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1.
Eur Spine J ; 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31832873

RESUMO

STUDY DESIGN: Case report. PURPOSE: The authors used spine shortening as an alternative strategy to intercalary graft fixation to restore permanent spine stability for a 17-month-old infant who received total en bloc spondylectomy (TES) of T11 to treat an embryonic rhabdomyosarcoma. TES involves complete removal of vertebra, compensated by spine reconstruction using intercalary allografts and permanent posterior instrumentation, which is not possible for skeletally immature patients with high growth potential and non-ossified vertebrae. METHODS: Surgery was performed over two consecutive days. During the first day, the tumor was released from its dorsal attachments through the posterior approach. During the second day, the tumor was dissected and excised through the anterior approach, leaving a gap between T10 and T12. The two vertebrae were then drawn toward each other until the gap was bridged. The dural sac slipped into the canal under T10 and T12 with no observable kinking. RESULTS: Fifteen weeks after surgery, thoraco-abdominal CT confirmed fusion of the T10 and T12 vertebral bodies. Three years later, the patient lives a normal life with no major neurological deficits or recurrence of sarcoma. CONCLUSIONS: This case report is the first to demonstrate the feasibility of TES with spine shortening of an entire thoracic segment without spine kinking or damage in an infant. This unprecedented surgical technique allowed complete removal of an embryonic rhabdomyosarcoma, while granting rapid stability and growth potential. LEVEL OF EVIDENCE: IV.

2.
PLoS One ; 14(7): e0220016, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31318948

RESUMO

BACKGROUND: In 2015, an earthquake killing 9,000 and injuring 22,000 people hit Nepal. The Tribhuvan University Teaching Hospital (TUTH), a reference tertiary hospital, was operational immediately after the earthquake. We studied the profile of earthquake victims admitted in TUTH and assessed what factors could influence hospital length of stay. METHODS: An earthquake victim dataset was created based on patient records, with information on sex, age, date of admission and discharge, diagnosis, and surgical intervention. We performed an initial descriptive overview of the earthquake victims followed by a time-to-event analysis to compare length of hospital stay in different groups, using log rank test and cox regression to calculate Hazard Ratios. RESULTS: There were in total 501 admitted victims, with the peak of admissions occurring on the fifth day after the earthquake. About 89% had injury as main diagnosis, mostly in lower limbs, and 66% of all injuries were fractures. Nearly 69% of all patients underwent surgery. The median length of hospital stay was 10 days. Lower limb and trunk injuries had longer hospital stays than injuries in the head and neck (HR = 0.68, p = 0.009, and HR = 0.62 p = 0.005, respectively). Plastic surgeries had longer hospital stays than orthopaedic surgeries (HR = 0.57 p = 0.006). Having a crush injury and undergoing an amputation also increased time to discharge (HR = 0.57, p = 0.013, and HR = 0.65 p = 0.045 respectively). CONCLUSIONS: Hospital stay was particularly long in this sample in comparison to other studies on earthquake victims, indirectly indicating the high burden TUTH had to bear to treat these patients. To strengthen resilience, tertiary hospitals should have preparedness plans to cope with a large influx of injured patients after a large-scale disaster, in particular for the initial days when there is limited external aid.


Assuntos
Vítimas de Desastres/estatística & dados numéricos , Terremotos , Hospitalização , Centros de Atenção Terciária , Adolescente , Adulto , Criança , Pré-Escolar , Demografia , Vítimas de Desastres/história , Feminino , História do Século XXI , Humanos , Lactente , Recém-Nascido , Masculino , Registros Médicos , Pessoa de Meia-Idade , Nepal/epidemiologia , Modelos de Riscos Proporcionais , Adulto Jovem
3.
Gait Posture ; 61: 141-148, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29353740

RESUMO

PURPOSE: To assess radiological and gait biomechanical changes before, at one and 10 years after surgery in AIS patients. METHODS: This clinical prospective study included fifteen adult women (mean[SD] age: 26 [1] years) diagnosed with thoraco-lumbar/lumbar AIS and operated 10 years ago. Clinical, radiological and gait variables, including kinematics, electromyography (EMG), mechanics and energetics were compared between presurgery (S0), 1 year (S1) and 10 years (S2) postsurgery period using a one way repeated measure ANOVA. RESULTS: The Cobb angle of the scoliosis curve was reduced by 55% at 1 year postsugery but only by 37% at 10 years postsurgery suggesting a loss of 32% over time. Frontal plumb line C7-S1 distance was significantly improved by surgery (-44%) and remained stable at 10 years postsurgery. Lower limb kinematics was not affected by the surgery at long term. Excessive bilateral activation of lombo-pelvic muscles, observed before surgery, decreased significantly at S1 and S2 period. Mechanical energy increased significantly between S0, S1 and S2 session, without any change for the energetic variables. CONCLUSIONS: Between 1 and 10 years post-surgery, thoraco-lumbar/lumbar AIS women showed a few decompensation of the curve without any change of the improved frontal body balance. Lower limbs and pelvic motion, during gait, was not affected by the surgery. But presurgical excessive EMG activity of the lumbo-pelvic muscle and reduced mechanical energy produced to walk get similar to normal patterns. Only the oxygen consumption remained excessive probably due to physical deconditioning or postural instability.


Assuntos
Previsões , Marcha/fisiologia , Vértebras Lombares/cirurgia , Músculo Esquelético/fisiopatologia , Escoliose/fisiopatologia , Fusão Vertebral , Caminhada/fisiologia , Adolescente , Adulto , Eletromiografia/métodos , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Escoliose/cirurgia , Adulto Jovem
4.
Eur Spine J ; 26(11): 2818-2827, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28735464

RESUMO

PURPOSE: Spine surgery still remains a challenge for every spine surgeon, aware of the potential serious outcomes of misplaced instrumentation. Though many studies have highlighted that using intraoperative cone beam CT imaging and navigation systems provides higher accuracy than conventional freehand methods for placement of pedicle screws in spine surgery, few studies are concerned about how to reduce radiation exposure for patients with the use of such technology. One of the main focuses of this study is based on the ALARA principle (as low as reasonably achievable). METHOD: A prospective randomized trial was conducted in the hybrid operating room between December 2015 and December 2016, including 50 patients operated on for posterior instrumented thoracic and/or lumbar spinal fusion. Patients were randomized to intraoperative 3D acquisition high-dose (standard dose) or low-dose protocol, and a total of 216 pedicle screws were analyzed in terms of screw position. Two different methods were used to measure ionizing radiation: the total skin dose (derived from the dose-area product) and the radiation dose evaluated by thermoluminescent dosimeters on the surgical field. RESULTS: According to Gertzbein and Heary classifications, low-dose protocol provided a significant higher accuracy of pedicle screw placement than the high-dose protocol (96.1 versus 92%, respectively). Seven screws (3.2%), all implanted with the high-dose protocol, needed to be revised intraoperatively. The use of low-dose acquisition protocols reduced patient exposure by a factor of five. CONCLUSION: This study emphasizes the paramount importance of using low-dose protocols for intraoperative cone beam CT imaging coupled with the navigation system, as it at least does not affect the accuracy of pedicle screw placement and irradiates drastically less.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Vértebras Lombares , Doses de Radiação , Fusão Vertebral/métodos , Vértebras Torácicas , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Parafusos Pediculares , Estudos Prospectivos , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia
5.
Eur Spine J ; 26(11): 2917-2926, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28631190

RESUMO

PURPOSE: The goals of this study were to assess the accuracy of pedicle screw insertion using an intraoperative cone beam computed tomography (CBCT) system, and to analyze the factors potentially influencing this accuracy. METHODS: Six hundred and ninety-five pedicle screws were inserted in 118 patients between October 2013 and March 2016. Screw insertion was performed using 2D-fluoroscopy or CBCT-based navigation. Accuracy was assessed in terms of breach and reposition. All the intraoperative CBCT scans, done after screw insertion, were reviewed to assess the accuracy of screw placement using two established classification systems: Gertzbein and Heary. Generalized linear mixed models were used to model the odds (95% CI) for a screw to lead to a breach according to the independent variables. RESULTS: The breach rate was 11.7% using the Gertzbein classification and 15.4% using the Heary classification. Seventeen screws (2.4%) were repositioned intraoperatively. The only factor affecting statistically the odds to have a breach was the indication of surgery. The patients with non-degenerative disease had a significantly higher risk of breach than those with degenerative disease. CONCLUSION: Use of intraoperative CBCT as 2D-fluoroscopy or coupled with a navigation system for pedicle screw insertion is accurate in terms of breach occurrence and reposition. However, these rates depend on the classification or grading system used. Use of a navigation system does not decrease the risk of breach significantly. And the risk of breach is higher in non-degenerative conditions (trauma, scoliosis, infection, and malignancy disease) than in degenerative diseases.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Parafusos Pediculares/estatística & dados numéricos , Fusão Vertebral , Cirurgia Assistida por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Tomografia Computadorizada de Feixe Cônico/estatística & dados numéricos , Humanos , Degeneração do Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/cirurgia , Estudos Retrospectivos , Fusão Vertebral/métodos , Fusão Vertebral/estatística & dados numéricos , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/estatística & dados numéricos
6.
Eur Spine J ; 26(11): 2906-2916, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28528479

RESUMO

PURPOSE: The goal of this study was to compare the accuracy of a novel intraoperative cone beam computed tomography (CBCT) imaging technique with that of conventional computed tomography (CT) scans for assessment of pedicle screw placement and breach detection. METHODS: Three hundred and forty-eight pedicle screws were inserted in 58 patients between October 2013 and March 2016. All patients had an intraoperative CBCT scan and a conventional CT scan to verify the placement of the screws. The CBCT and CT images were reviewed by two surgeons to assess the accuracy of screw placement and detect pedicle breaches using two established classification systems. Agreement on screw placement between intraoperative CBCT and postoperative CT was assessed using Kappa and Gwet's coefficients. Using CT scanning as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the ability of CBCT imaging to accurately evaluate screw placement. RESULTS: The Kappa coefficient was 0.78 using the Gertzbein classification and 0.80 using the Heary classification, indicating a substantial agreement between the intraoperative CBCT and postoperative CT images. Gwet's coefficient was 0.94 for both classifications, indicating almost perfect agreement. The sensitivity, specificity, positive predictive value and negative predictive value of the CBCT images were 77, 98, 86, and 96%, respectively, for the Gertzbein classification and 79, 98, 88, and 96%, respectively, for the Heary classification. CONCLUSIONS: Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws. This technique may make postoperative CT imaging unnecessary.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Parafusos Pediculares , Fusão Vertebral , Cirurgia Assistida por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Tomografia Computadorizada de Feixe Cônico/estatística & dados numéricos , Humanos , Período Pós-Operatório , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Fusão Vertebral/instrumentação , Fusão Vertebral/métodos , Fusão Vertebral/estatística & dados numéricos , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/estatística & dados numéricos
7.
Interact Cardiovasc Thorac Surg ; 24(1): 90-98, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27659148

RESUMO

OBJECTIVES: Porcine small intestinal submucosa extracellular matrix (CorMatrix; CorMatrix Cardiovascular, Rosewell, GA) is a relatively novel tissue substitute used in cardiovascular applications. We investigated the biological reaction and remodelling of CorMatrix as a tri-leaflet valved conduit in a pig model. We hypothesized that CorMatrix maintains a durable architecture as a valved conduit and remodels to resemble surrounding tissues. METHODS: We fashioned the valved conduit using a 7 × 10 cm 4-ply CorMatrix sheet and placed it in the thoracic aorta of seven landrace pigs for 3, 4, 5 and 6 months. Biodegradation, replacement by native tissue, strength and durability were examined by histology, immunohistochemistry and mechanical testing. RESULTS: Four pigs, one per time frame, completed the study. The conduit lost its original architecture as a tri-leaflet valve due to cusp immobility, subsequent attachment to the wall segment and consequent maintenance of a thick arterial wall-like structure. Scaffold resorption was incomplete, with disorganized inconsistent spatial and temporal degradation even at 6 months. Fibrosis, scarring and calcification started at 4 months and chronic inflammation persisted. The partially remodelled scaffold did not resemble the aortic wall, suggesting impaired remodelling. Mechanical testing showed progressive weakening of the tissues over time, which were liable to breakage. CONCLUSIONS: CorMatrix is biodegradable; however, it failed to remodel in a structured and anatomical fashion in an arterial environment. Progressive mechanical and remodelling failure in this scenario might be explained by the complexity of the conduit design and the host's chronic inflammatory response, leading to early fibrosis and calcification.


Assuntos
Aorta Torácica/cirurgia , Bioprótese , Prótese Vascular , Matriz Extracelular , Animais , Calcinose/patologia , Estudos de Viabilidade , Fibrose , Inflamação/patologia , Modelos Animais , Suínos
8.
Chirurgia (Bucur) ; 111(5): 439-444, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27819644

RESUMO

The pelvis bone resection-reconstruction surgery is one of the most challenging fields in orthopedics. Being applied for tumors, as for other complex reconstruction cases, this type of surgery needs careful planning and is time consuming, in order to obtain proper accuracy. Unfortunately not all the time the expected accuracy is met, with consequences for the patients. PSI proved to provide good cutting accuracy during simulated tumor surgery within the pelvis. This article present a series of 4 patients operated in our department between June 2014 and Mars 2015 for tumors resectionreconstructions. The patients were imaged using a CT and an MRI scan and the images were reconstructed in 3D. According to the bone bank stock, the most similar allograft was chosen and the stored CT scan was reconstructed in 3D. Patient specific instruments (PSI) were designed and manufactured using rapid-prototyping technology for the resection of the native tissues as for the resection of the careful selected hemipelvic allografts. Allografts fitting to the pelvis of the patients was excellent and allowed stable osteosynthesis.


Assuntos
Neoplasias Ósseas/cirurgia , Carcinoma de Células Renais/cirurgia , Procedimentos Ortopédicos/instrumentação , Ossos Pélvicos/cirurgia , Procedimentos Cirúrgicos Reconstrutivos/instrumentação , Sarcoma de Ewing/cirurgia , Adolescente , Adulto , Biópsia , Neoplasias Ósseas/complicações , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Carcinoma de Células Renais/complicações , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/secundário , Humanos , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/complicações , Procedimentos Ortopédicos/métodos , Ossos Pélvicos/patologia , Procedimentos Cirúrgicos Reconstrutivos/métodos , Estudos Retrospectivos , Fatores de Risco , Sarcoma de Ewing/complicações , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/patologia , Resultado do Tratamento , Síndrome de Wolff-Parkinson-White/complicações
9.
Sarcoma ; 2014: 686790, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24701131

RESUMO

Introduction. In surgical oncology, histological analysis of excised tumor specimen is the conventional method to assess the safety of the resection margins. We tested the feasibility of using MRI to assess the resection margins of freshly explanted tumor specimens in rats. Materials and Methods. Fourteen specimen of sarcoma were resected in rats and analysed both with MRI and histologically. Slicing of the specimen was identical for the two methods and corresponding slices were paired. 498 margins were measured in length and classified using the UICC classification (R0, R1, and R2). Results. The mean difference between the 498 margins measured both with histology and MRI was 0.3 mm (SD 1.0 mm). The agreement interval of the two measurement methods was [-1.7 mm; 2.2 mm]. In terms of the UICC classification, a strict correlation was observed between MRI- and histology-based classifications (κ = 0.84, P < 0.05). Discussion. This experimental study showed the feasibility to use MRI images of excised tumor specimen to assess the resection margins with the same degree of accuracy as the conventional histopathological analysis. When completed, MRI acquisition of resected tumors may alert the surgeon in case of inadequate margin and help advantageously the histopathological analysis.

10.
Spine J ; 14(8): 1510-9, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24314903

RESUMO

BACKGROUND CONTEXT: A previous study showed subtle biomechanical changes in the gait of unbraced adolescent idiopathic scoliosis (AIS) patients such as a reduction of pelvic, hip, knee, and ankle displacements. However, lumbopelvic muscles' timing activity was bilaterally increased during gait and correlated to excessive oxygen consumption as compared with healthy subjects. Usually, a brace, when indicated, is worn strictly for 22 hours every day in skeletally immature idiopathic scoliotic girls. To our knowledge, no study has assessed the long-term brace effect (6 months) on functional activities such as level walking. PURPOSE: To assess the stiffening effects of 6 months' brace wearing on instrumented gait analysis in girls with thoracolumbar/lumbar adolescent idiopathic scoliosis. STUDY DESIGN/SETTING: Clinical prospective study. PATIENT SAMPLE: Thirteen girls diagnosed as progressive adolescent idiopathic scoliosis with left thoracolumbar/lumbar curves (curves ranging 25°-40°). OUTCOME MEASURES: All patients underwent a radiographic and instrumented gait analysis, including assessment of kinematics, mechanics, electromyography (EMG), and energetics of walking. METHODS: The scoliotic girls were prospectively studied at S1 (before bracing) and 6 months later at S2 (out-brace: treatment effect). The gait parameters were compared with those of 13 matched healthy girls. A t paired test was conducted to evaluate the effect of the 6-month orthotic treatment in AIS girls. Student t test was performed to compare the scoliotic group at S2 and the healthy subjects to identify if the observed changes in gait parameters meant improvement or worsening of gait. RESULTS: After 6 months of orthotic treatment in AIS, thoracolumbar/lumbar curves and apical rotation remained reduced by 25% and 61%, respectively. During gait, frontal pelvis and hip motions were significantly increased. Muscular mechanical work increased becoming closer but still different as compared with healthy subjects. Bilateral lumbopelvic muscles were almost 40% more active in AIS at S1 compared with healthy subjects and did not change at S2 except for the erector spinae muscles EMG activity, which decreased significantly. Energy cost exceeded by 30% in AIS at S1 compared with healthy subjects and did not change at 6 months' follow-up. CONCLUSIONS: After 6 months of orthotic treatment, in an out-brace situation, the main structural thoracolumbar/lumbar curve remained partly corrected. Frontal pelvis and hip motion increased, contributing to an improvement of muscular mechanical work during walking. EMG activity duration of lumbopelvic muscles did not change except for the erector spinae muscles, which was decreased but without any beneficial change in the energy cost of walking. In summary, brace treatment, after 6 months, did not significantly influence the gait variables in AIS girls deleteriously, but did not reduce the excessive energy cost, which was 30% above the values of normal adolescents.


Assuntos
Braquetes , Marcha/fisiologia , Escoliose/reabilitação , Adolescente , Fenômenos Biomecânicos , Estudos de Casos e Controles , Criança , Eletromiografia , Feminino , Humanos , Pelve/diagnóstico por imagem , Estudos Prospectivos , Radiografia , Escoliose/diagnóstico por imagem , Escoliose/fisiopatologia , Coluna Vertebral/diagnóstico por imagem
11.
Ann Biomed Eng ; 42(1): 205-13, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23963884

RESUMO

In orthopaedic surgery, resection of pelvic bone tumors can be inaccurate due to complex geometry, limited visibility and restricted working space of the pelvis. The present study investigated accuracy of patient-specific instrumentation (PSI) for bone-cutting during simulated tumor surgery within the pelvis. A synthetic pelvic bone model was imaged using a CT-scanner. The set of images was reconstructed in 3D and resection of a simulated periacetabular tumor was defined with four target planes (ischium, pubis, anterior ilium, and posterior ilium) with a 10-mm desired safe margin. Patient-specific instruments for bone-cutting were designed and manufactured using rapid-prototyping technology. Twenty-four surgeons (10 senior and 14 junior) were asked to perform tumor resection. After cutting, ISO1101 location and flatness parameters, achieved surgical margins and the time were measured. With PSI, the location accuracy of the cut planes with respect to the target planes averaged 1 and 1.2 mm in the anterior and posterior ilium, 2 mm in the pubis and 3.7 mm in the ischium (p < 0.0001). Results in terms of the location of the cut planes and the achieved surgical margins did not reveal any significant difference between senior and junior surgeons (p = 0.2214 and 0.8449, respectively). The maximum differences between the achieved margins and the 10-mm desired safe margin were found in the pubis (3.1 and 5.1 mm for senior and junior surgeons respectively). Of the 24 simulated resection, there was no intralesional tumor cutting. This study demonstrates that using PSI technology during simulated bone cuts of the pelvis can provide good cutting accuracy. Compared to a previous report on computer assistance for pelvic bone cutting, PSI technology clearly demonstrates an equivalent value-added for bone cutting accuracy than navigation technology. When in vivo validated, PSI technology may improve pelvic bone tumor surgery by providing clinically acceptable margins.


Assuntos
Neoplasias Ósseas , Simulação por Computador , Imageamento Tridimensional , Modelos Biológicos , Ossos Pélvicos , Neoplasias Pélvicas , Neoplasias Ósseas/patologia , Neoplasias Ósseas/cirurgia , Humanos , Ossos Pélvicos/patologia , Ossos Pélvicos/cirurgia , Neoplasias Pélvicas/patologia , Neoplasias Pélvicas/cirurgia
12.
Eur Spine J ; 22(11): 2399-406, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23702685

RESUMO

PURPOSE: Adolescent idiopathic scoliotic (AIS) deformity induces excessive oxygen consumption correlated to a bilateral increase of lumbo-pelvic muscles timing activity (EMG) during gait. Wearing a brace, the usual treatment for AIS, by supporting the spine and the pelvis, would generate lumbo-pelvic muscular relaxation and consequently reduce excessive oxygen consumption. The purpose of this study was to evaluate the short-term effect of bracing on gait biomechanics in scoliotic spine when compared with normal braced spine. METHODS: Thirteen healthy volunteers were compared to 13 AIS girls. In both samples, gait analysis was assessed using a three-dimensional motion analysis, including synchronous kinematic, electromyographic, mechanical and energy measurements, first without brace, then wearing a brace. RESULTS: For scoliotic patients, comparison of in-brace and out-brace situations revealed a significant decrease of frontal pelvis (p < 0.001), hip (p < 0.001) and shoulder (p = 0.004) motion in brace associated with a significant reduction of pelvis rotation (p = 0.003). However, the brace did not change significantly the lumbo-pelvic muscle activity duration (EMG) or the mechanical and energetic parameters. Transversal pelvis motion was reduced by 39% (p = 0.04), frontal hip and shoulder motions by 23% (p = 0.004) and 30% (p = 0.01) respectively, and energy cost of walking remained increased by 37% in braced AIS girls relatively to braced healthy subjects. Mechanical and electromyographic variables were not significantly different between the two braced populations during gait except for the gluteus medius muscle that showed bilaterally an increase of duration of electrical activity in healthy subjects and contrarily a decrease in AIS patients (healthy: -3.5 ± 9.6% of gait cycle vs. scoliotic: 3.7 ± 7.7% of gait cycle; p = 0.04). CONCLUSIONS: Bracing changed neither the oxygen consumption nor the timing of the lumbo-pelvic muscles activity in both groups during gait. However, in brace the timing activity of bilateral gluteus medius muscles tended to decrease in AIS patients and increase in healthy subjects. Moreover, braced AIS patients had more restricted frontal hips and shoulder motion as well as pelvis rotation than braced healthy subjects.


Assuntos
Braquetes , Marcha , Escoliose/terapia , Adolescente , Fenômenos Biomecânicos , Feminino , Marcha/fisiologia , Humanos , Músculo Esquelético/fisiopatologia , Consumo de Oxigênio , Escoliose/fisiopatologia , Caminhada/fisiologia
13.
Eur Spine J ; 22(8): 1868-76, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23397190

RESUMO

PURPOSE: To examine the time needed from a surgeon's viewpoint to treat a patient operated for lumbar spinal stenosis. We firstly aimed to give evidence of the wide ranging duration of standardized procedure. Secondly, we investigated factors affecting the time allocated to each patient. METHODS: 438 medical records of patients operated on for lumbar decompression without fusion (2005-2011) were retrospectively examined. Primary data were operative time (OT, min), length of stay (LoS, days) and number of postoperative visits. A fourth parameter was calculated, the time spent per patient (TSPP, min) by summing the time spent in surgery, during inpatient and outpatient follow-up visits. Factors that influenced these medical resources were examined. RESULTS: Median (5th-95th percentile) LoS was 5 days (2-15), OT 106 min (60-194), number of medical visits 5 (2-11) and TSPP 329 min (206-533). In descending order, factors predicting LoS were age, no. of levels, sex, operative technique, cardiovascular risk index, dural tear and haematoma. Factors predicting OT were number of levels, dural tear, foraminotomy, synovial cyst and body mass index. The statistical model could predict 36% of the TSPP variance. We recommend that surgeons add 35 min for each level, 29 min for patients over 65 years, 30 min for women, 132 min for dural tear and 108 min for epidural haematoma. CONCLUSION: TSPP treated for lumbar spinal stenosis is highly variable, yet partially predictable. These data may help individual surgeons or heads of departments to plan their activities.


Assuntos
Vértebras Lombares/cirurgia , Duração da Cirurgia , Procedimentos Ortopédicos , Estenose Espinal/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Estudos Retrospectivos , Fatores Sexuais
14.
Comput Aided Surg ; 18(1-2): 19-26, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23176154

RESUMO

BACKGROUND: Resection of bone tumors within the pelvis requires good cutting accuracy to achieve satisfactory safe margins. Manually controlled bone cutting can result in serious errors, especially due to the complex three-dimensional geometry, limited visibility, and restricted working space of the pelvic bone. This experimental study investigated cutting accuracy during navigated and non-navigated simulated bone tumor cutting in the pelvis. METHODS: A periacetabular tumor resection was simulated using a pelvic bone model. Twenty-three operators (10 senior and 13 junior surgeons) were asked to perform the tumor cutting, initially according to a freehand procedure and later with the aid of a navigation system. Before cutting, each operator used preoperative planning software to define four target planes around the tumor with a 10-mm desired safe margin. After cutting, the location and flatness of the cut planes were measured, as well as the achieved surgical margins and the time required for each cutting procedure. RESULTS: The location of the cut planes with respect to the target planes was significantly improved by using the navigated cutting procedure, averaging 2.8 mm as compared to 11.2 mm for the freehand cutting procedure (p < 0.001). There was no intralesional tumor cutting when using the navigation system. The maximum difference between the achieved margins and the 10-mm desired safe margin was 6.5 mm with the navigated cutting process (compared to 13 mm with the freehand cutting process). CONCLUSIONS: Cutting accuracy during simulated bone cuts of the pelvis can be significantly improved by using a freehand process assisted by a navigation system. When fully validated with complementary in vivo studies, the planning and navigation-guided technologies that have been developed for the present study may improve bone cutting accuracy during pelvic tumor resection by providing clinically acceptable margins.


Assuntos
Neoplasias Ósseas/cirurgia , Simulação por Computador , Osteotomia/métodos , Cirurgia Assistida por Computador/métodos , Humanos , Modelos Anatômicos , Ossos Pélvicos/cirurgia , Sensibilidade e Especificidade
15.
Stud Health Technol Inform ; 176: 95-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22744467

RESUMO

In idiopathic scoliotic patients, dynamical intervertebral efforts acting between vertebrae seem to be correlated with the spinal deformity. The quantification of these efforts, which is useful for the orthopedic surgeons to set up their surgical planning is the final objective of the present research. As a first step, we focus in this contribution on the geometrical reconstruction of the spine and especially on the rotation sequences between vertebrae in a multibody approach. The reconstruction process is performed in the standing position with possible bending, using an optimization process based on geometrical data reconstructed from radiographs. The obtained results will serve as input for the subsequent gait motion for which the limited set of geometrical information must be compensated.


Assuntos
Disco Intervertebral/fisiopatologia , Modelos Biológicos , Movimento , Amplitude de Movimento Articular , Escoliose/fisiopatologia , Coluna Vertebral/fisiopatologia , Articulação Zigapofisária/fisiopatologia , Simulação por Computador , Humanos
16.
Cell Tissue Bank ; 12(4): 281-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20703816

RESUMO

Freeze-drying and irradiation are common process used by tissue banks to preserve and sterilize bone allografts. Freeze dried irradiated bone is known to be more brittle. Whether bone brittleness is due to irradiation alone, temperature during irradiation or to a synergetic effect of the freeze-drying-irradiation process was not yet assessed. Using a left-right femoral head symmetry model, 822 compression tests were performed to assess the influence of sequences of a 25 kGy irradiation with and without freeze-drying compared to the unprocessed counterpart. Irradiation of frozen bone did not cause any significant reduction in ultimate strength, stiffness and work to failure. The addition of the freeze-drying process before or after irradiation resulted in a mean drop of 35 and 31% in ultimate strength, 14 and 37% in stiffness and 46 and 37% in work to failure. Unlike irradiation at room temperature, irradiation under dry ice of solvent-detergent treated bone seemed to have no detrimental effect on mechanical properties of cancellous bone. Freeze-drying bone without irradiation had no influence on mechanical parameters, but the addition of irradiation to the freeze-drying step or the reverse sequence showed a detrimental effect and supports the idea of a negative synergetic effect of both procedures. These findings may have important implications for bone banking.


Assuntos
Osso e Ossos/fisiologia , Osso e Ossos/efeitos da radiação , Raios gama , Idoso , Fenômenos Biomecânicos/efeitos da radiação , Força Compressiva/efeitos da radiação , Gelo-Seco , Liofilização , Humanos
17.
Sarcoma ; 2010: 125162, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21127723

RESUMO

Pelvic sarcoma is associated with a relatively poor prognosis, due to the difficulty in obtaining an adequate surgical margin given the complex pelvic anatomy. Magnetic resonance imaging and computerized tomography allow valuable surgical resection planning, but intraoperative localization remains hazardous. Surgical navigation systems could be of great benefit in surgical oncology, especially in difficult tumor location; however, no commercial surgical oncology software is currently available. A customized navigation software was developed and used to perform a synovial sarcoma resection and allograft reconstruction. The software permitted preoperative planning with defined target planes and intraoperative navigation with a free-hand saw blade. The allograft was cut according to the same planes. Histological examination revealed tumor-free resection margins. Allograft fitting to the pelvis of the patient was excellent and allowed stable osteosynthesis. We believe this to be the first case of combined computer-assisted tumor resection and reconstruction with an allograft.

18.
J Bone Joint Surg Am ; 92(11): 2076-82, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20810857

RESUMO

BACKGROUND: In orthopaedic surgery, many interventions involve freehand bone cutting with an oscillating saw. Such freehand procedures can produce large cutting errors due to the complex hand-controlled positioning of the surgical tool. This study was performed to investigate the potential improvements in cutting accuracy when computer-assisted and robot-assisted technologies are applied to a freehand bone-cutting process when no jigs are available. METHODS: We designed an experiment based on a geometrical model of the cutting process with use of a simulated bone of rectangular geometry. The target planes were defined by three variables: a cut height (t) and two orientation angles (beta and gamma). A series of 156 cuts were performed by six operators employing three technologically different procedures: freehand, navigated freehand, and robot-assisted cutting. After cutting, we measured the error in the height t, the absolute error in the angles beta and gamma, the flatness, and the location of the cut plane with respect to the target plane. RESULTS: The location of the cut plane averaged 2.8 mm after use of the navigated freehand process compared with 5.2 mm after use of the freehand process (p < 0.0001). Further improvements were obtained with use of the robot-assisted process, which provided an average location of 1.7 mm (p < 0.0001). CONCLUSIONS: Significant improvements in cutting accuracy can be achieved when a navigation system or an industrial robot is integrated into a freehand bone-cutting process when no jigs are available. The procedure for navigated hand-controlled positioning of the oscillating saw appears to be easy to learn and use.


Assuntos
Osso e Ossos/cirurgia , Osteotomia/métodos , Robótica/métodos , Cirurgia Assistida por Computador/métodos , Humanos , Erros Médicos/prevenção & controle , Osteotomia/instrumentação
19.
Acta Orthop ; 81(2): 250-5, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20175643

RESUMO

BACKGROUND AND PURPOSE: Massive bone allografts are used when surgery causes large segmental defects. Shape-matching is the primary criterion for selection of an allograft. The current selection method, based on 2-dimensional template comparison, is inefficient for 3-dimensional complex bones. We have analyzed a 3-dimensional (3-D) registration method to match the anatomy of the allograft with that of the recipient. METHODS: 3-D CT-based registration was performed to match the shapes of both bones. We used the registration to align the allograft volume onto the recipient's bone. Hemipelvic allograft selection was tested in 10 virtual recipients with a panel of 10 potential allografts, including one from the recipient himself (trap graft). 4 observers were asked to visually inspect the superposition of allograft over the recipient, to classify the allografts into 4 categories according to the matching of anatomic zones, and to select the 3 best matching allografts. The results obtained using the registration method were compared with those from a previous study on the template method. RESULTS: Using the registration method, the observers systematically detected the trap graft. Selections of the 3 best matching allografts performed using registration and template methods were different. Selection of the 3 best matching allografts was improved by the registration method. Finally, reproducibility of the selection was improved when using the registration method. INTERPRETATION: 3-D CT registration provides more useful information than the template method but the final decision lies with the surgeon, who should select the optimal allograft according to his or her own preferences and the needs of the recipient.


Assuntos
Transplante Ósseo/métodos , Imageamento Tridimensional/métodos , Ossos Pélvicos/transplante , Bancos de Ossos , Humanos , Tamanho do Órgão , Ossos Pélvicos/anatomia & histologia , Transplante Homólogo
20.
Int J Med Robot ; 5(4): 435-43, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19670352

RESUMO

BACKGROUND: Preoperative planning and intraoperative assistance are needed to improve accuracy in tumour surgery. To be accepted, these processes must be efficient. An experiment was conducted to compare a mouse and a haptic device, with and without force feedback, to perform plan positioning in a 3D space. Ergonomics and performance factors were investigated during the experiment. Positioning strategies were observed. METHODS: The task completion time, number of 3D orientations and failure rate were analysed. A questionnaire on ergonomics was filled out by each participant. RESULTS: The haptic device showed a significantly lower failure rate and was quicker and more ergonomic than the mouse. The force feedback was not beneficial to the accomplishment of the task. CONCLUSIONS: The haptic device is intuitive, ergonomic and more efficient than the mouse for positioning a 3D plane into a 3D space. Useful observations regarding positioning strategies will improve the integration of haptic devices into medical applications.


Assuntos
Neoplasias Ósseas/cirurgia , Periféricos de Computador , Imageamento Tridimensional/instrumentação , Osteotomia/instrumentação , Cirurgia Assistida por Computador/instrumentação , Análise e Desempenho de Tarefas , Tato , Neoplasias Ósseas/patologia , Comportamento do Consumidor , Desenho de Equipamento , Análise de Falha de Equipamento , Ergonomia , Humanos , Imageamento Tridimensional/métodos , Osteotomia/métodos , Cirurgia Assistida por Computador/métodos , Interface Usuário-Computador
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