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1.
J Pediatr Orthop ; 39(Issue 6, Supplement 1 Suppl 1): S53-S55, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31169650

RESUMEN

BACKGROUND: In order to determine whether treatments are effective in the treatment of meniscus tears, it is first necessary to understand the natural history of meniscus tears. The purpose of this paper is to review the literature to ascertain the natural history of meniscus tears in children and adolescents. METHODS: A search of the Pubmed and Embase databases was performed using the search terms "meniscus tears," "natural history of meniscus tears," "knee meniscus," "discoid meniscus," and "natural history of discoid meniscus tears." RESULTS: A total of 2567 articles on meniscus tears, 28 articles on natural history of meniscus tears, 8065 articles on "menisci," 396 articles on "discoid meniscus," and only 2 on the "natural history of discoid meniscus" were found. After reviewing the titles of these articles and reviewing the abstracts of 237 articles, it was clear that there was little true long-term natural history data of untreated meniscus tears nor whether treating meniscus tears altered the natural history. Twenty-five articles were chosen as there was some mention of natural history in their studies. CONCLUSIONS: There are few long-term data on untreated meniscal tears or discoid meniscus, or tears in children and adolescents. The literature suggests that there is a higher incidence of chondral injury and subsequent osteoarthritis, but there are many confounding variables which are not controlled for in these relatively short-term papers.


Asunto(s)
Tratamiento Conservador , Deformidades Congénitas de las Extremidades Inferiores/complicaciones , Meniscos Tibiales/anomalías , Lesiones de Menisco Tibial/complicaciones , Adolescente , Niño , Humanos , Incidencia , Deformidades Congénitas de las Extremidades Inferiores/terapia , Osteoartritis de la Rodilla/etiología , Lesiones de Menisco Tibial/terapia
2.
Mol Genet Genomic Med ; 10(3): e1843, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35150089

RESUMEN

BACKGROUND: Angelman syndrome (AS) is a rare neurogenetic disorder present in approximately 1/12,000 individuals and characterized by developmental delay, cognitive impairment, motor dysfunction, seizures, gastrointestinal concerns, and abnormal electroencephalographic background. AS is caused by absent expression of the paternally imprinted gene UBE3A in the central nervous system. Disparities in the management of AS are a major problem in preparing for precision therapies and occur even in patients with access to experts and recognized clinics. AS patients receive care based on collective provider experience due to limited evidence-based literature. We present a consensus statement and comprehensive literature review that proposes a standard of care practices for the management of AS at a critical time when therapeutics to alter the natural history of the disease are on the horizon. METHODS: We compiled the key recognized clinical features of AS based on consensus from a team of specialists managing patients with AS. Working groups were established to address each focus area with committees comprised of providers who manage >5 individuals. Committees developed management guidelines for their area of expertise. These were compiled into a final document to provide a framework for standardizing management. Evidence from the medical literature was also comprehensively reviewed. RESULTS: Areas covered by working groups in the consensus document include genetics, developmental medicine, psychology, general health concerns, neurology (including movement disorders), sleep, psychiatry, orthopedics, ophthalmology, communication, early intervention and therapies, and caregiver health. Working groups created frameworks, including flowcharts and tables, to help with quick access for providers. Data from the literature were incorporated to ensure providers had review of experiential versus evidence-based care guidelines. CONCLUSION: Standards of care in the management of AS are keys to ensure optimal care at a critical time when new disease-modifying therapies are emerging. This document is a framework for providers of all familiarity levels.


Asunto(s)
Síndrome de Angelman , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Síndrome de Angelman/terapia , Humanos , Nivel de Atención
3.
JBJS Case Connect ; 11(1)2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33755639

RESUMEN

CASE: We present a case of an 18-month-old child with early-onset scoliosis in the setting of spinal muscular atrophy (SMA) type 1 whose rapidly progressive scoliosis is successfully managed with magnetic growing rods, the youngest age of implantation in a patient with SMA we are currently aware of. Technical challenges, complications, and outcome are described in this case presentation. CONCLUSION: Patients with SMA type 1 and early-onset scoliosis can be managed with growing-rod constructs given dramatic improvements in medical care that have expanded life expectancy.


Asunto(s)
Atrofia Muscular Espinal , Escoliosis , Fusión Vertebral , Atrofias Musculares Espinales de la Infancia , Humanos , Lactante , Atrofia Muscular Espinal/complicaciones , Atrofia Muscular Espinal/cirugía , Escoliosis/complicaciones , Escoliosis/cirugía , Fusión Vertebral/efectos adversos , Atrofias Musculares Espinales de la Infancia/complicaciones , Atrofias Musculares Espinales de la Infancia/cirugía
4.
J Pediatr Orthop ; 30(2): 186-91, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20179568

RESUMEN

BACKGROUND: Ankle sprains in adolescents usually resolve with conservative management but a few patients may develop ankle impingement syndrome. There have been adult studies addressing surgical treatment of this pathology, but our study evaluated the surgical management of anterolateral ankle impingement in adolescents by comparing their outcomes after nonoperative treatment and subsequent surgical intervention. METHODS: Thirteen patients (children and adolescents) diagnosed with ankle impingement by history, physical examination, and magnetic resonance imaging during a 9-year period at our institution underwent eventual arthroscopic debridement. A retrospective chart review of these patients was performed and they were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) functional rating scale on 3 separate occasions: (1) initial presentation, (2) termination of nonoperative management, and (3) final postoperative follow-up visit. RESULTS: Thirteen adolescents (11 girls and 2 boys; 14 ankles) with a mean age of 15.6 (11.9-18.3) years met the inclusion criteria; of these, all had arthroscopic surgery. Mean duration of reported symptoms was 9.6 (4-15) months and mean duration of nonoperative management (physical therapy, activity modifications) was 6.9 (2-12) months. The mean AOFAS rating (out of 100 total) at initial presentation was 68.4 (40-84) and after nonoperative management was no better with a mean of 68.2 (63-76). The mean AOFAS rating at final follow-up was 90.6 (52-100), which was statistically significant (P

Asunto(s)
Traumatismos del Tobillo/complicaciones , Articulación del Tobillo/cirugía , Artropatías/terapia , Esguinces y Distensiones/complicaciones , Adolescente , Traumatismos del Tobillo/terapia , Articulación del Tobillo/fisiopatología , Artroscopía/métodos , Niño , Femenino , Estudios de Seguimiento , Humanos , Artropatías/etiología , Artropatías/fisiopatología , Imagen por Resonancia Magnética/métodos , Masculino , Rango del Movimiento Articular , Recuperación de la Función , Estudios Retrospectivos , Esguinces y Distensiones/terapia , Síndrome , Factores de Tiempo
5.
Spine Deform ; 7(1): 27-32, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30587317

RESUMEN

BACKGROUND: Intraoperative neuromonitoring (IONM) is used to detect impending neurologic damage during complex spinal surgeries. Although IONM is increasingly used during pediatric scoliosis surgeries in the United States, the effect of IONM on the outcomes of such surgeries at a national level is unclear. METHODS: Using National Inpatient Sample (NIS) from 2009 to 2012, 32,305 spinal fusions performed in children 18 years old or younger of age with scoliosis were identified using ICD-9 procedure and diagnosis codes. IONM was identified using the ICD-9 procedure code 00.94. The effects of IONM use on length of stay (LOS), discharge disposition, hospital charges, and in-hospital complications were assessed using multivariate regression analysis adjusting for patient and hospital characteristics. RESULTS: IONM was used in 5,706 (18%) of the surgeries. IONM was associated with increased home discharge (adjusted odds ratio [AOR] = 1.25 [95% confidence interval 1.10-1.40], p = .001). There was no difference in LOS (p = .096) and hospital charges (p = .750). Neurologic complications were noted in 52 (0.9%) surgeries using IONM and 368 (1.4%) surgeries without IONM (p = .005). Although IONM use trended toward lower risk of neurologic complications in multivariate analysis, it failed to achieve statistical significance (AOR = 0.77 [0.57-1.04], p = .084). CONCLUSIONS: Reported use of IONM in this database was significantly less compared with other databases, suggesting that IONM might be underreported in the NIS database. Nevertheless, in this database, IONM was significantly associated with increased home discharge. Hospital charges and LOS were not affected by IONM. There was a trend toward lower risk of neurologic complications with IONM use, though this finding was not statistically significant.


Asunto(s)
Monitorización Neurofisiológica Intraoperatoria/estadística & datos numéricos , Enfermedades del Sistema Nervioso/epidemiología , Complicaciones Posoperatorias/epidemiología , Escoliosis/cirugía , Fusión Vertebral/estadística & datos numéricos , Adolescente , Niño , Bases de Datos Factuales , Femenino , Precios de Hospital , Humanos , Tiempo de Internación , Masculino , Análisis Multivariante , Enfermedades del Sistema Nervioso/etiología , Alta del Paciente , Complicaciones Posoperatorias/etiología , Análisis de Regresión , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Resultado del Tratamiento , Estados Unidos
6.
Burns ; 43(2): 265-272, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27915096

RESUMEN

OBJECTIVE: The prevalence of antibiotic-resistant organisms (ARO) in burn units is increasing worldwide and contributes significantly to morbidity and mortality. Study aims are to describe the burden of AROs in burn patients admitted to a tertiary burn unit, to evaluate the impact of contact precautions implemented after an outbreak of antibiotic-resistant Acinetobacter baumannii, and to identify possible predictors of ARO acquisition. METHODS: Data of burn inpatients between 2006 and 2010 were retrospectively reviewed. The antibiotic susceptibility profiles of ARO colonization/infection at or after admission were reviewed in detail. Organisms of interest included: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum beta-lactamase-producing Escherichia coli, and carbapenem-resistant Pseudomonas and Acinetobacter. Univariate and multivariate logistic regression analysis was employed with the p-value set at 0.05. RESULTS: Complete data analysis was available for 340 patients. The mean age was 41.8 years with male predominance. Among the AROs, the most prevalent was MRSA from clinical specimens. Prior to contact precaution implementation, the prevalence of all AROs was 27.9%, compared to 27.6% afterwards. There was an increase in Pseudomonas and VRE isolates and a disappearance of Acinetobacter. The most common isolate sites were the burn wounds. ICU stay, burns >20% TBSA, and surgical management were significant predictors of ARO acquisition. CONCLUSION: This study describes the ARO profile of burn patients admitted to a tertiary burn unit. The results suggest that implementation of unit-wide contact precautions may not significantly reduce the frequency of AROs among burn patients. Contact precautions for patients transferred from the ICU, undergoing surgery, and large burns may be of benefit.


Asunto(s)
Farmacorresistencia Bacteriana , Infecciones por Bacterias Gramnegativas/prevención & control , Infecciones por Bacterias Grampositivas/prevención & control , Control de Infecciones/métodos , Infecciones Estafilocócicas/prevención & control , Precauciones Universales/métodos , Infecciones por Acinetobacter/epidemiología , Infecciones por Acinetobacter/microbiología , Infecciones por Acinetobacter/prevención & control , Acinetobacter baumannii , Adulto , Unidades de Quemados , Escherichia coli , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Femenino , Infecciones por Bacterias Gramnegativas/epidemiología , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina , Persona de Mediana Edad , Prevalencia , Infecciones por Pseudomonas/epidemiología , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/prevención & control , Pseudomonas aeruginosa , Estudios Retrospectivos , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Centros de Atención Terciaria , Enterococos Resistentes a la Vancomicina , Adulto Joven
7.
J Spine Surg ; 3(3): 387-391, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29057347

RESUMEN

BACKGROUND: Isthmic spondylolysis (ISY) is a common cause of back pain in the pediatric population. Historically, non-operative treatments have had a very high success rate. The purpose of this study was to review the mid-term results of an indirect pars repair technique on reducing the visual analog score for pain (VAS), spondylolysis defect healing, complication rates and rates of return to pre-surgery activity level in pediatric patients who failed conservative care for ISY. METHODS: A retrospective review of all pediatric patients (<18 years old) treated surgically by one surgeon over a 5-year period was performed. Patients were treated with indirect pars repair utilizing pedicle screws and laminar hooks and local autograft. Preoperative VAS was compared to the final follow-up score, and return to activity was evaluated. Radiographs were reviewed to evaluate healing. RESULTS: Nine patients (6 females, 3 males) were treated surgically. Average age at the time of surgery was 15.4 years, (range, 13 to 17 years). Average length of final follow-up was 11.9 months (range, 6 to 24 months). Preoperative VAS averaged 5.6 points (range, 2 to 8 points) compared to final follow-up of 1.2 (range, 0 to 3). Definitive bony healing was noted in 7 of 9 cases (77.8%) with at least 6 months follow-up. Eight of nine patients (88.9%) returned to preoperative competitive sports activity level. No complications were noted during the follow-up period. CONCLUSIONS: Pediatric patients treated surgically with indirect pars repair appear to achieve satisfactory mid-term outcomes. This technique appears safe, and has both a high healing rate and return to competitive athletics. Further study is needed to determine durability of this procedure.

8.
Spine (Phila Pa 1976) ; 36(2): 109-17, 2011 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-20595923

RESUMEN

STUDY DESIGN: in vivo analysis in an immature porcine model. OBJECTIVE: to evaluate the effect of intraoperative tensioning of an anterolateral flexible spinal tether on growth modulation manifested as deformity creation, disc response, spinal motion, and screw fixation using radiographs, computed tomography, magnetic resonance imaging, biomechanical testing, and histology. SUMMARY OF BACKGROUND DATA: spinal growth modulation using an anterolateral flexible tether has been proposed as a nonfusion surgical deformity correction strategy for idiopathic scoliosis and has been successfully demonstrated in a porcine model to create spinal deformity while maintaining disc viability. METHODS: twelve 7-month-old mini-pigs were instrumented with a screw-staple and polyethylene tether construct over 4 consecutive thoracic vertebrae (T8-T11). Intraoperative tensioning of the tether (250 N) was performed in alternate pigs (Pretensioned and Untensioned groups, n = 6 per group). Screws were coated with hydroxyapatite in half of the animals in each surgical group. Preoperative, postoperative, and monthly radiographs were evaluated, comparing deformity creation, vertebral body wedging, and disc wedging between the groups. Vertebral body shape was evaluated by computed tomography. Magnetic resonance and histology evaluated disc health. Biomechanical testing was performed to determine the effect of tensioning the tether on spinal motion and screw fixation. RESULTS: intraoperative tensioning produced immediate coronal deformity (8° ± 4° vs. 2° ± 1° in untensioned spines; P = 0.01) and apical disc (T9-T10) wedging, vertex on tethered side, (5° ± 2° vs. 2° ± 1°; P = 0.01). After 12 months, the groups were similar in coronal deformity (28° ± 18° pretensioned, 27° ± 11° untensioned, P = 0.88), sagittal deformity (25° ± 3° vs. 22° ± 3°; P = 0.14), vertebral body wedging (10° ± 5° vs. 8° ± 3°; P = 0.45), and disc wedging (-4° ± 1° vs. -4° ± 3°; P = 0.88). There was no radiographic evidence of screw loosening. One of the discs from each group had diminished T2 signal after 12 months of tethering. Tether pretensioning did not affect spinal stiffness or motion. Interestingly, screw fixation increased with pretensioning; however, there was no significant advantage with hydroxyapatite coating. Histology demonstrated normal-appearing discs. CONCLUSION: pretensioning of the tether created immediate deformity without effecting ultimate vertebral or disc deformity creation. Spinal motion and stiffness were not altered by pretensioning; however, pretensioning increased the torque required for screw extraction.


Asunto(s)
Modelos Animales , Procedimientos Ortopédicos/métodos , Vértebras Torácicas/fisiología , Vértebras Torácicas/cirugía , Animales , Fenómenos Biomecánicos , Tornillos Óseos , Durapatita , Humanos , Imagen por Resonancia Magnética , Masculino , Procedimientos Ortopédicos/instrumentación , Rango del Movimiento Articular , Porcinos , Porcinos Enanos , Vértebras Torácicas/crecimiento & desarrollo , Factores de Tiempo , Tomografía Computarizada por Rayos X
9.
Spine (Phila Pa 1976) ; 36(14): E904-13, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21217429

RESUMEN

STUDY DESIGN: Single- or dual-shape memory metal (nitinol) rods were used to create spinal deformity in a mini-pig model. OBJECTIVE: To determine the practicality of employing nitinol rods for clinical spinal deformity correction using an animal deformity creation model. SUMMARY OF BACKGROUND DATA: Nitinol rods can, theoretically, be approximated to curved spines when cooled/malleable, achieving spinal deformity correction on warming and returning to their original (straight) shape. Square cross-sectional rods may allow transverse plane correction. Single-rod constructs could achieve greater deformity correction clinically, whereas dual rods provide lower implant failure risk. The clinical feasibility and potential effectiveness of single versus dual nitinol rod constructs in creating spinal deformity in an animal model was studied. METHODS: Twenty mature mini-pigs were grouped: single rod with screws locked to the rod, single rod with screws unlocked, dual rods--locked, dual rods--unlocked. Square nitinol rods (80° manufactured curvature) were cooled (-20°C), straightened, placed into multilevel square-headed pedicle screws and warmed (40°C). Serial radiographs followed deformity creation over 12 weeks. Single versus dual rods, locked versus unlocked rods were compared (P<0.01). Computed tomography showed screw placement and fusion (none attempted). Preoperative and 12-week postoperative serum nickel levels were compared (P<0.05). RESULTS: Scoliotic deformities were created immediately in single and dual rod groups (28°±8°, 26°±7°; P=0.59); locked and unlocked groups (24°±7°, 30°±6°; P=0.08). At final follow-up, there was no difference between single and dual rods (31°±11°, 28°±10°; P=0.58); unlocked rods and locked rods were 34.9°±9.4° and 25.0°±8.1° (P=0.02). No implant failure occurred, however, the aggressive rod contour led to vertebral endplate fractures. Serum nickel 12 weeks post rod placement were unchanged from preop levels (5.1±0.6 µg/L, 4.7±0.2 µg/L, P=0.10). CONCLUSION: Nitinol rods, reliable in creating spinal deformity in an animal model, could potentially straighten deformed spines. Square rods, facilitated by markedly reduced stiffness when cooled, have the potential to predictably perform axial plane correction.


Asunto(s)
Aleaciones , Clavos Ortopédicos , Procedimientos Ortopédicos/instrumentación , Columna Vertebral/cirugía , Animales , Tornillos Óseos , Femenino , Masculino , Modelos Animales , Procedimientos Ortopédicos/métodos , Reproducibilidad de los Resultados , Escoliosis/cirugía , Columna Vertebral/diagnóstico por imagen , Porcinos , Porcinos Enanos , Temperatura , Tomografía Computarizada por Rayos X
10.
J Bone Joint Surg Am ; 93(15): 1408-16, 2011 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-21915546

RESUMEN

BACKGROUND: Spinal growth modulation has been proposed as a non-fusion strategy for treatment of idiopathic scoliosis, although the effect of this treatment modality on intervertebral disc health has not been evaluated in detail. The objectives of this in vivo study were to assess the creation of three-dimensional spinal deformity during six months of growth modulation compared with that in sham-surgery controls, and to compare, with use of magnetic resonance imaging (MRI), gross morphological, histological, and biochemical analyses, disc health between control animals and animals treated with a spinal tether. METHODS: Six immature Yucatan mini-pigs underwent anterior spinal instrumentation with vertebral screws connected by a polyethylene tether over four consecutive thoracic vertebrae (T8-T11). An additional six animals underwent sham surgery (screw placement only [the control group]). Radiographs were obtained preoperatively, postoperatively, and monthly thereafter during six months of growth. Computed tomography (CT) and MRI studies were performed ex vivo, and the spines were sectioned for histological and biochemical analyses. Multivariate analysis of variance (MANOVA) was used to compare six-month postoperative data between the control and tethered animals, with the alpha level of significance set at 0.05. RESULTS: Radiographs and CT images demonstrated the creation of significant three-dimensional deformity (p < 0.013) in the tethered animals compared with the controls. Macroscopic, MRI, and histological evaluation revealed no signs of disc degeneration, with a bulging gelatinous nucleus pulposus, discrete fibrous anular lamellae, and uniformly hyperintense T2-signal intensity within the nuclei pulposi. Biochemical analysis demonstrated no significant difference in the nuclei pulposus between the tethered and control vertebrae; however, the water content (p < 0.001) of both sides of the anulus fibrosus and the glycosaminoglycan content (p < 0.001) of the left side of the anulus fibrosus differed significantly between the two groups. CONCLUSIONS: Six months of spinal growth modulation created significant spinal deformity in all three planes compared with what was found in the sham-surgery controls. Although disc health was qualitatively maintained, quantitative changes in the anulus fibrosus water content and the disc height were observed on the side opposite to the tether. These changes likely represent metabolic responses of the discs to compressive loads generated by the flexible tether.


Asunto(s)
Disco Intervertebral/crecimiento & desarrollo , Escoliosis/cirugía , Vértebras Torácicas/crecimiento & desarrollo , Análisis de Varianza , Animales , Desarrollo Óseo/fisiología , Distribución de Chi-Cuadrado , Modelos Animales de Enfermedad , Disco Intervertebral/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Rango del Movimiento Articular/fisiología , Escoliosis/diagnóstico por imagen , Porcinos , Porcinos Enanos , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/cirugía , Tomografía Computarizada por Rayos X
11.
Spine (Phila Pa 1976) ; 34(17): 1855-62, 2009 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-19644337

RESUMEN

STUDY DESIGN: Bench-top and retrospective analysis to assess vertebral rotation based on the appearance of bilateral pedicle screws in patients with adolescent idiopathic scoliosis (AIS). OBJECTIVE: To develop a clinically relevant radiographic grading system for evaluating postoperative thoracic apical vertebral rotation that would correlate with computed tomography (CT) measures of rotation. SUMMARY OF BACKGROUND DATA: The 3-column vertebral body control provided by bilateral pedicle screws has enabled scoliosis surgeons to develop advanced techniques of direct vertebral derotation. Our ability to accurately quantify spinal deformity in the axial plane, however, continues to be limited. METHODS: Trigonometry was used to define the relationship between the position of bilateral pedicle screws and vertebral rotation. This relationship was validated using digital photographs of a bench-top model. The mathematical relationships were then used to calculate vertebral rotation from standing postoperative, posteroanterior radiographs in AIS patients and correlated with postoperative CT measures of rotation. RESULTS: Fourteen digital photographs of the bench-top model were independently analyzed twice by 3 coauthors. The mathematically calculated degree of rotation was found to correlate significantly with the actual degree of rotation (r = 0.99; P < 0.001) and the intra- and interobserver reliability for these measurements were both excellent (kappa = 0.98 and kappa = 0.97, respectively). In the retrospective analysis of 17 AIS patients, the average absolute difference between the radiographic measurement of rotation and the CT measure was only 1.9 degrees +/- 2.0 degrees (r = 0.92; P < 0.001). Based on these correlations a simple radiographic grading system for postoperative apical vertebral rotation was developed. CONCLUSION: An accurate assessment of vertebral rotation can be performed radiographically, using screw lengths and screw tip-to-rod distances of bilateral segmental pedicle screws and a trigonometric calculation. These data support the use of a simple radiographic grading system to approximate apical vertebral rotation in AIS patients treated with bilateral apical pedicle screws.


Asunto(s)
Tornillos Óseos/normas , Escoliosis/diagnóstico por imagen , Fusión Vertebral/instrumentación , Columna Vertebral/diagnóstico por imagen , Adolescente , Antropometría/instrumentación , Antropometría/métodos , Niño , Femenino , Lateralidad Funcional/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Procedimientos Neuroquirúrgicos/instrumentación , Procedimientos Neuroquirúrgicos/métodos , Variaciones Dependientes del Observador , Evaluación de Resultado en la Atención de Salud/métodos , Valor Predictivo de las Pruebas , Procedimientos de Cirugía Plástica/instrumentación , Procedimientos de Cirugía Plástica/métodos , Estudios Retrospectivos , Rotación , Escoliosis/patología , Escoliosis/cirugía , Sensibilidad y Especificidad , Fusión Vertebral/métodos , Columna Vertebral/patología , Columna Vertebral/cirugía , Tomografía Computarizada por Rayos X/métodos
12.
Spine (Phila Pa 1976) ; 34(4): 335-43, 2009 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19182704

RESUMEN

STUDY DESIGN: Biomechanical and histologic analysis. OBJECTIVE: To compare the strength of the bone-screw interface of standard uncoated pedicle screws with screws treated with hydroxyapatite (HA), titanium plasma spray (TPS), and a composite HA-TPS coating. SUMMARY OF BACKGROUND DATA: Transpedicular screw fixation has become the gold standard in the treatment of various thoracolumbar spinal conditions. Pedicle screw loosening, however, has been reported, especially in mechanically demanding constructs or in vertebrae with low bone mineral density. METHODS: Six mature porcine were instrumented with 4 types of titanium monoaxial pedicle screws (uncoated, HA-only coated, TPS-only coated, and HA-TPS composite coated) in a systematically varied, single-blinded fashion. After a 3-month survival period, the spines were harvested en-bloc and "time zero" control screws were instrumented in adjacent vertebrae. Screw placement and bone mineral density were evaluated with a postharvest computed tomography, and the strength of the tissue-implant interface was evaluated with a torsional screw extraction analysis (60 screws) and a nondecalcified histologic analysis (16 screws). RESULTS: At 3 months postoperative, peak torque increased for all 3 types of coated screws (increased fixation) and decreased significantly for the uncoated screws (P < 0.001). Although 3-month peak torque was not statistically different between the 3 screw coatings, 4 of 10 TPS-only coated screws had a peak torque that was nearly 0 (<0.1 N m) versus only 1 of 10 HA-only screws and 0 of 10 HA-TPS composite screws. Histologic analysis confirmed the biomechanical findings with improved osseointegration in the HA-only and HA-TPS composite screws. CONCLUSION: Pedicle screw coatings that promote mechanical interlocking, TPS, or direct osteoblast bonding(HA) increased screw fixation in this nonfusion model. More non-HA coated screws, however, were thought to be "loose" with a nearly zero peak extraction torque and fibrous encapsulation. Increased osseointegration with HA may result in a decreased incidence of screw loosening and improved outcomes of transpedicular spinal instrumentation in nonfusion procedures.


Asunto(s)
Tornillos Óseos , Materiales Biocompatibles Revestidos , Durapatita/química , Fijación Interna de Fracturas/instrumentación , Vértebras Lumbares/cirugía , Vértebras Torácicas/cirugía , Titanio/química , Animales , Fenómenos Biomecánicos , Densidad Ósea , Vértebras Lumbares/patología , Vértebras Lumbares/fisiopatología , Ensayo de Materiales , Modelos Animales , Oseointegración , Diseño de Prótesis , Porcinos , Porcinos Enanos , Vértebras Torácicas/patología , Vértebras Torácicas/fisiopatología , Factores de Tiempo , Tomografía Computarizada por Rayos X , Torque
13.
J Child Orthop ; 2(4): 301-7, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19308558

RESUMEN

PURPOSE: Computed tomography (CT) is the current imaging standard for confirming the diagnosis of a calcaneonavicular coalition. The purpose of this study was to evaluate three-dimensional (3D) multi-planar CT images of calcaneonavicular coalitions and adjacent tarsal relationships, compared to controls, in order to obtain an understanding of the 3D anatomy for classification and as an aid to surgical resection. METHODS: All patients who underwent CT of bilateral feet at our institution to evaluate a suspected calcaneonavicular coalition between 9/2005 and 3/2008 were retrospectively reviewed. Seventy-four feet (37 patients) were included in this analysis. In addition, 12 patients with a presumed normal calcaneonavicular relationship, who underwent CT of bilateral feet for various other diagnoses, were included as a control cohort. Seven measurements were performed on the 3D reconstructions to quantify the shape of the coalition (dorsal and plantar widths of the calcaneal and navicular contributions, coalition depth of the calcaneal and navicular contributions, and coalition length). The coalitions were classified into four types based on their appearance and their relationship to adjacent tarsal bones. RESULTS: 32/37 patients (86%) were noted to have bilateral involvement (69 coalitions). Coalitions were categorized into four types: Type I (forme fruste)-28%, Type II (fibrous)-23%, Type III (cartilaginous)-45% and Type IV (osseous)-4%. The average shape of the coalition was found to be a curved wedge, which was on average 16 mm wide dorsally, 7 mm wide on the plantar surface, 10 mm in length, and 25 mm in depth. CONCLUSIONS: 3D CT reconstructions enabled the classification of the spectrum of calcaneonavicular coalitions. The shape of the cuboid was found to correlate with the extent of ossification. In Type I or II coalitions, the cuboid extended medially plantar to the fibrous connection. In more complete Type III or IV coalitions, the cuboid was "squared off" and remained lateral to the osseous bridge. An understanding of the 3D anatomy is important when diagnosing milder forms of coalitions, and during resection in order to avoid iatrogenic injury to the calcaneus, head of the talus, or cuboid.

14.
J Bone Joint Surg Am ; 90(12): 2695-706, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19047716

RESUMEN

BACKGROUND: Spinal growth modulation by tethering the anterolateral aspect of the spine, as previously demonstrated in a nonscoliotic calf model, may be a viable fusionless treatment method for idiopathic scoliosis. The purpose of the present study was to evaluate the radiographic, histologic, and biomechanical results after six and twelve months of spinal growth modulation in a porcine model with a growth rate similar to that of adolescent patients. METHODS: Twelve seven-month-old mini-pigs underwent instrumentation with a vertebral staple-screw construct connected by a polyethylene tether over four consecutive thoracic vertebrae. The spines were harvested after six (n = 6) or twelve months (n = 6) of growth. Monthly radiographs, computed tomography and magnetic resonance imaging scans (made after the spines were harvested), histologic findings, and biomechanical findings were evaluated. Analysis of variance was used to compare preoperative, six-month postoperative, and twelve-month postoperative data. RESULTS: Radiographs demonstrated 14 degrees +/- 4 degrees of coronal deformity after six months and 30 degrees +/- 13 degrees after twelve months of growth. Coronal vertebral wedging was observed in all four tethered vertebrae and progressed throughout each animal's survival period. Disc wedging was also created; however, in contrast to the findings associated with vertebral wedging, the tethered side was taller than the untethered side. Magnetic resonance images revealed no evidence of disc degeneration; however, the nucleus pulposus had shifted toward the side of the tethering. Midcoronal undecalcified histologic sections showed intact bone-screw interfaces with no evidence of implant failure or loosening. With the tether cut, stiffness decreased and range of motion increased in lateral bending away from the tether at both time-points (p < 0.05). CONCLUSIONS: In this porcine model, mechanical tethering during growth altered spinal morphology in the coronal and sagittal planes, leading to vertebral and disc wedging proportional to the duration of tethering. The resulting concave thickening of the disc in response to the tether was not anticipated and may suggest a capacity for the nucleus pulposus to respond to the compressive loads created by growth against the tether.


Asunto(s)
Desarrollo Óseo/fisiología , Fijadores Internos , Cifosis/cirugía , Escoliosis/cirugía , Fusión Vertebral/instrumentación , Vértebras Torácicas/crecimiento & desarrollo , Animales , Modelos Animales de Enfermedad , Diseño de Equipo , Rango del Movimiento Articular , Porcinos , Porcinos Enanos , Factores de Tiempo , Soporte de Peso
15.
Proc Am Thorac Soc ; 4(8): 692-4, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18073405

RESUMEN

This workshop summary examines current research that addresses the question: Are women more susceptible than men to the effects of inhaled pollutants, namely those found in work or residential environments? A systematic literature review was performed in preparation for the workshop. A total of 73 recent (since 2000) articles were retrieved reporting on occupational and environmental exposures and their impact on chronic obstructive pulmonary disease, of which only nine provided gender-stratified results. In two mortality studies, results were contrary (one finding increased chronic obstructive pulmonary disease mortality in relation to traffic among elderly women compared with men, the other finding no gender difference). Two other environmental studies suggested small gender differences with slightly greater effect of biomass or traffic-related pollution among women. Four of five occupational studies also found increased effects of workplace pollutant exposure on measures of chronic airflow obstruction or bronchitis symptoms in women; again the differences were small. Preliminary findings from analysis of pooled data from six cross-sectional occupational surveys by our team also indicated increased relative risk for airflow obstruction in relation to work in industrial or service jobs among women compared with men, but only when airflow obstruction was measured using a gender-specific approach to determining the lower limit of normal. Workshop participants identified five key gaps and research needs, including the development of gender-sensitive tools for conducting future research in this area.


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Exposición Profesional/efectos adversos , Enfermedad Pulmonar Obstructiva Crónica/etiología , Susceptibilidad a Enfermedades , Femenino , Humanos , Masculino , Factores Sexuales
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