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1.
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
2.
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
3.
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
4.
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
5.
J Hand Surg Am ; 38(11): 2293-302; quiz 2302, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23707597

RESUMO

Radial, ulnar, and central deficiencies represent a spectrum of abnormalities in the development of the upper limb. Radial longitudinal deficiency is often associated with abnormalities in other organ systems, such as cardiac and renal, and so requires a comprehensive medical evaluation. On the other hand, ulnar longitudinal deficiency tends to be associated only with other musculoskeletal abnormalities. In all of these conditions, there is a high incidence of ipsilateral thumb abnormalities. Given the importance of the thumb in overall hand function, abnormalities of the thumb often guide treatment for these conditions. Surgical treatment of the wrist and forearm in radial longitudinal deficiency is controversial, as will be outlined in this review.


Assuntos
Rádio (Anatomia)/anormalidades , Ulna/anormalidades , Deformidades Congênitas das Extremidades Superiores , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/terapia , Antebraço/diagnóstico por imagem , Antebraço/cirurgia , Humanos , Radiografia , Deformidades Congênitas das Extremidades Superiores/classificação , Deformidades Congênitas das Extremidades Superiores/etiologia , Deformidades Congênitas das Extremidades Superiores/cirurgia , Deformidades Congênitas das Extremidades Superiores/terapia , Punho/cirurgia
6.
J Hand Surg Am ; 37(10): 2074-81, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22960030

RESUMO

PURPOSE: To describe a case series of congenital metacarpal synostosis treated with longitudinal osteotomy and bone graft substitute interposition. METHODS: We retrospectively reviewed charts of all patients with metacarpal synostosis treated with a longitudinal osteotomy and bone graft substitute interposition at 2 institutions. Radiographic and clinical appearances were analyzed at initial diagnosis, intraoperatively, and at last follow-up. RESULTS: A total of 10 patients (14 hands) met the inclusion criteria. Six patients (8 hands) demonstrated ring-little finger metacarpal synostosis and 4 patients (6 hands) had a middle-ring finger metacarpal synostosis. The median age at operation was 5 years (range, 2-16 y). Follow-up ranged from 1 to 14 years (average, 3 y). Associated hand anomalies included polydactyly, symbrachydactyly, and clinodactyly. Before surgery, the little finger proximal phalanx was angulated away from the middle finger metacarpal on average 46° (range, 26°-60°), and the angulation between the middle and the ring fingers averaged 43° (range, 26°-50°). Postoperative correction at 1 year was statistically significant for both ring-little finger metacarpal synostosis, average 23° (range, 10°-30°), and middle-ring finger metacarpal synostosis, average 16° (range, 5°-44°). Recurrence of digital abduction was evident in 2 patients who had middle-ring finger metacarpal synostosis. CONCLUSIONS: Metacarpal synostosis is an uncommon congenital hand anomaly characterized by the coalescence of 2 adjacent metacarpals. In the most common form, the ring and little finger metacarpals are associated with abduction of the small finger in an awkward position. Use of the described technique is safe and effective, yet concerns remain regarding mild persistent angulation and risk of recurrence. CLINICAL RELEVANCE: Congenital metacarpal synostosis may be effectively treated with a longitudinal osteotomy, realignment of component metacarpals, and interposition of bone graft substitute. When the procedure is performed at a young age, we recommend follow-up until skeletal maturity to identify recurrence of the deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.


Assuntos
Substitutos Ósseos/uso terapêutico , Cerâmica/uso terapêutico , Hidroxiapatitas/uso terapêutico , Ossos Metacarpais/anormalidades , Ossos Metacarpais/cirurgia , Osteotomia/métodos , Sinostose/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Ossos Metacarpais/diagnóstico por imagem , Radiografia , Recidiva , Estudos Retrospectivos , Sinostose/diagnóstico por imagem
7.
J Hand Surg Am ; 37(11): 2286-93, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23040641

RESUMO

PURPOSE: Multiple hereditary osteochondromatosis (MHO) is an autosomal-dominant skeletal dysplasia that may result in forearm deformity. The purpose of this study was 2-fold: to describe the natural history of forearm deformity in patients with MHO, with particular attention to those who develop radial head dislocation, and to determine predictors of deformity. METHODS: We retrospectively reviewed charts of all patients with MHO evaluated at our institution. Patients with the presence of a radiographically visible osteochondroma in the forearm were divided into 5 groups or types based on location of the osteochondroma(s). Radiographic measurements included radial articular angle, percent ulnar variance, radial bow, radial length, ulnar length, and ulnar bow. The predictive values of each measure were statistically evaluated for each type with relation to radial head dislocation. RESULTS: Of 146 patients with MHO, 102 patients (70%) had forearm involvement. Appropriate anteroposterior and lateral radiographs were available on 48 patients (76 forearms). Average age at initial radiographic evaluation was 12 years (range, 2-18 y). Average follow-up period was 7 years (range 1-19 y). Thirteen forearms demonstrated radial head dislocation, with all but 1 reported in the type 1 limbs (solitary distal ulna osteochondroma). Radial head dislocation was noted in 34% (12/35 forearms) of type 1 limbs. CONCLUSIONS: Forearms with isolated osteochondromas of the distal ulna are the ones most likely to develop radial head dislocation. Because the ulna growth is disproportionately less than radial growth, the soft tissues may act as a tether, linking the distal radius and ulna, and lead to radial head dislocation. Changes in radiographic measurements may predict limbs at risk for radial head dislocation.


Assuntos
Exostose Múltipla Hereditária/complicações , Antebraço/anormalidades , Luxações Articulares/etiologia , Rádio (Anatomia)/cirurgia , Adolescente , Criança , Pré-Escolar , Progressão da Doença , Exostose Múltipla Hereditária/diagnóstico por imagem , Exostose Múltipla Hereditária/cirurgia , Feminino , Humanos , Luxações Articulares/diagnóstico por imagem , Masculino , Radiografia , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/patologia , Estudos Retrospectivos , Ulna/diagnóstico por imagem , Ulna/patologia
8.
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.

9.
J Hand Surg Am ; 35(5): 732-5, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20363566

RESUMO

Scapholunate interosseous ligament repair with dorsal capsular augmentation is an established surgical treatment for traumatic scapholunate instability. We report a case of scaphoid osteonecrosis that developed after this procedure and discuss the possible causes of this complication.


Assuntos
Cápsula Articular/cirurgia , Ligamentos Articulares/cirurgia , Osteonecrose/etiologia , Complicações Pós-Operatórias , Osso Escafoide , Traumatismos do Punho/cirurgia , Adulto , Humanos , Masculino , Radiografia , Osso Escafoide/diagnóstico por imagem , Traumatismos do Punho/diagnóstico por imagem , Articulação do Punho/diagnóstico por imagem
10.
J Hand Surg Am ; 35(5): 834-7, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20438998

RESUMO

Clinodactyly, the angulation of a digit in the anteroposterior plane, is often due to a longitudinal epiphyseal bracket on the radial side of the middle phalanx of the little finger. Treatment options include observation, osteotomy, and epiphyseal bar resection. Epiphyseal bar resection is a simple surgery that requires neither postoperative pin fixation nor immobilization. The most appropriate indications are in children 3 to 6 years old with radial deviation of at least 25 degrees. The procedure reliably diminishes the extent of deformity.


Assuntos
Epífises/cirurgia , Dedos/anormalidades , Dedos/cirurgia , Criança , Pré-Escolar , Dedos/diagnóstico por imagem , Humanos , Radiografia , Procedimentos de Cirurgia Plástica/métodos
11.
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 (

12.
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
13.
J Hand Surg Am ; 34(9): 1739-47, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19896016

RESUMO

Radial and ulnar longitudinal deficiencies are the 2 most common types of congenital longitudinal deficiencies of the arm, with radial deficiency being 3 to 4 times more common. They are a spectrum of abnormalities, ranging from mild deficiency of the digits to complete loss of one-half the forearm, wrist, and fingers. Radial longitudinal deficiency is associated with a number of medical syndromes that require a comprehensive medical evaluation, while ulnar longitudinal deficiency (ULD) is associated with other musculoskeletal anomalies. Both conditions have a high incidence of ipsilateral thumb abnormalities. Wrist and forearm procedures, such as soft tissue distraction and centralization, are more often required in radial longitudinal deficiencies than in ULD. Elbow involvement can occur in both conditions but is more frequent and often more severe in ULD.


Assuntos
Rádio (Anatomia)/anormalidades , Ulna/anormalidades , Deformidades Congênitas das Extremidades Superiores/patologia , Anormalidades Múltiplas , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Procedimentos Ortopédicos , Deformidades Congênitas das Extremidades Superiores/cirurgia
14.
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
16.
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
17.
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
18.
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
20.
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
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