Brian Snyder

Boston Children's Hospital · Department of Orthopaedic Surgery

Background Clinically significant proximal junctional kyphosis (PJK) occurs in 20% of children with scoliosis treated with posterior distraction-based growth-friendly surgery. In an effort to identify modifiable risk factors, it has been theorized biomechanically that low radius of curvature (ROC) implants (i.e., more curved rods) may increase post...

Purpose: Evaluate parental perception of the quality of discharge teaching, readiness for discharge, and the impact of these on post discharge coping difficulty and resource utilization in children with cerebral palsy (CP) following surgery. Design and methods: Prospective cohort study conducted from September 2017-March 2021 at a pediatric acad...

Purpose: Consensus and uncertainty in early onset scoliosis (EOS) treatment were evaluated in 2010. It is currently unknown how treatment preferences have evolved over the past decade. The purpose of this study was to re-evaluate consensus and uncertainty among treatment options for EOS patients to understand how they compare to 10 years ago. Met...

Arthrofibrosis, or rigid contracture of major articular joints, is a significant morbidity of many neurodegenerative disorders. The pathogenesis depends on the mechanism and severity of the precipitating neuromuscular disorder. Most neuromuscular disorders, whether spastic or hypotonic, culminate in decreased joint range of motion. Limited range of...

Background: Hip reconstruction surgery in patients with neurological complex chronic conditions (CCC) is associated with prolonged hospitalization and extensive resource utilization. This population is vulnerable to cognitive, developmental, and medical comorbidities which can increase length of stay (LOS). The aims of this study were to character...

Background: Children with medical complexity are at increased risk of low bone mineral density (BMD) and complications after spinal fusion compared with idiopathic scoliosis patients. Our aim was to compare treatments and outcomes of children with medical complexity undergoing spinal fusion in those who had dual-energy x-ray absorptiometry (DXA) s...

Longitudinal bone growth, achieved through endochondral ossification, is accomplished by a cartilaginous structure, the physis or growth plate, comprised of morphologically distinct zones related to chondrocyte function: resting, proliferating and hypertrophic zones. The resting zone is a stem cell-rich region that gives rise to the growth plate, a...

Purpose: Vertebral body tethering (VBT) continues to grow in interest from both a patient and surgeon perspective for the treatment of scoliosis. However, the data are limited when it comes to surgeon selection of both procedure type and instrumented levels. This study sought to assess surgeon variability in treatment recommendation and level sele...

Purpose: Spinal muscular atrophy (SMA) is a genetic disease resulting in orthopaedic problems that warrant intervention. Recent genetic therapies appear to improve the natural course of this disease, prompting care providers to rethink treatment strategies. Insufficient high-quality evidence exists to guide optimal intervention in this new landscap...

Objectives: Cerebral palsy (CP) is the most common childhood motor disability, yet its link to single-gene disorders is under-characterized. To explore the genetic landscape of CP, we conducted whole exome sequencing (WES) in a cohort of patients with CP. Methods: We performed comprehensive phenotyping and WES on a prospective cohort of individu...

Background: Epidural analgesia is commonly used for pain control after reconstructive hip surgery, but its use is controversial in the presence of an intrathecal baclofen pump (ITB). The purpose of this retrospective study was to investigate the rate of serious anesthetic and postoperative complications as well as the efficacy of epidural analgesi...

Background: The purpose of this study was to report mortality and associated risk factors in neuromuscular early onset scoliosis following spinal deformity surgery. Methods: This is a multicenter retrospective cohort study of patients with cerebral palsy (CP), spinal muscular atrophy, myelodysplasia, muscular dystrophy, or myopathy undergoing in...

CA4+ is a novel cationic iodinated contrast agent utilized for contrast-enhanced microCT (CECT). In this study, we compared CA4+ CECT for cartilage quantification of unfixed and neutral buffered formalin (NBF)-fixed rabbit distal femur cartilage after 8-, 24- and 30-hours of contrast agent diffusion. The stability of CA4+ binding to cartilage after...

The development of treatments for osteoarthritis (OA) is burdened by the lack of standardized biomarkers of cartilage health that can be applied in clinical trials. We present a novel arthroscopic Raman probe that can “optically biopsy” cartilage and quantify key ECM biomarkers for determining cartilage composition, structure, and material properti...

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, cerebra...

Aim To evaluate the effect of hip reconstruction or spinal fusion on health-related quality of life (HRQoL) in non-ambulatory children with spastic cerebral palsy (CP) and caregiver burden. Method This was a prospective, longitudinal study of changes in HRQoL and caregiver burden over the 5 years after surgical correction of hip instability or sco...

The development of treatments for osteoarthritis (OA) is burdened by the lack of standardized biomarkers of cartilage health that can be applied in clinical trials. We present a novel arthroscopic Raman probe that can optically biopsy cartilage and quantify key ECM biomarkers for determining cartilage composition, structure, and material properties...

Background: Recent focus on surgical site infections (SSIs) after posterior spine fusion (PSF) has lowered infection rates by standardizing perioperative antibiotic prophylaxis. However, efforts have neglected to detail antibiotic treatment of SSIs. Our aim was to document variability in antibiotic regimens prescribed for acute and latent SSIs fol...

PurposeMany patients with presumed idiopathic scoliosis are found to have Chiari I malformation (CM-I) on MRI. The objective of this study is to report on scoliosis progression in CM-I with no syringomyelia.MethodsA retrospective review of patients with scoliosis and CM-I was conducted from 1997 to 2015. Patients with syringomyelia and/or non-idiop...

Cationic contrast‐enhanced computed tomography (CECT) is a quantitative imaging technique that characterizes articular cartilage, though its efficacy in differentiating repair tissue from other disease states is undetermined. We hypothesized that cationic CECT attenuation will distinguish between reparative, degenerative, and healthy equine articul...

Background: The risk of surgical site infection in pediatric posterior spine fusion (PSF) is up to 4.3% in idiopathic populations and 24% in patients with neuromuscular disease. Twenty-three percent of pediatric PSF tissue cultures are positive before closure, with a higher rate in neuromuscular patients. Our primary aim was to evaluate the feasib...

Osteoarthritis (OA) is a multifactorial disease of the entire joint which afflicts 140 million individuals worldwide regardless of economic or social status. Current clinical treatments for OA primarily center on reducing pain and increasing mobility, and there are limited therapeutic interventions to restore degraded cartilage or slow disease path...

Background: The purpose of this study is to examine the relationship between preoperative comorbidities, surgical complications, and length of stay (LOS) after hip reconstruction in nonambulatory children with cerebral palsy (CP). Methods: This single-center retrospective cohort study included 127 patients undergoing hip surgery between 2007 and...

A longstanding goal in science and engineering is to mimic the size, structure, and functionality present in biology with synthetic analogs. Today, synthetic globular polymers of several million molecular weight are unknown, and, yet, these structures are expected to exhibit unanticipated properties due to their size, compactness, and low inter-cha...

Study designRetrospective case series.Objectives To describe how pediatric patients with spinal and pelvic osteomyelitis are diagnosed and treated and assess the diagnostic value of magnetic resonance imaging (MRI), needle aspiration biopsy (NAB), and blood cultures in this population.Summary of background dataSpinal and pelvic osteomyelitis de nov...

Background: Occipital plate fixation has been shown to improve outcomes in cervical spine fusion. There is a paucity of literature describing occipital plate fixation, especially in the pediatric population. The authors reviewed a case series of 34 patients at a pediatric hospital who underwent cervical spine fusion with occipital plate fixation b...

Background: Children with neuromuscular complex chronic conditions (NMCCC) frequently undergo hip reconstruction surgery requiring blood transfusion. The purpose of this study is to examine the efficacy of tranexamic acid (TXA) to reduce blood loss and transfusion requirement in NMCCC children undergoing hip reconstruction surgery. Methods: Chil...

Disclosures: None INTRODUCTION: Infants with developmental defects are immobilized for an extended time for medical treatments, which in addition to the disease pathophysiology and nutritional deficiencies make them susceptible for fragility fractures related to disuse osteopenia. Whole body vibration (WBV) can provide dynamic forces that stimulate...

Background: The incidence of venous thromboembolism (VTE) after elective surgery in children with mobility impairments, including those with a neuromuscular complex chronic condition (NCCC), is unknown. Therefore, our objectives were to assess the incidence of VTE after elective spine and lower-extremity surgery in children with NCCC. Methods: A...

MRI and CT are widely used to image cartilage and their diagnostic capability is enhanced in the presence of contrast agents. The aim of the study is to directly compare the performance between commercial anionic MRI (Gd(DTPA), Gd2−) and CT (Ioxaglate, Iox1−) contrast agents with novel cationic MRI (Gd(DTPA)Lys2, Gd4+) and CT (CA4+) contrast agents...

Understanding hip osteoarthritis requires new investigational tools for quantitative studies of biophysical and biomechanical properties as well as for determination of structure. Three new protocols to study pathological changes in cartilage and to measure cartilage thickness in intact human hips are described using synchrotron contrast enhanced c...

Cervical-spine (C-spine) pathoanatomy is commonly evaluated by plane radiographs, CT or MRI; however, these modalities are unable to directly measure the dynamic mechanical properties of the functional spinal units (FSU) comprising the C-spine that account for its functional performance. We have developed an ultrasound-based technique that provides...

Aim: To assess changes in the developmental trajectory of corticospinal tracts (CST) maturation in children with hemiplegic cerebral palsy (HCP). Methods: Neuroimaging data were obtained from 36 children with HCP for both the more affected (MA) and less affected (LA) hemispheres, and, for purposes of direct comparison, between groups, 15 typically...

A poly(7-oxanorbornene-2-carboxylate) polymer containing pendent triethyleneglycol (TEG) chains of 2.8 MDa ("2.8M TEG") was synthesized and evaluated for long-term lubrication and wear reduction of ex vivo bovine cartilage as well as for synovitis in rats and dogs after intra-articular administration. Bovine cartilage surfaces were tested under tor...

Objective: Cationic agent contrast-enhanced computed tomography (cationic CECT) characterizes articular cartilage ex vivo, however, its capacity to detect post-traumatic injury is unknown. The study objectives were to correlate cationic CECT attenuation with biochemical, mechanical and histological properties of cartilage and morphologic computed...

Early detection of osteoarthritis (OA) remains a diagnostic challenge owing to insensitive diagnostic techniques currently available. Herein a new semi‐quantitative scoring system, based upon contrast‐enhanced computed tomographic (CECT) imaging, is described for further refinement of early OA disease staging. Trochlear ridge cartilage defects were...

Disclosures: None INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is a common spinal disease characterized by lateral curvature of the spine greater than 10 degrees. AIS comprises roughly 80% of all scoliosis cases and affects 2-4% of predominantly female adolescents between ages 10 and 16. Patients with AIS undergo serial radiographic evaluati...

Disclosures: None INTRODUCTION: Infants with developmental defects that induce immobilization for extended periods of time are at elevated risk for fragility fractures related to profound osteopenia. Due to a lack of physical activity, the bones of these infants become too fragile to support body weight or undergo typical manipulation of the skelet...

Design: Retrospective comparative study. Objective: The purpose of this study is to measure SSI outcomes before and after implementation of our center's multidisciplinary clinical pathway protocol for high-risk spinal surgery. Background: Surgical site infections (SSIs) after spinal fusion harm patients and are associated with significant heal...

Objective: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). Design: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cat...

Background: Heterotopic ossification (HO) is a well-recognized complication of proximal femoral resection (PFR) surgery in children with cerebral palsy (CP). Although single-dose radiation prophylaxis (SDRP) has been shown to be effective at lowering the rates of HO following adult total hip arthroplasty; there has been limited study examining the...

Background: The trapeziometacarpal joint is a common site for osteoarthritis development in the hand. When osteoarthritis is present, it results in significant functional disabilities due to the broad range of activities performed by this joint. However, our understanding of osteoarthritis initiation and progression at this joint is limited becaus...

Despite extensive literature showing damages in the sensorimotor projection fibers of children with hemiplegic cerebral palsy (HCP), little is known about how these damages affect the global brain network. In this study, we assess the relationship between the structural integrity of sensorimotor projection fibers and the integrity of intergyral ass...

Normal functioning of articulating tissues is required for many physiological processes occurring across length scales from the molecular to whole organism. Lubricating biopolymers are present natively on tissue surfaces at various sites of biological articulation, including eyelid, mouth, and synovial joints. The range of operating conditions at t...

Study design: Retrospective case series. Objectives: To report operative outcomes of contemporary surgical treatment of spondylolisthesis in the pediatric population. Summary of background data: Surgical treatment of developmental spondylolisthesis is controversial, with limited data on complication and reoperation rates. Methods: A retrospe...

Intra-articular injection of hyaluronic acid (HA) is used to treat osteoarthritis (OA) as a viscosupplement, yet it only provides short-term benefit because HA is cleaved by hyaluronidase and cleared out of the joint after several days. Therefore, we developed a new polymer biolubricant based on poly-oxanorbornane carboxylate to enhance joint lubri...

Objective: The purpose of this study was to (1) investigate the construct validity and (2) test-retest reliability of the Pediatric Evaluation of Disability Inventory - Computer Adaptive Test (PEDI-CAT) in children with cerebral palsy (CP). Design: A prospective convenience cross-sectional sample SETTING: Multidisciplinary CP clinic in a tertiar...

Contrast-enhanced computed tomography (CECT) using charged contrast-agents enables quantification of cartilage glycosaminoglycan content. Since glycosaminoglycan content is a key determinant of cartilage compressive stiffness, CECT measurements have the potential to non-invasively assess cartilage stiffness. The objective of this study was to deter...

INTRODUCTION: Cervical spine pathoanatomy is typically evaluated by static radiographs, CT or MRI; however, these modalities are unable to directly measure the dynamic performance of the C-spine in-vivo that account for its functionality. Ex-vivo spine models may be insufficient to replicate in-vivo kinematics, predict acute/chronic injury mechanic...

INTRODUCTION: Understanding the pathophysiology of acute and chronic degenerative intervertebral disc (IVD) disease induced by repetitive load scenarios encountered in the work environment remains a challenge since the etiology of these injuries are not evident in static X-ray, CT, or MRI imaging or pathoanatomic grading systems. Current methods to...

Study design: In a treatment-control animal study expansion thoracoplasty (ET) was performed in a juvenile rabbit model of thoracic insufficiency syndrome (TIS) and benefits to thoracic development and respiratory function quantified. Rabbits treated early versus late were compared to age-matched normal and disease control rabbits through to skele...

Objective: Depletion of glycosaminoglycans (GAGs) and degradation of collagen network are early hallmarks of osteoarthritis. Currently, there are no chondroprotective therapies that mitigate the loss of GAGs or effectively restore the collagen network. Recently, a novel polymeric cartilage supplement was described that forms a charged interpenetra...

This is the second half of a two-part document updating the standard of care recommendations for spinal muscular atrophy published in 2007. This part includes updated recommendations on pulmonary management and acute care issues, and topics that have emerged in the last few years such as other organ involvement in the severe forms of spinal muscula...

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Its incidence is approximately 1 in 11,000 live births. In 2007, an International Conference on the Standard of Care for SMA published a consensus statement on SMA standard of care that has been widely used throughout the wor...

Functional neuroimaging studies argue that sensory deficits in hemiplegic cerebral palsy (HCP) are related to deviant somatosensory processing in the ipsilesional primary somatosensory cortex (S1). A separate body of structural neuroimaging literature argues that these deficits are due to structural damage of the ascending sensory tracts (AST). The...

Contrast-enhanced micro-computed tomography (CEμCT) with cationic and anionic contrast agents reveals glycosaminoglycan (GAG) content and distribution in articular cartilage (AC). The advantage of using cationic stains (e.g., CA4+) compared to anionic stains (e.g., Hexabrix®), is that it distributes proportionally with GAGs, while anionic stain dis...

Purpose: Limited research has been conducted on the non-medical out-of-pocket expenses (NOOPEs) incurred by families of children with chronic health conditions. The study objectives were to: 1) calculate the estimated NOOPEs incurred by families during hospitalization of their child, 2) identify predictors of high NOOPEs, and 3) assess the impact...

Contrast agents that go beyond qualitative visualization and enable quantitative assessments of functional tissue performance represent the next generation of clinically useful imaging tools. An optimized and efficient large-scale synthesis of the cationic iodinated contrast agent (CA4+) is described for imaging articular cartilage. Contrast enhanc...

Articular cartilage lines the load-bearing surfaces of long bones and undergoes compositional and structural degeneration during osteoarthritis progression. Contrast enhanced microcomputed tomography (μCT) is being applied to a variety of preclinical models, including the mouse, to map structural and compositional properties in 3-D. The thinness (˜...

Background: The PEDI-CAT is a new clinical assessment for children and youth from birth through 20 years of age. Objective: To determine the discriminant validity of the PEDI-CAT according to Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS) in children with cerebral palsy (CP). Design: A prospe...

INTRODUCTION: Neck pain, instigated by acute or chronic injury sustained in the work place, is a common occupational health complaint associated with cervical spine inter-vertebral disc (IVD) degeneration. Laborers and military personnel exposed to repetitive loads and vibrations are at highest risk. Currently there are no methods to measure the dy...

INTRODUCTION: Neck pain, instigated by acute or chronic injury sustained in the work place, is a common occupational health complaint associated with cervical spine inter-vertebral disc (IVD) degeneration. Evaluating the deformation of the cervical spine IVD in response to applied loads is important to understanding the mechanical behavior of cervi...