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1.
J Bone Joint Surg Am ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38574165

RESUMO

ABSTRACT: Promoting equitable health care is to ensure that everyone has access to high-quality medical services and appropriate treatment options. The definition of health equity often can be misinterpreted, and there are challenges in fully understanding the disparities and costs of health care and when measuring the outcomes of treatment. However, these topics play an important role in promoting health equity. The COVID-19 pandemic has made us more aware of profound health-care disparities and systemic racism, which, in turn, has prompted many academic medical centers and health-care systems to increase their efforts surrounding diversity, equity, and inclusion. Therefore, it is important to understand the problems that some patients have in accessing care, promote health care that is culturally competent, create policies and standard operating procedures (at the federal, state, regional, or institutional level), and be innovative to provide cost-effective care for the underserved population. All of these efforts can assist in promoting equitable care and thus result in a more just and healthier society.

2.
J Am Acad Orthop Surg ; 31(19): 1033-1039, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467400

RESUMO

INTRODUCTION: The adoption of technology-assisted total joint arthroplasty (TA-TJA) is increasing; however, the extent to which TA-TJA is used among orthopaedic trainees is unknown. The purpose of this study was to assess the current use of TA total knee arthroplasty (TKA) and total hip arthroplasty (THA) by orthopaedic residents and to evaluate resident perceptions toward TA-TJA in their surgical training. METHODS: In this cross-sectional study, an anonymous electronic survey was sent to all Accreditation Council for Graduate Medical Education-accredited orthopaedic surgery residency program coordinators to distribute to their PGY-2 to PGY-5 residents. The survey consisted of 24 questions, including resident demographics, utilization of TA-TJA in their training, and perceptions regarding TA-TJA. RESULTS: A total of 103 orthopaedic residents completed the survey, of whom 68.0% reported using TA-TJA at their institution. Of the residents using TA-TJA, 28.6% used TA for total TKA only, 71.4% used TA for both TKA and THA, and none used TA solely for THA. One-third of residents (33.3%) use TA for more than half of all TKAs conducted, whereas 57.0% use TA for <10% of all THAs conducted. Approximately half of all residents (49.5%) thought that training in TA-TJA should be required during residency, with no significant differences between junior and senior level residents ( P = 0.24). Most (82.0%) thought that trainees should be required to learn conventional TJA before learning TA-TJA. 63.0% thought that technology had a positive effect on their primary TJA training experience; however, 26.0% reported concern that their training conducting conventional TJA may be inadequate. DISCUSSION: This study demonstrates that most orthopaedic residents currently conduct TA-TJA and highlights notable differences in TJA training experiences. These results provide a platform for future work aimed at further optimizing TJA training in residency, particularly as technology continues to rapidly evolve and utilization of TA-TJA is projected to grow exponentially. LEVEL OF EVIDENCE: N/A, survey-based study.


Assuntos
Artroplastia do Joelho , Internato e Residência , Ortopedia , Humanos , Ortopedia/educação , Estudos Transversais , Educação de Pós-Graduação em Medicina
3.
Am J Sports Med ; 51(5): 1347-1355, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-34904902

RESUMO

Platelet-rich plasma (PRP) is a blood product that contains several growth factors and active proteins. PRP is thought to be used autologously to assist in the repair of injured tissues as well as to treat pain at the site of injury. The mechanism behind PRP in regenerative medicine has been well investigated and includes the identification and concentration of released growth factors and exosomes. The benefits of PRP have been highly recommended and are used widely in orthopaedics and sports medicine, including repair of injured skeletal muscle. This current report summarizes some of the more recent studies in the use of PRP as it relates to muscle healing, in both the in vitro and clinical arenas.


Assuntos
Doenças Musculares , Plasma Rico em Plaquetas , Medicina Esportiva , Humanos , Cicatrização/fisiologia , Músculo Esquelético/lesões , Doenças Musculares/terapia , Plasma Rico em Plaquetas/fisiologia
4.
J Bone Joint Surg Am ; 104(12): e52, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35133994

RESUMO

ABSTRACT: The ability to train an orthopaedic resident in all aspects of orthopaedics in 5 years has become increasingly difficult due to the growth in knowledge and techniques, work-hour restrictions, and reduced resident autonomy. It has become nearly universal for our residents to complete at least 1 subspecialty fellowship prior to entering practice. In some subspecialties, the skills necessary to practice competently have become difficult to master. Simply adding to the current length of training may not address these issues effectively and would add to the economic cost of residency training. Novel training pathways that allow residents to focus earlier and in greater depth on their intended subspecialty while maintaining general orthopaedic competencies can be created without lengthening training. It is time to initiate discussions about these possibilities.


Assuntos
Internato e Residência , Procedimentos Ortopédicos , Ortopedia , Educação de Pós-Graduação em Medicina , Bolsas de Estudo , Humanos , Ortopedia/educação
5.
J Cell Biochem ; 123(5): 843-851, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35064936

RESUMO

Fibrosis continues to challenge the regeneration and repair of the Orthopaedic tissues in states of injury or disease. The mechanism behind developmental fibrosis has been widely investigated in the last few decades. However, the current efficacy of treatment for existing fibrous scars remains insufficient from both basic research and clinical perspectives. Scarred fibrotic tissue impedes the physical function of affected local tissues and organs and may also be associated with abnormal pain conduction or tissue reinjury. It is necessary to discover the functional treatment for fibrous scars as this pathology is medically demanding to effected patients. The current article will review the mechanisms behind fibrosis formation and the treatment potential in the field of the musculoskeletal system, especially in the pathology and treatment of injured skeletal muscle and the development of osteoarthritis.


Assuntos
Cicatriz , Músculo Esquelético , Cicatriz/patologia , Fibrose , Humanos , Músculo Esquelético/patologia
6.
Iowa Orthop J ; 41(1): 69-75, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34552406

RESUMO

BACKGROUND: The purpose of this study was to compare the outcomes of pediatric patients who were surgically treated for a supracondylar humerus fracture by pediatric fellowship-trained orthopaedic surgeons (PFT) to the outcomes of those surgically treated by orthopaedic surgeons without pediatric fellowship training (NPFT). We hypothesized that there would be no differences in patient outcomes. METHODS: A retrospective review of pediatric patients who underwent surgical treatment for a supracondylar humerus fracture with closed reduction and percutaneous pinning (CRPP) or open reduction and percutaneous pinning (ORPP) at a regional level 1 trauma center over a 5-year period was performed. Exclusion criteria were inadequate follow up or absence of postoperative radiographs. RESULTS: A total of 201 patients met the inclusion criteria. Pediatric-fellowship trained orthopaedic surgeons treated 15.9% of patients. There was no statistically significant difference in carrying angle, Baumann's angle, or lateral rotation percentage at final follow up between PFT and NPFT groups. There was no permanent neurovascular compromise in either group. Patients treated by NPFT were more likely to return to the operating room for pin removal. CONCLUSION: In this study, there was no difference in radiographic outcomes for patients with supracondylar humerus fractures surgically treated by either group. This suggests that pediatric supracondylar humerus fractures may be appropriately treated in communities without a pediatric-fellowship trained orthopaedic surgeon without compromised outcomes.Level of Evidence: III.


Assuntos
Fraturas do Úmero , Cirurgiões Ortopédicos , Pinos Ortopédicos , Criança , Bolsas de Estudo , Humanos , Fraturas do Úmero/cirurgia , Úmero , Estudos Retrospectivos
7.
J Sports Med (Hindawi Publ Corp) ; 2020: 7059057, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376749

RESUMO

Skeletal muscle injuries occur often in athletics and in daily life. In minor injuries, muscles are able to regenerate completely and recover their functional capabilities. However, in the case of severe injuries, the injured muscle cannot recover to a functional level because of the formation of fibrous scar tissue. The physical barrier of scars is significantly challenged in both research and clinical treatment. Fibrous scar tissue not only limits cells' migration, but also contributes to normal tissue biomechanical properties. This scar formation creates an unsuitable environment for tissue structure resulting in frequent pain. Antifibrosis treatment is one of the major strategies used to augment muscle regeneration and accelerate its functional recovery. This review will discuss the currently available methods for improving muscle regeneration with a specific focus on antifibrosis applications. We also discussed several novel hypotheses and clinical applications in muscle fibrosis treatment currently in practice.

8.
HSS J ; 15(3): 276-285, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31624484

RESUMO

BACKGROUND: Rotator cuff tears are a common cause of disability. Some patients with massive and irreparable tears can develop cuff tear arthropathy (CTA), which makes management more challenging. QUESTIONS/PURPOSES: We sought to examine how orthopedists determine treatment for patients with CTA. Specifically, we investigated (1) the effect of patient age, symptoms, activity level, range of motion, and radiographic findings on the decision making of shoulder specialists and (2) the observer reliability of the Seebauer and Hamada grading systems. METHODS: Five shoulder surgeons were each sent 108 simulated patient cases. Each simulated patient had a different combination of factors, including patient age, symptoms, activity level, range of motion, and radiographs. Responders graded the radiographs and chose a treatment (non-operative, arthroscopic, hemiarthroplasty, or reverse total shoulder arthroplasty). Spearman's correlations and χ 2 tests were used to assess the relationship between factors and treatments. Sub-analysis was performed on surgical cases. An intra-class correlation (ICC) was used to assess observer agreement. RESULTS: The significant Spearman's correlations were symptoms (0.45), Hamada grade (0.38), patient age (0.34), and Seebauer type (0.29). In sub-analysis of operative cases, the significant correlations were Hamada grade (0.56), patient age (0.51), Seebauer type (0.46), activity level (-0.13). The χ 2 analysis was significant for all factors except activity level. The inter- and intraobserver reliabilities were, respectively, Seebauer type (0.59 and 0.63) and Hamada grade (0.58 and 0.65). Interobserver reliability for patient management was 0.44. CONCLUSION: When evaluating CTA, patient symptoms, radiographic grade, and patient age are the factors most strongly associated with the decision making of shoulder specialists. Additionally, the Seebauer and Hamada classifications had similar reliability and clinical utility. However, there was only fair agreement regarding treatment, which indicates that CTA management remains controversial.

9.
J Bone Joint Surg Am ; 100(14): e96, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30020134

RESUMO

Orthopaedic specialization has increased substantially over the past several decades, partly due to the desire of residents to improve their clinical expertise and to increase the likelihood that they will obtain a position with better compensation and a more balanced lifestyle. The American Academy of Orthopaedic Surgeons (AAOS) census data support this trend, demonstrating a substantial rise in the percentage of practicing orthopaedic surgeons who identify themselves as specialists rather than as general orthopaedic surgeons. There is a perception that a more narrowed scope of practice may prevent the current orthopaedic workforce from being able to adequately care for populations in rural areas of the United States. Additional consideration should be given to clearly defining the necessary knowledge and skills of a general orthopaedist in the twenty-first century, to understanding their role in musculoskeletal care, and to reevaluating residency educational experiences relative to their ability to prepare graduates to practice general orthopaedics independently.


Assuntos
Ortopedia/tendências , Especialização/tendências , Humanos , Estados Unidos
11.
J Bone Joint Surg Am ; 99(14): e78, 2017 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-28719565

RESUMO

Burnout, depression, suicidal ideation, and dissatisfaction with work-life balance have been reported in all medical specialties and at all stages of medical education and practice experience. Burnout consists of progressive emotional, attitudinal, and physical exhaustion. Physicians with burnout may treat patients as objects and feel emotionally depleted. Burnout is characterized by a loss of enthusiasm for work (emotional exhaustion), feelings of cynicism (depersonalization), and a low sense of personal accomplishment. The most complete study of emotional burnout among different medical specialties demonstrated that orthopaedic surgery is one of the specialties with the highest burnout rate. Qualitative descriptive studies are available. There was a 45.8% burnout rate among physicians in the U.S. in 2012, and a 2014 update suggested even higher rates. Burnout has a correlation with medical education. Burnout rates are similar to those in the general population when medical students enter school, and increase steadily through medical education prior to residency. Burnout rates in residents are high, reported to be between 41% and 74% across multiple specialties. This impacts our young physician workforce in orthopaedics. The purpose of this review is to provide the available information that characterizes burnout and addresses the issues inherent to preventing burnout, and to build awareness in orthopaedic surgeons. Wellness "goes beyond merely the absence of distress and includes being challenged, thriving, and achieving success in various aspects of personal and professional life." The challenge for the orthopaedic community is to develop interventions and strategies that are personalized to the individuals in this specialty.


Assuntos
Esgotamento Profissional/etiologia , Cirurgiões Ortopédicos/psicologia , Esgotamento Profissional/prevenção & controle , Escolha da Profissão , Educação em Saúde , Humanos , Internato e Residência , Satisfação no Emprego , Inabilitação do Médico/psicologia , Estudantes de Medicina/psicologia
12.
J Comput Assist Tomogr ; 39(6): 945-50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26418539

RESUMO

OBJECTIVE: Superolateral Hoffa's fat pad (SHFP) edema is a previously described magnetic resonance (MR) finding located between the patellar tendon and the lateral femoral condyle. The purpose of our study was to determine the prevalence and clinical significance of SHFP edema in female collegiate volleyball players. MATERIALS AND METHODS: Sixteen female collegiate volleyball players were consented for bilateral knee evaluations which consisted of history, physical examination and MR imaging. Each MR study was reviewed for the presence of SHFP edema, and 6 patellar maltracking measurements were done. These were tibial tuberosity-trochlear groove distance, patellar translation, lateral patellofemoral angle, trochlear depth, trochlear sulcus angle, and lateral trochlear inclination angle. RESULTS: A total of 16 athletes, 32 knees (16 girls; age range, 18-22 years; mean, 19.9) were enrolled in the study. Sixteen knees (50%) in 8 athletes had SHFP edema, with 100% bilaterality; 16 knees in 8 athletes had no evidence of SHFP edema (50%). Functional outcomes and physical examination findings were within normal limits for all athletes with no difference noted between SHFP edema-positive and -negative individuals. There was a statistically significant difference in the tibial tuberosity-trochlear groove distance, patellar translation, and patellofemoral angle (P value of < 0.001, 0.03 and 0.01, respectively) between the SHFP edema-positive and -negative individuals. CONCLUSIONS: Elite female volleyball athletes have a very high prevalence of SHFP edema, which is always bilateral. Although the exact etiology of SHFP edema remains inconclusive, it could potentially be a sensitive indicator of subtle patellar maltracking which cannot be distinguished by history and physical examination findings. Given the very high prevalence of SHFP edema and this being an asymptomatic finding, there is likely little clinical significance of this in majority of high-performance athletes.


Assuntos
Tecido Adiposo/patologia , Atletas , Edema/patologia , Articulação do Joelho/patologia , Voleibol , Adolescente , Adulto , Feminino , Fêmur , Humanos , Imageamento por Ressonância Magnética , Patela , Estudos Prospectivos , Adulto Jovem
13.
J Orthop Res ; 33(11): 1693-703, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25982892

RESUMO

Musculoskeletal injuries greatly affect the U.S. population and current clinical approaches fail to restore long-term native tissue structure and function. Tissue engineering is a strategy advocated to improve tendon healing; however, the field still needs to establish biological benchmarks for assessing the effectiveness of tissue-engineered structures. Investigating superior healing models, such as the MRL/MpJ, offers the opportunity to first characterize successful healing and then apply experimental findings to tissue-engineered therapies. This study seeks to evaluate the MRL/MpJ's healing response following a central patellar tendon injury compared to wildtype. Gene expression and histology were assessed at 3, 7, and 14 days following injury and mechanical properties were measured at 2, 5, and 8 weeks. Native patellar tendon biological and mechanical properties were not different between strains. Following injury, the MRL/MpJ displayed increased mechanical properties between 5 and 8 weeks; however, early tenogenic expression patterns were not different between the strains. Furthermore, expression of the cyclin-dependent kinase inhibitor, p21, was not different between strains, suggesting an alternative mechanism may be driving the healing response. Future studies will investigate collagen structure and alignment of the repair tissue and characterize the complete healing transcriptome to identify mechanisms driving the MRL/MpJ response.


Assuntos
Modelos Animais , Traumatismos dos Tendões , Cicatrização , Animais , Fenômenos Biomecânicos , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Feminino , Perfilação da Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Ligamento Patelar/lesões , Ligamento Patelar/fisiologia
15.
Orthopedics ; 37(3): e286-91, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24762157

RESUMO

Several predisposing conditions have been associated with complex regional pain syndrome I (CRPS I). The purpose of this study was to determine the relationship between a history of allergy/hypersensitivity reactions and CRPS I in orthopedic patients. Orthopedic patients with CRPS I (n=115) who experienced pain relief after a successful sympathetic nerve blockade were identified for study inclusion; a control group (n=115) matched to the CRPS I group by age, sex, and location of injury was also included. All patients in the study had an average age of 42 years. In the CRPS I group, all participants were Caucasian and the majority (80.8%) were women. The skin of patients with CRPS I was described as fair (57.7%), mottled (57.7%), or sensitive (80.8%). Of the patients with CRPS I, 78 (67.8%) reported a statistically significant history of allergies compared with the 39 (33.9%) patients in the control group (P<.0001). Patients with CRPS I who experienced complete pain relief for at least 1 month following a single sympathetic nerve block were asked to answer a questionnaire (n=35), and some then underwent immediate hypersensitivity testing using a skin puncture technique (n=26). Skin hypersensitivity testing yielded an 83.3% positive predictive value with an accuracy of 76.9%. Based on these results, a positive history for allergy/hypersensitivity reactions is a predisposing condition for CRPS I in this subset of orthopedic patients. These hypersensitivity reactions may prove important in gaining a better understanding in the pathophysiology of CRPS I as a regional pain syndrome.


Assuntos
Hipersensibilidade/epidemiologia , Artropatias/epidemiologia , Artropatias/cirurgia , Procedimentos Ortopédicos/estatística & dados numéricos , Dor/epidemiologia , Distrofia Simpática Reflexa/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Boston/epidemiologia , Comorbidade , Feminino , Humanos , Hipersensibilidade/diagnóstico , Incidência , Artropatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Dor/diagnóstico , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
16.
J Comput Assist Tomogr ; 38(4): 499-502, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24651756

RESUMO

OBJECTIVE: The trochlear cleft is a recently described vertically oriented, low-signal cartilage lesion centered in the trough of the trochlear cartilage. The purpose of our study was to determine the incidence of clefts in an at-risk group of athletes and correlate these findings with clinical and physical examination results. MATERIALS AND METHODS: Sixteen female collegiate volleyball players consented to bilateral knee evaluations, which consisted of history, physical examination, and magnetic resonance (MR) imaging. Two fellowship-trained musculoskeletal radiologists reviewed each MR study by consensus. The trochlear cartilage was considered to be either normal, at risk of developing a cleft, or meeting the previously described criteria for clefts. The Fisher exact test was used for categorical variables, and the Mann-Whitney U test was used for nonparametric continuous variable. RESULTS: A total of 16 athletes (32 knees; 16 women; age range, 18-22 years; mean, 19.9 years) were enrolled in the study. Four knees (13%) in 3 athletes were diagnosed with a trochlear cleft; 6 knees (19%) in 4 athletes had clefts or were at risk of developing clefts. Among those players with unilateral cartilage lesions, 67% had contralateral abnormalities (P = 0.0783). Functional outcomes and physical examination findings were within normal limits for all athletes, with no difference noted between those with and without clefts. CONCLUSIONS: Elite athletes have a much higher incidence of trochlear clefts than the general population and are at risk of bilateral disease. Clefts are likely to be an incidental finding at MR imaging for unrelated symptoms.


Assuntos
Atletas/estatística & dados numéricos , Cartilagem Articular/patologia , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/patologia , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Feminino , Humanos , Variações Dependentes do Observador , Voleibol , Adulto Jovem
17.
J Biomech ; 47(9): 2035-42, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-24210849

RESUMO

Tendon-to-bone healing following acute injury is generally poor and often fails to restore normal tendon biomechanical properties. In recent years, the murine patellar tendon (PT) has become an important model system for studying tendon healing and repair due to its genetic tractability and accessible location within the knee. However, the mechanical properties of native murine PT, specifically the regional differences in tissue strains during loading, and the biomechanical outcomes of natural PT-to-bone healing have not been well characterized. Thus, in this study, we analyzed the global biomechanical properties and regional strain patterns of both normal and naturally healing murine PT at three time points (2, 5, and 8 weeks) following acute surgical rupture of the tibial enthesis. Normal murine PT exhibited distinct regional variations in tissue strain, with the insertion region experiencing approximately 2.5 times greater strain than the midsubstance at failure (10.80±2.52% vs. 4.11±1.40%; mean±SEM). Injured tendons showed reduced structural (ultimate load and linear stiffness) and material (ultimate stress and linear modulus) properties compared to both normal and contralateral sham-operated tendons at all healing time points. Injured tendons also displayed increased local strain in the insertion region compared to contralateral shams at both physiologic and failure load levels. 93.3% of injured tendons failed at the tibial insertion, compared to only 60% and 66.7% of normal and sham tendons, respectively. These results indicate that 8 weeks of natural tendon-to-bone healing does not restore normal biomechanical function to the murine PT following injury.


Assuntos
Ligamento Patelar/fisiopatologia , Tíbia/fisiopatologia , Animais , Fenômenos Biomecânicos , Masculino , Camundongos , Ligamento Patelar/lesões , Ligamento Patelar/fisiologia , Ruptura , Tíbia/lesões , Tíbia/fisiologia , Cicatrização/fisiologia
18.
J Orthop Traumatol ; 14(4): 247-57, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23989900

RESUMO

BACKGROUND: Understanding the biological mechanisms of why certain fractures are at risk for delayed healing or nonunion requires translational animal models that take advantage of transgenic and other genetic manipulation technologies. Reliable murine nonunion models can be an important tool to understand the biology of nonunion. In this study, we report the results of a recently established model for creating critical defects that lead to atrophic nonunions based on a unique fracture fixation technique. MATERIALS AND METHODS: Subcritical (0.6 mm long) and critical (1.6 mm long) defects were created in femurs of 10-week-old double transgenic (Col1/Col2) mice and stabilized using a custom-designed plate and four screws. Four groups were used: normal, sham, subcritical, and critical. Histology (n = 3 for each group) was analyzed at 2 and 5 weeks, and micro-computed tomography (µCT) and torsional biomechanics (n = 12 for each group) were analyzed at 5 weeks. RESULTS: Subcritical defects showed healing at 2 weeks and were completely healed by 5 weeks, with biomechanical properties not significantly different from normal controls. However, critical defects showed no healing by histology or µCT. These nonunion fractures also displayed no torsional stiffness or strength in 10 of 12 cases. CONCLUSIONS: Our murine fracture model creates reproducible and reliable nonunions and can serve as an ideal platform for studying molecular pathways to contrast healing versus nonhealing events and for evaluating innovative therapeutic approaches to promote healing of a challenging osseous injury.


Assuntos
Fraturas do Fêmur/fisiopatologia , Fraturas do Fêmur/cirurgia , Consolidação da Fratura/fisiologia , Fraturas não Consolidadas/fisiopatologia , Fraturas não Consolidadas/cirurgia , Animais , Fenômenos Biomecânicos/fisiologia , Placas Ósseas , Parafusos Ósseos , Modelos Animais de Doenças , Fraturas do Fêmur/diagnóstico por imagem , Fraturas não Consolidadas/diagnóstico por imagem , Fixadores Internos , Masculino , Camundongos , Distribuição Aleatória , Torque , Microtomografia por Raio-X
20.
PLoS One ; 8(3): e59944, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23555841

RESUMO

The origin of cells that contribute to tendon healing, specifically extrinsic epitenon/paratenon cells vs. internal tendon fibroblasts, is still debated. The purpose of this study is to determine the location and phenotype of cells that contribute to healing of a central patellar tendon defect injury in the mouse. Normal adult patellar tendon consists of scleraxis-expressing (Scx) tendon fibroblasts situated among aligned collagen fibrils. The tendon body is surrounded by paratenon, which consists of a thin layer of cells that do not express Scx and collagen fibers oriented circumferentially around the tendon. At 3 days following injury, the paratenon thickens as cells within the paratenon proliferate and begin producing tenascin-C and fibromodulin. These cells migrate toward the defect site and express scleraxis and smooth muscle actin alpha by day 7. The thickened paratenon tissue eventually bridges the tendon defect by day 14. Similarly, cells within the periphery of the adjacent tendon struts express these markers and become disorganized. Cells within the defect region show increased expression of fibrillar collagens (Col1a1 and Col3a1) but decreased expression of tenogenic transcription factors (scleraxis and mohawk homeobox) and collagen assembly genes (fibromodulin and decorin). By contrast, early growth response 1 and 2 are upregulated in these tissues along with tenascin-C. These results suggest that paratenon cells, which normally do not express Scx, respond to injury by turning on Scx and assembling matrix to bridge the defect. Future studies are needed to determine the signaling pathways that drive these cells and whether they are capable of producing a functional tendon matrix. Understanding this process may guide tissue engineering strategies in the future by stimulating these cells to improve tendon repair.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Regulação da Expressão Gênica , Ligamento Patelar/lesões , Ligamento Patelar/metabolismo , Traumatismos dos Tendões/metabolismo , Actinas/metabolismo , Animais , Movimento Celular , Colágeno/metabolismo , Proteínas da Matriz Extracelular/biossíntese , Fibromodulina , Proteínas de Fluorescência Verde/metabolismo , Imuno-Histoquímica , Camundongos , Músculo Liso/metabolismo , Fenótipo , Análise de Componente Principal , Proteoglicanas/biossíntese , Tenascina/biossíntese , Fatores de Tempo , Cicatrização/genética
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