Down syndrome in children: the role of the orthopaedic surgeon

Outcomes of surgical treatment of patellar instability in children with Down syndrome

BACKGROUND

patellar instability is a relatively frequent musculoskeletal disorder in children with Down syndrome (DS). However, such a condition has seldom been studied in the literature, even less its surgical treatment. Different techniques have been offered for this condition; the evidence for surgical options is scarce and primarily based on case reports or case series with few patients and heterogeneous techniques. Given this background, we aimed to evaluate the outcomes of a uniform kind of surgical procedure for such a condition that combined lateral soft tissue release, medial patellofemoral ligament (MPFL) reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty (if needed).

MATERIALS AND METHODS

This retrospective study involved 11 skeletally immature patients (12 knees; 9 males and 2 females), 5.5 to 14.1 years of age, with DS who had patellofemoral instability (PFI) and were managed by this technique between October 2018 and March 2020. Preoperative radiography, CT scan, and MRI were performed to evaluate the physis status, lower limb alignment, patellar height, trochlear morphology, and any associated knee pathology. A functional knee assessment was done by using the Kujala score and the modified Lysholm score.

RESULTS

The mean time of follow-up (± SD) was 47.7 ± 5.8 months (range: 39-56). Pre-operatively, the Kujala score (± SD) was 52.6 ± 14.3 (range: (31-74), and at final follow-up, it was 92.2 ± 4.4 (range: (88-98), showing a significant improvement (P < 0.001). The preoperative modified Lysholm score (± SD) was 54.3 ± 8.1 (range: 39-62), and at final follow-up it was 92.4 ± 5.3 (range: 82-96), showing a significant improvement (P < 0.001). All patients had a stable patella without a recurrence of instability and regained full ROM. There was no incidence of a patellar fracture or femoral physis injury.

CONCLUSIONS

Our proposed technique of combined soft tissue procedures, including lateral soft tissue release, MPFL reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty, was an effective method for treating patellar instability in children with DS while avoiding physeal injury and patellar fracture. Functional scores and radiological outcomes were improved.

LEVEL OF EVIDENCE

IV; retrospective case series.

Surgical strategies in the management of atlantoaxial dislocation in Down syndrome

Aims

To study the clinicoradiological features and treatment outcomes of atlantoaxial dislocation (AAD) in Down syndrome.

Settings and Design

Retrospective case series.

Subjects and Methods

A retrospective chart and radiology review of 9 Down syndrome patients with AAD managed at our center from 2007 to 2018.

Statistical Analysis Used

Chi-squared/Fisher's exact test.

Results

There were 4 males and 5 females (n = 9). The median age was 14 years (interquartile range [IQR]: 7-15.5). 77.7% (7/9) of patients had severe spasticity (Nurick Grades 4 and 5). The median duration of symptoms was 9 months (IQR: 5-39). The AAD was reducible in all (n = 9) cases. Eight (88.8%) patients had os odontoideum. The mean atlantodental interval (ADI) was 8.5 mm (±2.9). T2W cord hyperintensity was seen in 66.6% (6/9). Posterior C1-2 transarticular fixation was done in 8 and occipitocervical fusion in 1 patient. Follow-up of more than 6 months (7-57 months) was available in 8/9 (88.9%) patients. There was a significant improvement in spasticity (n = 8, mean Nurick Grade 1.7 (±1.1), P = 0.003). Follow-up radiographs (n = 8) showed good reduction and fusion. A preoperative bedbound patient with poor respiratory reserve expired at 10 months following surgery. There were no other complications.

Conclusions

Posterior surgical approach for AAD in Down syndrome resulted in good alignment and fusion, with excellent clinical improvement. Patients with elevated PCO2 are poor surgical candidates and require home ventilation facility.

The Diagnostic Capacity of Physical Examinations in Diagnosing Musculoskeletal Disorders of the Lower Limbs in Children with Down Syndrome

Background and Objectives: although musculoskeletal alterations are common in patients with Down syndrome (DS), studies investigating this association are scarce, and proposals for diagnostic standardization are limited. We aimed to evaluate the prevalence of musculoskeletal disorders in the lower limbs in a sample of children and adolescents with DS and to investigate the diagnostic capacity of orthopedic clinical examinations performed by orthopedists and pediatricians to diagnose these alterations. Materials and Methods: Twenty-two patients aged between three and ten years with DS were included. Patients and guardians answered a simple questionnaire regarding orthopedic complaints and underwent a systematic orthopedic physical examination, performed twice: once by an orthopedist and again by a pediatrician. Patients underwent a series of radiographs to diagnose anisomelia, hip dysplasia, epiphysiolysis, flatfoot valgus, mechanical axis varus, and mechanical axis valgus. The radiological diagnosis was considered the gold standard, and the diagnostic capacity of the physical examination performed by each physician was determined. Results: The median age was 6.50 years. Only four patients (18.2%) presented with orthopedic complaints. All patients were diagnosed with at least one musculoskeletal disorder. The only musculoskeletal disorder with a good diagnostic capacity was flatfoot valgus. Limited sensitivity values were found for hip dysplasia, mechanical axis varus, and mechanical axis valgus. The agreement between the orthopedic physical examinations performed by the two examiners was weak, poor, or indeterminate for most of the analyzed items. Conclusions: There was a high prevalence of orthopedic alterations in children with DS who did not present with musculoskeletal complaints. The diagnostic capacity of the physical examination was limited. Therefore, all children with DS should undergo a radiological evaluation of the musculoskeletal system and subsequent specialized orthopedic evaluation. Level of Evidence: Level II (Diagnostic Studies).

Is There a Relationship Between the Functional Level of Juvenile and Adolescent Patients With Down Syndrome and Hip Dysplasia?

BACKGROUND

The prevalence of hip dysplasia among patients with Down syndrome (DS) is higher than in the general population. We hypothesize that a relationship may exist between functional level and hip dysplasia in DS, but this has not been studied to date. The aim of this study is to evaluate whether there is a relationship between functional level and radiographic parameters of hip dysplasia or other measures.

METHODS

Retrospective cross-sectional comparative study of 652 patients with DS from a pediatric referral center database. Patients over 8 years of age with an anteroposterior pelvis radiograph and with no exclusion criteria were selected, totaling 132 patients (264 hips; 54.55% females; mean age 12.96 ± 2.87 y). Several radiographic parameters of the acetabulum [Sharp angle (SA), Tönnis angle (TA), Wiberg center-edge angle (W-CEA), extrusion index (EI), and acetabular retroversion signs], the proximal femur [neck shaft angle (NSA)], and joint congruence [Shenton line (SL)] were assessed. Patients were classified into 2 levels based on functional skills. A multivariate association analysis was performed between radiographic parameters and functional level.

RESULTS

Sixty-one patients were compatible with a functional level I and 71 with a level II. Forty-six hips were dysplastic and 60 were borderline according to the W-CEA. A statistically significant relationship was found between the categorical distribution of certain radiographic measurements of hip dysplasia (EI, SA, TA, W-CEA, SL, and classification by functional level ( P < 0.0005). A significant receiver operating characteristic curve was obtained for W-CEA with a cutt-off point at 26.4 degrees for level I (area under the curve = 0.763; P < 0.005; sensitivity = 0.800 and specificity = 0.644). There was a fairly high correlation between EI and TA (0.749; P < 0.0005), EI and W-CEA (-0.817; P < 0.0005), and TA and W-CEA (-0.748; P < 0.0005). Numerous hips showed signs of acetabular retroversion, with no significant differences found between functional levels or association with hip dysplasia measures.

CONCLUSIONS

The present study reveals a relationship between an increased risk of hip dysplasia and reduced functional levels in DS children older than 8 years. These findings may guide individualized clinical follow-up of hip development in DS children considering their functional level.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Long-term Impact of Planovalgus Foot on Activities of Daily Living in Patients With Down Syndrome

INTRODUCTION

Planovalgus foot (PVF) is the most common orthopaedic abnormality in children with Down syndrome (DS), and as a result these patients rarely develop an adequate plantar arch in adulthood. The present study aims to evaluate the impact of PVF on activities of daily living and participation in sports among young adults with DS and determine whether this impact is related to the degree of foot deformity based on clinical and imaging studies.

METHODS

Observational analytical study examining a database of 649 patients with DS from a pediatric referral center, identifying those individuals over age 20 years at the time of the study with a childhood diagnosis of PVF. Finally, 51 patients (102 feet) were evaluated based on clinical and imaging studies, and function was assessed using the The Foot and Ankle Outcome Score (FAOS) and the Visual Analogue Scale (VAS) pain scale. A correlation analysis was performed to determine the clinical and radiographic variables associated with functional outcomes. Linear regression models were obtained to quantify the impact of these variables on function.

RESULTS

Patients had a mean age of 26.14±3.88 years and body mass index of 24.51±4.57. Clinically, 63.65% presented grade 3 or 4 PVF, and most were flexible. Radiographically, midfoot flattening was mild-moderate in 92.16%, 58.82% had medial talo-navicular uncoverage, and 30.39% had an increased hallux valgus (HV) angle. Mean scores for all FAOS subscales were between 65 and 71% and the mean VAS score was 1.45±1.96. An association analysis revealed a tendency toward lower scores on all FAOS subscales and greater pain according to the VAS scale in more severe PVF and in cases of moderate HV with asymmetry between feet. Linear regression models showed that major contributors to functional scores were radiographic evidence of hindfoot valgus, midfoot abduction, and flattening, and HV.

CONCLUSIONS

Young adults with DS who are diagnosed with PVF in childhood have acceptable functional scores and low pain. Alteration of radiographic parameters toward flatter, more valgus and abducted feet and greater and asymmetric HV tend to be associated with worse long-term functional scores in activities of daily living and sports participation and increased pain. Therefore, non-operative management of these patients is justified, although individualized treatment is recommended.

LEVEL OF EVIDENCE

Level IV, Case series.

Clinical practice - latest insights in optimizing the care of children with Down syndrome

An essential part of the care of children with Down syndrome is secondary screening for comorbidity. It is well known that comorbidity frequently occurs in these children. A new update of the Dutch Down syndrome medical guideline was developed to create a sound evidence base for several of these conditions. We present the latest insights and recommendations from this Dutch medical guideline which are based on the most relevant literature currently available and developed with rigorous methodology. The main focus of this revision of the guideline was on obstructive sleep apnea and other airway problems and hematologic disorders, such as transient abnormal myelopoiesis, leukemia, and thyroid disorders. Conclusion: This is a short summary of the latest insights and recommendations from the updated Dutch medical guideline for children with Down syndrome.

Developmental Foot Deformities in Patients with Connective Tissue Disorders

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Foot deformities make up a large percentage of all orthopaedic complaints in patients with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta.

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Some common causes of foot deformities in these conditions include increased ligament laxity, hypotonia, and hypermobility of the joints.

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Treatment options for syndromic foot deformities include the use of foot orthoses, physical therapy, bracing, and various surgical procedures.

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There is limited evidence supporting the use of surgical intervention to correct foot deformities associated with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta. Therefore, further research is needed to determine the short-term and long-term outcomes of these procedures.

The Ponseti Method for the Treatment of Clubfeet Associated With Down Syndrome: A Single-institution 18-year Experience

BACKGROUND

Although the Ponseti method has been used with great success in a variety of nonidiopathic clubfoot deformities, the efficacy of this treatment in clubfeet associated with Down syndrome remains unreported. The purpose of this study is, therefore, to compare treatment characteristics and outcomes of clubfoot patients with Down syndrome to those with idiopathic clubfoot treated with the Ponseti method.

METHODS

An Institutional Review Board-approved, retrospective review of prospectively gathered data were performed at a single pediatric hospital over an 18-year period. Patients with either idiopathic clubfeet or clubfeet associated with Down syndrome who were less than 1 year of age at the outset of treatment were treated by the Ponseti method, and had a minimum of 2 year's follow-up were included. Initial Dimeglio score, number of casts, need for heel cord tenotomy, recurrence, and need for further surgery were recorded. Outcomes were classified using the Richards classification system: "good" (plantigrade foot +/- heel cord tenotomy), "fair" (need for a limited procedure), or "poor" (need for a full posteromedial release).

RESULTS

Twenty clubfeet in 13 patients with Down syndrome and 320 idiopathic clubfeet in 215 patients were identified. Average follow-up was 73 months for the Down syndrome cohort and 62 months for the idiopathic cohort. Down syndrome patients presented for treatment at a significantly older age (61 vs. 16 d, P =0.00) and with significantly lower average initial Dimeglio scores than the idiopathic cohort (11.3 vs. 13.4, P =0.02). Heel cord tenotomy was performed in 80% of the Down syndrome cohort and 79% of the idiopathic cohort ( P =1.00). Recurrence rates were higher in the Down syndrome cohort (60%) compared with the idiopathic group (37%), but this difference was not statistically significant ( P =0.06). Need for later surgical procedures was similar between the 2 cohorts, though recurrences in the Down syndrome group were significantly less likely to require intra-articular surgery (8.3% vs. 65.5%, P =0.00). Clinical outcomes were 95% "good," 0% "fair," and 5% "poor" in the Down syndrome cohort and 69% "good," 27% "fair," and 4% "poor" in the idiopathic cohort ( P =0.01).

CONCLUSIONS

Despite the milder deformity and an older age at presentation, clubfeet associated with Down syndrome have similar rates of recurrence and may have better clinical outcomes when compared with their idiopathic counterparts. When deformities do relapse in Down syndrome patients, significantly less intra-articular surgery is required than for idiopathic clubfeet.

LEVEL OF EVIDENCE

Level III.

Outcomes of Posterior Spinal Fusion in Pediatric Patients with Down Syndrome

BACKGROUND

Trisomy 21 or Down syndrome is associated with multiple orthopaedic manifestations. Although cervical instability is the most common spinal condition associated with Down syndrome, the prevalence of scoliosis has been estimated at 4.8% to 8.7%. Very few prior studies have documented the role of spinal fusion in this population, and all have included ≤10 patients.

METHODS

An institutional review board-approved multicenter retrospective analysis of patients with Down syndrome treated with spinal fusion between January 2009 and December 2019 was performed by cross-referencing Current Procedural Terminology (CPT) and International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10) codes. Patients were followed for ≥2 years, with a mean follow-up of 3.77 years. Clinical and radiographic outcomes were collected, and complications were documented using the Clavien-Dindo-Sink (CDS) classification.

RESULTS

A total of 23 patients were included: 96% had ≥1 medical comorbidities, including 16 (70%) with congenital heart disease, of whom 88% had previous cardiac surgery, and 10 (44%) with thyroid disorders. All 23 patients underwent posterior spinal fusion. The mean estimated blood loss was 617 ± 459 mL, the mean length of the surgical procedure was 290 ± 92.7 minutes, and the mean length of hospital stay was 6.03 ± 2.91 days. The major Cobb angle measured 61.7° ± 17.6°, which corrected to 19.4° ± 14.8° (68.6% correction; p < 0.001), with well-maintained correction at 2 years of 22.0° ± 10.3° (64.3% correction; p = 0.158). Thirteen (57%) of 23 patients had a change in curve of >5°. There were no intraoperative complications; however, 12 patients (52%) sustained postoperative complications (e.g., need for reoperation, implant failure, and pulmonary complications), including 6 patients with CDS type 3 or 4 (e.g., wound dehiscence, late superficial abscess, pleural effusion, pseudarthrosis, and readmission for hypoxia). Four patients (17%) required a revision surgical procedure. One patient (4%) required an unplanned intensive care unit admission.

CONCLUSIONS

Although instrumented spinal fusion can effectively correct spinal deformity in these patients, complications are more frequent than in children with adolescent idiopathic scoliosis, with over half of patients sustaining a complication.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Reliability and Reference Norms of Single Heel-Rise Test Among Children: A Cross-sectional Study

There is a lack of data regarding the single heel-rise test (SHRT) among children. Hence, we aimed to establish reliability and reference norms of SHRT among children aged 8 to 12 years. About 500 healthy children were randomly selected from the recognized school and community settings. After demographic measurements, SHRT was conducted to evaluate the strength of each plantar flexors. SHRT repetitions were assessed by the same rater on 2 occasions for intrarater (on the same day) and test-retest reliability (on different days) and by 2 raters for inter-rater reliability. Relative reliability was described in terms of the intraclass correlation coefficient (ICC) and Pearson correlation coefficient (r). Absolute reliability was indicated by the standard error of measurement (SEm), minimal detectable change (MDC), and Bland-Altman graph. The mean of the number of repetitions of SHRT was calculated to derive the reference norm of SHRT. The anthropometric parameters were correlated with SHRT for multiple regression analysis. Intrarater, test-retest, and inter-rater reliability of SHRT were, ICC = 0.81, ICC = 0.70, and ICC = 0.57, respectively. The Bland-Altman graph confirmed limits of agreement for intrarater, test-retest, and inter-rater reliability. The reference norm of SHRT is documented to be 20.6 ± 4.8. SEm and MDC are found to be 2 and 3, respectively. Multiple regression analysis predicted a correlation of age, weight, and calf muscle girth with SHRT. SHRT is moderate to good reliable in assessing the strength of plantar flexors. The reference norms of SHRT have been derived for healthy children aged 8 to 12 years.

Psychosocial aspects of sports medicine in pediatric athletes: Current concepts in the 21st century

Behavioral aspects of organized sports activity for pediatric athletes are considered in a world consumed with winning at all costs. In the first part of this treatise, we deal with a number of themes faced by our children in their sports play. These concepts include the lure of sports, sports attrition, the mental health of pediatric athletes (i.e., effects of stress, anxiety, depression, suicide in athletes, ADHD and stimulants, coping with injuries, drug use, and eating disorders), violence in sports (i.e., concepts of the abused athlete including sexual abuse), dealing with supervisors (i.e., coaches, parents), peers, the talented athlete, early sports specialization and sports clubs. In the second part of this discussion, we cover ergolytic agents consumed by young athletes in attempts to win at all costs. Sports doping agents covered include anabolic steroids (anabolic-androgenic steroids or AAS), androstenedione, dehydroepiandrostenedione (DHEA), human growth hormone (hGH; also its human recombinant homologue: rhGH), clenbuterol, creatine, gamma hydroxybutyrate (GHB), amphetamines, caffeine and ephedrine. Also considered are blood doping that includes erythropoietin (EPO) and concepts of gene doping. In the last section of this discussion, we look at disabled pediatric athletes that include such concepts as athletes with spinal cord injuries (SCIs), myelomeningocele, cerebral palsy, wheelchair athletes, and amputee athletes; also covered are pediatric athletes with visual impairment, deafness, and those with intellectual disability including Down syndrome. In addition, concepts of autonomic dysreflexia, boosting and atlantoaxial instability are emphasized. We conclude that clinicians and society should protect our precious pediatric athletes who face many challenges in their involvement with organized sports in a world obsessed with winning. There is much we can do to help our young athletes find benefit from sports play while avoiding or blunting negative consequences of organized sport activities.

Pathoanatomy, biomechanics, and treatment of upper cervical ligamentous instability: A literature review

BACKGROUND

Cervical spine instability broadly refers to compromise of the articular congruity. It can be stratified according to spinal level, functional compromise, and mechanism of instability. Conventional wisdom advocates for use of bracing and physical therapy with only a subset of patients proceeding to obtain surgical treatment.

OBJECTIVE

The purpose of this review article is to summarize the current state of knowledge on upper cervical ligamentous instability.

METHODS

The literature search was performed in Mendeley. Search fields were varied until redundant. All articles were screened by title and abstract and a preliminary decision to include an article was made. The full-text screening was performed on the selected articles. Any question regarding the inclusion of an article was discussed by 3 authors until an agreement was reached.

RESULTS

Many articles report on the etiological factors including ligamentous laxity, traumatic injury, syndrome instability, iatrogenic instability, congenital, and inflammatory causes. A few recent studies elucidate new findings regarding pathoanatomy through the use of finite element analysis. A few articles demonstrate the diagnosis and show that radiographs alone have a low diagnostic rate and that functional MRI may be able to better quantify instability. Conservative treatment has been described, but there are no outcome studies in the literature. Surgical treatment has been described in many different populations with good radiologic and clinical outcomes. Recently the use of preoperative 3D CT reconstruction has been described with radiographic and immediate postoperative patient-reported outcomes.

CONCLUSION

The presentation of upper cervical spinal instability can be asymptomatic, symptoms of isolated instability, symptoms of nerve irritation, vertebrobasilar insufficiency, or severe neurologic compromise. 3D fine element analysis models and motion-capture systems have the potential to increase our understanding of the pathoanatomic cascade in both traumatic and non-traumatic cases of upper cervical spinal instability. A few modalities on the horizon could increase diagnostic potential. More efforts are needed regarding the use of fine element analysis in understanding the pathoanatomic cascade, the long-term outcomes of children over a spectrum of syndromic causes, and the potential of preoperative virtual simulation to improve surgical outcomes.

Treatment of Atlantoaxial Dislocation in Children with Down Syndrome Using Posterior Atlantoaxial Screw Fixation

Background

To investigate the effect of posterior atlantoaxial screw fixation for the treatment of atlantoaxial dislocation in children with Down syndrome (DS).

Methods

Children diagnosed with DS who underwent posterior atlantoaxial screw fixation or occipitocervical fusion from January 2017 to January 2020 in Hebei Children’s Hospital were retrospectively included. Preoperative CT and MRI were performed to check the os odontoideum (OsO) and spinal cord compression, signal changes and spinal cord injury grade (ASIA grade).

Results

All 5 children have atlantoaxial dislocation and OsO. Among which 60% (3/5) of children had changes in spinal cord signals and 40% (2/5) had dural sac compression. Every child underwent posterior atlantoaxial screw fixation (3.5-mm diameter), and the average fusion level was 1.8 (1–2). All 5 cases wore the head-neck-chest brace for 3–6 months after the operation. 1 case had dural tear and recovered well after timely suturing. 1 case had internal fixation breakage of the prosthetic joint and underwent revision surgery. At the last follow-up, all cases were fused and the neurological function were all ASIA grade E.

Conclusion

After posterior atlantoaxial screw fixation, fusion and nerve recovery were achieved in all children with atlantoaxial dislocation and OsO. Postoperative head-neck-chest braces are necessary for children, especially those with occipitocervical fusion.

Treatment of Chronic Dislocated Patella in a Skeletally Mature Down Syndrome Patient: A Case Report

CASE

A 55-year-old man with Down syndrome (DS) suffered from chronic irreducible right patellar dislocation. Imaging studies showed an attenuated appearance of the medial patellar retinaculum, and the tibial tubercle to trochlear groove distance measured 1.6 cm. Right medial patellofemoral ligament reconstruction (MPFLR) and lateral lengthening (LL) with proximalization of the tibial tubercle (PTT) were performed with good surgical outcomes.

CONCLUSION

The combination of MPFLR, LL, and PTT is a viable option for treating a skeletally mature DS patient with patellofemoral instability causing recurrent patellar dislocation.

Otolaryngologic Disease in Down syndrome

As the most common human chromosomal abnormality, Trisomy 21 is a condition that many otolaryngologists and likely all pediatric otolaryngologists will encounter during their careers. There are several considerations regarding airway obstruction, otologic conditions, anesthetic implications, and endocrine disorders that will impact the treatment of these patients. Further, there is increasing literature supporting the use of early instrumental assessment of swallowing, drug-induced sleep endoscopy at the time of first surgical intervention for sleep apnea, consideration of concurrent upper and lower airway evaluation, and early otologic management including potential surgical hearing rehabilitation.

Complications of Posterior Fusion for Atlantoaxial Instability in Children With Down Syndrome

Objective

To clarify the complications of posterior fusion for atlantoaxial instability (AAI) in children with Down syndrome and to discuss the significance of surgical intervention.

Methods

Twenty pediatric patients with Down syndrome underwent posterior fusion for AAI between February 2000 and September 2018 (age, 6.1±1.9 years). C1–2 or C1–3 fusion and occipitocervical fusion were performed in 14 and 6 patients, respectively. The past medical history, operation time, estimated blood loss (EBL), duration of Halo vest immobilization, postoperative follow-up period, and intra- and perioperative complications were examined.

Results

The operation time was 257.9±55.6 minutes, and the EBL was 101.6±77.9 mL. Complications related to the operation occurred in 6 patients (30.0%). They included 1 major complication (5.0%): hydrocephalus at 3 months postoperatively, possibly related to an intraoperative dural tear. Other surgery-related complications included 3 cases of superficial infections, 1 case of bone graft donor site deep infection, 1 case of C2 pedicle fracture, 1 case of Halo ring dislocation, 1 case of pseudoarthrosis that required revision surgery, and 1 case of temporary neurological deficit after Halo removal at 2 months postoperatively. Complications unrelated to the operation included 2 cases of respiratory infections and 1 case of implant loosening due to a fall at 9 months postoperatively.

Conclusion

The complication rate of upper cervical fusion in patients with Down syndrome remained high; however, major complications decreased substantially. Improved intra- and perioperative management facilitates successful surgical intervention for upper cervical instability in pediatric patients with Down syndrome.

Effect of the Sharrard procedure on hip instability in children with Down syndrome: a retrospective study

PURPOSE

The aim of this study was to retrospectively analyze the effect of the Sharrard procedure on hip instability in children with Down syndrome (DS), as measured by the migration index.

METHODS

In total, 17 children (21 hips) were included from six hospitals in the Netherlands between 2003 and 2019. The primary outcome, hip instability, was assessed with the Reimers' migration index on preoperative and postoperative plain anteroposterior pelvic radiographs. The mean age at surgery was 8.1 years, the majority of children were male (64.7%) and the mean follow-up time was 7.3 years.

RESULTS

The mean preoperative migration index was 46% (sd 23.5) and the mean postoperative migration index was 37% (sd 28.4). The mean Delta migration index (the difference in pre-operative migration index and most recent post-operative migration index) showed an improvement of 9.3% (sd 22.7). An improvement in migration index was observed in 52%, no change in 29% and deterioration in 19% of hips. No (re)dislocations occurred in 91% of the hips. No major complications were observed during the follow-up period.

CONCLUSION

Early intervention is warranted in children with DS showing hip instability or hip migration, in order to succeed with less complex procedures. The Sharrard procedure should be considered in children with DS showing hip instability or hip migration, since it aims to rebalance the muscles of the hip joint, is less complex than bony procedures of the femur and acetabulum, surgery time is often shorter, there are fewer major complications and the rehabilitation period is shorter.

LEVEL OF EVIDENCE

IV - retrospective case series.

Footprint measurement methods for the assessment and classification of foot types in subjects with Down syndrome: a systematic review

Background

Musculoskeletal disorders, especially in the feet, are common in people with Down syndrome (DS). Evaluation of podiatric footprints is important to prevent and manage orthopedic symptoms. The reliability of a wide variety of footprint measurement methods has been evaluated in healthy people, but few studies have considered the specific morphotype features of the feet in subjects with DS. The aim of this systematic review was to identify the podometric measurement tools used to typologically classify the footprints in the population with DS.

Methods

The following electronic databases were searched for studies describing footprint measurement tools to assess and classify the foot types in patients with DS published from inception to December 2020: PubMed, Web of Science, CINAHL, and Scopus. Articles were initially searched by screening titles and abstracts. Potentially relevant studies were then further screened by reviewing full texts. Studies that met the inclusion criteria were included in the review.

Results

Of the 122 articles identified by the search strategy, 14 full texts were retained to assess for eligibility, of which 11 studies met the inclusion criteria and were included. All the studies used footprint measurement methods to classify the foot types in subjects with DS, but only two studies assessed the reliability of those methods for the population with DS. The footprint measurement tools identified were a podoscope, a pressure-sensitive mat, a PressureStat^TM carbon paper, and a 3D scanner. The Arch Index was the most common footprint measurement analyzed (seven studies). Two studies used the “gold standard” indexes that include Hernández-Corvo Index, Chippaux-Smirak Index, Staheli Index, and Clarke Angle to measure footprints.

Conclusions

There is a need to determine the reliability and validity of the footprint measurement methods used for clinical classification of the foot types in subjects with DS. This can contribute to an early diagnosis of foot abnormalities that would help to reduce mobility impairments, improving the quality of life of patients with DS.

Trisomy 21 impairs PGE2 production in dermal fibroblasts

The triplication of human chromosome 21 results in Down syndrome (DS), the most common genetic form of intellectual disability. This aneuploid condition also results in an enhanced risk of a spectrum of comorbid conditions, such as leukemia, early onset Alzheimer's disease, and diabetes. Individuals with DS also display an increased incidence of wound healing complications and resistance to solid tumor development. Due to this unique phenotype and the involvement of eicosanoids in key comorbidities like poor healing and tumor development, we hypothesized that cells from DS individuals would display altered eicosanoid production. Using age- and sex-matched dermal fibroblasts we interrogated this hypothesis. Briefly, assessment of over 90 metabolites derived from cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome p450 systems revealed a possible deficiency in the COX system. Basal gene expression and Western blotting experiments showed significantly decreased gene expression of COX1 and 2, and COX2 protein abundance in DS fibroblasts compared to euploid controls. Further, using two different stressors, scratch wound or LPS, we found that DS fibroblasts could not upregulate COX2 abundance and prostaglandin E2 production. Together, these findings show that dermal fibroblasts from DS individuals have a deficient COX2 response, which may contribute to wound healing complications and tumor resistance in DS.

Finite element modeling to compare craniocervical motion in two age-matched pediatric patients without or with Down syndrome: implications for the role of bony geometry in craniocervical junction instability

OBJECTIVE

Instability of the craniocervical junction (CCJ) is a well-known finding in patients with Down syndrome (DS); however, the relative contributions of bony morphology versus ligamentous laxity responsible for abnormal CCJ motion are unknown. Using finite element modeling, the authors of this study attempted to quantify those relative differences.

METHODS

Two CCJ finite element models were created for age-matched pediatric patients, a patient with DS and a control without DS. Soft tissues and ligamentous structures were added based on bony landmarks from the CT scans. Ligament stiffness values were assigned using published adult ligament stiffness properties. Range of motion (ROM) testing determined that model behavior most closely matched pediatric cadaveric data when ligament stiffness values were scaled down to 25% of those found in adults. These values, along with those assigned to the other soft-tissue materials, were identical for each model to ensure that the only variable between the two was the bone morphology. The finite element models were then subjected to three types of simulations to assess ROM, anterior-posterior (AP) translation displacement, and axial tension.

RESULTS

The DS model exhibited more laxity than the normal model at all levels for all of the cardinal ROMs and AP translation. For the CCJ, the flexion-extension, lateral bending, axial rotation, and AP translation values predicted by the DS model were 40.7%, 52.1%, 26.1%, and 39.8% higher, respectively, than those for the normal model. When simulating axial tension, the soft-tissue structural stiffness values predicted by the DS and normal models were nearly identical.

CONCLUSIONS

The increased laxity exhibited by the DS model in the cardinal ROMs and AP translation, along with the nearly identical soft-tissue structural stiffness values exhibited in axial tension, calls into question the previously held notion that ligamentous laxity is the sole explanation for craniocervical instability in DS.

Neurologic complications of Down syndrome: a systematic review

Down syndrome (DS) is one of the most well-recognized genetic disorders. Persons with DS are known to have a variety of co-morbid medical problems, affecting nearly all organ systems. Improved healthcare interventions and research have allowed for increased life span of persons with DS, although disorders of the neurologic system remain underexplored. The purpose of this systematic review is to provide clinically pertinent information on the neurological phenotypes of frequently occurring or clinically relevant conditions. A retrospective review of MEDLINE, Scopus, and Pubmed were used to identify sources among seventeen, clinically relevant, search categories. MeSH terms all contained the phrase "Down Syndrome" in conjunction with the topic of interest. 'Frequently-occurring' was defined as prevalent in more than 10% of persons with DS across their lifespan, whereas 'clinically-relevant' was defined as a disease condition where early diagnosis or intervention can augment the disease course. In total, 4896 sources were identified with 159 sources meeting criteria for inclusion. Seventeen clinical conditions were grouped under the following subjects: hypotonia, intellectual and learning disability, cervical instability, autism spectrum disorder, epilepsy, cerebrovascular disease, Alzheimer's disease and neuropsychiatric disease. The results of this review provide a blueprint for the clinical neurologist taking care of persons with DS across the age spectrum and indicate that there are many underrecognized and misdiagnosed co-occurring conditions in DS, highlighting the need for further research.

Anesthetic Management of Elderly Patients With Down Syndrome: A Case Report

In 1930, the life expectancy of patients with Down syndrome was about 10 years; today, their life expectancy is more than 60 years. With aging, there is an increased need for anesthesia and surgery. There is, however, no published information regarding the anesthetic management of older adults with Down syndrome. In this report, we described the anesthetic management of a 50-year-old woman with Down syndrome undergoing major cervical spine surgery. Components of the anesthetic that we thought would be difficult such as intravenous line placement and endotracheal intubation were accomplished without difficulty. Despite our best efforts, our patient nevertheless experienced both emergence delirium and postoperative vomiting. We advocate that physicians, advanced practice providers, and registered nurses be aware of the unique perianesthesia needs of older patients with Down syndrome.

Atlantoaxial dislocation due to os odontoideum in patients with Down's syndrome: literature review and case reports

PURPOSE

To clarify etiology, clinical features, and diagnostic and treatment options of atlantoaxial dislocation (AAD) due to os odontoideum (OsO) in patients with Down's syndrome (DS).

METHODS

We described and analyzed three clinical cases of AAD due to OsO in DS patients and reviewed descriptions of similar cases in the scientific sources.

RESULTS

According to literature review, more than 80% of DS patients with odontoid ossicles had atlantoaxial instability (AAI). AAI in DS patients with OsO is more often manifested in childhood and adolescence, rarely in adults when ligament relaxation is reduced. Some patients had acute clinical manifestation after a minor trauma without any precursors; in some of the cases, neurological deterioration increased during several years. We found that the earlier surgical treatment of AAD due to OsO in DS patients carries the higher recovery potential.

CONCLUSIONS

Most patients with DS and OsO had AAI. The method of appropriate treatment in such cases is a posterior screw fixation. Preoperative halo traction and posterior fusion have proved to be a very useful tool in the treatment of AAD due to OsO in DS patients. Even if irreducibility of the AAD established preoperatively, it should not be an absolute indication for anterior decompression. In such cases, an attempt to reduce the AAD should be made under general anesthesia during posterior fixation.

Efficacy of custom-fitted footwear to increase physical activity in children and adolescents with Down syndrome (ShoeFIT): randomised pilot study

PURPOSE

To determine the feasibility of conducting a definitive randomised trial to evaluate the efficacy of custom-fitted footwear for increasing physical activity in children and adolescents with Down syndrome.

METHODS

Assessor-blinded, parallel-group randomised pilot study. Thirty-three children and adolescents with Down syndrome were randomly allocated to a custom-fitted footwear group (Clarks^® footwear) or a wait-list control group. Six feasibility domains were evaluated at baseline, 6 and 12 weeks; demand (recruitment), implementation (co-interventions and adherence), acceptability, practicality (adverse events), limited efficacy testing (physical activity, disability associated with foot and ankle problems, and gait parameters), and adaptation (shoe-fit).

RESULTS

Three participants were recruited per month. The use of co-interventions was common with six control group participants purchasing new footwear during the study. Mean adherence was 35 h/week in the custom-fitted footwear group, and there were few minor adverse events. There were trends for differences in physical activity favouring the custom-fitted footwear, but no trends for differences in disability associated with foot and ankle problems or gait parameters. The fit of the custom-fitted footwear was no better than participants' regular footwear.

CONCLUSIONS

A definitive randomised trial is feasible. However, recruitment, use of co-interventions and footwear fit need further consideration.Implications for rehabilitationConducting a definitive randomised trial to determine the efficacy of custom-fitted footwear in increasing physical activity in children and adolescents with Down syndrome is feasible.Custom-fitted footwear may improve physical activity in children and adolescents with Down syndrome.Commercially available footwear may not be suitable for children and adolescents with Down syndrome due to their unique foot shape.

Musculoskeletal anomalies in children with Down syndrome: an observational study

BACKGROUND

Musculoskeletal complications of Down syndrome (DS) are common but infrequently reported. The combination of ligamentous laxity and low muscle tone contributes to increased risk of a number of musculoskeletal disorders and a delay in acquisition of motor milestones. The primary aim of this study was to describe musculoskeletal anomalies reported in a national cohort of children with DS.

METHODS

This was an observational study. Children with DS, aged 0-21 years, were invited to attend a musculoskeletal assessment clinic conducted by a paediatric physician. Relevant musculoskeletal history and clinical findings were documented.

RESULTS

Over an 18-month period, 503 children with DS were examined (56% male). The median age was 8.1 years (0.6-19.2). Pes planus was almost universal, occurring in 91% of the cohort. A range of other musculoskeletal anomalies were observed, with inflammatory arthritis (7%) and scoliosis (4.8%) occurring most frequently after pes planus. Delay in ambulation was common; the median age to walk was 28 months (12-84).

CONCLUSION

Children with DS are at increased risk of a number of potentially debilitating musculoskeletal problems. These conditions can present in variable manners or be completely asymptomatic. Pes planus is common; therefore, early consideration of orthotics and lifelong appropriate supportive footwear should be considered. Delayed ambulation is frequently noted. A significant proportion of children with DS have arthritis; however, despite a high prevalence, it is often missed, leading to delayed diagnosis. An annual musculoskeletal assessment for all children with DS could potentially enable early detection of problems, allowing for timely multidisciplinary team intervention and better clinical outcomes.

Determination of mandibular morphology in a TURKISH population with Down syndrome using panoramic radiography

Background

Down syndrome (DS) is by far the most common known chromosomal disorder. Some characteristic features of DS are generalised growth deficiency, craniofacial abnormalities such as mandibular prognathism and underdevelopment of the midfacial region, dental abnormalities such as taurodontism and hypodontia. Individuals with DS have an increased prevalence of periodontal disease compared with age-matched control patients. The aim of the present study is to determine the morphologic features of the mandible among individuals with DS.

Methods

Thirty-four DS patients and thirty four age- and gender-matched control subjects underwent panoramic radiography, which included measurement of the mandibular canal (MC), the mandibular foramen (MF), the mandibular ramus (MR), the distance from the MC to the mandibular lower border (C-MLB), and the distance between the MC and the alveolar crest upper limit (C-AUL). Patients were separated into two groups based on age: < 15 (n = 15) and ≥ 15 (n = 19). In order to determine whether the MF, MR, MC, C-AUL, and C-MLB scores differed according to the groups (DS and control), one-way multivariate analysis of covariance (MANCOVA) was applied in which gender and age were taken as covariates.

Results

When the main effect according to the group was examined separately according to each measurement, the MF in the DS group was high with a moderate effect (F = 9207; p = 0.003). MR (F = 40,518; p < 0.001), MC (F = 23,747; p < 0.001), and C-AUL (F = 58,571; p < 0.001) in the DS group were lower with a larger effect. C-MLB did not significantly differ between the groups, and the effect size was quite low (p > 0.05).

Conclusions

Mandibular canal morphology may exhibit anatomical variations in DS. The alveolar bone level may differ from non-DS due to growth development retardation and/or periodontal diseases.

Iatrogenic neurological injury in children with trisomy 21

PURPOSE

Children with trisomy 21 are at a greater risk for craniocervical junction instability than the general population. These children frequently require administration of anesthesia due to surgical (including otolaryngological) interventions and are at risk for neurological injury. We reviewed the current literature describing iatrogenic neurological injury in children with trisomy 21 undergoing anesthesia in order to facilitate the development of safety recommendations.

METHODS

A systematic review of the literature was performed using Medline, Embase, Scopus, and Google Scholar, following the PRISMA statement. All cases of perioperative neurological injury in children with trisomy 21, aged 18 and under were identified. Clinical and radiographic data were extracted for each report. The data were synthesized to develop recommendations regarding perioperative management.

RESULTS

Of 348 articles screened, 16 cases of iatrogenic neurological injury (in children ages 0.7-18 years) were identified. Three injuries occurred during otolaryngological surgeries, nine during sedation for intubation for non-otolaryngological surgery, one during sedation for neuroimaging, one while restraining a child, and two were due to intraoperative head and neck positioning while anesthetized. Preoperative screening was reported in four cases. A diagnosis of atlantoaxial instability (AAI) or atlantooccipital instability (AOI) was made immediately following symptom presentation in three cases but was often delayed by a median (IQR) of 30(11.5-912.5) days. No cases resolved spontaneously, with 2 patients progressing to brain death and 12 requiring surgical stabilization. Of the latter, seven showed improvement, whereas one died 5 months later. No intraoperative precautions during the index procedure were reported in any of the 16 cases.

CONCLUSION

Iatrogenic neurological injury in children with trisomy 21 are rare but severe and likely under reported. Although the role of preoperative screening remains controversial, all children with trisomy 21 undergoing surgery should be considered at risk for neurological injury due to confirmed or undiagnosed AAI or AOI and should be transferred and positioned with appropriate caution. Children with instability should be referred for neurosurgical attention for preoperative stabilization to mitigate perioperative risk. It is imperative to consider the possibility of neurological injury secondary to medical procedures, as it is clear that neck manipulation of any sort places these children at risk.

Knee Deformities in Children With Down Syndrome: A Focus on Knee Malalignment

BACKGROUND

Patellofemoral instability (PFI) has been the most reported knee abnormality in people with Down syndrome. Other reported knee abnormalities have been associated with PFI and different management approaches have been described with variable outcomes. The aim of this study was to describe the anatomic variations of the knee in children with Down syndrome. A comparison between knees with and without PFI was performed and our experience in treating knee abnormalities in Down syndrome was also reported.

METHODS

Records of all children with Down syndrome were reviewed. Two groups were identified (knees with and without PFI). Radiographic measurements included the mechanical and anatomic lateral distal femoral angles, medial proximal tibial angle, angle of depression of medial tibial plateau, lateral tibial translation, and distal femoral physis-joint angle. On the lateral view, Insall-Salvati and Blackburne-Peel ratios were measured. The sulcus angle was measured on the tangential view. Measurements were compared between the 2 groups (with and without PFI).Knees with PFI were divided into 3 subgroups based on their treatment (group A: surgical valgus correction, group B: surgical soft tissue procedures for PFI, and group C: conservative treatment). Preoperative radiographs were used for the surgical group and last available radiographs were used for the conservative group. Clinical and radiographic data were compared between the groups. For groups A and B, clinical and radiographic data were also compared between preoperative and last visits.

RESULTS

Of the 581 children with Down syndrome, 5% (31 children: 22 females, 9 males) had PFI in 56 knees. Mean age at diagnosis was 11.5±3.5 years. Of the remaining 550 children, 75 children had radiographs for 130 knees. Knees with PFI had significantly more valgus and a larger distal femoral physis-joint angle. Depression of the medial tibial plateau and lateral tibial translation were noted in knees with PFI. Insall-Salvati ratio was higher and the sulcus angle was larger in the PFI group.Of the 56 knees with PFI; 10 knees were in group A, 11 knees in group B, 33 knees in group C, and the remaining 2 knees had combined procedures. Preoperative mechanical and anatomic lateral distal femoral angles were smaller in group A than in group B or C. Grades of PFI improved in group B after surgery. This improvement was not noted in group A.

CONCLUSIONS

In children with Down syndrome, different variations of the knee anatomy can be found. Although PFI might be the most evident knee abnormality, other underlying deformities are common. Treatment of the PFI should be planned through a comprehensive anatomic approach that addresses all aspects of knee deformity.

LEVEL OF EVIDENCE

Level IV-prognostic and therapeutic study.

Hip Instability in Patients With Down Syndrome

The incidence of hip instability in children with Down syndrome is 1% to 7%. The natural history is often progressive, with the typical onset of hypermobility of the hip evolving to habitual dislocation, persistent subluxation, and fixed dislocation, and eventually leading to the loss of independent mobility. Treatment focuses on stabilizing the hip joint and depends on the patient's age and the severity of the disease. Typically, surgical intervention is recommended for the treatment of patients with habitual dislocation, subluxation, and complete dislocation of the hip. When indicated, surgical management must take into account associated anatomic abnormalities of the femur and acetabulum. Hip instability in Down syndrome may persist despite surgical intervention and remains a difficult condition to manage.

Spinopelvic Alignment in Subjects With Down Syndrome

STUDY DESIGN

This was a cross-sectional study.

OBJECTIVE

The aim of this study was to describe the spinopelvic alignment of subjects with Down syndrome (DS).

SUMMARY OF BACKGROUND DATA

Subjects with DS are known to suffer from a large prevalence of scoliosis. While scoliosis is known to significantly affect postural alignment, there are currently no studies on the spinopelvic alignment of subjects with DS.

MATERIALS AND METHODS

In total, 41 subjects (28 female subjects and 13 male subjects) with DS, age and sex-matched to 41 asymptomatic subjects, underwent biplanar x-rays with 3-dimensional reconstructions of their spines and pelvises, followed by measurement of commonly used spinopelvic sagittal and coronal alignment parameters. Subjects were then classified into one of Roussouly's 4 types of sagittal alignment. Alignment parameters and prevalence of alignment patterns were compared between the 2 groups.

RESULTS

Subjects with DS were found to be relatively hypokyphotic (T4-T12=-29.0 vs. -37.5 degrees; P<0.001) and hyperlordotic (L1-L5=53.8 vs. 44.3 degrees; P<0.001) with larger pelvic incidence (53.2 vs. 45.1 degrees; P<0.001), sacral slope (47.7 vs. 36.8 degrees; P<0.001), Cobb angle (10.2 vs. 8.0 degrees; P=0.005), and axial rotation of the apical vertebra (6.6 vs. 3.7 degrees; P<0.001) but had smaller pelvic tilt (4.9 vs. 8.1 degrees; P<0.001) compared with control subjects. Roussouly's type 4 was found to be the most frequent pattern in DS subjects (68.3% vs. 14.6%; P<0.001).

CONCLUSIONS

Subjects with DS were found to have a peculiar pattern of hypokyphosis, hyperlordosis, large pelvic incidence, and small pelvic tilt. The altered spinopelvic alignment found in DS could predispose these subjects to hip instability and osteoarthritis.

LEVEL OF EVIDENCE

Level III.

Foot and ankle deformities in children with Down syndrome

PURPOSE

Foot and ankle deformities are common orthopaedic disorders in children with Down syndrome. However, radiographic measurements of the foot and ankle have not been previously reported. The aim of this study is to describe the foot and ankle deformity in children with Down syndrome.

METHODS

Children who had foot and ankle radiographs in the standing weight-bearing position were selected. Three groups of patients were identified. The relationship of radiographic measurements with age, body mass index and pain is discussed. In all, 41 children (79 feet) had foot radiographs and 60 children (117 ankles) had ankle radiographs, with 15 children overlapping between Groups I and II.

RESULTS

In Group I, hallux valgus deformity was seen before ten years of age and hallux valgus angle increased afterwards. Metatarsus adductus angle showed a significant increase (p = 0.006) with obesity and was higher in patients who had foot pain (p = 0.05). In Group II, none of the ankle measurements showed a significant difference with age or body mass index percentiles. Tibiotalar angle (TTA) and medial distal tibial angle (MDTA) were higher in patients who had ankle pain. In Group III, correlation analysis was performed between the different measurements with the strongest correlations found between TTA and MDTA.

CONCLUSION

In children with Down syndrome, radiographic evaluation of the foot and ankle reveals higher prevalence of deformities than clinical examination. However, foot and ankle radiographs are needed only for symptomatic children with pain and gait changes.

LEVEL OF EVIDENCE

Level IV - Prognostic Study.

Femoral and Dega osteotomies in the treatment of habitual hip dislocation in Down syndrome patients - is it efficient or not?

PURPOSE

The purpose of this case series study is to report on the intermediate-term outcomes following a femoral varus derotational osteotomy (FVDO) performed in conjunction with a Dega osteotomy (DO) in management of hip -instability in Down syndrome (DS) patients.

METHODS

Ten hips in seven children with DS suffering from hip dislocation were included. All patients included in this study had hip dislocation in the habitual phase and painless mobile hip to full abduction. All patients were firstly subjected to FVDO. An additional DO was added if intraoperative assessment demonstrated posterior instability. The mean age at time of surgery was 5.6 years (3 to 7). There were three male and four female patients. All patients were followed up after two years with a mean follow-up of 3.27 years (2 to 5). All operations were performed by the first author.

RESULTS

There was improvement of neck shaft angles (130° to 175°, median = 160° preoperatively, to 120° to 140°, median =130° postoperatively). The Shenton line was restored in all our cases. There was also improved percentage of the femoral head uncovered by the lateral wall of the acetabulum (25° to 100° with median = 45° preoperatively, to 0° to 15° with median = 5° postoperatively) and improved posterior acetabular coverage, which was assessed by CT.

CONCLUSION

FVDO combined with DO without -capsulorrhaphy is efficient in the management of hip instability in DS, as it corrects hip biomechanics and increases posterior acetabular coverage.

LEVEL OF EVIDENCE

IV - retrospective case series.

Preliminary results of an anteverting triple periacetabular osteotomy for the treatment of hip instability in Down syndrome

PURPOSE

To investigate the outcomes of an anteverting triple periacetabular osteotomy for the treatment of hip instability in skeletally immature patients with Down syndrome.

METHODS

We evaluated 16 patients (21 hips) with Down syndrome and hip instability who underwent an anteverting triple periacetabular osteotomy between 2007 and 2016. There were nine females and seven males with an average age of 7.4 years SD 2.0. We assessed the level of hip pain, gait ability and clinical stability at a minimum of one year after surgery. Radiographic evaluation included pre- and postoperative lateral centre-edge angle (LCEA), Tönnis acetabular angle and extrusion index.

RESULT

After an average follow-up of 4.1 years SD 2.6, 20 of 21 hips (95%) remained clinically stable. In all, 12 of 16 (75%) patients had a full gait without a major limp, but three patients (19%) had a persistent limp. Of the 21 procedures, one hip (5%) was considered a failure due to persistent instability. There was a mean increase of 18.3º SD 15.3º of the LCEA (p < 0.001); a mean decrease of 15.2º SD 11.6º (p < 0.001) for the Tönnis angle and the extrusion index had a mean decrease of 0.27 SD 0.20 (p < 0.001). The most common complications were minor and included nonunion of the pubis or ischium (24%) and stress fractures of the pubis and ischium (14%). Only one patient required unplanned surgery for the treatment of an infection; which was considered a major complication.

CONCLUSION

The anteverting triple periacetabular osteotomy provided global deformity correction and achieved hip stability in 95% of the hips after a mean follow-up of 4.1 years.

LEVEL OF EVIDENCE

Therapeutic level IV.

Acetabular Global Insufficiency in Patients with Down Syndrome and Hip-Related Symptoms: A Matched-Cohort Study

BACKGROUND

The etiology of hip instability in Down syndrome is not completely understood. We investigated the morphology of the acetabulum and femur in patients with Down syndrome and compared measurements of the hips with those of matched controls.

METHODS

Computed tomography (CT) images of the pelvis of 42 patients with Down syndrome and hip symptoms were compared with those of 42 age and sex-matched subjects without Down syndrome or history of hip disease who had undergone CT for abdominal pain. Each of the cohorts had 23 male and 19 female subjects. The mean age (and standard deviation) in each cohort was 11.3 ± 5.3 years. The lateral center-edge angle (LCEA), acetabular inclination angle (IA), acetabular depth-width ratio (ADR), acetabular version, and anterior and posterior acetabular sector angles (AASA and PASA) were compared. The neck-shaft angle and femoral version were measured in the patients with Down syndrome only. The hips of the patients with Down syndrome were further categorized as stable (n = 21) or unstable (n = 63) for secondary analysis.

RESULTS

The hips in the Down syndrome group had a smaller LCEA (mean, 10.8° ± 12.6° compared with 25.6° ± 4.6°; p < 0.0001), a larger IA (mean, 17.4° ± 10.3° compared with 10.9° ± 4.8°; p < 0.0001), a lower ADR (mean, 231.9 ± 56.2 compared with 306.8 ± 31.0; p < 0.0001), a more retroverted acetabulum (mean acetabular version as measured at the level of the centers of the femoral heads [AVC], 7.8° ± 5.1° compared with 14.0° ± 4.5°; p < 0.0001), a smaller AASA (mean, 55.0° ± 9.9° compared with 59.7° ± 7.8°; p = 0.005), and a smaller PASA (mean, 67.1° ± 10.4° compared with 85.2° ± 6.8°; p < 0.0001). Within the Down syndrome cohort, the unstable hips showed greater femoral anteversion (mean, 32.7° ± 14.6° compared with 23.6° ± 10.6°; p = 0.002) and worse global acetabular insufficiency compared with the stable hips. No differences between the unstable and stable hips were found with respect to acetabular version (mean AVC, 7.8° ± 5.5° compared with 7.6° ± 3.8°; p = 0.93) and the neck-shaft angle (mean, 133.7° ± 6.7° compared with 133.2° ± 6.4°; p = 0.81).

CONCLUSIONS

Patients with Down syndrome and hip-related symptoms had more retroverted and shallower acetabula with globally reduced coverage of the femoral head compared with age and sex-matched subjects. Hip instability among those with Down syndrome was associated with worse global acetabular insufficiency and increased femoral anteversion, but not with more severe acetabular retroversion. No difference in the mean femoral neck-shaft angle was observed between the stable and unstable hips in the Down syndrome cohort.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

A podoscopic and descriptive study of foot deformities in patients with Down syndrome

INTRODUCTION

Subjects with Down syndrome (DS) are known to be affected by various foot deformities. Despite the fact that some of these deformities have been reported in the literature, a more comprehensive description would be of benefit. The aim of this study is to investigate the prevalence of known foot deformities in patients with DS and of other previously non-described foot anomalies in this population.

HYPOTHESIS

Subjects with DS have an increased prevalence of foot deformities compared to control subjects.

METHODS

Fifty-five subjects with DS (age: 14.6±7.4 years) had undergone podiatric clinical and podoscopic examinations to study their main foot deformities and their footprints, respectively. The results of these examinations were compared to those of an age-matched asymptomatic control group of fifty-three subjects (age: 13.4±11.2 years).

RESULTS

Significantly more prevalent foot deformities were found in the DS group: hallux valgus (36.4%), syndactyly between the 2nd and 3rd toes (9.1%), grade II pes planus (39.1%) and grade III pes planus (30%). Moreover, joint laxity (43.6%) was significantly more prevalent in the DS group. Furthermore, the presence of an increased space between the 1st and 2nd toes in patients with DS and its prevalence (73.6%) were described for the first time. A multivariate analysis revealed a significant relationship between the presence of joint laxity and flatfoot in only the control but not the DS group. Other foot deformities were found to be consistently more frequent in the DS population but not significantly higher than the control group.

DISCUSSION

Although subjects with DS had significantly greater joint laxity and BMI compared to the control group, neither of these factors was found to be related to the increased prevalence of flatfoot in DS patients.

LEVEL OF EVIDENCE

IV-retrospective study.

Proteolytic Cleavage of Apolipoprotein E in the Down Syndrome Brain

Down syndrome (DS) is one of the most common genetic causes of intellectual disability and is characterized by a number of behavioral as well as cognitive symptoms. Many of the neuropathological features of early-onset Alzheimer’s disease (AD) including senile plaques and neurofibrillary tangles (NFTs) are also present in people with DS as a result of triplication of the amyloid precursor gene on chromosome 21. Evidence suggests that harboring one or both apolipoprotein E4 (APOE4) alleles may increase the risk for AD due to the proteolytic cleavage of apoE4 and a subsequent loss of function. To investigate a role for the apoE proteolysis in vivo, we compared three autopsy groups; 7 DS with AD neuropathology cases over 40 years, 5 young DS cases without AD pathology under 40 years (YDS) and 5 age-matched control cases over 40 years by immunohistochemistry utilizing an antibody that detects the amino-terminal fragment of apoE. Application of this antibody, termed the amino-terminal apoE fragment antibody (nApoECF) revealed labeling of pyramidal neurons in the frontal cortex of YDS cases, whereas in the DS-AD group, labeling with nApoECF was prominent within NFTs. NFT labeling with nApoECF was significantly greater in the hippocampus versus the frontal cortex in the same DS-AD cases, suggesting a regional distribution of truncated apoE. Colocalization immunofluorescence experiments indicated that 52.5% and 53.2% of AT8- and PHF-1-positive NFTs, respectively, also contained nApoECF. Collectively, these data support a role for the proteolytic cleavage of apoE in DS and suggest that apoE fragmentation is closely associated with NFTs.

Down Syndrome Increases the Risk of Short-Term Complications After Total Hip Arthroplasty

BACKGROUND

Down syndrome is the most common chromosomal abnormality and is associated with degenerative hip disease. Because of the recent increase in life expectancy for patients with this syndrome, orthopaedic surgeons are likely to see an increasing number of these patients who are candidates for total hip arthroplasty (THA).

METHODS

Using Nationwide Inpatient Sample (NIS) data from 1998 to 2010, we compared the short-term adverse outcomes of THA among 241 patients with Down syndrome and a matched 723-patient cohort. Specifically, we assessed: (1) incidence of THA; (2) perioperative medical and surgical complications during the primary hospitalization; (3) length of stay; and (4) hospital charges.

RESULTS

The annual mean number of patients with Down syndrome undergoing THA was 19. Compared to matched controls, Down syndrome patients had an increased risk of perioperative (OR, 4.33; P<.001), medical (OR, 4.59; P<.001) and surgical (OR, 3.51; P<.001) complications during the primary hospitalization. Down syndrome patients had significantly higher incidence rates of pneumonia (P=.001), urinary tract infection (P<.001), and wound hemorrhage (P=.027). The mean lengths of stay for Down syndrome patients were 26% longer (P<.001), but there were no differences in hospital charges (P=.599).

CONCLUSION

During the initial evaluation and pre-operative consultation for a patient with Down syndrome who is a candidate for THA, orthopaedic surgeons should educate the patient, family and their clinical decision makers about the increased risk of medical complications (pneumonia and urinary tract infections), surgical complications (wound hemorrhage), and lengths of stay compared to the general population.

The incudomalleolar articulation in Down syndrome (trisomy 21): a temporal bone study

HYPOTHESIS

One reason for conductive hearing loss (HL) in patients with Down syndrome (DS) is structural anomalies in the incudomalleolar joint (IMJ) that impair sound transmission.

BACKGROUND

The majority of hearing losses in patients with DS are conductive. One reason is the high incidence of inflammatory processes such as otitis media. However, in some patients, the middle ear seems to be normal. The assumption of structural disorders causing a HL is supported by a previous study revealing structural abnormalities of the incudostapedial joint (ISJ) in these patients.

METHODS

In a retrospective analysis, histologic sections of the IMJ of 16 patients with DS were compared with 24 age- and sex-matched subjects with normal middle ear ossicles. The length of 8 parameters of the IMJ were measured at 3 positions and compared between the 2 groups.

RESULTS

Age (p = 0.318) and sex distribution (p = 1) for the DS group and the matched controls were comparable. The IMJs (p < 0.001) and the cartilage of patients with DS are significantly wider in most measurements compared with controls. However, the joint space is not significantly different in the 2 groups.

CONCLUSION

Conductive HL might be caused by a significantly wider IMJ in patients with DS supporting the findings of a previous study reporting similar findings for the ISJ. The etiology of these findings is unclear. Patients with DS have a high prevalence of deficient collagen synthesis. Immunohistochemical analysis may be needed to investigate the collagen structure of the ISJ and IMJ in patients with DS.

The association of foot structure and footwear fit with disability in children and adolescents with Down syndrome

Background

Foot deformity, flat feet, and the use of ill-fitting footwear are common in children and adolescents with Down syndrome (DS). The aim of this study was to determine whether these observations are associated with foot-specific disability in this group.

Methods

A cross-sectional study design. Foot structure (foot posture determined using the Arch Index, presence of hallux valgus and lesser toe deformities) and footwear fit (determined by length and width percentage differences between the participant’s foot and footwear) were assessed in 50 participants with DS (22 females, 28 males) aged five to 18 with a mean (SD) age of 10.6 (3.9) years. Foot-specific disability was determined using the parent-reported Oxford Ankle Foot Questionnaire for Children (OxAFQ-C). Associations between foot structure and footwear fit with the four domains (Physical, School and play, Emotional and Footwear) of the OxAFQ-C were determined using multivariate regression modelling.

Results

The mean (SD) Arch Index was 0.29 (0.08), and the prevalence of flat feet, hallux valgus and lesser toe deformities was 76%, 10% and 12% respectively. Few participants wore footwear that was too short (10%), but the use of footwear that was too narrow was common (58%). The presence of hallux valgus was significantly associated with increased disability for the OxAFQ-C School and play domain scores. The use of narrow-fitting footwear was significantly associated with increased levels of disability for the OxAFQ-C Physical, School and play, and Emotional domains. However, these variables only explained between 10% to 14% of the variance in the OxAFQ-C domain scores. There were no significant associations between foot structure and footwear fit with the OxAFQ-C Footwear domain scores.

Conclusions

Flatter feet and lesser toe deformities are not associated with foot-specific disability in children and adolescents with DS. Hallux valgus is associated with foot-specific disability during school and play activities. Ill-fitting footwear (too narrow) is common and is associated with foot-specific disability. Further research is required to identify if the relationship between narrow-fitting footwear and foot-specific disability is causal, and to identify other factors associated with foot-specific disability in children and adolescents with DS.

Aneuploidy and skeletal health

The normal human chromosome complement consists of 46 chromosomes comprising 22 morphologically different pairs of autosomes and one pair of sex chromosomes. Variations in either chromosome number and/or structure frequently result in significant mental impairment and/or a variety of other clinical problems, among them, altered bone mass and strength. Chromosomal syndromes associated with specific chromosomal abnormalities are classified as either numerical or structural and may involve more than one chromosome. Aneuploidy refers to the presence of an extra copy of a specific chromosome, or trisomy, as seen in Down's syndrome (trisomy 21), or the absence of a single chromosome, or monosomy, as seen in Turner syndrome (a single X chromosome in females: 45, X). Aneuploidies have diverse phenotypic consequences, ranging from severe mental retardation and developmental abnormalities to increased susceptibility to various neoplasms and premature death. In fact, trisomy 21 is the prototypical aneuploidy in humans, is the most common genetic abnormality associated with longevity, and is one of the most widespread genetic causes of intellectual disability. In this review, the impact of trisomy 21 on the bone mass, architecture, skeletal health, and quality of life of people with Down syndrome will be discussed.

The effects of low arched feet on foot rotation during gait in children with Down syndrome

BACKGROUND

In children with Down syndrome (DS) hypotonia and ligament laxity are characteristic features which cause a number of orthopaedic issues, such as flat foot. The aim of this study was to determine if children with flat foot are characterised by an accentuated external foot rotation during walking.

METHOD

Fifty-five children with DS and 15 typically developing children recruited as control group were assessed using three-dimensional gait analysis, using an optoelectronic system, force platforms and video recording. Parameters related to foot rotation were identified and calculated and the participants' foot morphology was assessed using the arch index.

RESULTS

Data obtained in this study showed that while DS children without flat foot displayed the foot position on the transverse plane globally close to controls during the whole gait cycle, the DS children with flat foot were characterised by higher extra-rotation of the foot in comparison with those without flat foot and controls.

CONCLUSIONS

Our results suggest that the presence of flatfoot lead the children with DS to extra-rotate their feet more than the children without flat foot. From a clinical point of view, these results could enhance the rehabilitative programmes in DS.

Relationship between flat foot condition and gait pattern alterations in children with Down syndrome

BACKGROUND

In patients with Down syndrome (DS) one of the most common abnormalities is flat foot which can interfere significantly with normal daily activities, such as gait. The aim of this study was to quantitatively assess the relationship between the flat foot and the gait alterations in DS children.

METHOD

Twenty-nine patients with DS and 15 non-affected subjects were assessed using 3D Gait Analysis, using an optoelectronic system, force platforms and video recording. The degree of flat foot was assessed using the arch index and kinematic and kinetic parameters were identified and calculated from 3D Gait Analysis for each study participant.

RESULTS

Data showed that ankle plantarflexion moment and ankle power during terminal stance were significant to differentiate the patients with and without flat feet: their peak values were significantly lower for the patients with flat foot. In addition, the research for correlation demonstrated that the higher the arch index value, the lower the peak of ankle moment and of the generated ankle power during terminal stance and the minimum of absorbed ankle power.

CONCLUSIONS

Children with flat foot displayed a less functional gait pattern in terms of ankle kinetics than children without flat foot, suggesting that the presence of flat foot may lead to a weaker efficient walking. Then, the increasing flat foot tended to result in lower push-off ability, leading to a less functional walking.

Management of hip instability in trisomy 21

The unstable hip in Trisomy 21 presents with a spectrum of hip instability with different problems at different ages. What links this multiphase problem, in many patients, is the final common pathway of untreated instability, that of a stiff, dislocated, and often-painful hip, leading to significant functional disability. Historically, the results of treating hip instability in Trisomy 21 were variable with a notable frequency of poor results. With an improved understanding of the Trisomy 21 hip in terms of its pathoanatomy and a more contemporary surgical approach to hip reconstruction, much improved results can be expected and indeed have recently been shown. The mainstay of treatment for the habitual dislocation group presenting before 8 years of age is the femoral varus derotation osteotomy. The older group presenting with painful subluxation often show signs of secondary acetabular dysplasia and thus are best treated with redirectional acetabular osteotomy with or without the use of femoral varus derotation osteotomy. The presence of radiographic features of degenerative arthritis in the fixed dislocation group precludes the use of joint-preserving techniques for hip reconstruction, and these patients can achieve excellent results with total joint arthroplasty. The natural history, historical results, assessment, treatment, and management of complications of hip instability in Trisomy 21 are addressed in this paper.

Pathologic hip morphology in cerebral palsy and Down syndrome

The pathogenesis and clinical course of hip dysplasia in cerebral palsy and Down syndrome is different than idiopathic developmental dysplasia of the hip. Unlike idiopathic developmental hip dysplasia, hip development in cerebral palsy and Down syndrome is typically normal in utero and instability develops after birth secondary to musculoskeletal disorders associated with the disease condition. For this reason, treatment protocols in Down syndrome and cerebral palsy hip dysplasia differ greatly from protocols designed to treat idiopathic hip dysplasia. The purpose of this review is to describe the pathologic hip morphology that results from cerebral palsy and Down syndrome.

Orthopedic aspects of collagen disorders

PURPOSE OF REVIEW

The purpose of this article is to provide the pediatrician with a review of disorders that have the orthopedic manifestation of joint hypermobility. Hypermobility, also termed ligamentous laxity, may present in different parts of the body at different times throughout childhood and adolescence. It may be symptomatic or incidentally found on the physical examination. Many conditions that cause joint hypermobility resolve with nonoperative management, but occasionally operative intervention is required for the best patient outcome.

RECENT FINDINGS

In addition, hypermobility may be associated with collagen disorders that affect vital organ systems. Recognition of hypermobility combined with a thorough patient evaluation may be the initial opportunity for the pediatrician to uncover disease that may be managed promptly.

SUMMARY

Heightened awareness of subtle hypermobility or symptomatic joint laxity on physical examination facilitates optimal management and favorable outcomes in children with this condition.

Imaging of the craniovertebral junction anomalies in children

The craniovertebral junction (CVJ) is interposed between the unsegmented skull and the segmented spine; it is functionally unique as it allows the complex motion of the head. Because of its unique anatomy, numerous craniometric indices have been devised. Because of its complex embryology, different from that of the adjacent skull and spine, it is commonly the seat of malformations. Because of the mobility of the head, and its relative weight, the craniovertebral junction is vulnerable to trauma. Like the rest of the axial skeleton, it may be affected by many varieties of dysplasia. In addition, the bony craniovertebral junction contains the neural craniovertebral junction and its surrounding CSF: any bony instability or loss of the normal anatomic relationships may therefore compromise the neural axis. In addition, the obstruction of the meningeal spaces at this level can compromise the normal dynamics of the CSF and result in hydrocephalus and/or syringohydromyelia. To image the CVJ, plain X-rays are essentially useless. MR is optimal in depicting the soft tissues (including the neural axis) and the joints, as well as the bone itself. CT still may be important to better demonstrate the bony abnormalities.