Cervical instability in patients with Trisomy 21: The eternal gamble

Pediatric cervical spine instability: evolving concepts

The pediatric cervical spine is structurally and biomechanically unique in comparison to adults. Guidelines to assess for cervical spine instability and standard of care treatments in the pediatric population have yet to be delineated. This is due to the rarity of the condition and the lack of multicenter data published on the topic. Our review explores the biomechanics of the pediatric cervical spine and highlights evolving concepts/research over the last several decades, with special attention to the Down syndrome and complex Chiari malformation cohorts.

The effects of Kinesio taping on static and dynamic balance in children with down syndrome: a randomized controlled trial

AIM

This study aimed to determine the effects of Kinesio tape applied to the plantar soles on static and dynamic balance in children with Down syndrome (DS).

MATERIALS AND METHODS

The study was carried out in children with DS. The participants were grouped as Kinesio Taping (KT) (n = 12, DS) and Sham Taping (ST) (n = 12, DS). The Functional Reach Test (FRT) was used to evaluate functional balance and the Fast-Timed Up and Go (FAST-TUG) test to evaluate functional balance and capacity. The Modified Clinical test of Sensory Interaction on Balance (MCTSIB) was used to evaluate static balance. For both groups, all the assessments were made three times: at baseline (T0), right after the taping application (T1), and 40-45 minutes later (T2).

RESULTS

Baseline FAST-TUG, FRT, and Eyes Open (EO) and Closed (EC) Sway velocity scores of the KT (medians- FAST-TUG:7.75 s, FRT:23.90 cm, EO: 0.70 deg/s, EC: 0.60 deg/s) and ST (medians-FAST-TUG:7.98 s, FRT:24 cm, EO: 0.85 deg/s, EC: 0.95 deg/s) groups were similar (p >0.05). Intragroup comparisons showed that FAST-TUG and FRT scores improved after the taping compared with T0 values in both KT (KT (FAST-TUG:7.75s-FRT:23.90cm)/KT1(FAST-TUG:7.55 s-FRT:28.25cm), KT(FAST-TUG:7.75s-FRT:23.90cm)/KT2(FAST-TUG:6.85s-FRT:27.50cm)) and ST groups (ST(FAST-TUG:7.98s-FRT:24cm)/ST1(FAST-TUG:7,95s-FRT:26.40cm), ST(FAST-TUG:7.98s-FRT:24cm)/ST2(FAST-TUG:7.26s-FRT:26.15cm)) (p < 0.05), while the sway velocity values were similar before and after the taping (p > 0.05).

CONCLUSIONS

Taping on the plantar soles of children with DS may be affecting the immediate dynamic balance scores while it actually did not affect the static balance scores independent of the technique used. The interpretation of the results of this study should be made with caution. Further studies with long-term evaluations are needed.

Evaluating Airway Management in Patients With Trisomy 21 in the PICU and Cardiac ICU: A Retrospective Cohort Study

OBJECTIVES

Children with trisomy 21 often have anatomic and physiologic features that may complicate tracheal intubation (TI). TI in critically ill children with trisomy 21 is not well described. We hypothesize that in children with trisomy 21, TI is associated with greater odds of adverse airway outcomes (AAOs), including TI-associated events (TIAEs), and peri-intubation hypoxemia (defined as > 20% decrease in pulse oximetry saturation [Sp o2 ]).

DESIGN

Retrospective database study using the National Emergency Airway Registry for Children (NEAR4KIDS).

SETTING

Registry data from 16 North American PICUs and cardiac ICUs (CICUs), from January 2014 to December 2020.

PATIENTS

A cohort of children under 18 years old who underwent TI in the PICU or CICU from in a NEAR4KIDS center. We identified patients with trisomy 21 and selected matched cohorts within the registry.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 8401 TIs in the registry dataset. Children with trisomy 21 accounted for 274 (3.3%) TIs. Among those with trisomy 21, 84% had congenital heart disease and 4% had atlantoaxial instability. Cervical spine protection was used in 6%. The diagnosis of trisomy 21 (vs. without) was associated with lower median weight 7.8 (interquartile range [IQR] 4.5-14.7) kg versus 10.6 (IQR 5.2-25) kg ( p < 0.001), and more higher percentage undergoing TI for oxygenation (46% vs. 32%, p < 0.001) and ventilation failure (41% vs. 35%, p = 0.04). Trisomy 21 patients had more difficult airway features (35% vs. 25%, p = 0.001), including upper airway obstruction (14% vs. 8%, p = 0.001). In addition, a greater percentage of trisomy 21 patients received atropine (34% vs. 26%, p = 0.004); and, lower percentage were intubated with video laryngoscopy (30% vs. 37%, p = 0.023). After 1:10 (trisomy 21:controls) propensity-score matching, we failed to identify an association difference in AAO rates (absolute risk difference -0.6% [95% CI -6.1 to 4.9], p = 0.822).

CONCLUSIONS

Despite differences in airway risks and TI approaches, we have not identified an association between the diagnosis of trisomy 21 and higher AAOs.

Preoperative radiological indicators for prediction of difficult laryngoscopy in patients with atlantoaxial dislocation

Background

Difficult airway remains a great challenge in patients with atlantoaxial dislocation (AAD). Preoperative evaluation and reliable prediction are required to facilitate the airway management. We aimed to screen out reliable radiological indicators for prediction of difficult laryngoscopy in patients with AAD.

Methods

A retrospective nested case-control study within a single center longitudinal AAD cohort was conducted to investigate the radiological indicators. All the patients with difficult laryngoscopy from 2010 to 2021 were enrolled as the difficult laryngoscopy group. Others in the cohort without difficult laryngoscopy were randomly selected as the non-difficult laryngoscopy group by individually matching with the same gender, same surgery year, and similar age (±5 years) at a ratio of 6:1. Radiological data on preoperative lateral X-ray images between the two groups were compared. Bivariate logistic regression model was applied to screen out the independent predictive indicators and calculate the odds ratios of indicators associated with difficult laryngoscopy. Receiver operating characteristic curve and area under the curve (AUC) were used to describe the discrimination ability of indicators.

Results

A total of 154 patients were finally analyzed in this study. Twenty-two patients with difficult laryngoscopy and matched with 132 controls. Four radiological parameters showed significant difference between the two groups. Among which, ΔC1C2D (the difference of the distance between atlas and axis in the neutral and extension position), owned the largest AUC.

Conclusions

ΔC1C2D could be a valuable radiologic predictor for difficult laryngoscopy in patients with AAD.

Intraoperative neural monitoring during head and neck surgery in patients with concern for cervical spine instability

Cervical and craniocervical instability are associated with catastrophic procedural outcomes. We discuss three individuals who required otolaryngologic surgical intervention: two with symptomatic spinal instability and one in whom spinal stability was unable to be assessed. Two cases were managed with procedural positioning precautions and evoked potential monitoring, and the other with procedural positioning precautions alone. Methods of monitoring and triggers for repositioning are discussed. This series is intended to discuss the approach and potential added value of evoked potential monitoring for risk mitigation in pediatric patients with concern for cervical spine instability.

Long-Term Outcomes After External Maxillary Distraction Surgery in Patients With Down Syndrome

BACKGROUND

Patients with Down syndrome have severe facial deformities that can precipitate functional consequences and social stigmatization. Craniofacial surgical intervention can play a role in improving these symptoms and patient quality of life. The objective of this study was to investigate the long-term outcomes of distraction osteogenesis and orthognathic surgical intervention in patients with Down syndrome.

MATERIALS AND METHODS

Charts of 3 patients with Down syndrome who were treated with external maxillary distraction osteogenesis were retrospectively reviewed. The patients' caregivers were prospectively interviewed between 10 and 15 years after surgery to determine surgical stability, long-term function, and quality of life status.

RESULTS

All patients and their caregivers reported excellent results with improvements in function and quality of life. Facial skeletal changes have been stable over time. The cephalometric analysis demonstrated significant maxillary advancement in all 3 patients and mandibular changes to correct mandibular prognathism and asymmetry in the patient who underwent finishing orthognathic surgery.

CONCLUSIONS

External maxillary distraction osteogenesis and orthognathic surgery may be considered in select patients with Down syndrome as part of their multidisciplinary health care. These interventions can result in long-term improvements in patient function and quality of life.

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.

Down Syndrome: A Review of Key Perioperative Implications

Down syndrome (DS) is the most common chromosomal abnormality in humans that is compatible with life. This syndrome occurs when there is an extra copy of the 21st chromosome. Down syndrome is associated with numerous comorbidities that can pose challenges for the perioperative nurse caring for a patient with DS undergoing surgery. These challenges can affect the patient assessment, communication with the patient, and patient safety (eg, preventing complications). As the life expectancy of people with DS has increased, so too have the chances that perioperative nurses will care for a patient with this disorder. This article reviews the pathophysiology of DS, discusses common comorbidities that may directly affect perioperative care, and reviews an exemplar case study that demonstrates how personnel with knowledge of DS can positively influence surgical team decision making for these patients in the perioperative setting.

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.

Neurosurgical Evaluation and Management of Patients with Chromosomal Abnormalities

Patients with chromosomal abnormalities are at risk for numerous neurosurgical pathologies, given the broad impact and multisystem involvement of these disorders. Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), Klinefelter syndrome (47,XXY), and velocardiofacial or DiGeorge syndrome (22q11.2 deletion) are particularly associated with neurosurgical concerns. Given the heterogeneity of concerns and presentations, these patients benefit from multidisciplinary care provided by teams familiar with their specific syndrome.

Repeat Pediatric Trisomy 21 Radiographic Exam: Does Atlantoaxial Instability Develop Over Time?

BACKGROUND

Atlantoaxial instability (AAI) is common in pediatric patients with Trisomy 21 and can lead to spinal cord injury during sports, trauma, or anesthetized neck manipulation. Children with Trisomy 21 therefore commonly undergo radiographic cervical spine screening, but recommendations on age and timing vary. The purpose of this study was to determine if instability develops over time.

METHODS

We performed a retrospective review for all pediatric Trisomy 21 patients receiving at least 2 cervical spine radiographic series between 2008 and 2020 at our institution. Atlantodens interval (ADI) and space available for the cord at C1 (SAC) were measured; bony abnormalities such as os odontoidium, and age and time between radiographs were noted. AAI was determined by ADI ≥6 mm or SAC ≤14 mm based on our groups' prior study. Those who developed instability were compared with those who did not.

RESULTS

A total of 437 cervical spine radiographic series from 192 patients were evaluated, with 160 included. Mean age at first radiograph was 7.4±4.4 years, average ADI was 3.1 mm (±1.2), and SAC was 18.1 mm (±2.6). The average time between first and last radiographs was 4.3 years (±1.8), with average final ADI 3.2 mm (±1.4) and SAC 18.9 mm (±2.9). Seven patients (4%) had instability: 4 were unstable on their initial studies and 3 (1.6%) on subsequent imaging. Os odontoideum was found in 5 (71%) unstable spines and 3 (2%) stable spines (P<0.0001); only 1 patient that became unstable on subsequent radiograph did not have an os. There was no specific age cut-off or surveillance time period after which one could be determined no longer at risk.

CONCLUSIONS

Trisomy 21 patients have a 4.4% overall rate of AAI in our series with a 1.6% rate of progression to instability over ∼4 years. Given this nearly 1 in 23 risk of instability, we recommend initial surveillance radiograph for all children over 3 years with Trisomy 21; repeat asymptomatic surveillance should continue in those with os odontoideum given their high instability risk.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Reproducibility and diagnostic value of a new method using ratios to diagnose anterior atlanto-axial subluxation on plain radiographs

OBJECTIVES

Measures on conventional radiography are used to detect, especially in rheumatoid arthritis, upper cervical spine instabilities (CSIs) with the anterior and posterior atlanto-dental intervals (AADI and PADI) measurements. Our objective was to evaluate the diagnostic performance and reliability of AADIs and PADIs extrapolated based on ratios in assessing anterior atlanto-axial subluxation (aAAS) when plain radiographs do not allow the measures.

METHODS

Radiographies of 119 patients were randomly selected. Two blinded observers performed two measurements of the odontoid sagittal diameter (O), axis body base sagittal diameter (C2), AADI, PADI, Clark station and Ranawat index, and the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios were calculated. The diagnostic value of AADI and PADI extrapolated from the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios was evaluated using ROC curves, with AADI>2.9mm used as the gold standard.

RESULTS

Among the 119 patients, 12 patients had aAAS (AADI>2.9mm), 6 of them had severe aAAS (AADI>8.9mm and/or a PADI<14mm), and 6 patients had vertical AAS (Clarks station=2 or 3 and/or Ranawat index<13mm). The AADI extrapolated from the AADI/O and AADI/C2 ratios has excellent intra- and inter-observer reproducibility. The diagnostic value of the extrapolated AADI was high for aAAS (sensitivity 92%; specificity of 100%) and severe aAAS (sensitivity75%; specificity 100%). The diagnostic value of the extrapolated PADI was good but lower than the diagnostic value of the extrapolated AADI.

CONCLUSION

Extrapolated AADI can be used instead AADI to detect aAAS and severe aAAS.

Usefulness of ipsilateral translaminar C2 screws insertion for cervical fixation in children with a low laminar profile: a technical note

PURPOSE

The fusion of the upper cervical spine in children is demanding due to its reduced size, its anatomical complexity, or a severe pathology of the cranio-cervical junction. In some pediatric patients with today's more popular C1-C2 or, occipito-C2 techniques, it is impossible, or very risky to perform a short upper cervical fixation.

METHODS

We present the utility and good results of ipsilateral laminar C2 screws insertion technique in two pediatric cases with low C2 laminar profile. Case 1: a 5-year-old child with a C1-C2 unstable subluxation, and a condylar assimilation of C1, where we performed an occipito-C2 fixation using an occipital plate and this modified translaminar C2 screw technique. Case 2: a 8-year-old Down syndrome boy who suffered an unstable subluxation of C1-C2 upon whom we performed a C1-C2 screw fixation using the same technique.

RESULTS

Both cases have been followed up over a period of 7 and 2 years respectively, with good clinical results.

CONCLUSIONS

We describe the technique and the feasibility of the ipsilateral insertion of translaminar C2 screws in children with low laminar profiles, as a good alternative to other techniques when the anatomy of the C2 does not permit its use or make them very risky.

Evaluation of 2011 AAP cervical spine screening guidelines for children with Down Syndrome

PURPOSE

Atlantoaxial instability (AAI) has a higher incidence rate among individuals with Down syndrome (DS) than the non-DS population. In 2011, the American Academy of Pediatrics (AAP) updated its AAI screening guidelines for children with DS from radiographic screening to radiographs only if there are clinical symptoms suggestive of cervical spine pathology. An assessment of whether this alteration has been associated with an increase in AAI-associated spinal cord injury has not been undertaken.

METHODS

We provide the first neurosurgical review of a large experience implementing the 2011 AAP guidelines. We reviewed the courses of patients with DS seen at the Sie Center for Down Syndrome at Children's Hospital Colorado who were evaluated for cervical spine disease and determined whether screening radiographic imaging could have led to earlier diagnosis or prevented development of neurological deficits. We also report an illustrative case of a 5-year-old female with Down syndrome who presented with instability after normal screening radiographs per the pre-2011 guidelines.

RESULTS

The clinical experience of the Sie Center demonstrates that even when limiting imaging to patients who show signs or symptoms of spine pathology, the vast majority of x-rays are negative. Our exemplary patient presented to the emergency department for neck pain without a history of significant trauma. She was diagnosed and treated for atlantoaxial subluxation associated with os odontoideum.

CONCLUSION

Routine radiographic screening may not be sufficiently predictive of DS individuals at risk to develop AAI. This experience supports the appositeness of the de-escalation of care asserted by the guidelines.

Use of recombinant human bone morphogenetic protein for revision cervical spine fusion in children with Down syndrome: a case series

OBJECTIVE

Patients with trisomy 21 (Down syndrome; DS) often have atlantoaxial instability (AAI), which, if severe, causes myelopathy and neurological deterioration. Children with DS and AAI who undergo cervical spine fusion have a high rate of nonunion requiring revision surgery. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a TGF-β growth factor that is used to induce bone formation in spine fusion. Although previous studies in the adult population have reported no reduction in pseudarthrosis rates with the use of rhBMP-2, there is a lack of literature in the pediatric DS population. This study describes the use of rhBMP-2 in children with DS and AAI during revision to treat nonunion.

METHODS

A retrospective review of a cervical spine fusion database (n = 175) was conducted. This database included all cervical spine fusions using modern instrumentation at the authors' institution from 2002 to 2019. Patients with DS who underwent a revision utilizing rhBMP-2 were included in the study. The number of prior fusions, use of rhBMP-2 in fusions, length of stay, halo use, and surgical data were collected. Postoperative complications and length of follow-up were also recorded.

RESULTS

Eight patients (75% female) met the inclusion criteria. The average age at revision with rhBMP-2 was 11 years (range 3-19 years). All patients were diagnosed with nonunion after an initial cervical fusion. All revisions were posterior fusions of C1-2 (n = 2) or occiput to cervical (n = 6). All revisions included implant revisions, iliac crest bone grafting, and rhBMP-2 use. One patient required irrigation and debridement of an rhBMP-induced seroma. Another patient required return to the operating room to repair a dural tear. There were no neurological, infectious, airway, or implant-related complications. Revision utilizing rhBMP-2 achieved fusion in 100% (n = 8) of patients. The average length of follow-up was 42.6 months. All patients demonstrated solid fusion mass on the last radiograph.

CONCLUSIONS

This is the first case series reporting the successful use of rhBMP-2 to facilitate cervical spine fusion in patients with DS after previous nonunion. In addition, few rhBMP-2-related postoperative complications occurred.