability were evaluated to define change over different ages.

Methods

Children aged 1-12 years with spastic cerebral palsy, spinal muscular atrophy types 1 and 2, or typical development were reviewed to evaluate the neck-shaft angle and head-shaft angle. Patients were divided into five groups: Gross Motor Function Classification System levels I and II, Gross Motor Function Classification System level III, Gross Motor Function Classification System levels IV and V, spinal muscular atrophy types 1 and 2, and typical development. A linear mixed model was utilized to evaluate neck-shaft angle and head-shaft angle.

Results

Data from 196 children (mean age 4.8 ± 4.5 years) were included. Gross Motor Function Classification System levels I and II: 22 children, 130 hip radiographs measured, neck-shaft angle 143.7 ± 7.4, and head-shaft angle 160.0 ± 7.1. Gross Motor Function Classification System level III: 8 children, 33 hips evaluated, neck-shaft angle 153.1 ± 4.3, and head-shaft angle 163.4 ± 4.2. Gross Motor Function Classification System levels IV and V: 30 children, 137 hip radiographs measured, neck-shaft angle 156.4 ± 5.6, and head-shaft angle 167.9 ± 6.8. Spinal muscular atrophy types 1 and 2: 32 children, 83 hip radiographs measured, neck-shaft angle 161.9 ± 9.7, and head-shaft angle 173.4 ± 7.4. Typical development: 104 children, 222 hip radiographs measured, neck-shaft angle 138.6 ± 7.0, and head-shaft angle 156.4 ± 5.9. There were significant statistical differences when comparing neck-shaft angle and head-shaft angle.

Conclusion

As children grow, neck-shaft angle and head-shaft angle tend to decrease in typical development and Gross Motor Function Classification System levels I and II groups. However, in low-tone (spinal muscular atrophy types 1 and 2) and high-tone groups (Gross Motor Function Classification System levels IV and V), neck-shaft angle and head-shaft angle tend to increase with age. In both low-tone and high-tone groups, coxa valga is observed. When evaluating the effect of proximal femur-guided growth, these defined normal growth patterns should be considered.

Level of Evidence

Level III Retrospective comparative study.

Exploring the Relationship between Cerebral Palsy and Hip Dysplasia: Insights from the National Inpatient Sample

Background and Objective: Cerebral palsy (CP) significantly impacts quality of life globally. Hip dysplasia (HD) is a common musculoskeletal issue in CP patients. This study investigates the prevalence, risk factors, and impact of HD on CP patients using a large national database. Materials and Methods: Data from the National Inpatient Sample (NIS) database (2016-2019) were used, identifying CP and HD diagnoses through ICD-10 codes. Baseline characteristics were tabulated. Univariate and multivariate logistic regression analyses examined predictors of HD development in CP patients, presenting data as odds ratios (ORs) with 95% confidence intervals (CIs). Results: Among 3,951,040 pediatric patients, 28,880 had CP (27,466 without HD, and 1414 with HD), and 3,922,160 did not have CP. CP significantly increased the likelihood of developing HD in univariate (OR = 35.03, 95% CI [33.01, 37.17], p < 0.0001) and multivariate (OR = 26.61, 95% CI [24.94, 28.40], p < 0.0001) analyses. Among patients with CP, race was significantly associated with HD, with ORs below 1 for all racial categories compared to Whites. Females had nearly twice the odds of HD compared to males (OR = 1.96, 95% CI [1.86, 2.05], p < 0.0001). Age was significantly associated with HD, with each additional year increasing the odds (OR = 1.03, 95% CI [1.026, 1.034], p < 0.0001). Individuals in the high 51st-75th income quartile had a 17% increase in the odds of HD (OR = 1.17, 95% CI [1.09, 1.25], p < 0.0001) compared to the low 1st-25th income quartile. Conclusions: This study reinforces the strong association between CP and HD, highlighting the need for further research and prospective studies to validate these findings.

Hip displacement in children with cerebral palsy: surveillance to surgery - a current concepts review

This review brings together a multidisciplinary, multinational team of experts to discuss the current state of knowledge in the detection and treatment of hip displacement in cerebral palsy (CP), a global public health problem with a high disease burden. Though common themes are pervasive, different views are also represented, reflecting the confluence of traditional thinking regarding the aetiology and treatment of hip displacement in CP with emerging research that challenges these tried-and-true principles. The development of hip displacement is most closely related to gross motor function, with radiographic surveillance programs based on the Gross Motor Function Classification System (GMFCS), the goal being early detection and timely treatment. These treatments may include non-operative methods such as abduction bracing and Botulinum Neurotoxin A (BoNT-A), but outcomes research in this area has been variable in quality. This has contributed to conflicting opinions and limited consensus. Soft tissue lengthening of the hip adductors and flexors has traditionally been employed for younger patients, but population-based studies have shown decreased survivorship for this treatment when performed in isolation. Concerns with the identification of hip displacement in very young children are raised, noting that early reconstructive surgery has a high recurrence rate. This has prompted consideration of viable minimally invasive alternatives that may have better success rates in very young children with CP, or may at least delay the need for osteotomies. Recent reports have implicated the role of abnormal proximal femoral growth and secondary acetabular dysplasia as a primary cause of hip displacement, related to ambulatory status and abductor function. As such, guided growth of the proximal femur has emerged as a possible treatment that addresses this purported aetiology, with promising early results.

Prevalence and Regional Differences in Migrated Hips in Danish Children with Cerebral Palsy from 2008 to 2021-A Comparison of Ambulant vs. Non-Ambulant Children

PURPOSE

This study aims to assess the incidence of hip displacement and dislocation (denominated as hip migration) among ambulant and non-ambulant Danish children with cerebral palsy (CP) by estimating their cumulative incidence of migrated hips. A secondary objective is to compare the prevalence across different Danish regions.

METHODS

Data were obtained from the Danish Cerebral Palsy Follow-Up Program (CPOP) from the years 2008 to 2021. This population-based cohort study included 1388 children with CP (58% male; 42% female) as subjects; aged 0-15 years; with an average age of 5.4 years at their last follow-up. The children were categorized according to their Gross Motor Function Classification System (GMFCS) level into ambulators (GMFCS I-III) and non-ambulators (GMFCS IV-V). The Kaplan-Meier estimator was employed to calculate the cumulative incidence of migrated hips from birth until the date of their last radiographic follow-up. Differences between ambulatory and non-ambulatory children and regional differences were assessed with the Log-rank test.

RESULTS

Median radiological follow-up for ambulators was 51 months and 94 months for non-ambulators. The cumulative incidence of hip dislocation was 0.3% (95% CI: 0-0.8%) and 22.0% (95% CI: 9.2-34.8%) for ambulators and non-ambulators, respectively (p < 0.0001), whereas the incidence of hip displacement was 21.1% (95% CI: 16.3-25.9%) and 76.7% (95% CI: 68.6-84.7%) for ambulators and non-ambulators, respectively (p < 0.0001). There were no significant regional differences in the incidence of hip dislocation among ambulators, but there were significant differences for non-ambulators. Moreover, significant regional differences were detected in hip displacement for both ambulators and non-ambulators.

CONCLUSIONS

The prevalence of hip migration in Danish children with CP is significantly higher among non-ambulators, who are at an increased risk of hip migration compared to their ambulant counterparts. However, the low frequency of radiographic follow-up for ambulators might cause the incidence of hip migration to be underestimated. This study highlights the necessity of continued targeted surveillance and interventions in Danish non-ambulators.

Long-term outcomes of reconstructive treatment for painful dislocations in patients with cerebral palsy

Purpose

This report presents the long-term results of the hip joint reconstruction in patients with spastic hip disease through open reduction, proximal femur varus derotation osteotomy, and Dega transiliac osteotomy.

Methods

We analyzed retrospectively patients diagnosed with a spastic form of bilateral cerebral palsy with painful hip subluxation or dislocation. All patients underwent the same surgical procedure. The minimum follow-up time was 15 years. The study group comprised 15 patients (22 hips), classified with the Gross Motor Function Classification System as levels IV and V. The hip joint range of motion and anteroposterior X-ray examination at the final follow-up visit were compared with pre-operative data. The pain level was evaluated using the Visual Analogue Scale (VAS), and the femoral head shape was assessed using the Rutz classification. The patients' caregivers answered questions regarding pain during sitting, personal hygiene activities, and at rest. The caregivers' satisfaction with the treatment was also assessed with the Caregiver Priorities and Child Health Index of Life with Disabilities questionnaire.

Results

We observed a significant reduction of the hip joint pain and improvement in both radiological hip stability parameters and range of motion at the final follow-up visit. Based on the Rutz classification, one hip remained type B, while the other joints became type A. Reduced pain was reported in all three positions, with the most pronounced improvement during sitting and personal hygiene activities. Interestingly, patients with unilateral hip reconstruction were more prone to pain after reconstruction than those operated bilaterally.

Conclusion

Primary reconstruction of the painful hip joint neurogenic dislocation results in a stable joint reduction, pain decrease, and improved quality of life in patients with cerebral palsy.

Level of evidence

IV case series.

Morphometric and clinical comparison of MRI-based synthetic CT to conventional CT of the hip in children

BACKGROUND

MRI-based synthetic CT (sCT) generates CT-like images from MRI data.

OBJECTIVE

To evaluate equivalence, inter- and intraobserver reliability, and image quality of sCT compared to conventional (cCT) for assessing hip morphology and maturity in pediatric patients.

MATERIALS AND METHODS

We prospectively enrolled patients <21 years old with cCT and 3T MRI of the hips/pelvis. A dual-echo gradient-echo sequence was used to generate sCT via a commercially available post-processing software (BoneMRI v1.5 research version, MRIguidance BV, Utrecht, NL). Two pediatric musculoskeletal radiologists measured seven morphologic hip parameters. 3D surface distances between cCT and sCT were computed. Physeal status was established at seven locations with cCT as reference standard. Images were qualitatively scored on a 5-point Likert scale regarding diagnostic quality, signal-to-noise ratio, clarity of bony margin, corticomedullary differentiation, and presence and severity of artifacts. Quantitative evaluation of Hounsfield units (HU) was performed in bone, muscle, and fat tissue. Inter- and intraobserver reliability were measured by intraclass correlation coefficients. The cCT-to-sCT intermodal agreement was assessed via Bland-Altman analysis. The equivalence between modalities was tested using paired two one-sided tests. The quality parameter scores of each imaging modality were compared via Wilcoxon signed-rank test. For tissue-specific HU measurements, mean absolute error and mean percentage error values were calculated using the cCT as the reference standard.

RESULTS

Thirty-eight hips in 19 patients were included (16.6 ± 3 years, range 9.9-20.9; male = 5). cCT- and sCT-based morphologic measurements demonstrated good to excellent inter- and intraobserver correlation (0.77

CONCLUSION

sCT is equivalent to cCT for the assessment of hip morphology, physeal status, and radiodensity assessment in pediatric patients.

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Key Words

• Hip imaging
• Hip morphology
• Hounsfield units
• MRI based
• Quality
• Synthetic CT

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MESH Headings

• Humans
• Male
• Child
• Female
• Magnetic Resonance Imaging/methods
• Prospective Studies
• Reproducibility of Results
• Adolescent
• Tomography, X-Ray Computed/methods
• Hip Joint/diagnostic imaging
• Child, Preschool
• Imaging, Three-Dimensional/methods

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Affiliation(s)

Jade Iwasaka-Neder Department of Radiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA.
M Alejandra Bedoya Department of Radiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
James Connors Department of Radiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
Simon Warfield Computational Radiology Laboratory, Boston Children's Hospital, 401 Park Drive, Boston, MA, 02215, USA
Sarah D Bixby Department of Radiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA

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Identifying and Evaluating Young Children with Developmental Central Hypotonia: An Overview of Systematic Reviews and Tools

Children with developmental central hypotonia have reduced muscle tone secondary to non-progressive damage to the brain or brainstem. Children may have transient delays, mild or global functional impairments, and the lack of a clear understanding of this diagnosis makes evaluating appropriate interventions challenging. This overview aimed to systematically describe the best available evidence for tools to identify and evaluate children with developmental central hypotonia aged 2 months to 6 years. A systematic review of systematic reviews or syntheses was conducted with electronic searches in PubMed, Medline, CINAHL, Scopus, Cochrane Database of Systematic Reviews, Google Scholar, and PEDro and supplemented with hand-searching. Methodological quality and risk-of-bias were evaluated, and included reviews and tools were compared and contrasted. Three systematic reviews, an evidence-based clinical assessment algorithm, three measurement protocols, and two additional measurement tools were identified. For children aged 2 months to 2 years, the Hammersmith Infant Neurological Examination has the strongest measurement properties and contains a subset of items that may be useful for quantifying the severity of hypotonia. For children aged 2-6 years, a clinical algorithm and individual tools provide guidance. Further research is required to develop and validate all evaluative tools for children with developmental central hypotonia.

From Hip Screening to Hip Surveillance: Transforming Care for Patients With Cerebral Palsy: An Analysis of a Single Institution

INTRODUCTION

Surveillance programs aimed at monitoring hip displacement in patients with cerebral palsy have been demonstrated to decrease the incidence of hip dislocations and properly time surgical intervention, ultimately improving patient outcomes. The objective of this study was to determine whether the implementation of a hip screening to surveillance program at a tertiary academic teaching hospital in 2017 increased the frequency of radiographic evaluations and changed the timing of surgical intervention.

METHODS

A total of 592 patients with cerebral palsy were identified, and 468 of these patients had initial radiograph date data available. In this analysis, 246 patients with initial radiograph dates after 2012 were included. The study population was divided into two groups based on the initial radiograph date, 2012 to 2016 versus 2017 to 2022. One hundred sixty patients (65%) were in the 2012 to 2016 group, and 86 (35%) were in the 2017 to 2022 group. Statistical analysis was conducted using various techniques, such as two-sample Student t-test, Mann-Whitney U test, chi square/Fisher exact test, and multivariable linear regression analysis.

RESULTS

The average number of radiographs per year in the 2017 to 2022 group was 0.11 (95% CI: 0.02, 0.20, P = 0.017) higher than the 2012 to 2016 group. After adjusting for confounders using multivariable linear regression analysis, this difference was even larger (difference 0.16, 95% CI: 0.06, 0.25, P = 0.001). The surgical intervention rate was significantly lower in the 2017 to 2022 group compared with the 2012 to 2016 group (12.9% versus 40.6%, P < 0.001).

DISCUSSION

The results of this study suggest that the implementation of a hip screening to surveillance program results in more frequent radiographic evaluations and possibly a reduced need for surgical intervention from 2017 to 2022. In the 2012 to 2016 group, more surgical interventions were performed likely because of the lack of any hip surveillance or screening program in place.

The Effect of Selective Dorsal Rhizotomy on Hip Displacement in Children With Cerebral Palsy: A Long-term Follow-up Study

BACKGROUND

Hip displacement is common in children with cerebral palsy (CP). Spasticity in the hip adductor muscles, hip flexors, and medial hamstrings has been identified as a possible cause of progressive hip displacement. Selective dorsal rhizotomy (SDR) aims to reduce lower extremity spasticity in children with CP. Here, we investigate the influence of SDR on hip displacement in children with CP at long-term follow-up, a minimum of 5 years post-SDR.

METHODS

A retrospective review of children undergoing SDR at a Canadian pediatric hospital was completed. Migration percentage (MP) was measured on pelvis radiographs taken in the 6 months before SDR and minimum 5 years post-SDR or before hip surgery. The number of hips with displacement, defined as MP >30%, and the number of children with at least 1 hip displaced were determined. A linear mixed-effects model was used to assess potential risk factors for poor outcome post-SDR, defined as having MP >40% or surgical intervention for hip displacement.

RESULTS

Ninety children [50 males, 40 females, Gross Motor Function Classification System (GMFCS) levels I to V: 1/13/24/43/9] with a mean follow-up of 8.5 years (SD 5.1) were included. The mean age at SDR was 4.9 years (SD 1.5); more than half of children (52%) had hip displacement at the time of SDR. Post-SDR, MP exceeded 30% in 0 (0%) of children at GMFCS level I, 1 (8%) at II, 11 (46%) at III, 31 (72%) at IV, and 7 (78%) at V. A poor outcome was associated with preoperative MP, age, and GMFCS level.

CONCLUSIONS

The incidence of hip displacement post-SDR was consistent with population-based studies when evaluated by GMFCS. Our findings suggest that SDR has neither a positive nor negative effect on hip displacement when assessed at least 5 years postintervention.

LEVEL OF EVIDENCE

Level IV.

Editorial Highlights from the Comorbidities and Complications of Cerebral Palsy Special Issue

Cerebral palsy is a life-long condition and the most common cause of physical disability in childhood [...].

Study Confirms Safety and Effectiveness of Intra-Articular Glucocorticoids for Painful Hip Dislocation in Children and Young Adults with Neurologic Impairment

BACKGROUND

Hip dislocation is a common source of pain in children with neurologic impairment. When medical interventions fail, orthopedic surgery does not guarantee a definitive result as the displacement may continue postoperatively and a second operation is often required.

METHODS

Retrospective analysis of data regarding the safety and effectiveness of an intra-articular corticosteroid injection (IACI) in 11 patients, aged 15 ± 5 years old, collected through a telephonic questionnaire administered to parents.

RESULTS

21 IACIs were performed, a mean number of 1.9 ± 1.5 times for each patient, at a mean age (of the first IACI) of 13.5 ± 5 years. According to the parents, the IACI significantly lowered the number of participants experiencing pain (82% reduction) and using analgesics (60% reduction). There was also a significant improvement in the children's hip mobility (63% reduction in patients experiencing stiffness), decubitus (90% reduction in obligated positioning), behavior (80% reduction in lamenting or crying patients), sleep quality (87.5% reduction in patients awakening every night), and caregivers' quality of life (91% reduction in worried parents). The mean reported duration of the IACIs' benefit was 5.4 ± 2.4 months (range 1-9), with a positive correlation with the number of IACIs (r = 0.48; p-value = 0.04) and a negative correlation with the age at the first injection (r = -0.71; p-value = 0.02). The only reported adverse event was mild local swelling in one child.

CONCLUSIONS

the IACI could represent a safe and effective intervention for painful hip dislocation, both before and after surgery, with a long-lasting benefit which seems to increase as multiple IACIs are performed.

Reducing spasticity does not prevent hip displacement in cerebral palsy

This letter to the editor is on the commentary by Gormley on pages 1003–1004 of this issue.

Current Concept and Management of Spastic Hip in Children: A Narrative Review

Cerebral palsy (CP) is a non-progressive motor condition that hinders the development of movement and posture. One of the common problems faced in CP is spastic hips, which can cause discomfort, deformity, and functional restrictions. This review article seeks to offer a thorough summary of the most recent methods for treating spastic hips in cerebral palsy patients. Additionally, it describes the success and potential risks of various conservative and surgical procedures. It also looks at new treatments and potential avenues for managing this complicated ailment.

Intrathecal baclofen therapy does not prevent hip displacement in children with cerebral palsy

This letter to the editor is on the commentary by Gormley on pages 1003–1004 of this issue.