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1.
Curr Med Imaging ; 2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36876844

RESUMEN

BACKGROUND: Imaging studies play a crucial role in diagnosing femoroacetabular impingement (FAI), including plain radiography and Magnetic Resonance Imaging (MRI). FAI is a combined pathology of bony abnormality, labral and labrocartilagenous erosions. Surgical treatment for such cases has become more established and preoperative imaging is the roadmap that includes the assessment of labrum and articular cartilage. METHODS: During a period of 2 years, thirty-seven patients with a clinical diagnosis of FAI were retrospectively enrolled in this study, including 17 men and 20 women, aged 27-62 years. There were 22 right hips and 15 left hips. MRI was done for all patients to identify bony details, labral and chondral abnormalities and to exclude coexisting disorders. The imaging findings were compared with the arthroscopic data. RESULTS: 15 patients had Pincer FAI, 11 patients had CAM, and 11 patients had combined Cam/Pincer FAI. Labral tear was detected in 100 % of patients, 97 % had an anterosuperior labral tear. 82 % of patients had partial thickness cartilage lesions and 8 % had full thickness cartilage lesions. MRI had a sensitivity of 100 % compared to hip arthroscopy in detecting labral tear, 60 % in detecting cartilage erosion. CONCLUSION: Conventional hip MRI detects bony changes in FAI, type of impingement and associated labral tear and cartilage erosions in comparison to the hip arthroscopy.

2.
Case Rep Orthop ; 2022: 7956167, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36277026

RESUMEN

Pigmented villonodular synovitis (PVNS) is a benign proliferative disorder of synovium that surrounds the joints, tendon sheaths, and bursae. The elbow is rarely affected, making it difficult to establish treatment guidelines. This article relates on a case of a male patient who presented with elbow pain and decreased range of motion. Diagnosis was established with magnetic resonance imaging (MRI) and biopsy, followed by arthroscopic removal and synovectomy. The patient was pain free shortly after surgery and gained free range of motion after six weeks. At the most recent follow-up after six months, he remained clinically well. The most recent MRI did not reveal any recurrence.

3.
Mech Ageing Dev ; 198: 111539, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34242668

RESUMEN

The most common clinical manifestations of age-related musculoskeletal degeneration are osteoarthritis and osteoporosis, and these represent an enormous burden on modern society. Mesenchymal stromal cells (MSCs) have pivotal roles in musculoskeletal tissue development. In adult organisms, MSCs retain their ability to regenerate tissues following bone fractures, articular cartilage injuries, and other traumatic injuries of connective tissue. However, their remarkable regenerative ability appears to be impaired through aging, and in particular in age-related diseases of bones and joints. Here, we review age-related alterations of MSCs in musculoskeletal tissues, and address the underlying mechanisms of aging and senescence of MSCs. Furthermore, we focus on the properties of MSCs in osteoarthritis and osteoporosis, and how their changes contribute to onset and progression of these disorders. Finally, we consider current treatments that exploit the enormous potential of MSCs for tissue regeneration, as well as for innovative cell-free extracellular-vesicle-based and anti-aging treatment approaches.


Asunto(s)
Huesos , Cartílago Articular , Senescencia Celular/fisiología , Células Madre Mesenquimatosas/fisiología , Enfermedades Musculoesqueléticas , Osteoporosis , Regeneración/fisiología , Huesos/lesiones , Huesos/fisiología , Cartílago Articular/lesiones , Cartílago Articular/fisiología , Sistema Libre de Células , Humanos , Enfermedades Musculoesqueléticas/patología , Enfermedades Musculoesqueléticas/terapia , Osteoporosis/patología , Osteoporosis/terapia
4.
Case Rep Orthop ; 2021: 5519822, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33953999

RESUMEN

The anterior cruciate ligament (ACL) is a major stabilizing structure of the knee and one of the most common injured structures. The true incidence of ACL injury in children and adolescents is unknown, but recent studies suggest increased ACL injury rates, especially in the sports-participating population. The mechanism of injury, clinical examination, and diagnosis of ACL injury in children is the same as in adults. The main concerns in the management of pediatric ACL injuries are the open physes and the eventual long-term consequences of the ACL deficient knee. The ideal treatment strategy of pediatric ACL injuries is still controversial, because there is still no universal consensus for techniques, graft choices, and postoperative rehabilitation. We present a case of a 12-year-old male patient who underwent ACL reconstruction using an all-inside, physeal-sparing technique with a quadriceps tendon autograft and discuss the current treatment strategies.

5.
Am J Sports Med ; 47(3): 620-627, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30653344

RESUMEN

BACKGROUND: Given the unsatisfactory results and reported drawbacks of anterior cruciate ligament (ACL) reconstruction, such as donor site morbidity and the limited choice of grafts in revision surgery, new regenerative approaches based on tissue-engineering strategies are currently under investigation. PURPOSES: To determine (1) if a novel silk fiber-based ACL scaffold is able to initiate osteointegration in the femoral and tibial bone tunnels under in vivo conditions and (2) if the osteointegration process will be improved by intraoperatively seeding the scaffolds with the autologous stromal vascular fraction, an adipose-derived, stem cell-rich isolate from knee fat pads. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 33 sheep underwent ACL resection and were then randomly assigned to 2 experimental groups: ACL reconstruction with a scaffold alone and ACL reconstruction with a cell-seeded scaffold. Half of the sheep in each group were randomly chosen and euthanized 6 months after surgery and the other half at 12 months. To analyze the integration of the silk-based scaffold in the femoral and tibial bone tunnels, hard tissue histology and micro-computed tomography measurements were performed. RESULTS: Hard tissue histological workup showed that in all treatment groups, with or without the application of the autologous stromal vascular fraction, an interzone of collagen fibers had formed between bone and silk-based graft. This collagen-fiber continuity partly consisted of Sharpey fibers, comparable with tendon-bone healing known for autografts and allografts. Insertion sites were more broad based at 6 months and more concentrated on the slightly protruding, bony knoblike structures at 12 months. Histologically, no differences between the treatment groups were detectable. Analysis of micro-computed tomography measurements revealed a significantly higher tissue density for the cell-seeded scaffold group as compared with the scaffold-alone group in the tibial but not femoral bone tunnel after 12 months of implantation. CONCLUSION: The novel silk fiber-based scaffold for ACL regeneration demonstrated integration into the bone tunnels via the formation of a fibrous interzone similar to allografts and autografts. Histologically, additional cell seeding did not enhance osteointegration. No significant differences between 6 and 12 months could be detected. After 12 months, there was still a considerable amount of silk present, and a longer observation period is necessary to see if a true ligament-bone enthesis will be formed. CLINICAL RELEVANCE: ACL regeneration with a silk fiber-based scaffold with and without additional cell seeding may provide an alternative treatment option to current techniques of surgical reconstruction.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/fisiología , Ligamento Cruzado Anterior/cirugía , Oseointegración , Seda , Andamios del Tejido , Animales , Ligamento Cruzado Anterior/diagnóstico por imagen , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Lesiones del Ligamento Cruzado Anterior/cirugía , Femenino , Fémur/fisiología , Fémur/cirugía , Modelos Animales , Distribución Aleatoria , Ovinos , Tibia/fisiología , Tibia/cirugía , Trasplante Autólogo , Trasplante Homólogo , Microtomografía por Rayos X
6.
BMC Vet Res ; 14(1): 330, 2018 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-30400796

RESUMEN

BACKGROUND: The need for bone graft substitutes including those being developed to be applied together with new strategies of bone regeneration such as tissue engineering and cell-based approaches is growing. No large animal model of bone regeneration has been accepted as a standard testing model. Standardization may be the key to moving systematically towards better bone regeneration. This study aimed to establish a model of bone regeneration in the sheep that lends itself to strict standardization and in which a number of substances can be tested within the same animal. To this end the caudal border of the ovine scapula was used as a consistent bed of mineralized tissue that provided sufficient room for a serial alignment of multiple experimental drill holes. RESULTS: The findings show that for the sake of standardization, surgery should be restricted to the middle part of the caudal margin, an area at least 80 mm proximal from the Glenoid cavity, but not more than 140 mm away from it, in the adult female Land Merino sheep. A distance of 5 mm from the caudal margin should also be observed. CONCLUSIONS: This standardized model with defined uniform defects and defect sites results in predictable and reproducible bone regeneration processes. Defects are placed unilaterally in only one limb of the animal, avoiding morbidity in multiple limbs. The fact that five defects per animal can be evaluated is conducive to intra-animal comparisons and reduces the number of animals that have to be subject to experimentation.


Asunto(s)
Regeneración Ósea , Trasplante Óseo/veterinaria , Ovinos/cirugía , Animales , Trasplante Óseo/métodos , Modelos Animales de Enfermedad , Escápula/cirugía , Escápula/trasplante , Ovinos/crecimiento & desarrollo , Ovinos/fisiología
7.
Tissue Eng Part A ; 24(11-12): 1022-1033, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29373945

RESUMEN

Perfusion bioreactors have been an effective tool in bone tissue engineering. Improved nutrient delivery and the application of shear forces have stimulated osteoblast differentiation and matrix production, allowing for generation of large, clinically sized constructs. Differentiation of hypertrophic chondrocytes has been considered an alternative strategy for bone tissue engineering. We studied the effects of perfusion on hypertrophic chondrocyte differentiation, matrix production, and subsequent bone formation. Hypertrophic constructs were created by differentiation in chondrogenic medium (2 weeks) and maturation in hypertrophic medium (3 weeks). Bioreactors were customized to study a range of flow rates (0-1200 µm/s). During chondrogenic differentiation, increased flow rates correlated with cartilage matrix deposition and the presence of collagen type X. During induced hypertrophic maturation, increased flow rates correlated with bone template deposition and the increased secretion of chondroprotective cytokines. Following an 8-week implantation into the critical-size femoral defect in nude rats, nonperfused constructs displayed larger bone volume, more compact mineralized matrix, and better integration with the adjacent native bone. Therefore, although medium perfusion stimulated the formation of bone template in vitro, it failed to enhance bone regeneration in vivo. However, the promising results of the less developed template in the critical-sized defect warrant further investigation, beyond interstitial flow, into the specific environment needed to optimize hypertrophic chondrocyte-based constructs for bone repair.


Asunto(s)
Condrocitos/citología , Osteogénesis/fisiología , Animales , Huesos/citología , Cartílago/metabolismo , Diferenciación Celular/fisiología , Condrogénesis/fisiología , Perfusión , Ratas , Ratas Desnudas , Ingeniería de Tejidos/métodos
8.
Biomaterials ; 139: 202-212, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28622604

RESUMEN

Bone has innate ability to regenerate following injury. However, large and complex fractures exceed bone's natural repair capacity and result in non-unions, requiring external intervention to facilitate regeneration. One potential treatment solution, tissue-engineered bone grafts, has been dominated by recapitulating intramembranous ossification (bone formation by osteoblasts), although most serious bone injuries heal by endochondral ossification (bone formation by remodeling of hypertrophic cartilaginous anlage). The field has demonstrated that using endochondral ossification-based strategies can lead to bone deposition. However, stem cell differentiated hypertrophic chondrocytes, the key cell type in endochondral ossification, have not been studied for long bone defect repair. With translation in mind, we created tissue-engineered grafts using human adipose stem cells (ASC), a clinically relevant stem cell source, differentiated into hypertrophic chondrocytes in decellularized bone scaffolds, and implanted these grafts into critical-size femoral defects in athymic rats. Over 12 weeks of implantation, these grafts were compared to acellular scaffolds and grafts engineered using ASC-derived osteoblasts. Grafts engineered using hypertrophic chnodrocytes recapitulated endochondral ossification, as evidenced by the expression of genes and proteins associated with bone formation. Markedly enhanced bone deposition was associated with extensive bone remodeling and the formation of bone marrow, and with the presence of pro-regenerative M2 macrophages within the hypertrophic grafts. As a result, hypertrophic chondrocyte grafts bridged 7/8 defects, as compared to only 1/8 for osteoblast grafts and 3/8 acellular scaffolds. These data suggest that ASC-derived hypertrophic chondrocytes in osteogenic scaffolds can improve long bone repair.


Asunto(s)
Regeneración Ósea , Condrocitos/trasplante , Fracturas del Fémur/terapia , Fémur/patología , Ingeniería de Tejidos , Trasplantes/trasplante , Tejido Adiposo/citología , Análisis de Varianza , Animales , Diferenciación Celular , Condrogénesis , Modelos Animales de Enfermedad , Fémur/lesiones , Curación de Fractura , Humanos , Masculino , Osteoblastos/citología , Osteoclastos/citología , Osteogénesis , Ratas , Ratas Desnudas , Células Madre/metabolismo , Factores de Tiempo , Andamios del Tejido
9.
Sci Rep ; 7: 43425, 2017 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-28233833

RESUMEN

Nanocrystalline hydroxyapatite (HA) has good biocompatibility and the potential to support bone formation. It represents a promising alternative to autologous bone grafting, which is considered the current gold standard for the treatment of low weight bearing bone defects. The purpose of this study was to compare three bone substitute pastes of different HA content and particle size with autologous bone and empty defects, at two time points (6 and 12 months) in an ovine scapula drillhole model using micro-CT, histology and histomorphometry evaluation. The nHA-LC (38% HA content) paste supported bone formation with a high defect bridging-rate. Compared to nHA-LC, Ostim® (35% HA content) showed less and smaller particle agglomerates but also a reduced defect bridging-rate due to its fast degradation The highly concentrated nHA-HC paste (48% HA content) formed oversized particle agglomerates which supported the defect bridging but left little space for bone formation in the defect site. Interestingly, the gold standard treatment of the defect site with autologous bone tissue did not improve bone formation or defect bridging compared to the empty control. We concluded that the material resorption and bone formation was highly impacted by the particle-specific agglomeration behaviour in this study.


Asunto(s)
Cementos para Huesos/farmacología , Regeneración Ósea/efectos de los fármacos , Sustitutos de Huesos/farmacología , Durapatita/farmacología , Nanopartículas/química , Herida Quirúrgica/terapia , Animales , Cementos para Huesos/química , Sustitutos de Huesos/química , Trasplante Óseo/métodos , Modelos Animales de Enfermedad , Durapatita/química , Femenino , Osteogénesis/efectos de los fármacos , Tamaño de la Partícula , Escápula/diagnóstico por imagen , Escápula/efectos de los fármacos , Escápula/lesiones , Ovinos , Herida Quirúrgica/diagnóstico por imagen , Herida Quirúrgica/patología , Herida Quirúrgica/cirugía , Trasplante Autólogo , Microtomografía por Rayos X
10.
ISME J ; 11(3): 777-790, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27801904

RESUMEN

Plants associate through their roots with fungal assemblages that impact their abundance and productivity. Non-mycorrhizal endophytes constitute an important component of such fungal diversity, but their implication in ecosystem processes is little known. Using a selection of 128 root-endophytic strains, we defined functional groups based on their traits and plant interactions with potential to predict community assembly and symbiotic association processes. In vitro tests of the strains' interactions with Arabidopsis thaliana, Microthlaspi erraticum and Hordeum vulgare showed a net negative effect of fungal colonization on plant growth. The effects partly depended on the phylogenetic affiliation of strains, but also varied considerably depending on the plant-strain combination. The variation was partly explained by fungal traits shared by different lineages, like growth rates or melanization. The origin of strains also affected their symbioses, with endophytes isolated from Microthlaspi spp. populations being more detrimental to M. erraticum than strains from other sources. Our findings suggest that plant-endophyte associations are subject to local processes of selection, in which particular combinations of symbionts are favored across landscapes. We also show that different common endophytic taxa have differential sets of traits found to affect interactions, hinting to a functional complementarity that can explain their frequent co-existence in natural communities.


Asunto(s)
Endófitos/clasificación , Hongos/fisiología , Filogenia , Raíces de Plantas/microbiología , Plantas/microbiología , Ecosistema , Endófitos/genética , Hongos/genética , Fenotipo , Simbiosis
11.
Am J Sports Med ; 44(6): 1547-57, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26957219

RESUMEN

BACKGROUND: Because of ongoing problems with anterior cruciate ligament (ACL) reconstruction, new approaches in the treatment of ACL injuries, particularly strategies based on tissue engineering, have gained increasing research interest. To allow for ACL regeneration, a structured scaffold that provides a mechanical basis, has cells from different sources, and comprises mechanical as well as biological factors is needed. Biological materials, biodegradable polymers, and composite materials are being used and tested as scaffolds. The optimal scaffold for ACL regeneration should be biocompatible and biodegradable to allow tissue ingrowth but also needs to have the right mechanical properties to provide immediate mechanical stability. HYPOTHESES: The study hypotheses were that (1) a novel degradable silk fiber-based scaffold with mechanical properties similar to the native ACL will be able to initiate ligament regeneration after ACL resection and reconstruction under in vivo conditions and (2) additional cell seeding of the scaffold with autologous stromal vascular fraction-containing adipose-derived stem cells will increase regenerative activity. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 33 mountain sheep underwent ACL resection and randomization to 2 experimental groups: (1) ACL reconstruction with a scaffold alone and (2) ACL reconstruction with a cell-seeded scaffold. Histological evaluation of the intra-articular portion of the reconstructed/regenerated ligament was performed after 6 and 12 months. RESULTS: After 6 months, connective tissue surrounded the silk scaffold with ingrowth in some areas. The cell-seeded scaffolds had a significant lower silk content compared with the unseeded scaffolds and demonstrated a higher content of newly formed tissue. After 12 months, the density of the silk fibers decreased significantly, and the ingrowth of newly formed tissue increased in both groups. No differences between the 2 groups regarding silk fiber degradation and regenerated tissue were detected at 12 months. CONCLUSION: The novel silk fiber-based scaffold was able to stimulate ACL regeneration under in vivo conditions. Additional cell seeding led to increased tissue regeneration and decreased silk fiber content at 6 months, whereas these differences were not present at 12 months. CLINICAL RELEVANCE: ACL regeneration using a silk fiber-based scaffold with and without additional cell seeding may provide a new treatment option after joint injuries.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/fisiología , Regeneración , Seda , Andamios del Tejido , Animales , Femenino , Ovinos
13.
World J Orthop ; 6(1): 127-36, 2015 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-25621217

RESUMEN

Recent advancements in the field of musculoskeletal tissue engineering have raised an increasing interest in the regeneration of the anterior cruciate ligament (ACL). It is the aim of this article to review the current research efforts and highlight promising tissue engineering strategies. The four main components of tissue engineering also apply in several ACL regeneration research efforts. Scaffolds from biological materials, biodegradable polymers and composite materials are used. The main cell sources are mesenchymal stem cells and ACL fibroblasts. In addition, growth factors and mechanical stimuli are applied. So far, the regenerated ACL constructs have been tested in a few animal studies and the results are encouraging. The different strategies, from in vitro ACL regeneration in bioreactor systems to bio-enhanced repair and regeneration, are under constant development. We expect considerable progress in the near future that will result in a realistic option for ACL surgery soon.

14.
Acta Orthop ; 86(1): 92-9, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25175665

RESUMEN

BACKGROUND AND PURPOSE: We reviewed the current state of research on microRNAs in age-related diseases in cartilage and bone. METHODS: PubMed searches were conducted using separate terms to retrieve articles on (1) the role of microRNAs on aging and tissue degeneration, (2) specific microRNAs that influence cellular and organism senescence, (3) microRNAs in age-related musculoskeletal conditions, and (4) the diagnostic and therapeutic potential of microRNAs in age-related musculoskeletal conditions. RESULTS: An increasing number of studies have identified microRNAs associated with cellular aging and tissue degeneration. Specifically in regard to frailty, microRNAs have been found to influence the onset and course of age-related musculoskeletal conditions such as osteoporosis, osteoarthritis, and posttraumatic arthritis. Both intracellular and extracellular microRNAs may be suitable to function as diagnostic biomarkers. INTERPRETATION: The research data currently available suggest that microRNAs play an important role in orchestrating age-related processes and conditions of the musculoskeletal system. Further research may help to improve our understanding of the complexity of these processes at the cellular and extracellular level. The option to develop microRNA biomarkers and novel therapeutic agents for the degenerating diseases of bone and cartilage appears to be promising.


Asunto(s)
Envejecimiento/genética , Enfermedades de los Cartílagos/genética , Senescencia Celular/genética , MicroARNs/fisiología , Osteoartritis/genética , Osteoporosis/genética , Enfermedades Óseas/genética , Humanos
15.
Int Orthop ; 38(12): 2607-13, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25192687

RESUMEN

PURPOSE: Treatment of large-segmental bone defects still is a challenge in clinical routine. Application of gene-activated matrices (GAMs) based on fibrin, bone morphogenic protein (BMP) 2/7 plasmids and nonviral transfection reagents (cationic polymers) could be an innovative treatment strategy to overcome this problem. The aim of this study was to determine the therapeutic efficacy of fibrin GAMs with or without additional transfection reagents for BMP2 and 7 plasmid codelivery in a femur nonunion rat model. METHODS: In this experimental study, a critical-sized femoral defect was created in 27 rats. At four weeks after the surgery, animals were separated into four groups and underwent a second operation. Fibrin clots containing BMP2/7 plasmids with and without cationic polymer were implanted into the femoral defect. Fibrin clots containing recombinant human (rh) BMP2 served as positive and clots without supplement as negative controls. RESULTS: At eight weeks, animals that received GAMs containing the cationic polymer and BMP2/7 plasmids showed decreased bone volume compared with animals treated with GAMs and BMP2/7 only. Application of BMP2/7 plasmids in fibrin GAMs without cationic polymer led to variable results. Animals that received rhBMP2 protein showed increased bone volume, and osseous unions were achieved in two of six animals. CONCLUSIONS: Cationic polymers decrease therapeutic efficiency of fibrin GAM-based BMP2/7 plasmid codelivery in bone regeneration. Nonviral gene transfer of BMP2/7 plasmids needs alternative promoters (e.g. by sonoporation, electroporation) to produce beneficial clinical effects.


Asunto(s)
Terapia Genética/métodos , Osteogénesis/genética , Ingeniería de Tejidos/métodos , Animales , Proteína Morfogenética Ósea 2 , Proteínas Morfogenéticas Óseas , Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/genética , Modelos Animales de Enfermedad , Fibrina/fisiología , Técnicas de Transferencia de Gen , Masculino , Plásmidos , Ratas Sprague-Dawley , Proteínas Recombinantes , Factor de Crecimiento Transformador beta
16.
Hum Gene Ther Methods ; 25(1): 57-71, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24164605

RESUMEN

An ideal novel treatment for bone defects should provide regeneration without autologous or allogenous grafting, exogenous cells, growth factors, or biomaterials while ensuring spatial and temporal control as well as safety. Therefore, a novel osteoinductive nonviral in vivo gene therapy approach using sonoporation was investigated in ectopic and orthotopic models. Constitutive or regulated, doxycycline-inducible, bone morphogenetic protein 2 and 7 coexpression plasmids were repeatedly applied for 5 days. Ectopic and orthotopic gene transfer efficacy was monitored by coapplication of a luciferase plasmid and bioluminescence imaging. Orthotopic plasmid DNA distribution was investigated using a novel plasmid-labeling method. Luciferase imaging demonstrated an increased trend (61% vs. 100%) of gene transfer efficacy, and micro-computed tomography evaluation showed significantly enhanced frequency of ectopic bone formation for sonoporation compared with passive gene delivery (46% vs. 100%) dependent on applied ultrasound power. Bone formation by the inducible system (83%) was stringently controlled by doxycycline in vivo, and no ectopic bone formation was observed without induction or with passive gene transfer without sonoporation. Orthotopic evaluation in a rat femur segmental defect model demonstrated an increased trend of gene transfer efficacy using sonoporation. Investigation of DNA distribution demonstrated extensive binding of plasmid DNA to bone tissue. Sonoporated animals displayed a potentially increased union rate (33%) without extensive callus formation or heterotopic ossification. We conclude that sonoporation of BMP2/7 coexpression plasmids is a feasible, minimally invasive method for osteoinduction and that improvement of bone regeneration by sonoporative gene delivery is superior to passive gene delivery.


Asunto(s)
Proteína Morfogenética Ósea 2/genética , Proteína Morfogenética Ósea 7/genética , Técnicas de Transferencia de Gen , Vectores Genéticos/metabolismo , Animales , Proteína Morfogenética Ósea 2/metabolismo , Proteína Morfogenética Ósea 7/metabolismo , Regeneración Ósea , Huesos/diagnóstico por imagen , Doxiciclina/farmacología , Femenino , Fracturas Óseas/terapia , Expresión Génica/efectos de los fármacos , Terapia Genética , Vectores Genéticos/genética , Vectores Genéticos/uso terapéutico , Masculino , Ratones , Ratones Desnudos , Músculo Esquelético/patología , Osteogénesis , Ratas , Ratas Sprague-Dawley , Sonicación , Nicho de Células Madre , Tomografía Computarizada por Rayos X
17.
Int Orthop ; 37(11): 2305-11, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24045909

RESUMEN

PURPOSE: The purpose of this study was to evaluate in a sheep model the biomechanical performance of augmented and nonaugmented primary repair of the anterior cruciate ligament (ACL) following transection at the femoral end during a 12-month postoperative observation. METHODS: Forty sheep were randomly assigned to nonaugmented or augmented primary ACL repair using a polyethylene terephthalate (PET) band. At two, six, 16, 26 and 52 weeks postoperatively four sheep in each group were sacrificed and biomechanical testing performed. RESULTS: Compared with nonaugmented primary ACL repair, the PET-augmented repair demonstrated superior biomechanical results from 16 weeks postoperatively onwards in terms of anterioposterior (AP) laxity, tensile strength and ligament stiffness. The augmentation device works as a stress shield during the ligament healing process. The nonaugmented ACL repair also resulted in ligament healing, but the biomechanical properties were at a significantly lower level. CONCLUSION: These results support the previously reported histological findings following augmented primary ACL repair. This animal study on the healing capacity of the ACL may provide some important contributions to how primary healing in certain types of ruptures can be achieved. CLINICAL RELEVANCE: I.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior/instrumentación , Reconstrucción del Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/fisiología , Ligamento Cruzado Anterior/cirugía , Fenómenos Biomecánicos/fisiología , Animales , Lesiones del Ligamento Cruzado Anterior , Femenino , Modelos Animales , Periodo Posoperatorio , Rotura/cirugía , Ovinos , Resistencia a la Tracción/fisiología , Factores de Tiempo , Cicatrización de Heridas/fisiología
18.
Am J Sports Med ; 39(1): 173-9, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20807859

RESUMEN

BACKGROUND: The posterolateral corner of the knee consists of static and dynamic stabilizing structures. Knee injuries often include the posterolateral structures. The popliteus muscle-tendon unit is known as the major dynamic stabilizer of the posterolateral corner. HYPOTHESIS: The dynamic stabilization of the posterolateral structures of the knee via the popliteus muscle-tendon unit during a squatting exercise follows a constant activation pattern. STUDY DESIGN: Controlled laboratory study. METHODS: Within the pilot study, 6 volunteers performed 2 exercises to verify the electrode position scheme and to analyze cross-talk. In the main study 2 static exercises (standing and standing with knees flexed 90°) and 2 dynamic exercises (isolated popliteus muscle activation and squats) were recorded in 17 volunteers. Electromyograms were obtained of the popliteus, medial and lateral gastrocnemius, and quadriceps muscles. Knee angle-related muscle activity was recorded. RESULTS: In the pilot study it was assumed that the chosen electrode position allowed selective measurement of popliteus muscle activity. In the main study the mean popliteus onset angle was 43° ± 14° of flexion; activity lasted through the reversal point of the squat to 58° ± 21° of flexion during extension movement. Popliteus activity during all testing cycles revealed that the activity in the standing position is the smallest. The highest activity was recorded during the squat and the popliteus muscle-tendon unit exercise. CONCLUSION: This study demonstrates an activation pattern of the popliteus muscle-tendon unit with high interindividual differences in the onset angles. A constant activation during the reversal phase of the squatting exercise could be observed. CLINICAL RELEVANCE: Reconstructive procedures of the posterolateral structures often include reconstruction of the popliteus muscle-tendon unit. Reconstructive procedures are usually done in a static manner, thus not addressing the dynamic stabilizing structure in a true functional way. The findings of the current study may be a useful contribution to the ongoing discussion of this topic.


Asunto(s)
Electromiografía , Rodilla/fisiología , Músculo Esquelético/fisiología , Adulto , Ejercicio Físico/fisiología , Femenino , Humanos , Masculino , Adulto Joven
19.
Injury ; 42(1): 57-62, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20553680

RESUMEN

BACKGROUND: Appropriate triage of the trauma patient is essential to ensure prompt access to definitive care. Many trauma centres use a "tiered" trauma call protocol with the intention of providing a match between the facility's resources and the needs of the patient. This study describes the incidence and impact of undertriage on the trauma patient in the context of an Australian level 1 trauma centre with a tiered trauma call system. METHODS: This was a retrospective analysis of prospective data collected through the Trauma Registry. Undertriage was defined as sustaining an injury severity score greater than 15 and receiving a non optimal response (i.e., trauma standby call or no call). The level of association between outcome measures (such as LOS in ED, time to OT) and the level of trauma call the patient received was assessed using a general linear model, controlling for injury severity and haemodynamic stability. RESULTS: Between February 2004 and November 2008, 5233 patients meeting trauma criteria presented to the study hospital. There was an undertriage rate of 42% and overtriage rate of 21%. Patients were more likely to be undertriaged if they were older, self-presented, their cause of injury was assault or their head or chest were their most severely injured body region. Undertriaged patients had a significantly longer LOS in the ED (2 h) than appropriately triaged patients. CONCLUSION: The implementation of a tiered trauma call system resulted in significant undertriage,especially if the patient was older, had been assaulted or had a head/chest injury. Undertriaged patients experienced delay to definitive care. This study has highlighted the importance of compliance with trauma team activation criteria, trauma monitoring and evaluation.


Asunto(s)
Puntaje de Gravedad del Traumatismo , Sistema de Registros/estadística & datos numéricos , Centros Traumatológicos/estadística & datos numéricos , Triaje/estadística & datos numéricos , Heridas y Lesiones/clasificación , Australia , Femenino , Humanos , Masculino , Estudios Retrospectivos , Análisis de Sistemas , Centros Traumatológicos/organización & administración , Triaje/organización & administración , Heridas y Lesiones/epidemiología
20.
Australas J Ageing ; 29(3): 117-25, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20815841

RESUMEN

AIM: To examine fall-related hospitalised morbidity in New South Wales (NSW) and to describe the pattern of fall-related major trauma presentations at a Level 1 Trauma Centre in NSW for younger and older fallers. METHODS: Fall-related injuries were identified in the NSW Admitted Patients Data Collection during 1 July 1999-30 June 2008 and the trauma registry of the NSW St George Public Hospital during 1 January 2006-6 December 2008. RESULTS: There were 434 138 hospitalisations and 862 fall-related trauma presentations. Older fallers had a higher incidence of hospitalisation, being more likely to fall on the same level during general activities at home, injuring their hip or thigh. Older fallers were also more likely to have an Injury Severity Score > 9, undergo physiotherapy and stay in hospital for >1 day than younger fallers. CONCLUSION: Falls, particularly for older individuals, are an important cause of serious injury, representing a considerable burden in terms of hospitalised morbidity.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Envejecimiento , Hospitalización/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Distribución de Chi-Cuadrado , Humanos , Tiempo de Internación/estadística & datos numéricos , Persona de Mediana Edad , Nueva Gales del Sur/epidemiología , Modalidades de Fisioterapia/estadística & datos numéricos , Sistema de Registros , Análisis de Regresión , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Heridas y Lesiones/terapia , Adulto Joven
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