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.

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.

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.

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.

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.

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.

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.

Physical activity assessment in adolescents with limb salvage.

OBJECTIVES: To evaluate ambulatory activity differences between youth with limb salvage procedures and typically developing youth (TDY) and assess differences in self-reported activity levels in the 2 groups, to provide a basis for physical activity assessment in patients who had undergone limb salvage surgery and treatment planning that incorporates regaining normal physical and daily living activities. STUDY DESIGN: In this cohort comparison study, we compared ambulatory and self-reported activity levels in 20 youth (aged 11.7-20.8 years) who had undergone limb salvage surgery and a sex- and age-matched comparison cohort of 20 TDY. StepWatch activity monitor and Activity Scale for Kids data were used to answer these questions. RESULTS: Significant differences were found between the youth who had undergone limb salvage surgery and the TDY in total time active each day (43% vs 48%; P = .03), median total strides per day (4487 vs 7671; P = .001), and amount of time per day at high activity levels (20 minutes vs 47 minutes; P = .001). Self-reported overall physical activity, locomotion, and standing Activity Scale for Kids subscale scores were significantly lower in the youth undergoing limb salvage surgery compared with the TDY (summary score, 88.3 vs 97.7; P = .001). CONCLUSION: Patients undergoing limb salvage surgery exhibit reduced physical activity compared with normal age-matched controls.

Classic bladder exstrophy: orthopaedic surgical considerations.

Classic bladder exstrophy is an embryologic malformation that results in complex deficiency of the anterior midline, with urogenital and skeletal manifestations. Urogenital reconstruction is a challenging procedure that can be facilitated by closure of the bony pelvic ring by an orthopaedic team. Surgical options include a multiyear staged approach and the single-stage complete repair for exstrophy. The goals of urologic surgery include closure of the bladder and abdominal wall with eventual bladder continence, preservation of renal function, and cosmetic and functional reconstruction of the genitalia. Pelvic osteotomy is done at the time of bladder closure in the patient in whom the anterior pelvis cannot be approximated without tension. Traction or spica casting is used postoperatively. Good outcomes are probable with appropriate management at specialized treatment centers.

VEPTR™ growing rods for early-onset neuromuscular scoliosis: feasible and effective.

BACKGROUND: The Vertical Expandable Prosthetic Titanium Rib (VEPTR™; Synthes North America, West Chester, PA) reportedly controls spinal deformity associated with constrictive chest wall conditions. QUESTIONS/PURPOSES: We asked whether spine-to-spine constructs using VEPTR™ instrumentation in combination with standard spinal instrumentation could be deployed to salvage failed rib-to-spine constructs used originally in patients with constricted chest walls and to primarily treat progressive spinal deformity without chest wall abnormalities. PATIENTS AND METHODS: Fifty patients were treated with VEPTR™ constructs for thoracic insufficiency syndrome at our center between 2001 and 2007. Fourteen of these 50 patients had placement of a spine-to-spine construct using a VEPTR™ implant in combination with standard spinal implants and are the subject of this retrospective review. Five had prior rib-based VEPTR™ or growing implants with an average of two failures before this surgery. Radiographic variables, preceding treatment, complications, and changes in ambulatory status, were recorded. The minimum followup was 2 years (mean, 35 months; range, 2-4 years). RESULTS: After an average of five expansions in these 14 patients, positive changes were recorded for Cobb angle, T1-S1 height, sagittal balance, and space available for the lung. Complications included two rod fractures, two superficial infections, and one deep infection with rod removal. CONCLUSIONS: VEPTR™ instrumentation as a spine-to-spine growing-rod construct demonstrated ease of implantation and expansion, with complication rates similar to other reported devices. This study suggests growing constructs using VEPTR™ can be used with relatively few complications and extends the potential uses of this instrumentation system.

Walking stride rate patterns in children and youth.

PURPOSE: To describe walking activity patterns in youth who are typically developing (TD) using a novel analysis of stride data and compare to youth with cerebral palsy (CP) and arthrogryposis (AR). METHOD: Stride rate curves were developed from 5 days of StepWatch data for 428 youth ages 2 to 16 years who were TD. RESULTS: Patterns of stride rates changed with age in the TD group (P = .03 to < .001). Inactivity varied with age (P < .001); peak stride rate decreased with age (P < .001). Curves were stable over a 2-week time frame (P = .38 to .95). Youth with CP and AR have lower stride rate patterns (P = .04 to .001). CONCLUSION: This is the first documentation of pediatric stride-rate patterns within the context of daily life. Including peak stride rates and levels of walking activity, this single visual format has potential clinical and research applications.

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.

Spica casting compared to Bryant's traction after complete primary repair of exstrophy: safe and effective in a longitudinal cohort study.

PURPOSE: Bryant's traction is the most commonly used method for immobilization after bladder exstrophy repair. We hypothesized that spica casting is a safe and effective alternative to Bryant's traction after complete primary repair of exstrophy. MATERIALS AND METHODS: Complete primary repair of exstrophy was performed for initial repair in 39 consecutive children by all surgeons at Seattle Children's Hospital since 1998. Three sequential cohorts were evaluated-Bryant's traction without osteotomy (13 patients), spica casting without osteotomy (14) and spica casting with osteotomy. These 3 sequential cohorts represent eras of care and an evolution of practice. Primary outcomes included major complications related to immobilization, dehiscence, urinary incontinence and length of stay. We defined complications of immobilization as nonunion of pelvic osteotomy, femoral nerve palsy, revision of spica cast requiring return to the operating room, infection at the osteotomy site and activity limiting pain at the osteotomy site. Fisher's exact test or t test was used to determine statistical significance. RESULTS: There was no difference in urinary continence (p = 0.09). Use of Bryant's traction was associated with double the length of stay (p >0.001). There was no correlation of major complications to the type of immobilization used. CONCLUSIONS: Spica casting compared to Bryant's traction is associated with shorter hospitalization following complete primary repair of exstrophy and does not have a significant difference in the rate of complications. In our longitudinal cohort study with long-term followup spica cast was safe and effective for patients with bladder exstrophy, and should be considered an acceptable method of immobilization.

The usefulness of VEPTR in the older child with complex spine and chest deformity.

UNLABELLED: The vertical expandable prosthetic titanium rib (VEPTR) was originally designed to treat chest and spine deformities in young children. However, older children with complex spinal deformities may also benefit from placement of a VEPTR when vertebral column resections are deemed too risky neurologically. We report: (1) the changes in Cobb angle, T1 angle, and head tilt; and (2) the occurrence of complications in children older than 10 years of age treated with VEPTR. From a database of 214 patients treated in a Food and Drug Administration Investigational Device Exemption study of VEPTR, we identified 10 patients with assorted diagnoses who underwent surgery after age 10 and had a minimum of 24-month followup (mean, 39.6 months; range, 24-75 months). No patient sustained neurologic injury. Patients underwent an average of five lengthenings. The mean preoperative Cobb angle was 64.7 degrees and improved to 48.4 degrees. Head shift improved an average of 3.8 cm. Two device-related complications occurred (both in the same patient). Four patients have since undergone definitive spinal fusion. For a select group of patients 10 years of age or older, the VEPTR offers a reasonable alternative to potentially risky vertebral column resections for correcting deformities in selected patients. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Human motor evoked potential responses following spinal cord transection: an in vivo study.

Motor evoked potential (MEP) monitoring has been used increasingly in conjunction with somatosensory evoked potential monitoring to monitor neurological changes during complex spinal operations. No published report has demonstrated the effects of segmental spinal cord transection on MEP monitoring. The authors describe the case of an 11-year-old girl with lumbar myelomeningocele and worsening thoracolumbar scoliosis who underwent a T11-L5 fusion and spinal transection to prevent tethering. Intraoperative MEP and somatosensory evoked potential monitoring were performed, and the spinal cord was transected in 4 quadrants. The MEPs were lost unilaterally as each anterior quadrant was sectioned. This is the first reported case that demonstrates the link between spinal cord transection and MEP signaling characteristics. Furthermore, it demonstrates the relatively minor input of the ipsilateral ventral corticospinal tract in MEP physiology at the thoracolumbar junction. Finally, this study further supports the use of MEPs as a specific intraoperative neuromonitoring tool.

Effects of anesthetic regimens and other confounding factors affecting the interpretation of motor evoked potentials during pediatric spine surgery.

Children undergoing corrective spine surgery are at risk of serious neurologic injury. Monitoring transcranial electric motor evoked potentials (TCeMEPs) during these procedures may identify and help prevent injury to motor pathways. The difficulty in obtaining consistent motor evoked potential (MEP) responses during pediatric spine surgery can result in part to the suppression of evoked responses caused by volatile inhalational anesthetics, elevated levels of propofol, and/or physiologic variables. Data obtained from 140 pediatric patients who underwent spine surgery with MEP monitoring were retrospectively analyzed and evaluated for age and anesthetic effects on stimulation variables. MEPs acquired under inhalational anesthetic agents required greater stimulation compared to intravenous propofol anesthesia. Additionally, the responses were more variable when inhalational agents were used. These effects were more prominent in younger age patients. The number of alerts of MEP loss or reduction related to anesthetic levels or blood pressure changes was higher under inhalational agents.

Ambulatory activity in youth with arthrogryposis: a cohort study.

BACKGROUND: Arthrogryposis is characterized by multiple congenital joint contractures that affect ambulation. This study compared ambulatory activity of subjects with the 2 most common forms of arthrogryposis and a control group of typically developing youth. METHODS: This is a cross-sectional, cohort study. Thirteen ambulatory subjects with amyoplasia or distal arthrogryposis and 13 age- and sex-matched controls wore the StepWatch3 Activity Monitor on their ankles for 7 days. The daily frequency, duration, and intensity of ambulatory activity were measured. The parents of the subjects also completed Activities Scale for Kids, Performance-38 questionnaires to compare parent-reported activity levels with StepWatch3 Activity Monitor measurements. RESULTS: The mean ages of the subject and control groups were 10.83 and 10.95 years, respectively, with 8 males and 5 females in each group. Subjects as compared with controls took significantly fewer steps, 5668+/-1134 versus 7685+/-1164, respectively (P=0.02) and spent significantly less of their active time at high step rates, 8% versus 13% (P=0.05). The average Activities Scale for Kids, Performance summary scores for subjects (76.8+/-18.9) were significantly lower than controls (90.6+/-7.2) (P=0.003). CONCLUSIONS: We have been able to quantify the activity levels of children with amyoplasia and distal arthrogryposis relative to that of age- and sex-matched typically developing youth. Youth with arthrogryposis took significantly fewer steps, spent less time at high activity levels, and had significantly lower parental report of ambulatory and physical activity than controls. LEVEL OF EVIDENCE: Cross-sectional comparison study, level II.