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1.
Teach Learn Med ; : 1-17, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37431925

RESUMO

Construct: In 2021, Murry et al. put forward a model of Indigenous mentorship within the health sciences based on the behaviors of Indigenous mentors toward their Indigenous mentees. This study explored mentees' endorsements and/or criticisms of the IM model and how IM constructs and behaviors described in the model benefited them. Background: Models of Indigenous mentorship have been developed previously yet have not yet been empirically examined, restricting our ability to measure or make claims as to their consequences, correlates, and antecedents. Approach: Interviews with six Indigenous mentees asked about their: 1) resonance with the model, 2) stories related to mentors' behaviors, 3) perceived benefits of their mentors' behaviors on their journey, and 4) components they felt were missing from the model. Data were analyzed using qualitative content analysis. Findings: Overall, the model resonated with participants. Mentees told stories about mentors engaging in the IM constructs practicing relationalism most frequently, followed by fostering Indigenous identity development, utilizing a mentee-centered focus, and imbuing criticality, advocacy, and abiding by Indigenous ethics. Benefits included improved career and work attitudes, motivation, and overall well-being, engaging in helping behaviors, and enhanced criticality. Recommendations to expand the model included incorporating: 1) additional mentor behaviors (e.g., transference of traditional knowledge), 2) higher-order dimensions (e.g., the impact of the institution), 3) specific mentee characteristics (e.g., age and gender), and 4) additional types of mentoring relationships (e.g., peer, multiple mentors). Conclusions: This study showed that Murry et al.'s model resonated with primary stakeholders (i.e., Indigenous mentees), that Indigenous mentorship behaviors have perceived consequences that are important for adjustment, and ways the model is limited or mis-specified. This information can inform mentor practices, selection and support, and program evaluation.

2.
Artigo em Inglês | MEDLINE | ID: mdl-35620526

RESUMO

The American Board of Orthopaedic Surgery (ABOS) is the national organization charged with defining education standards for graduate medical education in orthopaedic surgery. The purpose of this article is to describe initiatives taken by the ABOS to develop assessments of competency of residents to document their progress toward the independent practice of orthopaedic surgery and provide feedback for improved performance during training. These initiatives are called the ABOS Knowledge, Skills, and Behavior Program. Web-based assessment tools have been developed and validated to measure competence. These assessments guide resident progress through residency education and better define the competency level by the end of training. The background and rationale for these initiatives and how they serve as steps toward competency-based education in orthopaedic residency education in the United States will be reviewed with a vision of a hybrid of time and competency-based orthopaedic residency education that will remain 5 years in length, with residents assessed using standardized tools.

4.
J Am Acad Orthop Surg ; 29(24): e1370-e1377, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34874336

RESUMO

INTRODUCTION: Previous research shows a correlation in performance between the Orthopaedic In-Training Examination (OITE) and the American Board of Orthopaedic Surgery (ABOS) Certifying Examination Part I; however, these studies are not current, with the most recent data from 2009. The purpose of this study was to update the relationship between the OITE and ABOS Part I scores with the five most recent nationwide cohorts of Part I scores and their corresponding OITE scores. METHODS: The American Academy of Orthopaedic Surgeons provided the results for each resident taking the OITE from 2013 to 2017. The ABOS provided the results for each resident taking the Part I examination from 2014 to 2018. These two datasets were matched at the individual level and analyzed. RESULTS: Between 2014 and 2018, 3,502 first-time test-takers were present for the ABOS Part I Examination. A 96.6% pass rate was noted (3,383 of 3,502). A statistically significant correlation between the OITE score and ABOS Part I score was observed at all levels of training: postgraduate year (PGY) 1 r = 0.380, PGY2 r = 0.463, PGY3 r = 0.498, PGY4 r = 0.504, and PGY5 r = 0.504 (P < 0.001 for all correlations). CONCLUSION: The OITE scores continue to correlate with the ABOS scores and the pass rate for the ABOS with moderate strength correlation. However, although a correlation of the examinations exists when evaluated as a group, the predictive value of the OITE for passing the Part I examination for any specific individual is far from perfect. Individuals with PGY5 OITE percentile scores less than 10 pass the Part I examination, and individuals with PGY5 OITE percentile scores greater than 90 fail the Part I examination.


Assuntos
Internato e Residência , Procedimentos Ortopédicos , Ortopedia , Competência Clínica , Avaliação Educacional , Humanos , Ortopedia/educação , Estados Unidos
5.
Artigo em Inglês | MEDLINE | ID: mdl-33244509

RESUMO

BACKGROUND: The purpose of this study was to determine the feasibility and evaluate the effectiveness of the American Board of Orthopaedic Surgery Behavior Tool (ABOSBT) for measuring professionalism. METHODS: Through collaboration between the American Board of Orthopaedic Surgery and American Orthopaedic Association's Council of Residency Directors, 18 residency programs piloted the use of the ABOSBT. Residents requested assessments from faculty at the end of their clinical rotations, and a 360° request was performed near the end of the academic year. Program Directors (PDs) rated individual resident professionalism (based on historical observation) at the outset of the study, for comparison to the ABOSBT results. RESULTS: Nine thousand eight hundred ninety-two evaluations were completed using the ABOSBT for 449 different residents by 1,012 evaluators. 97.6% of all evaluations were scored level 4 or 5 (high levels of professional behavior) across all of the 5 domains. In total, 2.4% of all evaluations scored level 3 or below reflecting poorer performance. Of 431 residents, the ABOSBT identified 26 of 32 residents who were low performers (2 or more < level 3 scores in a domain) and who also scored "below expectations" by the PD at the start of the pilot project (81% sensitivity and 57% specificity), including 13 of these residents scoring poorly in all 5 domains. Evaluators found the ABOSBT was easy to use (96%) and that it was an effective tool to assess resident professional behavior (81%). CONCLUSIONS: The ABOSBT was able to identify 2.4% low score evaluations (

6.
J Am Acad Orthop Surg ; 28(11): e465-e468, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32324709

RESUMO

The COVID-19 pandemic has disrupted every aspect of society in a way never previously experienced by our nation's orthopaedic surgeons. In response to the challenges the American Board of Orthopaedic Surgery has taken steps to adapt our Board Certification and Continuous Certification processes. These changes were made to provide flexibility for as many Candidates and Diplomates as possible to participate while maintaining our high standards. The American Board of Orthopaedic Surgery is first and foremost committed to the safety and well-being of our patients, physicians, and families while striving to remain responsive to the changing circumstances affecting our Candidates and Diplomates.


Assuntos
Controle de Doenças Transmissíveis/métodos , Infecções por Coronavirus , Saúde Ocupacional , Procedimentos Ortopédicos/educação , Pandemias/prevenção & controle , Segurança do Paciente , Pneumonia Viral , COVID-19 , Competência Clínica/normas , Educação Médica Continuada/normas , Educação de Pós-Graduação em Medicina/normas , Feminino , Humanos , Masculino , Pandemias/estatística & dados numéricos , Gestão da Segurança , Conselhos de Especialidade Profissional/normas , Estados Unidos
7.
Instr Course Lect ; 69: 291-316, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32017734

RESUMO

In this chapter, the authors describe hand conditions that can be "bad actors" and provide specific clues to identify these problems, and strategies to assess and successfully treat them. We will review pediatric and adult hand fractures, fractures of the distal radius, and trigger digits.


Assuntos
Fraturas do Rádio , Traumatismos do Punho , Articulação do Punho , Adulto , Criança , Fixação Interna de Fraturas , Humanos , Punho
8.
J Pediatr Orthop ; 40(5): 223-227, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31834237

RESUMO

BACKGROUND: Pediatric supracondylar humerus fractures are the most common elbow injury in children, accounting for 12% to 17% of all childhood fractures. A lack of information exists regarding complication rates on the basis of fellowship status and geography. METHODS: The American Board of Orthopaedic Surgery (ABOS) Part-II database was used to identify candidates who performed either percutaneous or open treatment of humeral supracondylar or transcondylar fractures between 2002 and 2016 on patients aged 0 to 12 years. Candidates were categorized by fellowship training experience. Information analyzed included fellowship status, surgical procedure, complications, and geographic location of treatment. Data were analyzed utilizing the χ and Fischer exact tests and were considered significant if P≤0.05. RESULTS: A total of 9169 cases (mean, 5.36+2.27 y; range, 0 to 12) were identified between 2002 and 2016, 8615 of which were treated with closed reduction and percutaneous pinning, whereas 554 were treated with an open procedure. The 5 most common fellowships treating these fractures were listed as pediatrics (4106), sports medicine (1004), none (912), trauma (732), and hand/upper extremity (543). Pediatrics performed the highest number of open reduction and internal fixation (ORIF), however, reported the statistically lowest percentage of ORIF. A statistically significant difference was identified between surgical complication rates and fellowship specialties, with pediatrics having the lowest complication rate (7.0%), followed by no fellowship (8.2%), trauma (9.0%), sports medicine (9.8%), and hand/upper extremity (11.2%) (P<0.001). This significant difference was also present when analyzing closed reduction and percutaneous pinning alone (P=0.002), however, not with the analysis of ORIF. CONCLUSIONS: Early career pediatric fellowship-trained orthopaedic surgeons are more likely to treat pediatric supracondylar humerus fractures. Overall, although they treat more patients with ORIF than any other group, their percentage treated with ORIF is statistically the lowest. A significant difference in reported complication rates was found to be associated with specific fellowship training, with pediatric fellowship-trained surgeons having the fewest complications and foot/ankle fellowship-trained surgeons associated with the highest rate of reported surgical complications. LEVEL OF EVIDENCE: Level III-retrospective cohort study.


Assuntos
Redução Fechada/estatística & dados numéricos , Bolsas de Estudo/estatística & dados numéricos , Fixação Interna de Fraturas/estatística & dados numéricos , Fraturas do Úmero/cirurgia , Redução Aberta/estatística & dados numéricos , Ortopedia/estatística & dados numéricos , Criança , Pré-Escolar , Bases de Dados Factuais , Fixação Interna de Fraturas/efeitos adversos , Humanos , Lactente , Recém-Nascido , Redução Aberta/efeitos adversos , Ortopedia/educação , Pediatria/educação , Pediatria/estatística & dados numéricos , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Medicina Esportiva/estatística & dados numéricos , Traumatologia/educação , Traumatologia/estatística & dados numéricos , Estados Unidos
9.
J Biomech ; 90: 143-148, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31101433

RESUMO

Rotator cuff stress during upper limb weight-bearing lifts presumably contribute to rotator cuff disease, which is the most common cause of shoulder pain in individuals with tetraplegia. Elbow extension strength appears to be a key determinant of rotator cuff stress during upper limb weight-bearing lifts since individuals with paraplegia who generate greater elbow extensor moments experience lower rotator cuff stress relative to individuals with tetraplegia. Biceps-to-triceps transfer surgery can increase elbow extension strength in individuals with tetraplegia. The purpose of this study was to determine whether active elbow extension via biceps transfer decreases rotator cuff stress during weight-bearing lifts in individuals with tetraplegia. A forward dynamics computational framework was used to estimate muscle stress during the lift; stress was computed as muscle force divided by the peak isometric muscle force. We hypothesized that rotator cuff stresses would be lower in simulated lifting with biceps transfer relative to simulated lifting without biceps transfer. We found that limited elbow extension strength in individuals with tetraplegia, regardless of whether elbow strength is enabled via biceps transfer or is residual after spinal cord injury, results in muscle stresses exceeding 85% of the peak isometric muscle stress in the supraspinatus, infraspinatus, and teres minor. The rotator cuff stresses we estimated suggest that performance of weight-bearing activities should be minimized or assisted in order to reduce the risk for shoulder pain. Our results also indicate that biceps transfer is unlikely to decrease rotator cuff stress during weight-bearing lifts in individuals with tetraplegia.


Assuntos
Músculo Esquelético/fisiologia , Quadriplegia/fisiopatologia , Manguito Rotador/fisiologia , Extremidade Superior/fisiologia , Suporte de Carga/fisiologia , Adulto , Simulação por Computador , Feminino , Humanos , Masculino , Modelos Biológicos
10.
J Am Acad Orthop Surg ; 26(16): e333-e341, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30024421

RESUMO

Individuals with tetraplegia face many obstacles with activities of daily living. Although approximately 65% to 75% of individuals with tetraplegia would benefit from upper extremity surgery that could make many of their activities of daily living more spontaneous, only 14% of patients who are surgical candidates undergo tendon transfer procedures. A good surgical candidate has an injury at one of the cervical spine levels and an International Classification for Surgery of the Hand in Tetraplegia group of 1 or better, has functional goals, and is committed to the postoperative rehabilitation process. Surgery primarily consists of tendon transfers, tenodesis, and arthrodesis to restore elbow extension and hand pinch, grasp, and release. Nerve transfers and functional electrical stimulation are also options for treatment.


Assuntos
Artrodese/métodos , Quadriplegia/cirurgia , Transferência Tendinosa/métodos , Tenodese/métodos , Extremidade Superior/cirurgia , Atividades Cotidianas , Mãos/cirurgia , Humanos , Quadriplegia/fisiopatologia , Extremidade Superior/fisiopatologia
11.
Instr Course Lect ; 66: 117-139, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28594493

RESUMO

Hand fractures are among the most common skeletal injuries. Approximately 150,000 hand fractures occur in the United States each year. The management of hand fractures consists of reduction, immobilization, and rehabilitation to return patients to their preinjury status. Hand fractures are managed by restoring articular congruity, reducing malrotation and angulation of the fracture, and maintaining the reduction, all of which should be accomplished with minimal surgical intervention. Surgeons must assess concomitant soft-tissue injuries and respect the soft tissues during the surgical management of hand fractures. Fractures through the metaphyseal bone at the base and neck will heal more quickly than fractures through the diaphyseal bone of the shaft, which makes provisional fixation of metaphyseal fractures more practical compared with provisional fixation of diaphyseal fractures. The fracture pattern determines the most practical type of fixation. Patterns of angulation should be anticipated and corrected during reduction. More rigid fixation is required if substantial comminution and bone loss are present. Bone loss also indicates a high-energy injury, which likely indicates more substantial soft-tissue injury. As the number of injured structures increases, the likelihood of full function after rehabilitation decreases.


Assuntos
Fixação Interna de Fraturas , Fraturas Ósseas , Fraturas Cominutivas , Traumatismos da Mão , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Fraturas Cominutivas/diagnóstico por imagem , Fraturas Cominutivas/cirurgia , Traumatismos da Mão/diagnóstico por imagem , Traumatismos da Mão/cirurgia , Humanos , Radiografia
12.
J Biomech ; 58: 97-104, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28552412

RESUMO

The wrist is essential for hand function. Yet, due to the complexity of the wrist and hand, studies often examine their biomechanical features in isolation. This approach is insufficient for understanding links between orthopaedic surgery at the wrist and concomitant functional impairments at the hand. We hypothesize that clinical reports of reduced force production by the hand following wrist surgeries can be explained by the surgically-induced, biomechanical changes to the system, even when those changes are isolated to the wrist. This study develops dynamic simulations of lateral pinch force following two common surgeries for wrist osteoarthritis: scaphoid-excision four-corner fusion (SE4CF) and proximal row carpectomy (PRC). Simulations of lateral pinch force production in the nonimpaired, SE4CF, and PRC conditions were developed by adapting published models of the nonimpaired wrist and thumb. Our simulations and biomechanical analyses demonstrate how the increased torque-generating requirements at the wrist imposed by the orthopaedic surgeries influence force production to such an extent that changes in motor control strategy are required to generate well-directed thumb-tip end-point forces. The novel implications of our work include identifying the need for surgeries that optimize the configuration of wrist axes of rotation, rehabilitation strategies that improve post-operative wrist strength, and scientific evaluation of motor control strategies following surgery. Our simulations of SE4CF and PRC replicate surgically-imposed decreases in pinch strength, and also identify the wrist's torque-generating capacity and the adaptability of muscle coordination patterns as key research areas to improve post-operative hand function.


Assuntos
Mãos/fisiopatologia , Modelos Biológicos , Osteoartrite/fisiopatologia , Fenômenos Biomecânicos , Simulação por Computador , Mãos/cirurgia , Humanos , Procedimentos Ortopédicos , Osteoartrite/cirurgia , Torque
13.
PLoS One ; 12(3): e0171141, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28253262

RESUMO

The biceps or the posterior deltoid can be transferred to improve elbow extension function for many individuals with C5 or C6 quadriplegia. Maximum strength after elbow reconstruction is variable; the patient's ability to voluntarily activate the transferred muscle to extend the elbow may contribute to the variability. We compared voluntary activation during maximum isometric elbow extension following biceps transfer (n = 5) and deltoid transfer (n = 6) in three functional postures. Voluntary activation was computed as the elbow extension moment generated during maximum voluntary effort divided by the moment generated with full activation, which was estimated via electrical stimulation. Voluntary activation was on average 96% after biceps transfer and not affected by posture. Individuals with deltoid transfer demonstrated deficits in voluntary activation, which differed by posture (80% in horizontal plane, 69% in overhead reach, and 70% in weight-relief), suggesting inadequate motor re-education after deltoid transfer. Overall, individuals with a biceps transfer better activated their transferred muscle than those with a deltoid transfer. This difference in neural control augmented the greater force-generating capacity of the biceps leading to increased elbow extension strength after biceps transfer (average 9.37 N-m across postures) relative to deltoid transfer (average 2.76 N-m across postures) in our study cohort.


Assuntos
Braço , Músculo Deltoide , Quadriplegia/cirurgia , Transferência Tendinosa/métodos , Adolescente , Adulto , Articulação do Cotovelo/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quadriplegia/fisiopatologia , Amplitude de Movimento Articular , Resultado do Tratamento , Adulto Jovem
14.
Neurorehabil Neural Repair ; 31(4): 354-363, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27932695

RESUMO

BACKGROUND: Following biceps transfer to enable elbow extension in individuals with tetraplegia, motor re-education may be facilitated by greater corticomotor excitability. Arm posture modulates corticomotor excitability of the nonimpaired biceps. If arm posture also modulates excitability of the transferred biceps, posture may aid in motor re-education. OBJECTIVE: Our objective was to determine whether multi-joint arm posture affects corticomotor excitability of the transferred biceps similar to the nonimpaired biceps. We also aimed to determine whether corticomotor excitability of the transferred biceps is related to elbow extension strength and muscle length. METHODS: Corticomotor excitability was assessed in 7 arms of individuals with tetraplegia and biceps transfer using transcranial magnetic stimulation and compared to biceps excitability of nonimpaired individuals. Single-pulse transcranial magnetic stimulation was delivered to the motor cortex with the arm in functional postures at rest. Motor-evoked potential amplitude was recorded via surface electromyography. Elbow moment was recorded during maximum isometric extension trials, and muscle length was estimated using a biomechanical model. RESULTS: Arm posture modulated corticomotor excitability of the transferred biceps differently than the nonimpaired biceps. Elbow extension strength was positively related and muscle length was unrelated, respectively, to motor-evoked potential amplitude across the arms with biceps transfer. CONCLUSIONS: Corticomotor excitability of the transferred biceps is modulated by arm posture and may contribute to strength outcomes after tendon transfer. Future work should determine whether modulating corticomotor excitability via posture promotes motor re-education during the rehabilitative period following surgery.


Assuntos
Braço/fisiopatologia , Córtex Motor/fisiopatologia , Músculo Esquelético/fisiopatologia , Postura/fisiologia , Quadriplegia/fisiopatologia , Adulto , Braço/patologia , Fenômenos Biomecânicos , Eletromiografia , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Modelos Biológicos , Força Muscular/fisiologia , Músculo Esquelético/patologia , Tamanho do Órgão , Quadriplegia/patologia , Estimulação Magnética Transcraniana , Adulto Jovem
15.
J Appl Biomech ; 33(1): 12-23, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27705062

RESUMO

At the wrist, kinematic coupling (the relationship between flexion-extension and radial-ulnar deviation) facilitates function. Although the midcarpal joint is critical for kinematic coupling, many surgeries, such as 4-corner fusion (4CF) and scaphoidexcision 4-corner fusion (SE4CF), modify the midcarpal joint. This study examines how 4CF and SE4CF influence kinematic coupling by quantifying wrist axes of rotation. Wrist axes of rotation were quantified in 8 cadaveric specimens using an optimization algorithm, which fit a 2-revolute joint model to experimental data. In each specimen, data measuring the motion of the third metacarpal relative to the radius was collected for 3 conditions (nonimpaired, 4CF, SE4CF). The calculated axes of rotation were compared using spherical statistics. The angle between the axes of rotation was used to assess coupling, as the nonimpaired wrist has skew axes (ie, angle between axes approximately 60°). Following 4CF and SE4CF, the axes are closer to orthogonal than those of the nonimpaired wrist. The mean angle (±95% confidence interval) between the axes was 92.6° ± 25.2° and 99.8° ± 22.0° for 4CF and SE4CF, respectively. The axes of rotation defined in this study can be used to define joint models, which will facilitate more accurate computational and experimental studies of these procedures.


Assuntos
Ossos do Carpo/cirurgia , Articulações do Carpo/fisiologia , Modelos Biológicos , Amplitude de Movimento Articular/fisiologia , Osso Escafoide/cirurgia , Articulação do Punho/fisiologia , Cadáver , Ossos do Carpo/fisiologia , Articulações do Carpo/cirurgia , Simulação por Computador , Humanos , Imobilização/métodos , Rotação , Osso Escafoide/fisiologia , Articulação do Punho/cirurgia
16.
Hand (N Y) ; 11(2): NP1-4, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27390571

RESUMO

BACKGROUND: Metastatic solid tumors to the hand and peripheral nerves are exceedingly rare independent occurrences. Their occurrence together has never been reported in the literature. METHODS: We present a case report of a 69 year old male with a previous history of renal cell carcinoma (RCC) presenting with a rapidly-growing painful mass located at the right volar ulnar wrist, found to have endoneural solid tumor metastatic RCC to the ulnar nerve. RESULTS: Preoperative MRI imaging of the wrist revealed a heterogeneous mass on the volar aspect of the wrist extending along the length of the ulnar artery and nerve to the level of Guyon's canal. Pathologic examination of an incisional biopsy of the mass was consistent with metastatic renal clear cell carcinoma cells, which were infiltrating nerve and surrounding soft tissue. The patient underwent local radiation therapy to the wrist and hand with interval decrease in size of the mass and symptom improvement. CONCLUSION: Solid tumor metastasis, although exceedingly rare, must be considered in the differential diagnosis of a patient with previous cancer history presenting with a wrist or hand mass associated with peripheral neuropathy.

17.
Hand Clin ; 32(3): 389-96, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27387082

RESUMO

It is estimated that 65% to 75% of patients with cervical spinal cord injuries could benefit from upper extremity tendon transfer surgery. The goals of surgery are to restore elbow extension, as well as hand pinch, grasp, and release. Patients who have defined goals, actively participate in therapy, and understand expected outcomes, appear to have the highest satisfaction following tendon transfer procedures.


Assuntos
Quadriplegia/cirurgia , Traumatismos da Medula Espinal/cirurgia , Transferência Tendinosa/métodos , Articulação do Cotovelo/fisiologia , Força da Mão , Humanos , Traumatismos da Medula Espinal/complicações , Extremidade Superior
18.
PLoS One ; 11(6): e0157346, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27310013

RESUMO

The utility of biomechanical models and simulations to examine clinical problems is currently limited by the need for extensive amounts of experimental data describing how a given procedure or disease affects the musculoskeletal system. Methods capable of predicting how individual biomechanical parameters are altered by surgery are necessary for the efficient development of surgical simulations. In this study, we evaluate to what extent models based on limited amounts of quantitative data can be used to predict how surgery influences muscle moment arms, a critical parameter that defines how muscle force is transformed into joint torque. We specifically examine proximal row carpectomy and scaphoid-excision four-corner fusion, two common surgeries to treat wrist osteoarthritis. Using models of these surgeries, which are based on limited data and many assumptions, we perform simulations to formulate a hypothesis regarding how these wrist surgeries influence muscle moment arms. Importantly, the hypothesis is based on analysis of only the primary wrist muscles. We then test the simulation-based hypothesis using a cadaveric experiment that measures moment arms of both the primary wrist and extrinsic thumb muscles. The measured moment arms of the primary wrist muscles are used to verify the hypothesis, while those of the extrinsic thumb muscles are used as cross-validation to test whether the hypothesis is generalizable. The moment arms estimated by the models and measured in the cadaveric experiment both indicate that a critical difference between the surgeries is how they alter radial-ulnar deviation versus flexion-extension moment arms at the wrist. Thus, our results demonstrate that models based on limited quantitative data can provide novel insights. This work also highlights that synergistically utilizing simulation and experimental methods can aid the design of experiments and make it possible to test the predictive limits of current computer simulation techniques.


Assuntos
Modelos Anatômicos , Músculo Esquelético/cirurgia , Osteoartrite/cirurgia , Rádio (Anatomia)/cirurgia , Osso Escafoide/cirurgia , Articulação do Punho/cirurgia , Adulto , Idoso , Cadáver , Simulação por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Osteoartrite/patologia , Osteoartrite/fisiopatologia , Rádio (Anatomia)/patologia , Rádio (Anatomia)/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Osso Escafoide/patologia , Osso Escafoide/fisiopatologia , Torque , Ulna/patologia , Ulna/fisiopatologia , Ulna/cirurgia , Articulação do Punho/patologia , Articulação do Punho/fisiopatologia
19.
Clin Biomech (Bristol, Avon) ; 30(5): 424-30, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25843482

RESUMO

BACKGROUND: Proximal row carpectomy and scaphoid-excision four-corner fusion are salvage procedures that relieve pain by removing arthritic joint surfaces. While numerous studies have examined how these procedures affect joint motion, few have examined how they influence muscle mechanical actions. This study examines whether muscle moment arms change after these procedures. METHODS: Moment arms of primary wrist muscles were measured in 8 cadaveric specimens using the tendon excursion method. In each specimen, moment arms were measured for two degrees of freedom (flexion-extension and radial-ulnar deviation) and three conditions (nonimpaired, scaphoid-excision four-corner fusion, and proximal row carpectomy). For each muscle and degree of freedom, moment arm versus joint angle curves for the three conditions were statistically compared. FINDINGS: Wrist salvage procedures significantly alter moment arms of the primary wrist muscles. Proximal row carpectomy primarily alters flexion-extension moment arms, while scaphoid-excision four-corner fusion primarily alters radial-ulnar deviation moment arms. Both procedures also alter the balance between agonist and antagonist wrist muscles. Following proximal row carpectomy, wrist extensors have smaller moment arms in extended postures. Following scaphoid-excision four-corner fusion, radial deviators have larger moment arms throughout radial-ulnar deviation. INTERPRETATION: Different moment arms indicate that different forces are required to complete the same tasks in nonimpaired and surgically altered wrists. The altered muscle moment arms likely contribute to post-operative impairments. Understanding how salvage procedures alter muscle mechanical actions is a critical first step toward identifying the cause of post-operative impairments and is necessary to develop effective interventions to augment deficient muscles and improve overall function.


Assuntos
Ossos do Carpo/cirurgia , Músculo Esquelético/fisiopatologia , Osso Escafoide/cirurgia , Punho/fisiopatologia , Punho/cirurgia , Adulto , Idoso , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/fisiopatologia , Osteoartrite/cirurgia , Período Pós-Operatório
20.
Artigo em Inglês | MEDLINE | ID: mdl-25570944

RESUMO

Following tendon transfer of the biceps to triceps after cervical spinal cord injuries (SCI), individuals must learn to activate the transferred biceps muscle to extend the elbow. Corticomotor excitability of the transferred biceps may play a role in post-operative elbow extension strength. In this study, we evaluated whether corticomotor excitability of the transferred biceps is related to an individuals' ability to extend the elbow, and whether posture and muscle length affects corticomotor excitability after SCI and tendon transfer similarly to the nonimpaired biceps. Corticomotor excitability was assessed in twelve nonimpaired arms and six arms of individuals with SCI and biceps-to-triceps transfer using transcranial magnetic stimulation (TMS) delivered at rest. Maximum isometric elbow extensor moments were recorded in transferred arms and the fiber length of the transferred biceps was estimated using a musculoskeletal model. Across the SCI subjects, corticomotor excitability of the transferred biceps increased with elbow extension strength. Thus, rehabilitation to increase excitability may enhance strength. Excitability of the transferred biceps was not related to fiber length suggesting that similar to nonimpaired subjects, posture-dependent changes in biceps excitability are primarily centrally modulated after SCI. All nonimpaired biceps were most excitable in a posture in the horizontal plane with the forearm fully supinated. The proportion of transferred biceps in which excitability was highest in this posture differed from the nonimpaired group. Therefore, rehabilitation after tendon transfer may be most beneficial if training postures are tailored to account for changes in biceps excitability.


Assuntos
Músculo Esquelético/fisiopatologia , Traumatismos da Medula Espinal/cirurgia , Adulto , Estudos de Casos e Controles , Articulação do Cotovelo/fisiopatologia , Antebraço/fisiopatologia , Humanos , Masculino , Córtex Motor/fisiopatologia , Contração Muscular , Músculo Esquelético/patologia , Postura , Traumatismos da Medula Espinal/reabilitação , Supinação , Transferência Tendinosa , Estimulação Magnética Transcraniana , Adulto Jovem
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