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1.
Cancer Treat Res ; 152: 125-45, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20213388

RESUMO

Surgical strategies for the primary tumor for patients with extremity and pelvis osteosarcoma have evolved from the ablative to limb-sparing approaches over the past three decades. Favorable oncologic and functional outcomes with contemporary tissue-conserving techniques consistently observed in skeletally mature patients have prompted the application of similar approaches to a growing number of eligible skeletally immature patients. In response to emerging long-term outcome data, current strategies have focused principally on refining the nature and scope of surgical resection to preserve uninvolved tissues, and on the adoption of novel biological and nonbiological skeletal and soft-tissue reconstruction methods to optimize function. We focus on these clinical issues and discuss current efforts to advance the surgical management of the primary tumor and address the limitations of the definitive treatment of the primary tumor, including locally recurrent disease and complications of skeletal reconstructions.


Assuntos
Neoplasias Ósseas/cirurgia , Osteossarcoma/cirurgia , Artroplastia , Extremidades/cirurgia , Humanos , Procedimentos de Cirurgia Plástica
2.
J Shoulder Elbow Surg ; 18(5): 705-10, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19186077

RESUMO

BACKGROUND: The proximal humerus is a common site for tumors, either metastatic or primary. Thus it is a frequent site of intervention in musculoskeletal oncology surgery. We looked at the use of endoprosthetic reconstructions in surgical intervention for tumors of the proximal humerus. METHODS: A review of our database from 1990 to 2005 revealed 83 proximal humeral endoprosthetic reconstructions following an intra-articular, deltoid muscle, and axillary nerve sparing resection. Medical records and radiographs were reviewed to determine shoulder range of motion, MSTS scores, and any complications. The median patient age was 55 years (range, 13-80). The mean follow-up was 30 months (range, 1-199). RESULTS: Mean active abduction was 41 degrees (range, 10-90 degrees) and mean active forward flexion was 42 degrees (range, 5-115 degrees). The mean MSTS score was 63% (range, 40-83%). Implant-related complications included 2 deep infections and 22 patients with proximal migration of the prosthesis. No prostheses loosened. Only 2 required removal (1 for infection and 1 for progression of metastatic disease). CONCLUSIONS: A proximal humeral endoprosthesis provides a durable reconstruction with a relatively low complication rate. Although it provides a stable platform for elbow and hand function, actual shoulder function is limited.


Assuntos
Artroplastia de Substituição/métodos , Neoplasias Ósseas/cirurgia , Úmero/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Amplitude de Movimento Articular/fisiologia , Articulação do Ombro/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/patologia , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Úmero/patologia , Estimativa de Kaplan-Meier , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Medição da Dor , Probabilidade , Radiografia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Medição de Risco , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/patologia , Estatísticas não Paramétricas , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
3.
J Am Acad Orthop Surg ; 16(9): 541-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18768711

RESUMO

High-dose radiation is injurious to bone and is a known risk factor for the development of late fracture. Management of radiation-induced fractures is generally thought to be difficult, with prolonged healing times and a high nonunion rate. There is a relative paucity of literature to guide treatment. Fractures of the long bones typically should be managed with intramedullary nailing. A low threshold should exist for supplemental bone grafting, and a vascularized fibula graft should be considered for persistent nonunion. To prevent refracture, fixation should be left in situ indefinitely. Resection of the fracture site and reconstruction with an oncologic endoprosthesis is an effective salvage procedure. Periarticular fractures should be treated with joint arthroplasty, which allows early mobilization and avoids prolonged healing times. Fractures of expendable bones, primarily the clavicle, typically should be managed with débridement or resection.


Assuntos
Fraturas Ósseas/etiologia , Fraturas Ósseas/terapia , Osteorradionecrose/complicações , Radioterapia/efeitos adversos , Humanos , Cicatrização/efeitos da radiação
4.
Orthopedics ; 31(4): 361, 2008 04.
Artigo em Inglês | MEDLINE | ID: mdl-19292288

RESUMO

Traditional reconstructive options may not always be adequate to treat the extensive bone loss that can occur with metastatic disease of the proximal femur. Another method of treatment is resection of the proximal femur and reconstruction with an endoprosthesis. However, the more extensive surgery raises concern for a higher perioperative complication rate in this potentially medically unstable population. This study reviewed 57 patients with metastatic disease treated with 58 proximal femoral endoprostheses. The only perioperative complications were 2 symptomatic deep venous thromboses. Late complications included 3 dislocations, 2 deep venous thromboses, 1 pulmonary embolism, and 4 infections. Three deaths occurred during the perioperative period, all from underlying cancer. Proximal femoral endoprostheses offer a safe treatment option for patients with extensive metastatic disease.


Assuntos
Neoplasias Femorais/secundário , Neoplasias Femorais/cirurgia , Prótese de Quadril/efeitos adversos , Instabilidade Articular/etiologia , Instabilidade Articular/prevenção & controle , Falha de Prótese , Infecções Relacionadas à Prótese/etiologia , Trombose Venosa/etiologia , Adulto , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/diagnóstico , Resultado do Tratamento , Trombose Venosa/diagnóstico
5.
Int J Antimicrob Agents ; 29(5): 593-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17317111

RESUMO

Gendine is a novel antiseptic dye with broad-spectrum antimicrobial activity that may be used to coat plastics and metal devices. Our objective was to determine the efficacy of gendine-coated orthopaedic metal devices in preventing methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Stainless steel and titanium Schanz rods were coated with gendine. The zone of inhibition (ZoI) around the rods with and without gamma-irradiation was determined by a modified Kirby-Bauer method. A previously published bioprosthetic biofilm colonisation model, modified Kuhn's method, was used to determine the adherence of MRSA to coated and uncoated rods, with and without irradiation, after insertion into bovine bone and after 3 months shelf life followed by 2 weeks of immersion in serum. The gendine-coated Schanz metal rods showed a net ZoI of 16 mm against MRSA before and after irradiation. Gendine-coated rods showed no biofilm formation (0 colony-forming units (CFU)), which was a significant reduction (P<0.001) compared with uncoated controls (>5000 CFU). Coated rods exposed to high-dose gamma-irradiation and coated rods drilled into bone also showed significant efficacy (P<0.001) in preventing biofilm adherence. After 2 weeks, gendine-coated rods maintained significant durability (P<0.01), resulting in 90% reduction in MRSA biofilm adherence compared with uncoated control rods. Results indicate that gendine-coated metal rods are highly efficacious in the prevention of MRSA biofilm.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Corantes/uso terapêutico , Infecções Relacionadas à Prótese/prevenção & controle , Aderência Bacteriana/efeitos dos fármacos , Clorexidina/uso terapêutico , Estabilidade de Medicamentos , Raios gama , Violeta Genciana/uso terapêutico , Metais , Resistência a Meticilina , Cloreto de Metileno/uso terapêutico , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Aço , Esterilização , Titânio
6.
AJR Am J Roentgenol ; 188(3): 855-63, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17312079

RESUMO

OBJECTIVE: The purpose of this article is the identification of recurrent tumor of bone utilizing radiography, CT, and MRI. CONCLUSION: Radiography is frequently used to identify recurrence of treated bone tumors through findings such as osteolysis, cortical reactions, and characteristic matrix mineralization. CT can help evaluate the character of osseous and calcific abnormalities. Comparison with prior radiographs can be crucial for differentiation between postoperative alterations of bone and subtle signs of recurrence. MRI can identify soft-tissue masses and is useful for imaging patients with metallic hardware when it is optimized to decrease artifacts.


Assuntos
Neoplasias Ósseas/diagnóstico , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Recidiva Local de Neoplasia/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Humanos , Técnica de Subtração
7.
J Bone Joint Surg Am ; 89(8): 1794-801, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17671020

RESUMO

BACKGROUND: Skeletal metastases from renal cell carcinoma are highly destructive vascular lesions. They pose unique surgical challenges due to the risk of life-threatening hemorrhage and resistance to other treatments. The goal of this retrospective study was to evaluate factors that may affect survival after surgical treatment of metastases of renal cell carcinoma. METHODS: We performed a retrospective review of a series of 295 consecutive patients who had been treated for metastatic renal cell carcinoma at one institution between 1974 and 2004. There were 226 men and sixty-nine women. A total of 368 metastases of renal cell tumors to the extremities and pelvis were treated. The surgical procedures included curettage with cementing and/or internal fixation (214 tumors), en bloc resection (117), closed nailing (twenty-seven), amputation (four), and other measures (six). Overall survival was calculated with Kaplan-Meier analysis. The log-rank test was used to evaluate the effect of different variables on overall survival. RESULTS: The overall patient survival rates at one and five years were 47% and 11%, respectively. The metastatic pattern had a significant effect on the survival rate (p < 0.0001): patients with a solitary bone metastasis had the most favorable overall survival rate. Patients with multiple bone-only metastases had a better survival rate than patients with pulmonary metastases (p = 0.009). A clear-cell histological subtype was also associated with better survival (p < 0.0001). The tumor grade did not predict survival (p = 0.17). Fifteen patients (5%) died within four weeks after surgery. The causes included acute pulmonary failure (seven patients), multiorgan failure (six), cerebrovascular accident (one), and hypercalcemia (one). There were no deaths attributable to intraoperative hemorrhage. DISCUSSION: Survival beyond twelve months is possible for a substantial proportion of patients with metastatic renal cell carcinoma. Patients with a clear-cell histological subtype, bone-only metastases, and a solitary metastasis have superior survival rates. The presence of pulmonary metastases does not predict early death in a reliable manner, and some patients may survive for years with pulmonary and systemic disease. The data are important for surgeons to consider when choosing treatment for these patients. For example, local control of disease and implant stability are important issues for patients with a potential for a long duration of survival.


Assuntos
Neoplasias Ósseas/secundário , Neoplasias Ósseas/cirurgia , Carcinoma de Células Renais/secundário , Carcinoma de Células Renais/cirurgia , Neoplasias Renais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Neoplasias Ósseas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Radiografia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
8.
J Am Acad Orthop Surg ; 15(8): 450-60, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17664365

RESUMO

Medications taken for the treatment of arthritis and psychotropic and epileptic disorders, as well as anticoagulants, antacids, bisphosphonates, corticosteroids, and antineoplastic drugs, can profoundly affect bone metabolism. In some scenarios (eg, osteoporosis), these effects are intended; in others (eg, rickets, osteomalacia secondary to antiepileptic drugs), potentially adverse side effects of medications on bone may occur. Nonsteroidal anti-inflammatory drugs appear to delay fracture healing and bone ingrowth, although these effects are reversible. Disease-modifying antirheumatic drugs do not appear to affect bone metabolism adversely when taken in the low dosages currently prescribed. Bisphosphonates are useful in restoring bone mass in cases of postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, Paget's disease, and neoplastic conditions with bone loss and hypercalcemia. Corticosteroids and cancer chemotherapeutic agents generally affect bone adversely and increase fracture risk.


Assuntos
Anti-Inflamatórios/efeitos adversos , Antineoplásicos/efeitos adversos , Antipsicóticos/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/metabolismo , Fraturas Ósseas/induzido quimicamente , Osso e Ossos/efeitos dos fármacos , Fraturas Ósseas/metabolismo , Humanos , Prognóstico , Fatores de Risco
9.
J Clin Oncol ; 20(2): 521-7, 2002 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11786582

RESUMO

PURPOSE: To evaluate the clinicopathologic features of extraosseous osteosarcoma (EOO), a rare soft tissue form of osteosarcoma, and to examine its response to multimodality therapy. PATIENTS AND METHODS: The medical records of all patients with EOO evaluated at The University of Texas M.D. Anderson Cancer Center between 1960 and 1999 were reviewed for clinicopathologic factors, treatment, and outcome. RESULTS: Sixty consecutive patients with EOO were identified, including 38 patients with localized (American Joint Committee on Cancer stages I to III) disease. The majority of patients presented with T2 tumors (n = 35, 58%), and 90% of tumors were located beneath the investing fascia. Twenty-seven patients with measurable and assessable disease were treated with doxorubicin-based chemotherapy (median doxorubicin starting dose, 75 mg/m(2); median number of cycles, four). The overall response rate was 19%, with two complete and three partial responses; one (6%) of 18 doxorubicin-treated patients who underwent subsequent surgery had a pathologic complete response. For the subset of 30 patients with localized disease treated at M.D. Anderson, the 5-year actuarial local recurrence-free, distant recurrence-free, event-free, and disease-specific survival rates were 82% (95% confidence interval [CI], 70% to 98%), 64% (95% CI, 43% to 93%), 47% (95% CI, 30% to 70%), and 46% (95% CI, 26% to 80%), respectively. CONCLUSION: EOO should be considered clinically and therapeutically distinct from osseous osteosarcoma. Radiographic response rates and pathologic complete response rates to doxorubicin-based systemic therapy are low.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Recidiva Local de Neoplasia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/cirurgia , Neoplasias de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecidos Moles/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Terapia Combinada , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteossarcoma/patologia , Prognóstico , Estudos Retrospectivos , Neoplasias de Tecidos Moles/patologia , Resultado do Tratamento
10.
J Clin Oncol ; 22(16): 3375-80, 2004 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15310783

RESUMO

PURPOSE: The primary objective of this phase I trial was to define the maximum-tolerated dose of continuous-infusion doxorubicin administered with standard preoperative radiation for patients with localized, potentially resectable soft tissue sarcomas of the extremities or body wall. PATIENTS AND METHODS: Twenty-seven patients with radiographically resectable intermediate- or high-grade soft tissue sarcomas were treated. Preoperative external-beam radiation was administered in 25 2-Gy fractions (total dose, 50 Gy). Concurrent continuous-infusion doxorubicin was administered by an initial bolus (4 mg/m(2)) and subsequent 4-day continuous infusion (12.5, 15.0, 17.5, or 20.0 mg/m(2)/wk). Radiographic restaging was performed 4 to 7 weeks after chemoradiation, and patients with localized disease underwent surgical resection. RESULTS: Chemoradiation was completed as an outpatient procedure in 25 patients (93%). The maximum-tolerated dose of continuous-infusion doxorubicin combined with standard preoperative radiation was 17.5 mg/m(2)/wk; at this dose level, seven (30%) of 23 patients had grade 3 dermatologic toxicity. Macroscopically complete resection (R0 or R1) was performed in all 26 patients who underwent surgery. Among 22 patients who were treated with doxorubicin 17.5/mg/m(2)/wk with concurrent radiation and subsequent surgery, 11 patients (50%) had 90% or greater tumor necrosis, including two patients who had complete pathologic responses. CONCLUSION: Preoperative doxorubicin-based chemoradiation appears safe and feasible. The maximum-tolerated dose of continuous-infusion doxorubicin with standard preoperative radiation was 17.5 mg/m(2)/wk. Pathologic response rates with this regimen are encouraging.


Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Doxorrubicina/efeitos adversos , Sarcoma/tratamento farmacológico , Sarcoma/radioterapia , Neoplasias de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecidos Moles/radioterapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/uso terapêutico , Terapia Combinada , Fracionamento da Dose de Radiação , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Feminino , Humanos , Infusões Intravenosas , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Necrose , Terapia Neoadjuvante , Sarcoma/cirurgia , Neoplasias de Tecidos Moles/cirurgia , Resultado do Tratamento
11.
Tissue Eng ; 11(9-10): 1356-67, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16259591

RESUMO

This study focused on the assessment of radiography, microcomputed tomography, and histology for the evaluation of bone formation in a 15.0-mm defect in the rabbit radius after the implantation of a tissue-engineered construct. Radiography was found to be useful as a noninvasive method for obtaining images of calcified tissue throughout the time course of the experiment. With this method, however, image quality was low, making it difficult to obtain precise information about the location and quantity of the bone formed. Microcomputed tomography was used to create three-dimensional reconstructions of the bone (25-microm resolution). These reconstructions allowed for greater spatial resolution than the radiography, but did not allow for imaging of the implanted scaffold material or the surrounding, nonmineralized tissue. To visualize all materials within the defect area at the cellular level, histology was used. Histological analysis, however, is a destructive technique that did not allow for any further analysis of the samples. Each technique examined here has its own advantages and limitations, but each yields unique information regarding bone regeneration. It is only through the use of all three techniques that complete characterization of the bone growth and tissue/construct responses after implantation in vivo.


Assuntos
Osso e Ossos/diagnóstico por imagem , Osso e Ossos/fisiologia , Técnicas Histológicas/métodos , Radiografia/métodos , Engenharia Tecidual/métodos , Tomografia Computadorizada por Raios X/métodos , Acrilatos/síntese química , Acrilatos/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Regeneração Óssea , Osso e Ossos/citologia , Preparações de Ação Retardada/farmacologia , Relação Dose-Resposta a Droga , Portadores de Fármacos , Feminino , Fumaratos/síntese química , Fumaratos/química , Glicolatos/química , Ácido Láctico , Microesferas , Peso Molecular , Tamanho da Partícula , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/química , Polipropilenos/síntese química , Polipropilenos/química , Coelhos , Rádio (Anatomia)/citologia , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Trombina/química , Trombina/farmacologia , Fatores de Tempo
12.
Int J Radiat Oncol Biol Phys ; 57(1): 158-65, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-12909228

RESUMO

PURPOSE: To evaluate the outcomes of patients with giant cell tumor of bone (GCTB) treated with radiotherapy (RT) with or without surgical resection. METHODS AND MATERIALS: We performed a retrospective review of the records from 25 consecutive patients with pathologically confirmed GCTB who had undergone RT between 1956 and 2000. RESULTS: Patients ranged in age from 11 to 69 years (median 32); 16 were female and 9 were male. The anatomic distribution of lesions was as follows: cervical spine, 3; temporal bone, 1; thoracic or lumbar spine, 9; sacrum, 8; ilium, 1, and humerus, radius, and thumb metacarpal, 1 each. Tumors ranged in size from 2 to 20 cm (median 9.5) at their maximal dimension. Thirteen patients had been referred for RT for primary GCTB and 12 had been referred with locally recurrent disease after having undergone one or more other treatments. Fourteen patients had undergone RT for gross disease, and the remaining 11 had been treated with RT after gross total resection. In 10 of these 11 patients, the treatment margins were positive or uncertain. Radiation doses ranged from 25 to 65 Gy (median 46). At a median follow-up of 8.8 years (range 0.67-34), 7 patients had developed isolated local recurrence, 2 had developed isolated distant recurrence, and 3 had developed both. The actuarial 5-year overall and disease-free survival rate was 91% and 58%, respectively, and the actuarial 5-year local control and distant metastasis-free survival rate was 62% and 81%, respectively. Univariate analysis suggested that treatment for recurrent disease correlated with a lower disease-free survival rate (83% vs. 33%, p = 0.06), distant metastasis-free survival rate (100% vs. 64%, p = 0.08), and local control rate (83% vs. 42%, p = 0.08) at 5 years. Of the 12 cases of recurrence, 7 were ultimately successfully treated with additional salvage therapy. In 4 of these patients, salvage therapy included interferon-alpha 2b. CONCLUSION: RT should be considered an adjuvant to surgery or as alternative therapy in cases of GCTB that are unresectable or in which excision would result in substantial functional deficits. When RT is used as primary therapy, the rate of local control seems to be satisfactory. In heavily pretreated patients, however, RT delivered as it was in this series can result in poor local control, and alternative therapies should be considered.


Assuntos
Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/radioterapia , Tumor de Células Gigantes do Osso/mortalidade , Tumor de Células Gigantes do Osso/radioterapia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/diagnóstico , Criança , Intervalo Livre de Doença , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Tumor de Células Gigantes do Osso/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia
13.
Biomaterials ; 23(22): 4359-71, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12219826

RESUMO

This study investigated the temporary encapsulation of rat marrow stromal osteoblasts in surface crosslinked gelatin microparticles. Cells were encapsulated in uncrosslinked gelatin microparticles of average diameter of 630 microm containing approximately 53 cells. Gelatin microparticles were crosslinked to shell thicknesses of approximately 75 microm via exposure to 1 mM dithiobis(succinimidylpropionate) (DSP) solution for 15 min or 5 mm DSP solution for 5 min for the production of microparticles dispersing approximately 60 min after placement into a physiologic fluid at 37 degrees C. Formed microparticles were placed into culture wells at a cell seeding density of 5.3 x 10(4) cells/cm2 and, following the degradation and/or dissolution of gelatin, the cells were cultured in the presence of osteogenic supplements for 28 days. Samples were taken at specified time points and analyzed by a DNA assay for cell number and a 3H-thymidine incorporation assay for proliferative potential. Samples were also obtained and analyzed at several time points by alkaline phosphatase, osteocalcin, and mineralization assays for early and late phenotypic expression markers of osteoblastic differentiation. The measurements from the different assays for encapsulated cells (EC) in uncrosslinked and crosslinked gelatin microparticles were normalized with the cell numbers from the DNA assay and compared with those for nonencapsulated control cells. The results demonstrated that the marrow stromal cells survived the encapsulation procedure in uncrosslinked gelatin microparticles and also retained their proliferative potential and osteoblastic phenotype over a 28 day period, although at a slightly lower level than the nonencapsulated cells. The results further showed that the marrow stromal cells survived the encapsulation in crosslinked gelatin microparticles prepared via exposure to 5mm DSP for 5 min and also retained their proliferative potential and osteoblastic phenotype over a 28 day period, but at a slightly lower level than the EC in uncrosslinked gelatin microparticles. In contrast, exposure to 1 mM DSP for 15 min led to severely limited cell viability and phenotypic expression probably due to the increased crosslinking time. These results suggest that temporary encapsulation of cells in gelatin microparticles may protect cells from short-term environmental effects such as those associated with the crosslinking of an injectable polymeric carrier for bone tissue engineering.


Assuntos
Materiais Biocompatíveis/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Sistemas de Liberação de Medicamentos , Osteoblastos/efeitos dos fármacos , Polímeros/química , Fosfatase Alcalina/metabolismo , Animais , Substitutos Ósseos/química , Divisão Celular , Reagentes de Ligações Cruzadas/administração & dosagem , DNA/metabolismo , Composição de Medicamentos , Gelatina/química , Injeções , Osteocalcina/metabolismo , Fenótipo , Polímeros/administração & dosagem , Ratos , Ratos Sprague-Dawley , Timidina/química , Timidina/metabolismo , Fatores de Tempo , Engenharia Tecidual/métodos
14.
Biomaterials ; 23(22): 4373-80, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12219827

RESUMO

The effect of temporary encapsulation of rat marrow stromal osteoblasts in crosslinked gelatin microparticles on cell viability and proliferation was investigated in this study for microparticles placed on a crosslinking poly(propylene fumarate) (PPF) composite over a 7 day time period. Encapsulated cells were seeded on crosslinking PPF composites at times up to 10 min following initiation of the crosslinking reaction, and also on fully crosslinked PPF composites and tissue culture polystyrene controls, with a cell seeding density of 5.3 x 10(4) cells/cm2. The crosslinked PPF composite exhibited an average gel point of 10.3 min and an average maximum crosslinking temperature of 47.5 degrees C. Cell viability and proliferation were assessed by DNA and 3H-thymidine assays and the results were compared with those for nonencapsulated cells. The results showed that the addition time of cells to a crosslinking PPF composite had a large effect on cell viability and proliferation for both encapsulated and nonencapsulated cells with more surviving cells added at later time points. Most importantly, the temporary encapsulation of cells significantly enhanced cell viability at earlier time points. The data indicate that the presence of gelatin microparticles does not affect the crosslinking of a PPF composite. They further suggest that the temporary encapsulation of cells in crosslinked gelatin microparticles may preserve the viability of cells contained in an actively crosslinking PPF composite used as an injectable polymeric scaffold serving also as a carrier for osteogenic cell populations.


Assuntos
Materiais Biocompatíveis/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Sistemas de Liberação de Medicamentos , Fumaratos/química , Osteoblastos/efeitos dos fármacos , Polímeros/química , Polipropilenos/química , Fosfatase Alcalina/metabolismo , Animais , Substitutos Ósseos/química , Divisão Celular , Sobrevivência Celular , Cromatografia , Corantes/farmacologia , Reagentes de Ligações Cruzadas/administração & dosagem , DNA/metabolismo , Composição de Medicamentos , Fumaratos/farmacologia , Gelatina/química , Géis/química , Injeções , Osteocalcina/metabolismo , Fenótipo , Polímeros/administração & dosagem , Polipropilenos/farmacologia , Ratos , Ratos Sprague-Dawley , Temperatura , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Timidina/química , Timidina/metabolismo , Fatores de Tempo , Engenharia Tecidual/métodos
15.
Biomaterials ; 23(22): 4381-7, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12219828

RESUMO

This study investigated the effect of temporary encapsulation of rat marrow stromal osteoblasts in crosslinked gelatin microparticles on long-term cell proliferation and phenotypic expression for microparticles placed on crosslinking poly(propylene fumarate) (PPF) composites using N-vinyl pyrollidinone (N-VP) as a crosslinking agent over a 28 day time period. Encapsulated cells (ECs) were seeded on actively crosslinking PPF composites 6 min after initiation of the crosslinking reaction, and also on fully crosslinked PPF composites and tissue culture polystyrene controls, with a cell seeding density of 5.3 x 10(4) cells/cm2. Composites prepared with three PPF:N-VP ratios were examined: 1:0.5, 1:0.1, and 1:0.05. Samples were taken at specified time points and analyzed by DNA, 3H-thymidine, alkaline phosphatase, osteocalcin, and calcium assays, and the measurements were compared with those for nonencapsulated cells (NCs). The results showed that encapsulated marrow stromal cells exhibited much higher viability, proliferation, and phenotypic expression when placed on crosslinking PPF composites than NCs. The assay results for ECs on crosslinking PPF composites were also similar to those on fully crosslinked PPF composites. The data further demonstrated that the PPF:N-VP ratio had no effect on the viability, proliferation, or phenotypic expression of the ECs. These results suggest that cells encapsulated in crosslinked gelatin microparticles may be part of an injectable, in situ crosslinkable, biodegradable polymeric composite for bone tissue engineering applications.


Assuntos
Materiais Biocompatíveis/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Sistemas de Liberação de Medicamentos , Fumaratos/química , Osteoblastos/efeitos dos fármacos , Polímeros/química , Polipropilenos/química , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Substitutos Ósseos/química , Cálcio/metabolismo , Diferenciação Celular , Divisão Celular , Reagentes de Ligações Cruzadas/administração & dosagem , DNA/metabolismo , Composição de Medicamentos , Fumaratos/farmacologia , Gelatina/química , Injeções , Osteocalcina/metabolismo , Fenótipo , Polímeros/administração & dosagem , Polipropilenos/farmacologia , Pirrolidinonas/farmacologia , Ratos , Ratos Sprague-Dawley , Temperatura , Timidina/química , Timidina/metabolismo , Fatores de Tempo , Engenharia Tecidual/métodos
16.
J Bone Joint Surg Am ; 91(7): 1646-56, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19571087

RESUMO

BACKGROUND: Allograft-prosthetic composite reconstruction of the proximal part of the tibia is one option following resection of a skeletal tumor. Previous studies with use of this technique have found a high prevalence of complications, including fracture, infection, extensor mechanism insufficiency, and loosening. To address some of these problems, we adopted certain measures, including muscle flap coverage, meticulous tendon reconstruction, rigid implant fixation, and careful rehabilitation. The goal of the present study was to evaluate the functional outcome and complications in patients undergoing allograft-prosthetic composite reconstruction of the proximal part of the tibia. METHODS: Twelve patients who underwent allograft-prosthetic composite reconstruction of the proximal part of the tibia after tumor resection were retrospectively evaluated at a median follow-up of forty-nine months. Clinical records and radiographs were reviewed to evaluate patient outcome, healing at the allograft-host junction, function, construct survival, and complications. RESULTS: Nine patients had no extensor lag, and three patients had 5 degrees to 15 degrees of extensor lag. The mean amount of knee flexion was 103 degrees (range, 60 degrees to 120 degrees ). The mean Musculoskeletal Tumor Society score was 24.3 (81%) of a maximum of 30. Complete bone union occurred in nine patients, and partial union occurred in three patients. At the time of writing, no secondary bone-grafting procedures had been required to achieve union, and no revision or removal of the reconstruction had been performed. Rotational or free flaps provided satisfactory wound coverage in all patients. A deep infection occurred in one patient whose allograft and prosthesis were successfully retained after treatment with surgical débridement and intravenous antibiotics. CONCLUSIONS: After osteoarticular resection of destructive tumors of the proximal part of the tibia, an allograft-prosthetic composite reconstruction can provide consistently good functional results with an acceptably low complication rate. Technical aspects of the procedure that may favorably affect outcome include soft-tissue coverage with muscle flaps and rigid fixation with a long-stemmed implant.


Assuntos
Neoplasias Ósseas/cirurgia , Transplante Ósseo , Procedimentos de Cirurgia Plástica/métodos , Próteses e Implantes , Tíbia/cirurgia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia , Amplitude de Movimento Articular , Procedimentos de Cirurgia Plástica/efeitos adversos , Transplante Homólogo , Suporte de Carga , Adulto Jovem
17.
J Biomed Mater Res A ; 88(2): 295-303, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18286641

RESUMO

In this study, the osteoinductive potential of an in vitro generated extracellular matrix (ECM) deposited by marrow stromal cells seeded onto titanium fiber mesh scaffolds and cultured in a flow perfusion bioreactor was investigated. Culture periods of 8, 12, and 16 days were selected to allow for different amounts of ECM deposition by the cells as well as ECM with varying degrees of maturity (Ti/ECM/d8, Ti/ECM/d12, and Ti/ECM/d16, respectively). These ECM-containing constructs were implanted intramuscularly in a rat animal model. After 56 days, histologic analysis of retrieved constructs revealed no bone formation in any of the implants. Surrounding many of the implants was a fibrous capsule, which was often interspersed with fat cells. Within the pore spaces, the predominant tissue response was the presence of blood vessels and young fibroblasts or fat cells. The number of blood vessels on a per area basis calculated from a histomorphometric analysis increased as a function of the amount of ECM within the implanted constructs, with a significant difference between Ti/ECM/d16 and plain Ti constructs. These results indicate that although an in vitro generated ECM alone may not induce bone formation at an ectopic site, its use may enhance the vascularization of implanted constructs.


Assuntos
Matriz Extracelular , Neovascularização Fisiológica , Osteogênese/fisiologia , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Matriz Extracelular/fisiologia , Matriz Extracelular/ultraestrutura , Implantes Experimentais , Masculino , Teste de Materiais , Ratos , Ratos Endogâmicos F344 , Células Estromais/citologia , Células Estromais/fisiologia , Titânio/química , Titânio/metabolismo
18.
Cancer ; 115(16): 3767-73, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19517468

RESUMO

BACKGROUND: The anatomy of the shoulder poses special challenges with regard to limb-sparing surgery. Resection of the deltoid muscle is considered by some surgeons to be necessary to achieve adequate margins for osteosarcoma of the proximal humerus. However, this can compromise the functional results after reconstruction of the shoulder. The goal of the current study was to determine whether deltoid-sparing resection can be safely performed for osteosarcoma of the proximal humerus. METHODS: Between 1978 and 2005, 23 consecutive patients with high-grade nonmetastatic osteosarcoma of the proximal humerus underwent limb-sparing surgery with preservation of the deltoid muscle. All patients received neoadjuvant chemotherapy followed by surgery and postoperative chemotherapy. The mean follow-up was 90 months (range, 7 months-279 months). RESULTS: The overall survival at 5 years was 77%. At the time of last follow-up, 14 (61%) of 23 of patients were alive without evidence of disease. Three (13%) patients developed local recurrence. Two of these patients had poor responses to chemotherapy, with tumor necrosis of 50% and 70%. The third patient had a pathologic fracture of the humerus. Positive surgical margins were associated with local recurrence, and 2 of 4 patients with a positive surgical margin developed local recurrence (P = .01). CONCLUSIONS: Preservation of the deltoid muscle can be performed for carefully selected patients with osteosarcoma of the proximal humerus. Routine use of the procedure is not justified, because it may be associated with an elevated risk of recurrence. The risk of local recurrence appears to be related to positive surgical margins and possibly the percentage of tumor necrosis.


Assuntos
Úmero , Procedimentos Ortopédicos/métodos , Osteossarcoma/cirurgia , Adolescente , Adulto , Quimioterapia Adjuvante , Criança , Feminino , Humanos , Masculino , Músculos/irrigação sanguínea , Músculos/cirurgia , Recidiva Local de Neoplasia , Fatores de Tempo
19.
J Palliat Med ; 12(5): 417-26, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19416037

RESUMO

Bone metastases remain a therapeutic challenge because of the diversity of the problems they cause, the relative paucity of data regarding their treatment, and the necessity for management by a multidisciplinary palliative care team. The American College of Radiology convened an Appropriateness Criteria Expert Panel on Radiation Oncology for the treatment of bone metastasis to create representative clinical case scenarios and then rank the appropriate use of treatment modalities as well as the most reasonable radiotherapy dose schema and treatment planning methods. Here we present both the resulting Appropriateness Criteria and the rationale for making these decisions. The treatment recommendations are placed within the larger framework of the role of radiation in palliative care by discussing the efficiency of palliative radiotherapy schedules, cost effectiveness issues, and the need for additional research regarding the proper multidisciplinary care of patients with symptomatic bone metastasis.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Cuidados Paliativos , Análise Custo-Benefício , Humanos , Cuidados Paliativos/economia , Qualidade de Vida , Dosagem Radioterapêutica , Estados Unidos
20.
Clin Orthop Relat Res ; 466(3): 722-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18202898

RESUMO

Aneurysmal bone cysts are associated with a high rate of recurrence. Many aneurysmal bone cysts arise near open physes or articular cartilage in skeletally immature patients. Fear of damaging these structures could cause surgeons to curette the tumors less aggressively. We hypothesized location of an aneurysmal bone cyst in a periarticular or juxtaphyseal location would increase the risk of recurrence. We retrospectively studied 53 patients with aneurysmal bone cysts treated between 1989 and 2004. All patients had primary disease, and all patients underwent curettage of the lesion. Ten patients (18.9%) had local recurrence. Gender, race, and size did not predict recurrence; however 12 years of age or younger was associated with recurrence. Of the 19 juxtaphyseal cysts directly adjacent to an open physis, eight developed recurrence. Of the five periarticular cysts, two developed recurrence. The data suggest the risk of recurrence is highest in pediatric patients with juxtaphyseal or periarticular aneurysmal bone cysts. Meticulous treatment of these cysts is necessary, but we believe an overly aggressive approach that destroys the physis or articular cartilage is not warranted. Preservation of these structures remains a high priority of treatment.


Assuntos
Cistos Ósseos Aneurismáticos/cirurgia , Doenças das Cartilagens/cirurgia , Cartilagem Articular/cirurgia , Curetagem , Diáfises/cirurgia , Epífises/cirurgia , Adolescente , Adulto , Fatores Etários , Cistos Ósseos Aneurismáticos/diagnóstico por imagem , Doenças das Cartilagens/diagnóstico por imagem , Cartilagem Articular/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Coortes , Curetagem/efeitos adversos , Diáfises/diagnóstico por imagem , Diáfises/crescimento & desenvolvimento , Intervalo Livre de Doença , Epífises/diagnóstico por imagem , Epífises/crescimento & desenvolvimento , Feminino , Lâmina de Crescimento/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Radiografia , Recidiva , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
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