Dysplasias in the Child's Spine.

Many of the skeletal dysplasias impact the spinal column causing scoliosis, kyphosis, stenosis, and/or instability at various segments of the spine. Understanding how a particular dysplasia is likely to manifest is important to ensure proper screening and treatment decisions. Equally important is understanding the natural history of specific spine abnormalities, such as awareness of the resolution of the cervical kyphosis common to infants with diastrophic dysplasia. Many patients with rarer dysplasias are best cared for by teams of providers including neurosurgeons, orthopedic surgeons, geneticists, pulmonologist, and anesthesiologists who are familiar with the various issues surrounding each particular dysplasia.

Anesthetic Concerns of Children With Skeletal Dysplasia.

Children with skeletal dysplasia present unique challenges for safe anesthetic care including differences in the anatomy of the respiratory system, possibility of cervical spine instability or spinal stenosis, and a unique body habitus. Even seemly routine anesthesia can result in respiratory arrest or spinal cord injury. These complications can largely be avoided by proper planning such as appropriate techniques for the intubation of difficult airways, recognition of cervical instability, neuromonitoring for any anesthesia over an hour in patients with severe spinal stenosis, and preoperative assessment of the trachea and avoidance of neuraxial anesthesia in children with Morquio syndrome.

Achondroplasia Natural History Study (CLARITY): 60-year experience in cervicomedullary decompression in achondroplasia from four skeletal dysplasia centers.

OBJECTIVE: The authors sought to determine the overall incidence of cervicomedullary decompression (CMD) in patients with achondroplasia and the characteristics associated with those surgeries across multiple institutions with experience caring for individuals with skeletal dysplasias. METHODS: Data from CLARITY (Achondroplasia Natural History Study) for 1374 patients with achondroplasia from four skeletal dysplasia centers (A. I. duPont Hospital for Children, Johns Hopkins University, University of Texas Health, and University of Wisconsin School of Medicine and Public Health) followed from 1957 to 2017 were recorded in a Research Electronic Data Capture (REDCap) database. Data collected and analyzed included surgeries, indications, complications, ages at time of procedures, screening procedures, and medical diagnoses. RESULTS: There were 314 CMD procedures in 281 patients (20.5% of the entire cohort). The median age of first CMD was 1.3 years in males and 1.1 years in females. Over time, there was a decrease in the median age of patients at first CMD. All patients born before 1980 who underwent CMD had the procedure after 5 years of age, whereas 98% of patients born after 2010 underwent CMD before 5 years of age. In addition, a greater proportion of patients born in more recent decades had documented neuroimaging and polysomnography (PSG) prior to CMD. Ventriculoperitoneal shunts (VPSs) were placed more frequently in patients undergoing CMD (23%) than in the entire cohort (8%). Patients who required either CMD or VPS were 7 times more likely to require both surgeries than patients who required neither surgery (OR 7.0, 95% CI 4.66-10.53; p < 0.0001). Overall, 10.3% of patients who underwent CMD required a subsequent CMD. CONCLUSIONS: The prevalence of CMD in this large achondroplasia cohort was 20%, with more recently treated patients undergoing first CMD at younger ages than earlier patients. The use of neuroimaging and PSG screening modalities increased over time, suggesting that increased and better surveillance contributed to earlier identification and intervention in patients with cervicomedullary stenosis and its complications.

Racial and sex disparities in HIV screening outcomes within emergency departments of Harris County, Texas.

OBJECTIVES: The emergency department provides opportunities for identifying undiagnosed HIV cases. We sought to describe the racial and sex epidemiology of HIV through ED screening in Harris County, Texas, one of the most diverse and populous metropolitan cities in the Southern United States. METHODS: We used a descriptive secondary analysis of a universal HIV screening program (2010-2017) to quantify demographic differences in HIV incidence. We applied a validated codebook to a dataset by the local health department containing 894,387 records of ED visits with 62 variables to assess race/ethnicity and sex differences. RESULTS: Of 885,199 (98.9%) patients screened for HIV during an ED visit, 1795 tested positive (incidence rate = 0.2%). Of those tested for HIV, most were White (66.3%), followed by racial minorities (African Americans (29.9%), Asians (3.6%), and American Indian, Alaska Native, Native Hawaiian or Pacific Islanders (natives) (0.1%). Half of those tested were Hispanic. Conversely, of patients testing positive (n = 1782, 99.3% of positive cases), most were African American (52.6%) followed by Whites (46.6%), Asians (0.7%), and natives (0.1%). Less than half (35.5%) of positives were Hispanic. A racial disparity in HIV incidence was discovered among African American females. This group represented 16.8% of the tested population; yet accounted for 65.8% of females who tested positive for HIV and 20.3% of all HIV-positive test results. CONCLUSION: Descriptive findings of the racial and sex epidemiology of HIV revealed that African American females had the largest disparity between the population tested and those who tested positive for HIV.

Basilar impression in osteogenesis imperfecta treated with staged halo traction and posterior decompression with short-segment fusion.

Basilar impression is a cranial base abnormality associated with osteogenesis imperfecta (OI) with serious neurologic implications but controversial treatment options. Combined anterior and posterior decompression with long-segment posterior fusion is often recommended. We report a patient with OI (Sillence type III) with basilar impression treated with halo traction followed by posterior surgery. The patient was a 12-year-old female with a presentation of hiccups and change in upper extremity function. Diagnostic imaging revealed syringomyelia, compensated hydrocephalus, basilar impression, and Chiari type I malformation. The patient was treated with halo traction followed by posterior decompression fusion from the occipital bone to C2. Bone fusion and improved syrinx were evident on images during the 5 years of follow-up. Five years after surgery, syrinx recurred and the fourth ventricular catheter was revised. The treatment with halo traction followed by posterior-only surgery of basilar impression associated with OI resulted in a good postoperative outcome.

Upper Cervical Fusion in Children With Spondyloepiphyseal Dysplasia Congenita.

BACKGROUND: Paraplegia or death secondary to upper cervical spine instability and spinal cord compression are known consequences of spondyloepiphyseal dysplasia congenita (SEDC). Stabilization and occasionally decompression of the upper cervical spine are indicated to treat upper cervical instability and stenosis. The purpose of this study was to report the results of upper cervical spine fusion in children with SEDC who had upper cervical instability. METHODS: Twenty children (17 females and 3 males) with SEDC who underwent upper cervical spine fusion at a mean age of 72 months were retrospectively analyzed. Three of these children were under the age of 2. Fifteen children had posterior instrumentation and fusion whereas 5 children had posterior in situ fusion without use of any implant. Thirteen of 20 children had iliac crest autograft. Radiographic and clinical results were reported. RESULTS: The average follow-up period was 8 years and 8 months. All children with instrumentation achieved fusion. Three of 5 children who had no instrumentation had nonunion (1 child had a stable nonunion and did not need revision; 1 had a single noninstrumented revision and ended up with a stable nonunion without further intervention; and the third one had a noninstrumented revision and had to have a second, instrumented, revision to achieve fusion). Six children had thoracolumbar scoliosis or kyphoscoliosis which required surgical management.No postoperative neurological deficits were observed. Two of the 3 children with a preoperative neurological deficit showed full recovery and the third one remained unchanged. Pseudarthrosis is the main complication for the noninstrumented group. Distal junctional instability after successful fusion is seen at long-term follow-up (average=6 y) for 13% of patients in instrumented group. CONCLUSIONS: Instrumentation and iliac bone grafting results in 100% upper cervical fusion for SEDC children who demonstrated instability before surgery. LEVEL OF EVIDENCE: Level IV-therapeutic.

Best practices in the evaluation and treatment of foramen magnum stenosis in achondroplasia during infancy.

Achondroplasia is the most common inherited disorder of bone growth (skeletal dysplasia). Despite this fact, consistent and evidence-based management approaches to recognized, life-threatening complications, such as foramen magnum stenosis, are lacking. This study aims to outline best practice, based on evidence and expert consensus, regarding the diagnosis, assessment, and management of foramen magnum stenosis in achondroplasia during infancy. A panel of 11 multidisciplinary international experts on skeletal dysplasia was invited to participate in a Delphi process. They were: 1) presented with a list of 26 indications and a thorough literature review, 2) given the opportunity to anonymously rate the indications and discuss in face to face discussion; 3) edit the list and rate it in a second round. Those indications with more than 80% agreement were considered as consensual. After two rounds of rating and a face-to-face meeting, consensus was reached to support 22 recommendations for the evaluation and treatment of foramen magnum stenosis in infants with achondroplasia. These recommendations include indications for surgical decompression, ventriculomegaly, and hydrocephalus, sleep-disordered breathing, physical exams and the use of polysomnography and imaging in this condition. We present a consensus-based best practice guidelines consisting of 22 recommendations. It is hoped that these guidelines will lead to more uniform and structured evaluation, standardizing care pathways, and improving mortality and morbidity outcomes for this cohort.

Occipitocervical fusion in skeletal dysplasia: a new surgical technique.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study describes clinical and radiological results of a new cable technique for occipitocervical fusion (OCF) in children with skeletal dysplasia (SD). SUMMARY OF BACKGROUND DATA: Anatomical variability and poor bone quality make upper cervical surgery technically challenging in patients with SD. We present a new cable technique for OCF in children with SD when the posterior elements are not of a size or quality for other types of instrumentation. METHODS: Retrospective review of 24 patients with SD (8 boys, 16 girls) who underwent OCF between 2001 and 2011. In this technique, cables provide compression across a bone graft that is prevented from entering the canal and the graft resists excessive lordosis. Demographic and radiographical data are presented. All patients were followed for initial outcomes of surgery, and 20 patients (83%) were followed for 2 years or more for mid- and long-term outcomes. RESULTS: Mean age at surgery was 6.5 years and mean follow-up was 4.1 ± 2.4 years. This technique was used as a primary procedure in 20 and a revision procedure in 4 patients. Diagnoses included Morquio syndrome (6), spondyloepiphyseal dysplasia (9), spondyloepimetaphyseal dysplasia (5), metatropic dysplasia (3), and Kniest syndrome (1). Ten patients had upper cervical instability and features of cervical myelopathy, and the remaining 14 patients had instability and signal changes on magnetic resonance image. Fusion extended from occiput to C2 in 71% patients, and upper cervical decompression was needed in 92% patients. Postoperatively, all patients were immobilized in a halo vest for mean duration of 12 weeks. Fusion was achieved in all patients. Complications included halo pin-tract infections (7), junctional instability (2), and extension of fusion (4). CONCLUSION: This new cable technique is a good alternative for OCF in patients with SD who have altered anatomy at the craniocervical junction not amenable to rigid internal fixation. LEVEL OF EVIDENCE: 4.

Quality measures for the management of hydrocephalus: concepts, simulations, and preliminary field-testing.

OBJECT: The authors define and examine the properties of 2 new, practice-based quality measures for the management of hydrocephalus. METHODS: The Surgical Activity Rate (SAR) is defined as the number of definitive operations for the treatment of hydrocephalus performed in a neurosurgical practice over the course of a year, divided by the number of patients with hydrocephalus seen in follow-up during that year. The Revision Quotient (RQ) is defined as the number of definitive revision operations performed in a neurosurgical practice in the course of a year, divided by the number of definitive initial operations during that year for patients with newly diagnosed hydrocephalus. Using published actuarial shunt survival data, the authors conducted Monte Carlo simulations of a pediatric neurosurgical practice to illustrate the properties and interpretations of the SAR and RQ. They used data from the Kids' Inpatient Database (KID) for 2009 to calculate RQs for hospitals accounting for more than 10 admissions coded for initial CSF shunt insertions. RESULTS: During the initial growth phase of a simulated neurosurgical practice, the SAR approached its steady-state value much earlier than the RQ. Both measures were sensitive to doubling or halving of monthly failure rates. In the 2009 KID, 117 hospitals reported more than 10 initial shunt insertions. The weighted mean (± standard deviation) RQ for these hospitals was 1.79 ± 0.69. Among hospitals performing 50 or more initial shunt insertions, the RQ ranged between 0.71 and 3.65. CONCLUSIONS: The SAR and RQ have attractive qualitative features as practice-based quality measures. The RQ, at least, exhibits clinically meaningful interhospital variation as applied to CSF shunt surgery. The SAR and RQ merit prospective field-testing as measures of quality in the management of childhood hydrocephalus.

Flexion-extension cervical spine MRI in children with skeletal dysplasia: is it safe and effective?

BACKGROUND: Skeletal dysplasias may be associated with cervical spinal instability or stenosis. Cervical spine flexion-extension plain radiographs in children with skeletal dysplasia are difficult to interpret. The purpose of this study was to review the indications, efficacy, and safety of performing flexion-extension magnetic resonance imaging (MRI) under sedation/anesthesia in these children. METHODS: Retrospective, Institutional Review Board-approved review of 31 children with skeletal dysplasia who underwent 38 cervical spine flexion-extension MRI studies under sedation/anesthesia. Indications included abnormal neurological examination, suspected instability, stenosis, or inconclusive findings on flexion-extension radiographs. Studies were performed by the radiology technologist as directed by the radiologist with an anesthesiologist present. MRI was evaluated for odontoid hypoplasia, os odontoideum, cerebrospinal fluid effacement, cord compression, spinal cord changes, cervical canal narrowing in the neutral, flexion, and extension positions. Neurological examinations were recorded before and after MRI to assess safety. RESULTS: The average age at MRI was 3 years, 2 months. In 6 patients whose plain radiographs showed C1-C2 or subaxial instability, flexion-extension MRI showed no cord compression. Nine patients with inconclusive plain radiographs had abnormal MRI findings. An os odontoideum not seen on plain radiographs was diagnosed in 3 patients on flexion-extension MRI. On the basis of the MRI findings, 14 patients underwent surgery, 9/14 had increased cord compression in flexion or extension compared with neutral, and observation was continued in 17 others. Patients who underwent surgery had significant cord compression on MRI. There were no significant changes in the neurological examinations after MRI. CONCLUSIONS: Cervical spine flexion-extension MRI under sedation/anesthesia in children with skeletal dysplasia is safe under adequate supervision and is necessary to guide accurate medical and surgical decision making. Flexion-extension MRI is useful for identifying dynamic changes in canal diameter resulting in cord compression not seen on plain radiographs, and it is also useful for identifying patients with suspected plain film instability who may not have stenosis or cord compression on MRI. STUDY DESIGN: Level IV-retrospective case series.

Spinal cord injury without radiographic abnormality and the Chiari malformation: controlled observations.

BACKGROUND: Case reports have suggested an association between the Chiari malformation type 1 (CM1) and spinal cord injury without radiographic abnormality (SCIWORA). No controlled observations have appeared. We report a case-control study. METHODS: The Kids' Inpatient Database (KID) is a product of the Healthcare Utilization Project of the Agency for Healthcare Research and Quality. For the years 1997, 2000, 2003, 2006, and 2009, the KID includes discharge data abstracted from almost 14 million pediatric admissions. We hypothesized that CM1 predisposes children to SCIWORA in the cervicomedullary region, and we reasoned that, if this hypothesis were true, then KID admissions coded for upper cervical SCIWORA would be associated with CM1 more frequently than admissions coded for lower cervical SCIWORA. RESULTS: After exclusion of admissions with a variety of confounding diagnostic codes, we identified 754 admissions coded for upper cervical SCIWORA and 424 coded for lower cervical SCIWORA. Concurrent coding for CM1 was more prevalent among admissions coded for upper cervical SCIWORA than for lower cervical SCIWORA, but the difference did not attain statistical significance (p = 0.093; Fisher's exact test). CONCLUSIONS: These controlled observations fail to support the hypothesis that CM1 is associated with SCIWORA in childhood. If there is a real association, in the context of recent estimates of the prevalence of CM1 in the pediatric population, the magnitude of the incremental risk must be very small.

Initial experience with combined endoscopic third ventriculostomy and choroid plexus cauterization for post-hemorrhagic hydrocephalus of prematurity: the importance of prepontine cistern status and the predictive value of FIESTA MRI imaging.

PURPOSE: Post-hemorrhagic hydrocephalus of prematurity (PHHP) is among the most common causes of infant hydrocephalus in developed nations. This population has a high incidence of shunt failure, infection, and slit ventricle syndrome. Although effective for other etiologies of infant hydrocephalus, the efficacy of combined endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) in PHHP has not been investigated. This pilot study reports the initial experience. METHODS: Ten patients (four grade III and six grade IV intraventricular hemorrhage) requiring definitive treatment for PHHP underwent ETV/CPC within 6 months of birth. Seven had a prior ventriculo-subgaleal shunt. Mean age at birth was -12.8 weeks, or 25.2 weeks gestation (24-28 weeks), and at surgery was -1.6 weeks (-11 to +11 weeks). Mean weight at surgery was 3.3 (1.0-5.5 kg). Each patient had preoperative magnetic resonance imaging (MRI) with fast imaging employing steady-state acquisition (FIESTA). RESULTS: Four of ten (40%) required no further operations related to hydrocephalus (mean follow-up, 29.7 months). Six required another procedure (five ultimately shunted). Prepontine cistern status correlated with outcome (p = 0.033). Procedures in all infants with unobstructed cisterns were successful but failed in six of seven with cisternal obstruction, with the one success having an alternative lamina terminalis endoscopic third ventriculostomy. Preoperative MRI FIESTA images correlated well with intraoperative assessment of the cistern. CONCLUSIONS: Results from this small homogenous cohort suggest cistern status is an important determinant of outcome. FIESTA imaging correlated with endoscopic observation. Preliminary analysis suggests ETV/CPC as an effective treatment for PHHP, but only when the cistern is unscarred. This information should guide patient selection for future study protocols.

Level of the conus in pediatric patients with skeletal dysplasia.

OBJECT: Skeletal dysplasias are a heterogeneous group of disorders that affect bone development and can result in reduced vertebral body growth and short stature. The level of the conus medullaris is unknown in this population. The purpose of this review was to determine the level of the conus in a population of pediatric patients with skeletal dysplasia. METHODS: A retrospective chart review of a 7-year period was undertaken at a tertiary care pediatric hospital to identify patients in whom skeletal dysplasia had been diagnosed. Radiographs and MR imaging studies were evaluated to discern the level of the conus with respect to the bony vertebral column. RESULTS: Four hundred sixty-seven patients with skeletal dysplasia were identified. One hundred eleven patients had quality MR images. Forty-seven different skeletal dysplasias were observed. The mean conus level was found at the L-1 vertebral body. No difference was noted with respect to the age of the patients or the type of skeletal dysplasia. Two patients (1.7%) had a conus level lower than L-2. CONCLUSIONS: Skeletal dysplasia leads to abnormal bone formation and can result in short stature. The location of the conus with respect to the vertebral bodies appears to be stable at the L-1 level regardless of patient age or the type of skeletal dysplasia involved. However, the appearance of a low-level conus and associated tethered cord syndrome may be slightly increased in this population.

Combined endoscopic third ventriculostomy and choroid plexus cauterization as primary treatment of hydrocephalus for infants with myelomeningocele: long-term results of a prospective intent-to-treat study in 115 East African infants.

OBJECT: Shunt dependence is more dangerous for children in less developed countries. Combining endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) was previously shown to treat hydrocephalus more effectively than ETV alone in infants < 1 year of age. The goal of this prospective study was to evaluate the effectiveness of ETV-CPC as primary treatment of hydrocephalus in infants with myelomeningocele. METHODS: One hundred fifteen consecutive East African infants with myelomeningocele requiring treatment for hydrocephalus were intended for primary management using ETV-CPC. Patient information was prospectively entered into a database. Outcomes were evaluated by life table analysis. Potential predictors for treatment failure were evaluated using multivariate logistic regression. RESULTS: Ninety-three patients had a completed ETV-CPC with > 1 month of follow-up. The ETV-CPC procedure was successful in 71 patients (76%), with a mean and median follow-up of 19.0 months. Treatment failures occurred before 6 months in 86% of the patients, and none occurred after 10 months. The operative mortality rate was 1.1%, and there were no infections. Life table analysis suggested that 72% of the patients would be successfully treated using a single ETV-CPC and 78% would remain shunt-independent with reopening of a closed ETV stoma. Multivariate logistic regression showed scarring of the cistern (p = 0.021) or choroid plexus (p = 0.026) as predictors of failure, but age at the time of surgery was not a significant predictor. CONCLUSIONS: Using ETV-CPC appears to successfully provide a more durable primary treatment of hydrocephalus for infants with spina bifida than does shunt placement. These results support ETV-CPC as the better treatment option for these children in developing countries.

The Dandy-Walker variant: a case series of 24 pediatric patients and evaluation of associated anomalies, incidence of hydrocephalus, and developmental outcomes.

OBJECT: The Dandy-Walker complex is a continuum of aberrant development of the posterior fossa that has been associated with multiple congenital anomalies, radiographic abnormalities, and developmental delay. The Dandy-Walker variant (DWV) is a unique entity believed to represent a milder form of the complex, and is characterized by a specific constellation of radiographic findings. In this retrospective case series, the authors report the association of the DWV with other congenital anomalies, the associated radiographic findings linked with DWV, and the developmental outcome in this population. METHODS: The charts and radiographs of 10 male and 14 female patients treated between 2000 and 2006 were examined. The patients' mean gestational age was 35.6 weeks (range 23-41 weeks), and the mean follow-up period was 5.1 years (range 1 month-15 years). RESULTS: Three patients died. Associated anomalies included cardiac (41.7%), neurological (33.3%), gastrointestinal (20.8%), orthopedic (12.5%), and genitourinary (12.5%) abnormalities. Less common were pulmonary and psychiatric findings. Developmental delay was identified in 11 of the 21 patients for whom follow-up was available. Five of 6 patients with isolated DWV had a normal developmental course. Radiographic findings associated with DWV included corpus callosum dysgenesis in 20.8%, ventricular enlargement in 29%, and vermian rotation in 8.3%. Shunts were placed in 4 of 7 patients with ventriculomegaly. Using the two-tailed Pearson correlation, the authors determined that developmental outcome was solely affected by neurological deficits and that ventricular enlargement predicted the need for shunt placement. CONCLUSIONS: The DWV was associated with both extra- and intracranial anomalies. Associated radiographic abnormalities including ventriculomegaly were observed. Hydrocephalus requiring cerebrospinal fluid diversion may be indicated. Isolated DWV was associated with a good developmental outcome.