Publications by authors named "Jason J Howard"

26 Publications

  • Page 1 of 1

Understanding skeletal muscle in cerebral palsy: a path to personalized medicine?

Dev Med Child Neurol 2021 Sep 9. Epub 2021 Sep 9.

Paediatric Neurosciences, Guy's and St Thomas' Foundation NHS Trust, Evelina Children's Hospital, London, UK.

Until recently, there has been little interest in understanding the intrinsic features associated with the pathomorphology of skeletal muscle in cerebral palsy (CP). Coupled with emerging evidence that challenges the role of spasticity as a determinant of gross motor function and in the development of fixed muscle contractures, it has become increasingly important to further elucidate the underlying mechanisms responsible for muscle alterations in CP. This knowledge can help clinicians to understand and apply treatment modalities that take these aspects into account. Thus, the inherent heterogeneity of the CP phenotype allows for the potential of personalized medicine through the understanding of muscle pathomorphology on an individual basis and tailoring treatment approaches accordingly. This review aims to summarize recent developments in the understanding of CP muscle and their relationship to musculoskeletal manifestations, in addition to proposing a treatment paradigm that incorporates this new knowledge.
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http://dx.doi.org/10.1111/dmcn.15018DOI Listing
September 2021

The change in sagittal plane gait patterns from childhood to maturity in bilateral cerebral palsy.

Gait Posture 2021 Aug 28;90:154-160. Epub 2021 Aug 28.

Nemours/Alfred I. duPont Hospital for Children, 1600 Rockland Rd., Wilmington, DE 19803, United States. Electronic address:

Background: The longitudinal stability of sagittal gait patterns in diplegic cerebral palsy (CP), stratified using the Rodda classification, is currently unknown.

Research Question: What is the trajectory of sagittal plane gait deformities as defined by the Rodda classification in a large cohort treated with orthopedic surgery guided by gait analysis?

Methods: A retrospective study utilized gait analysis to evaluate sagittal gait parameters before age 8 and after age 15 years. Individual limbs were categorized at each time point according to the Rodda classification based on mean sagittal plane knee and ankle angle during stance. Welch's t-tests compared gait variables from early childhood with maturity and examined changes associated with plantarflexor lengthening surgery.

Results: 100 youth with CP were evaluated twice: at a mean age of 5.49 ± 1.18 and 19.09 ± 4.32 years, respectively. Gross Motor Function Classification System distribution at maturity was I (10.5 %), II (55.2 %), III (28.6 %), and IV (5.7 %). At the initial visit, most limbs were in either true equinus (30 %) or jump-knee gait (26.5 %). At maturity, crouch gait (52.5 %) was the most common classification, of which 47.6 % were mild (1-3 standard deviations from age-matched norm; 21°-30°) and 52.4 % moderate or severe. For the entire cohort, at initial and final visits, respectively, mean knee flexion in stance was 26.8°±14.8° and 25.9°±11.4° (p = 0.320), ankle dorsiflexion in stance increased from -0.3°±11.5° to 9.0°±6.0° (p < 0.001), and passive knee flexion contracture was -2.3°±7.0° and -3.9°±8.0° (p = 0.043). In children who started in true equinus, apparent equinus, and crouch, there was no difference in stance phase knee flexion at maturity between those who underwent plantarflexor lengthenings versus those who did not (p > 0.18).

Significance: The trend in this cohort was toward crouch with increased stance phase ankle dorsiflexion from early childhood to maturity. Plantarflexor lengthenings were not a significant factor in the progression of stance phase knee flexion.
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http://dx.doi.org/10.1016/j.gaitpost.2021.08.022DOI Listing
August 2021

Hip Displacement in MECP2 Disorders: Prevalence and Risk Factors.

J Pediatr Orthop 2021 Oct;41(9):e800-e803

Department of Orthopedic Surgery, Division of Cerebral Palsy, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE.

Background: Methyl-CpG binding protein 2 (MECP2) disorders, including Rett syndrome and MECP2 duplication syndrome, are typified by profound intellectual disability, spasticity, and decline in gross motor function. Unlike scoliosis, linked to disease severity, little has been reported regarding the hip. The aim of this study was to report the prevalence and risk factors of hip displacement (HD) in MECP2 disorders.

Methods: This was a retrospective, comparative study. Children with a genetically confirmed MECP2 disorder were included. The primary outcome measure was the prevalence of HD (migration percentage>30%). Secondary outcomes included age at HD onset, ambulatory status, presence of clinically relevant scoliosis, genetic severity, presence of seizures, and associated comorbidities. Analysis of proportions of categorical variables was performed using χ2 testing (P=0.05).

Results: Fifty-six patients (54 Rett syndrome and 2 MECP2 duplication syndrome), diagnosed at 6.6 (SD: 4.7) years, met the inclusion criteria. The prevalence of HD was 36% [onset, 7.7 (SD: 3.8) y]. Risk factors for HD were nonwalker status (P=0.04), scoliosis (P=0.001), and refractory epilepsy (P=0.04).

Conclusions: The prevalence of HD in MECP2 disorders is comparable to cerebral palsy, associated with proxy measures of disease severity. These results can be used to develop hip surveillance programs for MECP2 disorders, allowing for timely management.

Level Of Evidence: Level III.
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http://dx.doi.org/10.1097/BPO.0000000000001898DOI Listing
October 2021

Pain Trajectories Following Adolescent Idiopathic Scoliosis Correction: Analysis of Predictors and Functional Outcomes.

JB JS Open Access 2021 Apr-Jun;6(2). Epub 2021 Apr 30.

Centre for Pediatric Pain Research (K.M.B. and J.C.) and Division of Orthopedic Surgery (R.E.-H.), IWK Health Centre, and Department of Psychology & Neuroscience (K.M.B. and J.C.), and Department of Psychiatry (J.C.), Dalhousie University, Halifax, Nova Scotia, Canada.

Background: A better understanding of early pain trajectories (patterns) following scoliosis surgery and how they relate to baseline patient characteristics and functional outcomes may allow for the development of mitigating strategies to improve patient outcomes.

Methods: This was a prospective cohort study. Adolescents with idiopathic scoliosis were recruited across multiple centers. Latent growth mixture modeling techniques were used to determine pain trajectories over the first postoperative year.

Results: The median numerical rating scale for pain in the hospital following surgery for adolescent idiopathic scoliosis was 5.0. It improved to 1.0 by 6 weeks, and was maintained at <1 by 3 to 12 months postoperatively. Three trajectories were identified, 2 of which involved moderate acute postoperative pain: 1 with good resolution and 1 with incomplete resolution by 1 year. The third trajectory involved mild acute postoperative pain with good resolution by 1 year. Membership in the "moderate pain with incomplete resolution" trajectory was predicted by higher baseline pain and anxiety, and patients in this trajectory reported worse quality of life than those in the trajectories with good resolution.

Conclusions: Pain recovery following surgery for idiopathic scoliosis was found to be substantial during the first 6 weeks and continued up to 1 year. We identified 3 main trajectories, 2 with favorable outcomes and 1 with persistent pain and worse quality of life at 1 year postoperatively. The risk factors most associated with the latter trajectory included increased baseline pain and anxiety.

Level Of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.2106/JBJS.OA.20.00122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8154436PMC
April 2021

Orthopaedic Manifestations of Transverse Myelitis in Children.

J Pediatr Orthop 2021 May 13. Epub 2021 May 13.

Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE Seton Hall Orthopaedics, St. Joseph's University Medical Center, Paterson, NJ Icahn School of Medicine at Mount Sinai, New York, NY Department of Orthopaedic Surgery, Nemours Children's Specialty Care, Jacksonville, FL.

Background: Transverse myelitis (TM) is a rare inflammatory disorder of the spinal cord. It can have a heterogeneous presentation with sensory, motor, and autonomic dysfunction. Neurological sequelae of TM include autonomic dysfunction, motor weakness, and/or spasticity. Studies describing orthopaedic deformities and treatments associated with TM are nonexistent. This purpose of this study was to describe the orthopaedic manifestations of TM in children.

Methods: A multicenter retrospective review was conducted of patients, 0 to 21 years of age, with TM presenting over a 15-year period at 4 academic children's hospitals. Those with confirmed diagnosis of TM and referred to an orthopaedic surgeon were included. Demographics, orthopaedic manifestations, operative/nonoperative treatments, and complications were recorded. Descriptive statistics were used for data reporting.

Results: Of 119 patients identified with TM, 37 saw an orthopaedic surgeon. By etiology, 23 were idiopathic (62%), 10 infectious (27%), 3 (8%) inflammatory/autoimmune, and 1 (3%) vascular. The mean age at diagnosis was 6.7 (SD: 5.5) years and at orthopaedic presentation was 8.4 (SD: 5.2) years. Orthopaedic manifestations included scoliosis in 13 (35%), gait abnormalities in 7 (19%), foot deformities in 7 (19%), upper extremity issues in 7 (19%), symptomatic spasticity in 6 (16%), lower extremity muscle contractures in 6 (16%), fractures in 6 (16%), hip displacement in 3 (8%), pain in 2 (5%), and limb length discrepancy in 2 (5%) patients. Seven children (19%) were seen for establishment of care. In all, 14 (38%) underwent operative intervention, mainly for soft-tissue and scoliosis management. Four patients had baclofen pump placement for spasticity management. Postoperative complications occurred in 36% of cases, most commonly because of infection. Neither topographic pattern nor location of lesion had a significant relationship with need for hip or spine surgery.

Conclusions: This report describes the orthopaedic manifestations associated with TM in children, nearly 40% of whom required operative intervention(s). Understanding the breadth of musculoskeletal burden incurred in TM can help develop surveillance programs to identify and treat these deformities in a timely manner.

Level Of Evidence: Level IV.
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http://dx.doi.org/10.1097/BPO.0000000000001845DOI Listing
May 2021

The impact of scoliosis surgery on pulmonary function in spinal muscular atrophy: a systematic review.

Spine Deform 2021 Jul 8;9(4):913-921. Epub 2021 Mar 8.

Department of Orthopedic Surgery, Nemours/Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA.

Scoliosis often occurs coincident with pulmonary function deterioration in spinal muscular atrophy but a causal relationship has not yet been reliably established. A systematic literature review was performed, with pulmonary function testing being the primary outcome pre- and post-scoliosis surgery. Levels of evidence were determined and GRADE recommendations made. Ninety studies were identified with only 14 meeting inclusion criteria. Four studies were level III and the rest were level IV evidence. The average age at surgical intervention was 11.8 years (follow-up 6.1 years). Post-operative pulmonary function progressively declined for the majority of studies. Otherwise, pulmonary function: improved (two studies), were unchanged (two studies), had a decreased rate of decline (three studies), declined initially then returned to baseline (two studies). Respiratory and spine-based complications were common. Given the available evidence, the following GRADE C recommendations were made: (1) surgery is most often associated with decreases in pulmonary function; (2) the impact of surgery on pulmonary function is variable, but does not improve over pre-operative baseline; (3) surgery may result in a decreased rate of decline in pulmonary function post-operatively. Given this lack of evidence-based support, the risk-benefit balance should be taken into consideration when contemplating scoliosis surgery.
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http://dx.doi.org/10.1007/s43390-021-00302-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270813PMC
July 2021

Skeletal Muscle in Cerebral Palsy: From Belly to Myofibril.

Front Neurol 2021 18;12:620852. Epub 2021 Feb 18.

Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.

This review will provide a comprehensive, up-to-date review of the current knowledge regarding the pathophysiology of muscle contractures in cerebral palsy. Although much has been known about the clinical manifestations of both dynamic and static muscle contractures, until recently, little was known about the underlying mechanisms for the development of such contractures. In particular, recent basic science and imaging studies have reported an upregulation of collagen content associated with muscle stiffness. Paradoxically, contractile elements such as myofibrils have been found to be highly elastic, possibly an adaptation to a muscle that is under significant tension. Sarcomeres have also been reported to be excessively long, likely responsible for the poor force generating capacity and underlying weakness seen in children with cerebral palsy (CP). Overall muscle volume and length have been found to be decreased in CP, likely secondary to abnormalities in sarcomerogenesis. Recent animal and clinical work has suggested that the use of botulinum toxin for spasticity management has been shown to increase muscle atrophy and fibrofatty content in the CP muscle. Given that the CP muscle is short and small already, this calls into question the use of such agents for spasticity management given the functional and histological cost of such interventions. Recent theories involving muscle homeostasis, epigenetic mechanisms, and inflammatory mediators of regulation have added to our emerging understanding of this complicated area.
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http://dx.doi.org/10.3389/fneur.2021.620852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7930059PMC
February 2021

Kyphectomy in Myelomeningocele for Severe Early-Onset Kyphosis Using Distal Intravertebral Fixation and Thoracic Growing Rods.

J Am Acad Orthop Surg Glob Res Rev 2019 Sep 23;3(9):e006. Epub 2019 Sep 23.

College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia (Dr. Alshaalan, Dr. Alshangiti, Dr. Aleissa, and Dr. Al Sayegh); Department of Orthopedic Surgery, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Deleware (Dr. Howard); and the King Abdullah Specialized Children Hospital (KASCH), King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia (Dr. Alshaalan, Dr. Alshangiti, Dr. Alkhalife, Dr. Aleissa, and Dr. Al Sayegh).

Most kyphectomy techniques require distal dissection of the bifid posterior spinal elements for implants placement in the thoracolumbar/pelvic regions, traversing the scarred tissue associated with previous MMC closure, thereby theoretically increasing the risk of wound complications. The technique avoids the MMC scar but does not reliably facilitate thoracic growth for early-onset kyphosis. This study aims to report the technique and outcomes of a combined Halifax kyphectomy (resection of the apical vertebrae with distal anterior multilevel vertebral body fixation) and thoracic growing rod construct used to treat early-onset symptomatic gibbus in a patient with myelomeningocele (MMC).

Methods: A 3-year-old girl with a thoracic MMC presented with symptomatic gibbus requiring surgical intervention. Correction by the Halifax kyphectomy technique combined with spine-based growing rods was performed.

Results: After the correction, the skin was closed primarily without the need for any flap for coverage. No wound complications or infection occurred post-operatively. The intraoperative blood loss was 200 mL, and the surgical time was 419 minutes. No pulmonary complications occurred postoperatively. At the final follow-up at 3 years 11 months postoperatively, the child had no recurrence of the deformity.

Conclusions: The combination of distal anterior multilevel vertebral body fixation with spine-based thoracic growing rods can successfully achieve kyphosis correction in MMC, with the potential to reduce complication rates and facilitate thoracic growth. Further investigation is necessary to prove whether the outcomes and the complication rates are superior to other established techniques.
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http://dx.doi.org/10.5435/JAAOSGlobal-D-19-00006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6860136PMC
September 2019

Sarcopenia, Cerebral Palsy, and Botulinum Toxin Type A.

JBJS Rev 2019 08;7(8):e4

Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.

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http://dx.doi.org/10.2106/JBJS.RVW.18.00153DOI Listing
August 2019

Relationship of muscle morphology to hip displacement in cerebral palsy: a pilot study investigating changes intrinsic to the sarcomere.

J Orthop Surg Res 2019 Jun 21;14(1):187. Epub 2019 Jun 21.

Faculty of Kinesiology, University of Calgary, 376 Collegiate Blvd NW, Calgary, AB, T2N 4V8, Canada.

Background: Cerebral palsy (CP) is the most common cause of childhood disability, typified by a static encephalopathy with peripheral musculoskeletal manifestations-most commonly related to spasticity-that are progressive with age. Hip displacement is one of the most common manifestations, observed to lead to painful degenerative arthritis over time. Despite the key role that spasticity-related adductor muscle contractures are thought to play in the development of hip displacement in CP, basic science research in this area to date has been limited. This study was initiated to correlate hip adductor muscle changes intrinsic to the sarcomere-specifically, titin isoforms and sarcomere length-to the severity of hip displacement in children with spastic cerebral palsy.

Methods: Single gracilis muscle biopsies were obtained from children with CP (Gross Motor Function Classification System (GMFCS) III-V; n = 10) who underwent adductor muscle release surgery for the treatment of hip displacement. Gel electrophoresis was used to estimate titin molecular weight. Sarcomere lengths were measured from muscle fascicles using laser diffraction. The severity of hip displacement was determined by measuring by Reimers migration percentage (MP) from anteroposterior pelvic x-rays. Correlation analyses between titin, sarcomere lengths, and MP were performed.

Results: The mean molecular weight of titin was 3588 kDa. The mean sarcomere length was 3.51 μm. Increased MP was found to be associated with heavier isoforms of titin (R = 0.65, p < 0.05) and with increased sarcomere lengths (R = 0.65, p < 0.05). Heavier isoforms of titin were also associated with increased sarcomere lengths (R = 0.80, p < 0.05).

Conclusions: Our results suggest that both larger titin isoforms and sarcomere lengths are positively correlated with increased severity of hip displacement and may represent adaptations in response to concomitant increases in spasticity and muscle shortening.

Trial Registration: As this study does not report the results of a health care intervention on human participants, it has not been registered.
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http://dx.doi.org/10.1186/s13018-019-1239-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6588916PMC
June 2019

Stiffness of hip adductor myofibrils is decreased in children with spastic cerebral palsy.

J Biomech 2019 04 28;87:100-106. Epub 2019 Feb 28.

Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada. Electronic address:

Cerebral palsy (CP) is the result of a static brain lesion which causes spasticity and muscle contracture. The source of the increased passive stiffness in patients is not understood and while whole muscle down to single muscle fibres have been investigated, the smallest functional unit of muscle (the sarcomere) has not been. Muscle biopsies (adductor longus and gracilis) from pediatric patients were obtained (CP n = 9 and control n = 2) and analyzed for mechanical stiffness, in-vivo sarcomere length and titin isoforms. Adductor longus muscle was the focus of this study and the results for sarcomere length showed a significant increase in length for CP (3.6 µm) compared to controls (2.6 µm). Passive stress at the same sarcomere length for CP compared to control was significantly lower in CP and the elastic modulus for the physiological range of muscle was lower in CP compared to control (98.2 kPa and 166.1 kPa, respectively). Our results show that CP muscle at its most reduced level (the myofibril) is more compliant compared to normal, which is completely opposite to what is observed at higher structural levels (single fibres, muscle fibre bundles and whole muscle). It is noteworthy that at the in vivo sarcomere length in CP, the passive forces are greater than normal, purely as a functional of these more compliant sarcomeres operating at long lengths. Titin isoforms were not different between CP and non-CP adductor longus but titin:nebulin was reduced in CP muscle, which may be due to titin loss or an over-expression of nebulin in CP muscles.
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http://dx.doi.org/10.1016/j.jbiomech.2019.02.023DOI Listing
April 2019

Intramuscular injection of collagenase clostridium histolyticum may decrease spastic muscle contracture for children with cerebral palsy.

Med Hypotheses 2019 Jan 9;122:126-128. Epub 2018 Nov 9.

Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.

In cerebral palsy (CP), the spastic motor type is most common, associated with a velocity-dependent increase in muscle stiffness that precedes the development of fixed muscle contracture - a permanent shortening of the muscle tendon unit even when relaxed. Intra-muscular injections of botulinum toxin type A (BTX-A) have become popular for the treatment of spastic muscle contractures but unfortunately its use has not resulted in long-term functional benefits and, paradoxically, has been associated with a persistent loss of contractile material. Recent biomechanical work has shown that the stiffness of the CP muscle increases in proportion to total collagen content within the perimysial extra-cellular matrix. Thus, rather than the use of tone-reducing agents, we hypothesize that the focal use of a selective collagenase, injected into spastic muscle at an appropriate dilution and concentration, may serve to reduce the extent of muscle contracture, improving clinical range of motion and perhaps sarcomere length.
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http://dx.doi.org/10.1016/j.mehy.2018.11.002DOI Listing
January 2019

Updating the Surgical Preference List.

Cureus 2018 Jul 18;10(7):e2997. Epub 2018 Jul 18.

Department of Surgery, Sidra Medicine, Ar-Rayyan, QAT.

Surgical procedure 'preference lists' are used worldwide, but their practice varies widely. Despite being positioned at a critical point in a surgical care pathway, they are often underemphasized, poorly maintained, and substandard. The following editorial material is gleaned from our experience in the set-up of a tertiary hospital on a green field site in Qatar. We comment on the use of preference lists, and contend that focus on standardizing and maintaining preference lists within an electronic record affords substantial opportunities for cost containment, whilst adding efficiency, safety, and value. We believe this approach represents an 'easy win' which would be applicable elsewhere.
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http://dx.doi.org/10.7759/cureus.2997DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6143367PMC
July 2018

QUESTION 2: What is the predictive value of an antenatal ultrasound showing apparently isolated talipes equinovarus?

Arch Dis Child 2016 Nov;101(11):1073-1078

Sidra Medical and Research Center, Doha, Qatar.

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http://dx.doi.org/10.1136/archdischild-2016-311594DOI Listing
November 2016

Robotic-assisted minimally invasive surgery of the spine (RAMISS): a proof-of-concept study using carbon dioxide insufflation for multilevel posterior vertebral exposure via a sub-paraspinal muscle working space.

Int J Med Robot 2017 Sep 19;13(3). Epub 2016 Oct 19.

Department of Surgery, Sidra Medical and Research Center; Department of Surgery, Weill Cornell Medical College, Doha, Qatar.

Background: Open posterior spinal procedures involve extensive soft tissue disruption, increased hospital length of stay, and disfiguring scars. Our aim was to demonstrate the feasibility of using robotic-assistance for minimally invasive exposure of the posterolateral spine with and without carbon dioxide (CO ) insufflation.

Methods: Sheep specimens underwent minimally invasive subperiosteal dissection of the spine during three trials. The da Vinci S Surgical system was used for access with and without working space support via CO insufflation.

Results: Without insufflation, a sub-paraspinal muscle tunnel measuring 16 cm was developed between two 5 cm incisions. With insufflation, the one-sided tunnel length was 12.5 cm but without the soft tissue trauma and obstructed visualization experienced without CO .

Conclusions: The use of robot-assistance for minimally invasive access to the posterior spine appears to be feasible. The use of CO insufflation greatly improved our ability to visualize and access the posterior vertebral elements.
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http://dx.doi.org/10.1002/rcs.1781DOI Listing
September 2017

Balancing innovation and medical device regulation: the case of modern metal-on-metal hip replacements.

Authors:
Jason J Howard

Med Devices (Auckl) 2016 9;9:267-75. Epub 2016 Aug 9.

Division of Orthopedic Surgery, Department of Surgery, Sidra Medical and Research Center; Department of Orthopedic Surgery, Weill Cornell Medical College, Doha, Qatar.

Due to problems with wear particle generation and subsequent loosening using conventional metal-on-polyethylene total hip replacements, there has been a shift toward alternative bearing systems, including metal-on-metal (MoM), for younger, more active patients with degenerative joint disease. Based on positive results from early short-term clinical studies, MoM hip replacements were readily adopted by orthopedic surgeons with thousands being implanted worldwide over the past decade. Unacceptably high revision rates reported by two national joint registries called into question the rigorousness of the regulatory approval process for these implants, particularly with respect to premarket data requirements to prove safety, effectiveness, and the appropriateness of the regulatory pathway chosen. The purpose of this review was to investigate the balance between facilitating the introduction of new medical technologies and the need to ensure safety and effectiveness through comprehensive regulatory assessment. The case of MoM hip replacement devices was used to frame the investigation and subsequent discussions. The regulatory approval processes and post-market surveillance requirements associated with three common MoM hip replacements (two resurfacings: the Birmingham and articular surface replacement and the articular surface replacement XL total hip replacement) were investigated. With respect to modern MoM hip replacement devices, the balance between facilitating the introduction of these new medical technologies and the need to ensure safety and effectiveness through comprehensive regulatory assessment was not achieved. The lessons learned from these experiences have application beyond joint replacements to the introduction of new medical technologies in general, particularly for those who have a significant potential for harm. In this regard, a series of recommendations have been developed to contribute to the evolution of the medical device regulatory process.
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http://dx.doi.org/10.2147/MDER.S113067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4984833PMC
August 2016

Comparison of Motor-Evoked Potentials Versus Somatosensory-Evoked Potentials as Early Indicators of Neural Compromise in Rat Model of Spinal Cord Compression.

Spine (Phila Pa 1976) 2017 Mar;42(6):E326-E331

IWK Health Centre, Halifax, Nova Scotia.

Study Design: Randomized controlled study comparing the efficacy of intraoperative somatosensory-evoked potentials (SSEPs) versus transcranial motor-evoked potentials (TcMEPs) as early indicators of neural compromise and predictors of postoperative function in a rat model of spinal cord compression.

Objective: To compare the relative efficacy of SSEPs and TcMEPs to detect spinal cord compromise and predict postoperative functional deficit after spinal cord compression.

Summary Of Background Data: There is controversy regarding the efficacy of SSEPs versus TcMEPs to detect intraoperative spinal cord compromise and predict functional outcomes. Previous trials provide some guidance as to the role of each modality in spinal cord monitoring but randomized controlled trials, which are not feasible in humans, are lacking.

Methods: Twenty-four adult male Wistar rats were evenly divided into three experimental groups and one control group. The experimental groups were determined according to the length of time that 100% TcMEP signal loss was maintained: 0, 5, or 15 minutes. All animals had standardized preoperative functional testing. Spinal cord compromise was initiated utilizing a validated protocol, which involved compression via a balloon catheter introduced into the thoracic sublaminar space. Both SSEPs and TcMEPs were recorded during cord compression for each experimental group. Functional behavioral testing using two validated methods (tilt and modified Tarlov) was repeated 24 hours after termination of spinal cord compression. Post hoc, animals were redistributed into two functional subgroups, noncompromised and compromised, for statistical analysis.

Results: TcMEPs consistently detected spinal cord compromise either in advance of or at the same time as SSEPs; however, the delay in SSEP response was not significant for cases when compromised postoperative function resulted. Both SSEP and TcMEP amplitude recovery correlated well with postoperative functional scores.

Conclusion: TcMEPs are more sensitive to spinal cord compromise than SSEPs, but the recovery profiles of both SSEP and TcMEP amplitudes are good predictors of postoperative function.

Level Of Evidence: 2.
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http://dx.doi.org/10.1097/BRS.0000000000001838DOI Listing
March 2017

Treatment of flexion-type supracondylar fractures in children: the 'push-pull' method for closed reduction and percutaneous K-wire fixation.

J Pediatr Orthop B 2016 Sep;25(5):412-6

aDivision of Paediatric Orthopaedics, IWK Health Centre, Halifax, Nova Scotia, Canada bDivision of Paediatric Orthopaedics, Sidra Medical and Research Center, Doha, Qatar.

Unlabelled: Flexion-type supracondylar fractures are challenging to treat because, unlike extension-type fractures, it is difficult to take advantage of the intact periosteal hinge to stabilize the fracture fragments during percutaneous pinning. Some authors have described closed reduction of these fractures with the elbow in extension, followed by percutaneous K-wire fixation. However, percutaneous pinning with elbow in extension is technically difficult, time consuming, and usually requires the help of a skilled assistant because of persistent fracture instability. To circumvent these difficulties, we utilized a 'push-pull' maneuver, which simplifies the closed reduction and fixation of these difficult fractures. We describe the surgical technique for the 'push-pull' method and report radiographic outcomes of a case series of children with flexion-type supracondylar fractures treated using this technique. A retrospective review of medical records and radiographs of all children who underwent operative treatment of a flexion-type supracondylar humeral fracture using the 'push-pull' method in a tertiary-level children's hospital between January 2009 and January 2014 was carried out. Radiographic outcomes were reported using descriptive statistics. There were a total of nine patients (five females, four males), average age 9.8 years (4-14 years). Seventy-eight percent (7/9 patients) of the children had type III injuries, whereas 22% (two children) had type II injuries. The average duration of surgery was 41 min (24-60 min). No intraoperative or postoperative complications were recorded. Postoperative radiographic measures showed that the anterior humeral line passed through the middle third of capitellum in 78% of patients (7/9 patients), whereas it passed posterior to it in 22% (two patients). The average humerocapitellar angle was 30° (21-44°) and the anterior coronoid line was unbroken in 44% (4/9 patients). The average humeroulnar angle was 13° (8-20°) of valgus. The 'push-pull' is a safe, effective, and easy method to treat unstable flexion-type supracondylar fractures in children with good radiographic postoperative outcomes.

Level Of Evidence: level IV.
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http://dx.doi.org/10.1097/BPB.0000000000000241DOI Listing
September 2016

Validity of transcranial motor evoked potentials as early indicators of neural compromise in rat model of spinal cord compression.

Spine (Phila Pa 1976) 2015 Apr;40(8):E492-7

*IWK Health Centre, Halifax, Nova Scotia, Canada †Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada ‡Division of Paediatric Orthopaedics, Sidra Medical and Research Center, Doha, Qatar; and §Department of Physiology & Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.

Study Design: Randomized controlled study of intraoperative transcranial motor evoked potentials (TcMEPs) as early indicators of neural compromise in a rat model of spinal cord compression.

Objective: To determine the temporal threshold at which a complete (100%) loss of intraoperative TcMEPs will result in significant postoperative functional deficits.

Summary Of Background Data: There is controversy about the best TcMEP alarm criteria for intraoperative spinal cord protection. Clinical trials provide some evidence, but randomized controlled trials, which are not feasible in humans, are lacking.

Methods: Twenty-four adult male Wistar rats were divided into 3 experimental groups according to the length of time that a 100% TcMEP signal loss was maintained; all animals had preoperative functional testing. After surgical placement of a balloon catheter in the thoracic sublaminar space, TcMEPs were recorded while the spinal cord was compressed by balloon inflation. The recordings were terminated after maintaining a 100% TcMEP loss for different time periods (0, 5, or 15 min). Functional behavioral testing was repeated after 24 hours.

Results: Only the groups wherein the catheter was left inflated for 5 or 15 minutes after a complete (100%) loss of TcMEP amplitude showed a significant deterioration in functional testing as compared with preoperative baseline values. Functional testing remained normal for both the control group and the group in which termination of spinal cord compression occurred immediately after a decrease of TcMEP amplitude to 100%. There was a strong correlation between TcMEP amplitude recovery postintervention and functional ability at 24 hours postsurgery.

Conclusion: If a 100% loss of TcMEP signals is immediately recognized and reversed by rapid removal of the compressive force on the spinal cord, normal postoperative function was observed in this rat model. However, delaying intervention for even 5 minutes can result in significant postoperative functional deficits.

Level Of Evidence: N/A.
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http://dx.doi.org/10.1097/BRS.0000000000000808DOI Listing
April 2015

Medical devices and the Middle East: market, regulation, and reimbursement in Gulf Cooperation Council states.

Authors:
Jason J Howard

Med Devices (Auckl) 2014 20;7:385-95. Epub 2014 Nov 20.

Division of Paediatric Orthopaedics, Department of Surgery, Sidra Medical and Research Center, Doha, Qatar.

With some of the richest economies in the world, the Gulf Cooperation Council (GCC) is undergoing rapid growth not only in its population but also in health care expenditure. Despite the GCC's abundance of hydrocarbon-based wealth, the drivers of the medical device industry in the GCC are still in flux, with gains yet to be made in areas of infrastructure, regulation, and reimbursement. However, the regional disease burden, expanding health insurance penetration, increasing privatization, and a desire to attract skilled expatriate health care providers have led to favorable conditions for the medical device market in the GCC. The purpose of this article is to investigate the current state of the GCC medical device industry, with respect to market, regulation, and reimbursement, paying special attention to the three largest medical device markets: Saudi Arabia, the United Arab Emirates, and Qatar. The GCC would seem to represent fertile ground for the development of medical technologies, especially those in line with the regional health priorities of the respective member states.
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http://dx.doi.org/10.2147/MDER.S73079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242697PMC
November 2014

Nerve blocks for initial pain management of femoral fractures in children.

Cochrane Database Syst Rev 2013 Dec 17(12):CD009587. Epub 2013 Dec 17.

Division of Emergency Medicine, Department of Pediatrics, University of British Columbia, BC Children's Hospital, 4480 Oak St, Vancouver, BC, Canada, V6H 3N1.

Background: Children and adolescents with femoral fractures are almost always admitted to hospital. They invariably start their hospital experience in the Emergency Department, often requiring transfer to a specialist children's hospital. They require analgesia or anaesthesia so that radiographs can be obtained and for management of their fractures. The initial care process involves from two to six transfers from stretcher to stretcher/imaging/operating-suite table or hospital bed within the first few hours, so prompt pain relief is essential. Systemic analgesia can be provided orally or parenterally. Alternatively, a nerve block may be used where local anaesthetic is injected around a nerve to block sensation or freeze the involved area.

Objectives: To assess the effects (benefits and harms) of femoral nerve block (FNB) or fascia iliaca compartment block (FICB) for initial pain management of children with fractures of the femur (thigh bone) in the pre-hospital or in-hospital emergency setting, with or without systemic analgesia.

Search Methods: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (11 January 2013), the Cochrane Central Register of Controlled Trials (2012 Issue 12), MEDLINE (1946 to January Week 1 2013), EMBASE (1980 to 2013 Week 01), Google Scholar (31 January 2013) and trial registries (31 January 2013). We handsearched recent issues of specialist journals and references of relevant articles.

Selection Criteria: Randomised and quasi-randomised controlled trials assessing the effects of FNB or FICB for initial pain management compared with systemic opiates in children (aged under 18 years) with fractures of the femur receiving pre-hospital or in hospital emergency care. Primary outcomes included failure of analgesia at 30 minutes, pain levels during procedures and transfers (e.g. to a stretcher or hospital ward) for up to eight hours, and adverse effects.

Data Collection And Analysis: Two review authors independently extracted data using a pre-piloted form. Two authors independently assessed the risk of bias for the included study and assessed quality of the evidence for each outcome using the GRADE approach; i.e. as very low, low, moderate or high. Meta-analysis of results was not possible as we found only one trial that could be included in the review.

Main Results: We included one randomised trial of 55 children aged between 16 months to 15 years. It compared anatomically-guided FICB versus systemic analgesia with intravenous morphine sulphate. The small sample size and the high risk of bias relating to lack of blinding resulted in a low quality rating for all outcomes.Overall, the trial provided low quality evidence for better pain management in the FICB group. Fewer children in the FICB group had analgesia failure at 30 minutes than in the morphine group (2/26 (8%) versus 8/28 (29%); risk ratio (RR) 0.33, 95% confidence interval (CI) 0.09 to 1.20; P value 0.09). The trial did not report on pain during procedures or transfers, or application of analgesia. The trial provided low quality evidence that FICB has a better safety profile than morphine, with only four (15%) reports of redness and pain at the injection site, and no reports of the type of adverse effects of systematic analgesia that occurred in the morphine group, such as respiratory depression (six cases (21%)) and vomiting (four cases (14%)). No long-term adverse events were reported for either intervention. Clinically significant pain relief was achieved in both groups at five minutes; with limited evidence of greater initial pain relief in the FICB group. Based on an inspection of graphically-presented data, at least 46% (12/26) of children in the FICB group had no supplementary medication (mainly analgesia) for the six hours of the study, while only 5% (1 or 2/28) of children in the intravenous morphine group went without additional analgesia. There was insufficient evidence to determine whether child or parental satisfaction with the method of analgesia favoured either method. Resource use was not measured.

Authors' Conclusions: Low quality evidence from one small trial suggests that FICB provides better and longer lasting pain relief with fewer adverse events than intravenous opioids for femur fractures in children. Well conducted and reported randomised trials that compare nerve blocks (both FNB and FICB) with systemic analgesia and that use validated pain scores are needed.
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http://dx.doi.org/10.1002/14651858.CD009587.pub2DOI Listing
December 2013

Sagittal Spinopelvic Parameters of Young Children With Scoliosis.

Spine Deform 2013 Sep 25;1(5):343-347. Epub 2013 Sep 25.

Primary Children's Hospital, Pediatric Orthopaedics, 100 N Mario Capecchi Drive, Suite 4550, Salt Lake City, UT, 84113, USA.

Study Design: Retrospective, multicenter review of the spinopelvic parameters in young children with scoliosis.

Objectives: To describe sagittal alignment of the spine and pelvis in young children with scoliosis.

Summary Of Background Data: The natural history of spinopelvic parameters has been defined for the first 10 years of life in normal children; however, they have not been described for children with scoliosis. Such information is important because these values can be used as a baseline for the assessment of radiographic outcomes after surgical intervention.

Methods: Seven measures of sagittal alignment were taken from standing lateral radiographs of 80 children with scoliosis (coronal Cobb angle greater than 50°) and compared with age-matched normal children described in the literature. Statistical analysis was performed using 2-tailed Student t tests (level of significance = .05) and Pearson correlation coefficient.

Results: Patients had a mean age of 4.8 years (range, 1-10 years) and a mean Cobb angle of 72.0° ± 16°. Mean sagittal spine parameters were sagittal balance (2.2 ± 4 cm), thoracic kyphosis (38.0° ± 20.8°), and lumbar lordosis (49.0° ± 16.6°). These values were similar to those of children without scoliosis. Mean sagittal pelvic parameters were: pelvic incidence (46.5° ± 15.8°), pelvic tilt (10.7° ± 13.6°), sacral slope (35.5° ± 12.1°), and pelvic radius (55.7° ± 21.3°). Pelvic incidence was not significantly different from that of age-matched normal children; however, pelvic tilt was significantly higher and sacral slope was significantly lower in children with scoliosis.

Conclusions: Sagittal plane spine parameters and some pelvic parameters were similar for young children with scoliosis versus age-matched normal children; however, children with scoliosis showed signs of increased pelvic tilt and decreased sacral slope. These values can be used as a baseline for both the natural history and the assessment of radiographic outcomes after surgical intervention.
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http://dx.doi.org/10.1016/j.jspd.2013.07.001DOI Listing
September 2013

Validity of somatosensory evoked potentials as early indicators of neural compromise in rat model of spinal cord compression.

Clin Neurophysiol 2013 May 21;124(5):1031-6. Epub 2012 Dec 21.

IWK Health Centre, Halifax, Nova Scotia, Canada.

Objective: To determine the percentage change in somatosensory evoked potential amplitude and the duration of spinal cord compression that can be tolerated intraoperatively in a rat model before there are significant post-operative functional deficits.

Methods: Thirty two adult male Wistar rats were divided into four groups according to the percentage of induced SSEP signal loss; all animals had pre-operative functional testing. Following surgical placement of a balloon catheter in the thoracic sub-laminar space, SSEPs were recorded while the spinal cord was compressed by inflation of the balloon. The recordings were terminated after a different percentage loss of SSEP amplitude in each group. Functional behavioral testing was repeated after 24 h.

Results: Only the group wherein the catheter was left inflated for 15 min after a complete (100%) loss of SSEP amplitude showed a significant deterioration in functional testing as compared to pre-operative baseline values. Functional testing remained normal for the groups in which termination of spinal cord compression occurred immediately after a decrease of SSEP amplitude to 50% or 100%.

Conclusions: SSEP loss of up to 100% can be tolerated in a rat model of spinal cord compression as long as the compression is terminated immediately after the SSEP decrease is detected. Prolonged spinal cord compression, with concomitant SSEP decrease, can result in post-operative functional deficits despite mitigating procedures to remove the compression.

Significance: This study is an important first step in providing basic science evidence for the establishment of acceptable "alarm criteria" during spinal surgery.
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http://dx.doi.org/10.1016/j.clinph.2012.10.023DOI Listing
May 2013

Thoracic myelopathy secondary to seizure following scoliosis surgery.

J Child Neurol 2012 Jul 2;27(7):914-6. Epub 2011 Dec 2.

Department of Pediatrics, Division of Neurology, Alberta Children's Hospital, Calgary, Alberta, Canada.

The incidence of spinal injuries is increased in people with epilepsy although compressive thoracic myelopathy has not been reported. We describe a 15-year-old girl with SCN1A mutation (Dravet syndrome), refractory generalized tonic-clonic seizures, and prior posterior instrumentation and fusion for scoliosis, who presented with progressive lower extremity weakness. Junctional kyphosis with disc herniation and spinal cord compression directly rostral to the instrumentation was apparent on imaging. On history, the patient had suffered a particularly severe convulsive seizure just before developing symptoms. Surgical decompression and stabilization led to a complete neurologic recovery. This unusual presentation of myelopathy illustrates the need to consider this complication in patients with epilepsy and spinal instrumentation.
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http://dx.doi.org/10.1177/0883073811426933DOI Listing
July 2012

Hip displacement in cerebral palsy.

J Bone Joint Surg Am 2006 Jan;88(1):121-9

Department of Orthopaedic Surgery, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia.

Background: Hip displacement is considered to be common in children with cerebral palsy but the reported incidence and the proposed risk factors vary widely. Knowledge regarding its overall incidence and associated risk factors can facilitate treatment of these children.

Methods: An inception cohort was generated from the Victorian Cerebral Palsy Register for the birth years 1990 through 1992, inclusive, and multiple data sources pertaining to the cohort were reviewed during 2004. Gross motor function was assessed for each child and was graded according to the Gross Motor Function Classification System (GMFCS), which is a valid, reliable, five-level ordinal grading system. Hip displacement, defined as a migration percentage of >30%, was measured on an anteroposterior radiograph of the pelvis with use of a reliable technique.

Results: A full data set was obtained for 323 (86%) of 374 children in the Register for the birth years 1990 through 1992. The mean duration of follow-up was eleven years and eight months. The incidence of hip displacement for the entire birth cohort was 35%, and it showed a linear relationship with the level of gross motor function. The incidence of hip displacement was 0% for children with GMFCS level I and 90% for those with GMFCS level V. Compared with children with GMFCS level II, those with levels III, IV, and V had significantly higher relative risks of hip displacement (2.7, 4.6, and 5.9, respectively).

Conclusions: Hip displacement is common in children with cerebral palsy, with an overall incidence of 35% found in this study. The risk of hip displacement is directly related to gross motor function as graded with the Gross Motor Function Classification System. This information may be important when assessing the risk of hip displacement for an individual child who has cerebral palsy, for counseling parents, and in the design of screening programs and resource allocation.
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http://dx.doi.org/10.2106/JBJS.E.00071DOI Listing
January 2006

Posterolateral dislocation of the C1-C2 articulation associated with fracture of the anterior arch of C1: a case report.

Spine (Phila Pa 1976) 2004 Dec;29(24):E562-4

University of Calgary Spine Program, Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.

Study Design: Case report.

Objective: To report a rare traumatic C1-C2 dislocation associated with fracture of the anterior arch of the atlas in a neurologically intact patient.

Summary Of Background Data: Isolated fractures of the anterior arch of C1 are very rare. There have been reports of horizontal fractures of the anterior arch thought to occur secondary to hyperextension injuries with subsequent avulsion of the anterior tubercle of the atlas. To our knowledge, however, there are no previously reported cases of isolated anterior arch fractures of C1 associated with posterolateral dislocation of the C1-C2 articulation.

Methods: A 53-year-old patient who presented with a posterolateral dislocation of the C1-C2 articulation and an associated anterior arch fracture of C1 is reported. Details of the initial presentation, diagnostic strategy, and initial and definitive management are provided.

Results: Closed reduction with halo ring application and gentle manipulation was followed with definitive internal fixation consisting of Magerl C1-C2 transarticular screw fixation coupled with modified Brooks fusion.

Conclusions: Posterolateral C1-C2 dislocation associated with atlantal anterior arch fracture is a rare injury that can be effectively treated with gentle closed reduction under fluoroscopic guidance followed by internal fixation with or without halo vest immobilization. Recognition of associated conditions including vertebral artery compromise, concomitant cervical spine fractures, and life-threatening injuries is paramount to the successful treatment of these patients.
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http://dx.doi.org/10.1097/01.brs.0000148248.78535.94DOI Listing
December 2004
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