BrAIST-Calc: Prediction of Individualized Benefit From Bracing for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Prospective multicenter study data were used for model derivation and externally validated using retrospective cohort data. OBJECTIVE: Derive and validate a prognostic model of benefit from bracing for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: The Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST) demonstrated the superiority of bracing over observation to prevent curve progression to the surgical threshold; 42% of untreated subjects had a good outcome, and 28% progressed to the surgical threshold despite bracing, likely due to poor adherence. To avoid over-treatment and to promote patient goal setting and adherence, bracing decisions (who and how much) should be based on physician and patient discussions informed by individual-level data from high-quality predictive models. MATERIALS AND METHODS: Logistic regression was used to predict curve progression to <45° at skeletal maturity (good prognosis) in 269 BrAIST subjects who were observed or braced. Predictors included age, sex, body mass index, Risser stage, Cobb angle, curve pattern, and treatment characteristics (hours of brace wear and in-brace correction). Internal and external validity were evaluated using jackknifed samples of the BrAIST data set and an independent cohort (n=299) through estimates of discrimination and calibration. RESULTS: The final model included age, sex, body mass index, Risser stage, Cobb angle, and hours of brace wear per day. The model demonstrated strong discrimination ( c -statistics 0.83-0.87) and calibration in all data sets. Classifying patients as low risk (high probability of a good prognosis) at the probability cut point of 70% resulted in a specificity of 92% and a positive predictive value of 89%. CONCLUSION: This externally validated model can be used by clinicians and families to make informed, individualized decisions about when and how much to brace to avoid progression to surgery. If widely adopted, this model could decrease overbracing of AIS, improve adherence, and, most importantly, decrease the likelihood of spinal fusion in this population.

Abnormal Bone Collagen Cross-Linking in Osteogenesis Imperfecta/Bruck Syndrome Caused by Compound Heterozygous PLOD2 Mutations.

Bruck syndrome (BS) is a congenital disorder characterized by joint flexion contractures, skeletal dysplasia, and increased bone fragility, which overlaps clinically with osteogenesis imperfecta (OI). On a genetic level, BS is caused by biallelic mutations in either FKBP10 or PLOD2. PLOD2 encodes the lysyl hydroxylase 2 (LH2) enzyme, which is responsible for the hydroxylation of cross-linking lysine residues in fibrillar collagen telopeptide domains. This modification enables collagen to form chemically stable (permanent) intermolecular cross-links in the extracellular matrix. Normal bone collagen develops a unique mix of such stable and labile lysyl-oxidase-mediated cross-links, which contribute to bone strength, resistance to microdamage, and crack propagation, as well as the ordered deposition of mineral nanocrystals within the fibrillar collagen matrix. Bone from patients with BS caused by biallelic FKBP10 mutations has been shown to have abnormal collagen cross-linking; however, to date, no direct studies of human bone from BS caused by PLOD2 mutations have been reported. Here the results from a study of a 4-year-old boy with BS caused by compound heterozygous mutations in PLOD2 are discussed. Diminished hydroxylation of type I collagen telopeptide lysines but normal hydroxylation at triple-helical sites was found. Consequently, stable trivalent cross-links were essentially absent. Instead, allysine aldol dimeric cross-links dominated as in normal skin collagen. Furthermore, in contrast to the patient's bone collagen, telopeptide lysines in cartilage type II collagen cross-linked peptides from the patient's urine were normally hydroxylated. These findings shed light on the complex mechanisms that control the unique posttranslational chemistry and cross-linking of bone collagen, and how, when defective, they can cause brittle bones and related connective tissue problems. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Reliability of StepWatch Activity Monitor to Measure Locomotor Activity in Youth With Lower Limb Salvage.

PURPOSE: The study purpose was to determine the minimum number of monitoring days necessary to reliably capture walking among individuals with lower limb salvage. METHODS: Nineteen participants with lower limb salvage wore an ankle-mounted motion sensor over a 7-day period to obtain step counts. Generalizability theory was used to examine the variance components in step counts (G study) and to determine the appropriate length of activity monitoring using various combinations of days (D study). RESULTS: Mean step counts were higher on weekends than on weekdays. Fifty percent of the total variance in step counts was accounted for by interindividual variability in walking (D study). Eighty percent was reached individually with 4 weekdays, 2 weekend days, or 3 week days + weekend days. CONCLUSION: The study provides data for an appropriate monitoring method to track walking outcomes of rehabilitation for individuals with lower limb salvage.

Lower Extremity Deformity Management in Amyoplasia: When and How.

This article presents an approach to the musculoskeletal problems of children with amyoplasia. Although a very high percentage of children with have ambulatory potential, activity and function decline over time. Strong consideration of external resources and support available to the child and family are important considerations in recommending surgery as is the timing of interventions to align with childhood development.

Complications in using the vertical expandable prosthetic titanium rib (VEPTR) in children.

PURPOSE: This report describes complications using the vertical expandable prosthetic titanium rib (VEPTR) for thoracic insufficiency syndrome (TIS) at a single center. METHODS: This is a prospective cohort evaluating 65 patients with rib-rib and rib-spine VEPTR devices for TIS placed between 10/2001 and 11/2014, for children with spinal or chest wall deformity. Patients were classified using the early onset scoliosis classification system (C-EOS). RESULTS: 65 patients are available for follow up. 23 congenital scoliosis, 12 neuromuscular, 14 syndromic, 2 idiopathic and 14 not classifiable by the C-EOS system including 11 chest wall reconstructions. Average age at implantation was 6.9years (range 1.3-24.8) with average follow up 6.9years (range 0.4-14.8). 22 patients had 37 complications. Those classifiable by C-EOS had complications in the normo- and hyperkyphotic groups. Implant erosion and infection were most common. The majority of complications required one additional unplanned surgery for resolution. Two complications required abandonment of a growth-friendly strategy. CONCLUSIONS: Use of VEPTR for TIS is associated with significant and frequent complications. C-EOS suggests that complications are more likely in those with normal or hyperkyphotic curves. Most complications are managed with one unplanned surgery. VEPTR is usually salvaged and abandonment of a growth-friendly strategy is unusual.

Delayed Postoperative Neurologic Deficits in Spinal Deformity Surgery.

STUDY DESIGN: A cross-sectional survey of surgeon members of the Scoliosis Research Society (SRS). OBJECTIVE: This study sought to characterize the incidence, clinical presentation, diagnostic workup, treatment, and neurologic prognosis following delayed postoperative neurologic deficit (DPND) in patients undergoing spinal deformity surgery. SUMMARY OF BACKGROUND DATA: DPND is a potentially devastating condition following spinal surgery, characterized by the development of a neurological deficit within hours or days of the surgical procedure. To date, only case reports and small case series have been published on the topic. METHODS: We developed a survey to characterize DPND following spinal deformity surgery. This survey was distributed to surgeon members of the SRS through email and standard mail. The overall response rate was 38% (352/929). RESULTS: Our results suggest an estimated DPND incidence of 1 of 9910 cases (0.01%). Eighty-one surgeons (23%) experienced at least 1 DPND in the past 10 years (92 total cases). Most common diagnoses were scoliosis (69%), kyphosis (23%), and spondylolisthesis (14%); 20% were revision surgeries. The number of hours to deficit onset was as follows: 1 to 12 (36%), 13 to 24 (27%), 25 to 48 (27%), more than 48 (10%). The most commonly cited sources of injury included ischemic injury (38%) and cord compression (15%). Forty-one percent experienced complete neurologic recovery, 26% partial, and 33% no recovery. Twenty-one percent of patients achieved final neurologic status within 1 week, 38% by 1 month, and 73% by 6 months. Patients with compression-related DPND had a significantly greater likelihood of experiencing some neurologic recovery (≥1 ASIA Grade) than ischemia-related DPND (86% versus 51%, P = 0.049). CONCLUSIONS: DPND occurs at an estimated incidence of 0.01%. Sixty-three percent of DPND cases occurred within the first 24 hours and 90% within 48 hours. Complete (41%) or partial (26%) neurologic recovery may be expected, especially in compression-related DPND, emphasizing the need for perioperative vigilance, prompt recognition, and early intervention. LEVEL OF EVIDENCE: 4.

Reliably estimating ambulatory activity in youth with arthrogryposis.

PURPOSE: Quantification of the physical activity levels using pedometers and accelerometers in children and adolescents with mobility limitations has recently allowed researchers and practitioners to track real-life outcomes of new interventions in this particular population. Questions remain concerning the reliability of ambulatory activity monitoring in functionally challenged youth. The purpose of the analysis, therefore, was to document the minimal number of days required to reliably estimate ambulatory activity levels in children with arthrogryposis. METHODS: Thirteen boys and girls with arthrogryposis (average age 10.9 years) completed stepping activity monitoring using a two-dimensional accelerometer over a period of up to 15 consecutive days. Generalizability theory was applied to identify sources of variance in daily step counts (generalizability study, G study) and to determine the number of days necessary to obtain a reliable coefficient of ≥0.80 (decision study, D study). RESULTS: G study results showed that intra-individual variability was larger (58.4% of total variance) than inter-individual variability (28.7% of total variance). D study indicated that 9 days of monitoring was required to reach a stable measure of ambulatory activity. CONCLUSIONS: Due to relatively greater variability in step counts across days of the week, a longer monitoring period was required for youth with arthrogryposis. Implication for Rehabilitation Large proportion of variance in daily step counts was attributable to unidentifiable sources of variance, suggesting further exploration of factors that influence on the walking activity in youth with arthrogryposis. Step activity monitoring of youth with arthrogryposis should occur over a 9-day period to reliably capture their habitual level of ambulation. Rehabilitation programs aimed to promote increased stepping in youth with arthrogryposis which can utilize the findings of the present study to appropriately track their effectiveness.

Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip in Infants up to Six Months of Age.

Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip in Infants up to Six Months of Age: Evidence-Based Clinical Practice Guideline is based on a systematic review of the current scientific and clinical research. This guideline has been endorsed by the Society of Diagnostic Medical Sonography, the Society for Pediatric Radiology, American Academy of Pediatrics, and the Pediatric Orthopaedic Society of North America. The purpose of this clinical practice guideline is to help improve treatment and management based on the current evidence. This guideline contains nine recommendations, including both diagnosis and treatment. In addition, the work group highlighted the need for better research in the early diagnosis and treatment of developmental dysplasia of the hip.

Spine Computed Tomography Radiation Dose Reduction: Protocol Refinement Based on Measurement Variation at Simulated Lower Radiation Acquisitions.

STUDY DESIGN: Retrospective dose-simulation comparison. OBJECTIVE: To determine if sufficient detail for preoperative analysis of bony anatomy can be acquired at substantially lower doses than those typically used. SUMMARY OF BACKGROUND DATA: Computed tomography (CT) is a preoperative planning tool for spinal surgery. The pediatric population is at risk to express the harmful effects of ionizing radiation. Preoperative CT scans are presently performed at standard pediatric radiation doses not tailored for surgical planning. METHODS: We used the validated GE Noise Injection software to retrospectively modify existing spine and chest CT scans from 10 patients to create CT images that simulated a standard dose (100%), 50% dose, and 25% dose scans. 4 orthopedic surgeons and a pediatric radiologist, blinded to dose, measured minimum medial-lateral pedicle width and maximum anterior-posterior bony length along the axis of presumed pedicle screw placement. A total of 90 axial images were generated to create our sample set. Measurements were evaluated for accuracy, precision, and consistency. RESULTS: For any given rater, there was no clinically relevant difference between measurements at the different dose levels and no apparent degradation in precision at the different dose levels. Consistent variation was observed between raters, the likely result of individual differences in measurement approach. CONCLUSION: Spinal CT scans done for preoperative planning can be performed at 25% of current radiation doses without a loss in surgical planning measurement accuracy or precision. These 25% dose-reduced scans would have average Computed Tomography Dose Index volume dose levels of roughly 1.0 to 2.5 mGy (depending on patient size) and size-specific dose estimates of roughly 2.5 mGy representing a substantial dose savings compared to current practice for many sites. Standardization of consistent landmarks may be useful to further improve inter-rater concordance.

Injection-induced gluteus muscle contractures: diagnosis with the "reverse Ober test" and surgical management.

BACKGROUND: Adoption rates are increasing in the United States and other developed countries. A large proportion of adopted children have been found to have unsuspected medical diagnoses, including orthopedic problems. One condition, termed injection-induced gluteus maximus contracture, has been previously described in several case series and can be difficult to diagnose if unfamiliar with this condition. By reviewing the etiology and pathoanatomy of this problem, as well as the typical examination findings, including the near-pathognomonic-positive "reverse Ober test," treating providers will be better prepared to recognize and properly treat this condition. METHODS: This is a retrospective review of 4 patients treated at our institution for injection-induced gluteus maximus contracture. Patient history, physical examination findings, and treatment outcomes were recorded. All had undergone surgical treatment through a longitudinal incision along the posterior margin of the iliotibial band, with division of thickened, contracted gluteus tissue down to the ischial tuberosity. RESULTS: All 4 of the patients were adopted from orphanages in developing countries. Chief complaints of the patients varied, but physical examination findings were very consistent. Three of the 4 patients had undergone rotational osteotomies for presumed femoral retroversion before their diagnosis and treatment for injection-induced gluteus maximus contracture. All patients had concave, atrophic buttock contours and numerous punctate buttock scars. All walked with an out-toed gait and had marked apparent femoral retroversion. Each patient was found to have full hip adduction when the hip was extended but a hip abduction contracture when the hip was flexed. This finding of increasing abduction as an extended/adducted hip is flexed to 90 degrees is described as a positive "reverse Ober test." After surgical treatment, all hips could adduct to neutral from full extension to full flexion. CONCLUSIONS: Although common in some countries, such as Russia and China, injection-induced gluteus muscle contractures are seldom seen in the United States and other developed countries. Diagnosis of this condition can be difficult leading to inappropriate treatment. Knowledge of the clinical presentation typical of a gluteus contracture and of the pathognomonic finding of a "reverse Ober test" can facilitate an effective surgical procedure to correct the associated functional impairment. LEVEL OF EVIDENCE: Level IV: retrospective case series.

Vertical expandable prosthetic titanium rib (VEPTR): a review of indications, normal radiographic appearance and complications.

Vertical expandable prosthetic titanium rib (VEPTR) is increasingly used in the treatment of thoracic insufficiency, idiopathic and neuromuscular scoliosis and chest wall defects in children. In contrast to spinal fusion surgery, the VEPTR allows for growth while stabilizing the deformity. We illustrate the common indications and normal radiographic appearance of the three common configurations of VEPTR (cradle-to-cradle assembly, cradle with lumbar extension assembly, cradle-to-ala hook assembly). There is a relatively high rate of reported complications with VEPTR in the literature. We discuss the potential complications of VEPTR, including infection, rib fracture, dislodged hardware and neurological injury, with an emphasis on imaging diagnosis.

The minimum number of days required to establish reliable physical activity estimates in children aged 2-15 years.

The purpose of this study was to determine the minimum number of days needed to assess reliable estimates of step-count data for children based on age and gender. A total of 428 developing children (at least 30 boys and 30 girls in seven two-year intervals from 2-3 years to 14-15 years of age) wore a StepWatch accelerometer for 7 consecutive days. Following data screening, the 422 children's data were finally analyzed by age and sex groups using the Generalizability theory. Single-facet crossed designs (i.e. Participant (P) × Days (D)) were applied for each of 14 datasets. G-studies were performed to quantify the percentage of variance associated with the facet and interaction in the model. Follow-up D-studies were performed to determine the minimum number of days of step-count data collection needed to achieve a desirable reliability coefficient (G ≥ 0.80). The results from the G-studies show that P explained a large percentage of the total variance (26-71%) while D had little effect on the total variance (0-5%). A relatively large percentage of variance was unidentified (i.e. the P × D interaction). The minimum number of days necessary to achieve a desirable reliability coefficient (G ≥ 0.80) ranged from 2 to 12 d. On average, boys required less days of monitoring than girls. Researchers should use the findings of this study to design data collection that ensures reliable data.

Walking activity patterns in youth with cerebral palsy and youth developing typically.

PURPOSE: To describe daily walking stride rate patterns of young children with cerebral palsy (CP) as compared to a typically developing youth (TDY) cohort relative to age and functional level. METHOD: A cross-sectional comparison cohort study compared 209 youth with CP with 368 TDY aged 2-13 years. Youth with CP had Gross Motor Function Classification System (GMFCS) levels I-III with 60% bilateral involvement and 79% spastic. Five days of StepWatch data were averaged and classified into low, moderate and high stride rates. Group differences were examined by t-test and analysis of variance. RESULTS: Children with CP walk significantly less each day than TDY (F = 245, p ≤ 0.001) and differ by GMFCS (F = 1.51, p < 0.001). TDY walk a similar number of strides in low and moderate stride rates each day while youth with CP do not. TDY attained high stride rates (>60 strides/min) for 8 min/d with levels I-III at 4.0, 3.2 and 0.53 min/d, respectively. CONCLUSIONS: The relative relationship of walking intensity levels within total daily stride activity differs for youth with CP as compared to TDY. The influence of functional walking ability on walking stride activity levels and intensity does not appear to differ significantly across age groups. IMPLICATIONS FOR REHABILITATION: Limitation in the ability to attain moderate stride-rate intensity, regardless of total number of strides taken each day for ambulatory youth with CP, is a potential area of focus for intervention. Understanding of stride activity levels and intensity in youth with CP may be employed to focus rehabilitation strategies to enhance habitual walking activity. Community-based stride rate data has potential as an effectiveness outcome for rehabilitation strategies focused on walking (i.e. orthopedic surgery, orthoses and injections therapies).

Best Practices in Intraoperative Neuromonitoring in Spine Deformity Surgery: Development of an Intraoperative Checklist to Optimize Response.

STUDY DESIGN: Consensus-based creation of a checklist and guideline. OBJECTIVE: To develop a consensus-based checklist to guide surgeon responses to intraoperative neuromonitoring (IONM) changes in patients with a stable spine and to develop a consensus-based best practice guideline for IONM practice in the United States. SUMMARY OF BACKGROUND DATA: Studies show that checklists enhance surgical team responses to crisis situations and improve patient outcomes. Currently, no widely accepted guidelines exist for the response to IONM changes in spine deformity surgery. METHODS: After a literature review of risk factors and recommendations for responding to IONM changes, 4 surveys were administered to 21 experienced spine surgeons and 1 neurologist experienced in IONM. Areas of equipoise were identified and the nominal group process was used to determine items to be included in the checklist. The authors reevaluated and modified the checklist at 3 face-to-face meetings over 12 months, including a period of clinical validation using a modified Delphi process. The group was also surveyed on current IONM practices at their institutions. This information and existing IONM position statements were used to create the IONM best practice guideline. RESULTS: Consensus was reached for the creation of 5 checklist headings containing 26 items to consider in the response to IONM changes. Consensus was reached on 5 statements for inclusion in the best practice guideline; the final guideline promotes a team approach and makes recommendations aimed at decreasing variability in neuromonitoring practices. CONCLUSIONS: The final products represent the consensus of a group of expert spine surgeons. The checklist includes the most important and high-yield items to consider when responding to IONM changes in patients with a stable spine, whereas the IONM guideline represents the group consensus on items that should be considered best practice among IONM teams with the appropriate resources.

Iatrogenic radiation exposure to patients with early onset spine and chest wall deformities.

STUDY DESIGN: Retrospective cohort series. OBJECTIVE: Characterize average iatrogenic radiation dose to a cohort of children with thoracic insufficiency syndrome (TIS) during assessment and treatment at a single center with vertically expandable prosthetic titanium rib. SUMMARY OF BACKGROUND DATA: Children with TIS undergo extensive evaluations to characterize their deformity. No standardized radiographical evaluation exists, but all reports use extensive imaging. The source and level of radiation these patients receive is not currently known. METHODS: We evaluated a retrospective consecutive cohort of 62 children who had surgical treatment of TIS at our center from 2001-2011. Typical care included obtaining serial radiographs, spine and chest computed tomographic (CT) scans, ventilation/perfusion scans, and magnetic resonance images. Epochs of treatment were divided into time of initial evaluation to the end of initial vertically expandable prosthetic titanium rib implantation with each subsequent epoch delineated by the next surgical intervention. The effective dose for each examination was estimated within millisieverts (mSv). Plain radiographs were calculated from references. Effective dose was directly estimated for CT scans since 2007 and an average of effective dose from 2007-2011 was used for scans before 2007. Effective dose from fluoroscopy was directly estimated. All doses were reported in mSv. RESULTS: A cohort of 62 children had a total of 447 procedures. There were a total of 290 CT scans, 4293 radiographs, 147 magnetic resonance images, and 134 ventilation/perfusion scans. The average accumulated effective dose was 59.6 mSv for children who had completed all treatment, 13.0 mSv up to initial surgery, and 3.2 mSv for each subsequent epoch of treatment. CT scans accounted for 74% of total radiation dose. CONCLUSION: Children managed for TIS using a consistent protocol received iatrogenic radiation doses that were on average 4 times the estimated average US background radiation exposure of 3 mSv/yr. CT scans comprised 74% of the total dose. LEVEL OF EVIDENCE: 3.

Hemodynamic instability during prone spine surgery in a patient with merosin-deficient congenital muscular dystrophy.

Trans-esophageal echocardiography (TEE) and/or central venous pressure (CVP) monitoring are important in the anesthetic management of spine fusion of pediatric patients with severe muscular weakness. This case highlights an unusual situation of apparent acute right ventricular mechanical obstruction after prone positioning and its prompt recognition with CVP monitoring. The anesthetic management of a patient with congenital muscular dystrophy, an uncommon neuromuscular disorder, is presented. Good communication and planning between the anesthesiology and surgical teams allowed completion of the procedure using a lateral approach.

Reliably measuring ambulatory activity levels of children and adolescents with cerebral palsy.

OBJECTIVE: To identify sources of variance in step counts and to examine the minimum number of days required to obtain a stable measure of habitual ambulatory activity in the cerebral palsy (CP) population. DESIGN: Cross-sectional. SETTING: Free-living environments. PARTICIPANTS: Children and adolescents with CP (N=209; mean age ± SD, 8y, 4mo ± 3y, 4mo; n=118 boys; Gross Motor Function Classification System [GMFCS] levels I-III) were recruited through 3 regional pediatric specialty care hospitals. INTERVENTIONS: Daily walking activity was measured with a 2-dimensional accelerometer over 7 consecutive days. An individual information-centered approach was applied to days with <100 steps, and participants with ≥3 days of missing values were excluded from the study. Participants were categorized into 6 groups according to age and functional level. Generalizability theory was used to analyze the data. MAIN OUTCOME MEASURES: Mean step counts, relative magnitude of variance components in total step activity, and generalizability coefficients (G coefficients) of various combinations of days of the week. RESULTS: Variance in step counts attributable to participants ranged from 33.6% to 65.4%. For youth ages 2 to 5 years, a minimum of 8, 6, and 2 days were required to reach acceptable G coefficient (reliability) of ≥.80 for GMFCS levels I, II, and III, respectively. For those ages 6 to 14 years, a minimum of 6, 5, and 4 days were required to reach stable measures of step activity for GMFCS levels I, II, and III, respectively. CONCLUSIONS: The findings of the study suggest that an activity-monitoring period should be determined based on the GMFCS levels to reliably measure ambulatory activity levels in youth with CP.