Outcomes and Complications in Management of Congenital Myopathy Early-Onset Scoliosis.

BACKGROUND: Congenital myopathies (CMs) are complex conditions often associated with early-onset scoliosis (EOS). The purpose of this study was to investigate radiographic outcomes in CM patients undergoing EOS instrumentation as well as complications. Secondarily, we sought to compare these patients to a population with higher prevalence, cerebral palsy (CP) EOS patients. METHODS: This is a retrospective study of a prospectively collected multicenter registry. The registry was queried for EOS patients with growth-sparing instrumentation (vertical expandable prosthetic titanium ribs, magnetically controlled growing rods, traditional growing rod, or Shilla) and a CM or CP diagnosis with minimum 2 years follow-up. Outcomes included major curve magnitude, T1-S1 height, kyphosis, and complications. RESULTS: Sixteen patients with CM were included. Six (37.5%) children with CM experienced 11 complications by 2 years. Mean major curve magnitude for CM patients was improved postoperatively and maintained at 2 years (P<0.01), with no significant increase in T1-S1 height or maximum kyphosis(P>0.05). Ninety-seven patients with CP EOS were included as a comparative cohort. Fewer CP patients required baseline respiratory support compared with CM patients (20.0% vs. 92.9%, P<0.01). Fifty-four (55.7%) CP patients experienced a total of 105 complications at 2 years. There was no evidence that the risk of complication or radiographic outcomes differs between cohorts at 2 years, though CP EOS patients experienced significant improvement in all measurements at 2 years. CONCLUSIONS: EOS CM children face a high risk of complication after growing instrumentation, with similar curve correction and risk of complication to CP patients. LEVEL OF EVIDENCE: Level III.

Growth Modulation by Stimulating the Growth Plate: A Pilot Study.

This study investigates the ability of low-intensity pulsed ultrasound (LIPUS) or direct injection of recombinant growth hormone (rGH) to stimulate local growth of long bones. In a randomized controlled animal trial, healthy immature rabbits were allocated to 1 of the following 4 conditions: epiphyseal rGH periosteal injection, transdermal LIPUS, saline periosteal injection, or no treatment. New bone deposition was labeled with calcein at days 1 and 18, and microscopic measurements of growth were conducted by blinded observers. Statistically significant differences in growth were observed between the LIPUS and rGH stimulated legs compared with contralateral control legs (35% p = 0.04 and 41% p = 0.04, respectively); whereas no difference was observed between the 4 control groups (p = 0.37). There was no evidence of physeal bar formation, suggesting that direct injection of rGH and application of LIPUS around the distal femoral physis in rabbits may have a positive effect on microscopic growth without short-term adverse sequelae.

Image quality of EOS low-dose radiography in comparison with conventional radiography for assessment of ventriculoperitoneal shunt integrity.

OBJECTIVE: Patients with shunted hydrocephalus often accumulate high levels of radiation over their lifetimes during evaluation of hardware integrity. Current practice involves the use of a series of conventional radiographs for this purpose. Newer low-dose EOS radiography is currently used to evaluate scoliosis but has not been explored to evaluate shunt integrity on a large scale. The goal of this study was to compare the quality of imaging using EOS low-dose radiography to conventional radiography to evaluate shunt tubing. METHODS: A retrospective chart review was performed on 57 patients who previously had both conventional radiographs and low-dose EOS images of their cerebral shunt tubing from 2000 to 2018. Patient demographics (age, sex, type of shunt tubing, primary diagnosis) were collected. Conventional radiographic images and low-dose EOS images were independently analyzed by a neurosurgeon and neuroradiologist in three categories: image quality, delineation of shunt, and distinction of shunt compared to adjacent anatomy. RESULTS: All patients had shunted hydrocephalus due to spina bifida and Chiari type II malformation. Ratings of EOS and conventional radiographic images by both raters did not differ significantly in terms of image quality (rater 1, p = 0.499; rater 2, p = 0.578) or delineation of shunt (p = 0.107 and p = 0.256). Conventional radiographic images received significantly higher ratings than EOS on the ability to distinguish the shunt versus adjacent anatomy by rater 1 (p = 0.039), but not by rater 2 (p = 0.149). The overall score of the three categories combined was not significantly different between EOS and conventional radiography (rater 1, p = 0.818; rater 2, p = 0.186). In terms of cost, an EOS image was less costly than a conventional radiography shunt series ($236-$366 and $1300-$1547, respectively). The radiation dose was also lower for EOS images, with an effective dose of 0.086-0.140 mSv compared to approximately 1.6 mSv for a similar field of view with conventional radiography. CONCLUSIONS: The image quality of low-dose EOS radiography does not significantly differ from conventional radiography for the evaluation of cerebral shunts. In addition, EOS affords a much lower radiation dose and a lower cost.

Implant Distribution Versus Implant Density in Lenke Type 1 Adolescent Idiopathic Scoliosis: Does the Position of the Screw Matter?

STUDY DESIGN: Retrospective study. OBJECTIVE: Previous studies have demonstrated that increased implant density (ID) results in improved coronal deformity correction. However, low-density constructs with strategically placed fixation points may achieve similar coronal correction. The purpose of this study was to identify key zones along the spinal fusion where high ID statistically correlated to improved coronal deformity correction. Our hypothesis was that high ID within the periapical zone would not be associated with increased percent Cobb correction. METHODS: We identified patients with Lenke type 1 curves with a minimum 2-year follow up. The instrumented vertebral levels were divided into 4 zones: (1) cephalad zone, (2) caudal zone, (3) apical zone, and (4) periapical zone. High and low percent Cobb correction groups were compared, high percent Cobb group was defined as percent correction >67%. Total ID, total concave ID, total convex ID, and ID within each zone of the curve were compared between the groups. A multivariable analysis was performed to identify independent predictors for coronal correction. Subsequently increased and decreased thoracic kyphosis (TK) groups were compared, increased TK was defined as post-operative TK being larger than preoperative TK and decreased TK was defined as post-operative TK being less than preoperative TK. RESULTS: The cohort included 68 patients. The high percent Cobb group compared with the low percent Cobb group had significantly greater ID for the entire construct, the total concave side, the total convex side, the apical convex zone, the periapical zone, and the cephalad concave zone. The high percent Cobb group had greater pedicle screw density for the total construct, total convex side, and total concave side. In the multivariate model ID and pedicle screw density remained significant for percent Cobb correction. Ability to achieve coronal balance was not statistically correlated to ID (P = .78). CONCLUSIONS: Increased ID for the entire construct, the entire convex side, the entire concave side, and within each spinal zone was associated with improved percent Cobb correction. The ability to achieve coronal balance was not statistically influence by ID. The results of this study support that increasing ID along the entire length of the construct improves percent Cobb correction.

Impact of growth friendly interventions on spine and pulmonary outcomes of patients with spinal muscular atrophy.

PURPOSE: Patients with spinal muscular atrophy (SMA) are often treated with growth friendly devices such as vertical expandable prosthetic titanium rib(VEPTR) and magnetically controlled growing rods(MCGR) to correct spinal deformity and improve pulmonary function. There is limited data on this topic, and the purpose of this study was to assess the effect of these constructs and the addition of chest wall support (CWS) on spinal deformity, thorax morphology and pulmonary outcomes. METHODS: This is a retrospective analysis of prospectively collected data. We included patients with chest wall deformity and scoliosis secondary to SMA who were treated with growth friendly interventions and had two-year follow-up. Descriptive statistics and univariate analyses were performed. RESULTS: This study included 66 patients (25% MCGR, 73% VEPTR, 2% unknown). Approximately 23% of constructs included CWS. The average Cobb angle improved from 67° (SD: 27°) to 50° (SD: 26°) at 2 years in patients with CWS (p = 0.02), and from 59° (SD: 20°) to 46° (SD: 15°) at 2 years in patients without CWS (p < 0.01). Hemithorax height improved in patients treated with and without CWS (p = 0.01), but hemithorax width only improved in patients with CWS (p = 0.01). One patient with CWS and two patients without CWS required additional respiratory support at 2 years. The rates of postoperative complications were not significantly different in patients treated with and without CWS (p = 0.31). CONCLUSIONS: Growth friendly constructs improve spinal deformity and may be effective in altering the progression toward respiratory failure in patients with SMA. Patients treated with CWS have significant improvements in thorax morphology compared to patients without CWS.

Staying ahead of the curve: the use of spinopelvic parameters to predict curve progression and bracing success in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To investigate radiographic sagittal and spinopelvic parameters of patients with adolescent idiopathic scoliosis (AIS) treated with bracing and assess differences among those treated successfully and unsuccessfully. AIS is a three-dimensional deformity of the spine, sharing an intricate relationship with pelvic morphology. However, the most relevant predictors of curve progression have historically been coronal parameters and skeletal maturity. Sagittal and spinopelvic parameters have not been thoroughly investigated as predictors of curve progression and brace treatment success. METHODS: Retrospective review of AIS patients who underwent brace treatment. Coronal Cobb angles (CC), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), lumbar lordosis (LL), and thoracic spinopelvic angles (T1SP, T9SP) were measured prior to initiation of bracing. The sagittal and spinopelvic parameters of patients requiring surgical treatment due to curve progression were compared to those treated successfully with bracing. RESULTS: No significant differences were found for age, race, gender, Risser category (0/1 vs 2/3), initial CC, TK, LL, T1SP, or T9SP between cohorts. The cohort requiring surgery had significantly lower PI (p < 0.001, 42.0 v. 54.6), SS (p < 0.001, 37.0 v. 44.5), and PT (p = 0.003, 5.0 v. 10.2) compared to those successfully treated with bracing. Multivariable models controlling for Risser stage and Initial CC revealed the odds for successful brace treatment increases with an increase in PI (OR = 1.47, CI 1.18-1.83, p < 0.001), SS (OR = 1.26, CI 1.07-1.48, p = 0.006), and PT (OR = 1.43, CI 1.09-1.86, p = 0.006) (Table 3). The odds of successful brace treatment is given per one-unit increase for each radiographic measure after adjusting for Initial CC and Risser sign which were forced into each multivariable model. CONCLUSIONS: Spinopelvic parameters may indicate potential spine adaptability and skeletal maturity. For these reasons, we proposed that spinopelvic parameters may be a potential predictor of curve progression and brace treatment success. Our results demonstrated a higher risk of curve progression with lower PI, PT, or SS which support this hypothesis, however, given the small sample size and high variability, the magnitude of this effect should be viewed with caution and should serve as an impetus to further, larger scale studies to investigate the value spinopelvic parameters in curve progression and bracing efficacy. LEVEL OF EVIDENCE: IV.

Effect of Instrument Navigation on C-arm Radiation and Time during Spinal Procedures: A Clinical Evaluation.

INTRODUCTION: As minimally invasive spine surgery gains popularity, a focused effort must be made to reduce intraoperative radiation exposure to levels as low as reasonably achievable. Here, we demonstrate the clinical efficacy of a novel technology to aid in instrument navigation that aims to reduce intraoperative radiation exposure, number of fluoroscopic images, and time required to perform the most radiation intensive portions of a multitude of spinal procedures. METHODS: An internally randomized controlled study was performed over a 1-month period in order to clinically evaluate the effect of the C-arm assisted instrument tracking system, TrackX, on surgeon workflow, time, and radiation emitted. Three surgeons performed multiple spinal procedures on a total of 10 study patients and an additional 3 control patients. The surgeries encompassed minimally invasive spinal techniques and spanned extreme lateral interbody fusion, oblique lumbar interbody fusion, transforaminal lumbar interbody fusion along with percutaneous iliac screw placement, hardware removal, and kyphoplasty. The tasks studied included skin marking, first dilator insertion, localization for hardware placement and hardware removal. RESULTS: Overall radiation reduction was 83% (P < .0001). Overall reduction in x-rays taken was 78% (P < .0001). Overall time reduction was 81% (P = .0003). Statistical significance held for each surgeon studied and for nearly every procedure type. In these 10 study procedures, over 2 hours of overall operating room time was saved, all while requiring negligible set up time and no system calibration or supplementary x-rays to be taken. There were no adverse outcomes for any study patient, and there was no case where TrackX was not able to successfully complete a given portion of a procedure. CONCLUSIONS: TrackX instrument navigation is a clinically efficacious and accurate instrument tracking modality. This is the first instrument navigational technology that reduces radiation exposure and images required to complete a procedure while decreasing operative time. TrackX thus allows increased surgical efficiency while increasing operative efficiency and improving intraoperative safety. LEVEL OF EVIDENCE: 2.

Complications After Pediatric Hip Fractures: Evaluation and Management.

Pediatric proximal femur fractures are high-energy injuries with predictable and morbid complications. Osteonecrosis of the femoral head is the most common complication with identified risk factors including fracture type, patient's age, degree of displacement, timing to reduction, and stability of fixation. Additional complications include nonunion, coxa vara, and premature physeal arrest. The mainstay of treatment for traumatic pediatric osteonecrosis is hip preservation with total hip arthroplasty being reserved as a salvage procedure. An anatomic fracture reduction and a biomechanically stable construct are critical to prevent both nonunion and osteonecrosis. This review will look at the individual surgical interventions for the management of the associated complications of pediatric proximal femur fractures.

Periapical Wires Result in Less Curve Correction Than Pedicle Screw Constructs in Idiopathic Scoliosis.

STUDY DESIGN: Retrospective study. PURPOSE: The objective of this study was to compare percent correction between apical and periapical pedicle screw (PS) and sublaminar wire constructs for Cobb correction and coronal balance correction. OVERVIEW OF LITERATURE: The current gold standard for deformity correction in adolescent idiopathic scoliosis (AIS) are PS constructs. Sublaminar wires provide an alternative means of fixation when PS fixation cannot be safely performed. Two previous studies have compared percent curve correction between sublaminar wires and PSs, with conflicting conclusions. METHODS: The study was a retrospective review of Lenke type 1 curves with minimum follow-up of at least 1 year. Cases were divided into two groups: constructs using apical/periapical sublaminar wires (SL group) versus PS only constructs (PS group). Percent Cobb correction and coronal balance were compared between the two groups at 1 year. A multivariable regression model was used to determine the impact of apical/periapical wires on percent Cobb correction and coronal balance at 1 year when accounting for additional variables. RESULTS: The cohort included 71 patients who were predominantly female (80.2%), with average age of 14.2 years. Only 21 (29.5%) of constructs utilized apical/periapical sublaminar wires. There was a significant difference in percent Cobb correction at 1 year for the PS and SL groups (70.26% vs. 60.09%, p=0.05). No difference was observed in overall coronal balance. A multivariable model revealed that apical/periapical wires were negatively associated with percent Cobb correction at 1 year (coefficient=-8.49, p=0.023), while total implant density of the construct was positively associated with correction (coefficient=24.2, p<0.001). CONCLUSIONS: Use of PSs in the apical and periapical zones resulted in improved percent Cobb correction at 1 year in patients with AIS Lenke type 1 curves. Sublaminar wires remain a useful surgical option and result in equivalent coronal balance compared to PSs.

Gradual Deformity Correction in Blount Disease.

BACKGROUND: Blount disease is a disorder of the posteromedial proximal tibial physis which causes a progressive varus, procurvatum, and internal rotation deformity of the tibia. Untreated, it can cause significant limb malalignment. The goal of this study is to evaluate the results of correction of Blount disease using types of external fixation. METHODS: We conducted a retrospective review of 41 patients (51 limbs) who underwent correction of Blount disease with an Ilizarov external fixator or a Taylor spatial frame (TSF) by a single surgeon. The medial proximal tibial angle (MPTA), mean axis deviation (MAD), posterior proximal tibial angle, and joint line congruence angle (JLCA) were measured on radiographs preoperatively, at frame removal and at final follow-up. RESULTS: The average age at treatment was 9.6 years old, with a mean follow-up time of 34 months. Mean preoperative MPTA, MAD, and JLCA were significantly improved at the time of frame removal as well as at final follow-up with no significant changes in correction between the time of frame removal and final follow-up. There was no difference in MPTA and MAD in patients treated with an Ilizarov frame versus a TSF. MPTA, MAD, and JLCA all significantly improved regardless of the underlying diagnosis (infantile vs. adolescent Blount disease) or history of prior surgical intervention. The most common complication was superficial pin-site infection. CONCLUSIONS: Both Iliazarov and TSF are viable treatment options for infantile and adolescent Blount disease, with the ability to significantly improve both the limb mechanical axis and the mechanical axis of the affected tibia. Correction can be attained regardless of whether patients have previously failed surgical intervention. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Orthopedic and Surgical Management of the Patient With Duchenne Muscular Dystrophy.

Orthopedic care is an important aspect of the overall management of patients with Duchenne muscular dystrophy (DMD). In addition to progressive muscle weakness and loss of function, patients may develop joint contractures, scoliosis, and osteoporosis, causing fractures; all of these necessitate intervention by a multidisciplinary team including an orthopedic surgeon as well as rehabilitation specialists such as physio- and occupational therapists. The causes of these musculoskeletal complications are multifactorial and are related to primary effects on the muscles from the disease itself, secondary effects from weak muscles, and the related side effects of treatments, such as glucocorticoid use that affect bone strength. The musculoskeletal manifestations of DMD change over time as the disease progresses, and therefore, musculoskeletal management needs change throughout the life span of an individual with DMD. In this review, we target pediatricians, neurologists, orthopedic surgeons, rehabilitation physicians, anesthesiologists, and other individuals involved in the management of patients with DMD by providing specific recommendations to guide clinical practice related to orthopedic issues and surgical management in this setting.

IRF2BPL Is Associated with Neurological Phenotypes.

Interferon regulatory factor 2 binding protein-like (IRF2BPL) encodes a member of the IRF2BP family of transcriptional regulators. Currently the biological function of this gene is obscure, and the gene has not been associated with a Mendelian disease. Here we describe seven individuals who carry damaging heterozygous variants in IRF2BPL and are affected with neurological symptoms. Five individuals who carry IRF2BPL nonsense variants resulting in a premature stop codon display severe neurodevelopmental regression, hypotonia, progressive ataxia, seizures, and a lack of coordination. Two additional individuals, both with missense variants, display global developmental delay and seizures and a relatively milder phenotype than those with nonsense alleles. The IRF2BPL bioinformatics signature based on population genomics is consistent with a gene that is intolerant to variation. We show that the fruit-fly IRF2BPL ortholog, called pits (protein interacting with Ttk69 and Sin3A), is broadly detected, including in the nervous system. Complete loss of pits is lethal early in development, whereas partial knockdown with RNA interference in neurons leads to neurodegeneration, revealing a requirement for this gene in proper neuronal function and maintenance. The identified IRF2BPL nonsense variants behave as severe loss-of-function alleles in this model organism, and ectopic expression of the missense variants leads to a range of phenotypes. Taken together, our results show that IRF2BPL and pits are required in the nervous system in humans and flies, and their loss leads to a range of neurological phenotypes in both species.

Pediatric proximal femur fractures.

Pediatric proximal femur fractures are rare injuries resulting from high-energy trauma. The Delbet classification is used when describing these injuries, and associates fracture type to the development of avascular necrosis. Historically, casting was utilized in the treatment of these injuries, but high complication rates following this approach have changed the treatment modality to early and anatomic fixation. Complications associated with these injuries including avascular necrosis, non-union, coxa-vara, and premature physeal fusion. Achieving anatomic reduction and performing internal fixation within 24 h from time of injury has become the standard of care in the treatment of pediatric proximal femur fractures.

Analysis of the impact of race on blood transfusion in pediatric scoliosis surgery.

INTRODUCTION: Surgical correction of pediatric scoliosis is associated with significant blood loss. Minimizing estimated blood loss and blood transfusion is beneficial as transfusions have been associated with increased morbidity, including risk of surgical site infections, longer hospitalizations, and increased cost. Although there is evidence that African-American or Black adults are more likely to require intraoperative blood transfusion compared with Caucasian or White adults, the reasons for this difference are unclear. METHODS: The electronic records for all patients <18 y/o undergoing primary corrective scoliosis surgery by a single pediatric orthopedic surgeon at a single academic medical center between 2013 and 2015 were collected and reviewed. Multivariate models were performed to assess the association between Black race and blood loss/transfusion in primary pediatric scoliosis surgery. RESULTS: In a multivariate model, Black race was independently associated with 1.61 times higher estimated blood loss than White race (P < .01; 95% CI = 1.16-2.23). Additionally, compared to a White patient, the odds a Black patient received blood transfusion was 6.25 times higher (P = .03; 95% CI = 1.56-25.06) and among the patients who received blood transfusion, Black race was independently associated with 2.61 times greater volume of blood transfusion than White race (P < .01; 95% CI = 1.54-4.41). CONCLUSION: Black race was independently associated with increased estimated blood loss, increased rate of blood transfusion, and increased amount of blood transfused during surgical correction of pediatric scoliosis. Further investigation is needed to better understand the etiology of the disparity and assess opportunities for improving outcomes.

Looking beyond the exome: a phenotype-first approach to molecular diagnostic resolution in rare and undiagnosed diseases.

PurposeTo describe examples of missed pathogenic variants on whole-exome sequencing (WES) and the importance of deep phenotyping for further diagnostic testing.MethodsGuided by phenotypic information, three children with negative WES underwent targeted single-gene testing.ResultsIndividual 1 had a clinical diagnosis consistent with infantile systemic hyalinosis, although WES and a next-generation sequencing (NGS)-based ANTXR2 test were negative. Sanger sequencing of ANTXR2 revealed a homozygous single base pair insertion, previously missed by the WES variant caller software. Individual 2 had neurodevelopmental regression and cerebellar atrophy, with no diagnosis on WES. New clinical findings prompted Sanger sequencing and copy number testing of PLA2G6. A novel homozygous deletion of the noncoding exon 1 (not included in the WES capture kit) was detected, with extension into the promoter, confirming the clinical suspicion of infantile neuroaxonal dystrophy. Individual 3 had progressive ataxia, spasticity, and magnetic resonance image changes of vanishing white matter leukoencephalopathy. An NGS leukodystrophy gene panel and WES showed a heterozygous pathogenic variant in EIF2B5; no deletions/duplications were detected. Sanger sequencing of EIF2B5 showed a frameshift indel, probably missed owing to failure of alignment.ConclusionThese cases illustrate potential pitfalls of WES/NGS testing and the importance of phenotype-guided molecular testing in yielding diagnoses.

An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete.

Manufactured sand differs from natural sea and river dredged sand in its physical and mineralogical properties. These can be both beneficial and detrimental to the fresh and hardened properties of concrete. This paper presents the results of a laboratory study in which manufactured sand produced in an industry sized crushing plant was characterised with respect to its physical and mineralogical properties. The influence of these characteristics on concrete workability and strength, when manufactured sand completely replaced natural sand in concrete, was investigated and modelled using artificial neural networks (ANN). The results show that the manufactured sand concrete made in this study generally requires a higher water/cement (w/c) ratio for workability equal to that of natural sand concrete due to the higher angularity of the manufactured sand particles. Water reducing admixtures can be used to compensate for this if the manufactured sand does not contain clay particles. At the same w/c ratio, the compressive and flexural strength of manufactured sand concrete exceeds that of natural sand concrete. ANN proved a valuable and reliable method of predicting concrete strength and workability based on the properties of the fine aggregate (FA) and the concrete mix composition.

Neuromuscular Scoliosis: Current Concepts.

Scoliosis is a common deformity in neuromuscular disorders. This spinal deformity usually presents at an early age, rapidly progresses during growth, and continues to progress even after skeletal maturity. Neuromuscular scoliosis classically involves the entire thoracolumbar spine, often extending to the pelvis and causing pelvic obliquity. Physical examination can be challenging, but it is important to assess the flexibility of the spinal curve and associated joint contractures. Upright anteroposterior and lateral radiographs are the preferred imaging. When formulating a treatment plan, it is important to take into account not only the degree of curvature, but also each patient's needs and quality of life, the potentially high perioperative complication rates, and the natural history of the underlying neuromuscular disorder. Different neuromuscular conditions behave differently and should therefore be treated differently. With the exception of steroids for Duchenne muscular dystrophy, bracing remains the only reliable nonoperative intervention available. Preoperative optimization of medical comorbidities is crucial given the relatively high complication rate. Posterior segmental instrumentation has revolutionized the surgical management of neuromuscular scoliosis and is the most commonly used technique today. Despite reported improvement in postoperative quality of life, there are several limitations with currently used outcome measures that prevent a well-informed discussion on the outcomes after surgery.