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Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was .43 during the landing phase (P = .04) and with peak hip internal rotation was -.68 (P < .001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r = .40, P = .05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior , Fútbol , Femenino , Humanos , Masculino , Fútbol/lesiones , Pierna , Articulación de la Rodilla , Rodilla , Fenómenos Biomecánicos

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OBJECTIVE: To evaluate the perceptions of students and teachers regarding remote teaching modality in comparison with the traditional face-to-face method. METHODS: In this observational, retrospective, comparative, single-center study, questionnaires containing three major assessment domains were sent to two groups: university professors and undergraduate and graduate students. The first domain collected demographic and general data on the platforms used. The second and third domains contained questions that compared the perception of the quality of information offered by the two systems. RESULTS: Between May and September 2020, 162 students and 71 teachers participated in the study. A greater proportion of students demonstrated previous contact with the online method, while professors had presented a greater number of courses. Most participants reported that their expectations regarding the remote teaching method were met (students, 80.3%; teachers, 94.4%). A significant number of students (83.3%) and teachers (88.7%) rated the classes as easier to attend and manage. Despite difficulties, such as concentration retention, most of the participants agree (at least partially) that the format should be maintained. CONCLUSION: The remote teaching methodology, although still incipient in Brazil, has become a reality in light of current health restrictions. Our study demonstrated a high level of overall satisfaction and a high sense of learning from both students and faculty. However, new challenges associated with this system have been identified, such as retention of attention and interference from the external environment. Longitudinal comparative studies that incorporate various aspects of medical education in all cycles are necessary to corroborate the findings of this study. DESIGN: Retrospective comparative study, level III evidence.

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COVID-19 , Educación Médica , Humanos , Pandemias , Estudios Retrospectivos , Estudiantes

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BACKGROUND: Surgical wound-related traumatic complications are rarely reported in the literature. Traumatic dehiscence is unpredictable because of the trauma magnitude and the potential of associated injuries. This study aims to report the clinical outcomes and complications of a case series due to traumatic dehiscence after total knee arthroplasty (TKA) and establish possible criteria for prognosis for maintaining the implant. METHODS: Patients admitted to an emergency room due to traumatic dehiscence after TKA were retrospectively evaluated. Patient data was analyzed and patients who maintained or not the arthroplasty were compared to establish prognosis factors. RESULTS: Thirty-two patients with traumatic dehiscence after TKA were evaluated. The trauma occurred on a mean of 14.3 +/- 25.0 days after the surgical procedure, and debridement in the operating room was performed on a mean of 6.2 +/- 4.9 hours after the trauma. Twenty patients maintained the arthroplasty until the end of follow-up and did not require revision. Factors related to arthroplasty removal were associated extensor mechanism injury (p = 0.026), time from trauma to surgical debridement (p = 0.035), and infection (p = 0.0001) CONCLUSION: Traumatic dehiscence after total knee arthroplasty is an event with a high rate of complications. Extensor mechanism Injury, infection, and extended time between trauma and surgical intervention were poor prognostic factors for arthroplasty maintenance.

Asunto(s)

Artroplastia de Reemplazo de Rodilla , Humanos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Estudios Retrospectivos , Reoperación

RESUMEN

ABSTRACT Objective To evaluate the perceptions of students and teachers regarding remote teaching modality in comparison with the traditional face-to-face method. Methods In this observational, retrospective, comparative, single-center study, questionnaires containing three major assessment domains were sent to two groups: university professors and undergraduate and graduate students. The first domain collected demographic and general data on the platforms used. The second and third domains contained questions that compared the perception of the quality of information offered by the two systems. Results Between May and September 2020, 162 students and 71 teachers participated in the study. A greater proportion of students demonstrated previous contact with the online method, while professors had presented a greater number of courses. Most participants reported that their expectations regarding the remote teaching method were met (students, 80.3%; teachers, 94.4%). A significant number of students (83.3%) and teachers (88.7%) rated the classes as easier to attend and manage. Despite difficulties, such as concentration retention, most of the participants agree (at least partially) that the format should be maintained. Conclusion The remote teaching methodology, although still incipient in Brazil, has become a reality in light of current health restrictions. Our study demonstrated a high level of overall satisfaction and a high sense of learning from both students and faculty. However, new challenges associated with this system have been identified, such as retention of attention and interference from the external environment. Longitudinal comparative studies that incorporate various aspects of medical education in all cycles are necessary to corroborate the findings of this study. Design Retrospective comparative study, level III evidence.

RESUMEN

BACKGROUND: Proximal humerus fractures (PHF) are frequent, however, several studies show low inter-rater agreement in the diagnosis and treatment of these injuries. Differences are usually related to the experience of the evaluators and/or the diagnostic methods used. This study was designed to investigate the hypothesis that shoulder surgeons and diagnostic imaging specialists using 3D printing models and shoulder CT scans in assessing proximal humerus fractures. METHODS: We obtained 75 tomographic exams of PHF to print three-dimensional models. After, two shoulder surgeons and two specialists in musculoskeletal imaging diagnostics analyzed CT scans and 3D models according to the Neer and AO/OTA group classification and suggested a treatment recommendation for each fracture based on the two diagnostic methods. RESULTS: The classification agreement for PHF using 3D printing models among the 4 specialists was moderate (global k = 0.470 and 0.544, respectively for AO/OTA and Neer classification) and higher than the CT classification agreement (global k = 0.436 and 0.464, respectively for AO/OTA and Neer). The inter-rater agreement between the two shoulder surgeons were substantial. For the AO/OTA classification, the inter-rater agreement using 3D printing models was higher (k = 0.700) than observed for CT (k = 0.631). For Neer classification,  inter-rater agreement with 3D models was similarly higher (k = 0.784) than CT images (k = 0.620). On the other hand, the inter-rater agreement between the two specialists in diagnostic imaging was moderate. In the AO/OTA classification, the agreement using CT was higher (k = 0.532) than using 3D printing models (k = 0.443), while for Neer classification, the agreement was similar for both 3D models (k = 0.478) and CT images (k = 0.421). Finally, the inter-rater agreement in the treatment of PHF by the 2 surgeons was higher for both classifications using 3D printing models (AO/OTA-k = 0.818 for 3D models and k = 0.537 for CT images). For Neer classification, we saw k = 0.727 for 3D printing models and k = 0.651 for CT images. CONCLUSION: The insights from this diagnostic pilot study imply that for shoulder surgeons, 3D printing models improved the diagnostic agreement, especially the treatment indication for PHF compared to CT for both AO/OTA and Neer classifications On the other hand, for specialists in diagnostic imaging, the use of 3D printing models was similar to CT scans for diagnostic agreement using both classifications. TRIAL REGISTRATION: Brazil Platform under no. CAAE 12273519.7.0000.5505.

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PURPOSE: The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR). METHODS: One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group. RESULTS: One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.). CONCLUSION: Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage. LEVEL OF EVIDENCE: II.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Humanos , Articulación de la Rodilla/cirugía , Resultado del Tratamiento

RESUMEN

Objective To translate into Brazilian Portuguese and to cross-culturally adapt the Banff Questionnaire for Patellar Instability. Methods The translation and cross-cultural adaptation followed the linguistic validation process proposed by international guidelines, which consists of six steps: translation, synthesis, back-translation, review by an expert committee, pretest, and final report presentation to the authors of the original questionnaire. Literate patients with recurrent patellar instability, older than 12 years of age, who signed the informed consent form or had it signed by a legal guardian were included in the study. Patients with neurological or systemic comorbidities were excluded from the study. Results A total of 62 patients (18 males and 44 females) were included in the study. Discrepancies observed during the processes of translation and harmonization of the back-translations were modified with no need for reformulation. No pretest version replacements were required. Conclusion The Banff Questionnaire for Patellar Instability has been successfully translated and cross-culturally adapted into Brazilian Portuguese, so it can be used to assess patients with patellar instability who speak this language.

RESUMEN

Abstract Objective To translate into Brazilian Portuguese and to cross-culturally adapt the Banff Questionnaire for Patellar Instability. Methods The translation and cross-cultural adaptation followed the linguistic validation process proposed by international guidelines, which consists of six steps: translation, synthesis, back-translation, review by an expert committee, pretest, and final report presentation to the authors of the original questionnaire. Literate patients with recurrent patellar instability, older than 12 years of age, who signed the informed consent form or had it signed by a legal guardian were included in the study. Patients with neurological or systemic comorbidities were excluded from the study. Results A total of 62 patients (18 males and 44 females) were included in the study. Discrepancies observed during the processes of translation and harmonization of the back-translations were modified with no need for reformulation. No pretest version replacements were required. Conclusion The Banff Questionnaire for Patellar Instability has been successfully translated and cross-culturally adapted into Brazilian Portuguese, so it can be used to assess patients with patellar instability who speak this language.

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Resumo Objetivo Realizar a tradução para a língua portuguesa falada no Brasil e a adaptação transcultural do questionário Banff para Instabilidade Patelar. Métodos A tradução e adaptação transcultural seguiu o processo de validação linguístico proposto por diretrizes internacionais, que consiste em seis etapas: tradução, síntese, retrotradução, revisão pelo comitê de especialistas, pré-teste, e apresentação do relatório final aos autores do questionário original. Foram incluídos no estudo pacientes alfabetizados, com diagnóstico de instabilidade patelar recorrente, com mais de 12 anos de idade, que assinaram ou tiveram o termo de consentimento livre e esclarecido assinado por um responsável legal. Foram excluídos do estudo pacientes portadores de comorbidades neurológicas ou sistêmicas. Resultados Um total de 62 pacientes (18 homens e 44 mulheres) foram incluídos no estudo. Durante os processos de tradução e harmonização das retrotraduções, foram observadas discrepâncias, que foram modificadas sem necessidade de reformulação. Não foram necessárias substituições na versão do pré-teste. Conclusão O Questionário Banff para Instabilidade Patelar foi traduzido e adaptado transculturalmente para a língua portuguesa falada no Brasil com sucesso, podendo ser utilizado para a avaliação de pacientes portadores de instabilidade patelar falantes desta língua.

Asunto(s)

Humanos , Calidad de Vida , Traducción , Traducciones , Encuestas y Cuestionarios , Adaptación a Desastres , Luxación de la Rótula

RESUMEN

PURPOSE: To biomechanically evaluate MPTL reconstruction and compare it with two techniques for MPFL reconstruction in regard to changes in patellofemoral contact pressures and restoration of patellar stability. METHODS: This is an experimental laboratory study in eight human cadaveric knees. None had patellofemoral cartilage lesions or trochlear dysplasia as evaluated by conventional radiographs and MRI examinations. The specimens were secured in a testing apparatus, and the quadriceps was tensioned in line with the femoral shaft. Contact pressures were measured using the TekScan sensor at 30°, 60° and 90°. The sensor was placed in the patellofemoral joint through a proximal approach between femoral shaft and quadriceps tendon to not violate the medial and lateral patellofemoral complex. TekScan data were analysed to determine mean contact pressures on the medial and lateral patellar facets. Patellar lateral displacement was evaluated with the knee positioned at 30° of flexion and 9 N of quadriceps load, then a lateral force of 22 N was applied. The same protocol was used for each condition: native, medial patellofemoral complex lesion, medial patellofemoral ligament reconstruction (MPFL-R) using gracilis tendon, MPFL-R using quadriceps tendon transfer, and medial patellotibial ligament reconstruction (MPTL-R) using patellar tendon transfer. RESULTS: No statistical differences were found for mean and peak contact pressures, medial or lateral, among all three techniques. However, while both techniques of MPFL-R were able to restore the medial restraint, MPTL-R failed to restore resistance to lateral patellar translation to the native state (mean lateralization of the patella [mm]: native: 9.4; lesion: 22; gracilis MPFL-R: 8.1; quadriceps MPFL-R: 11.3; MPTL-R: 23.4 (p < 0.001). CONCLUSION: MPTL-R and both techniques for MPFL-R did not increase patellofemoral contact pressures; however, MPTL-R failed to provide a sufficient restraint against lateral patellar translation lateral translation in 30° of flexion. It, therefore, cannot be recommended as an isolated procedure for the treatment of patellar instability.

Asunto(s)

Inestabilidad de la Articulación/cirugía , Ligamentos Articulares/cirugía , Articulación Patelofemoral/cirugía , Procedimientos de Cirugía Plástica/métodos , Fenómenos Biomecánicos , Cadáver , Femenino , Fémur/cirugía , Músculo Grácil/cirugía , Humanos , Articulación de la Rodilla/cirugía , Ligamentos Articulares/fisiopatología , Masculino , Persona de Mediana Edad , Rótula/fisiopatología , Rótula/cirugía , Luxación de la Rótula/cirugía , Ligamento Rotuliano/cirugía , Articulación Patelofemoral/fisiopatología , Músculo Cuádriceps/cirugía , Rango del Movimiento Articular , Transferencia Tendinosa , Tendones/cirugía

RESUMEN

Objectives To analyze the results of anterior cruciate ligament (ACL) reconstruction with remnant-preserving versus remnant-resecting technique, concerning the return to pre-lesion activity level. Methods The present retrospective cohort study has assessed adults > 18 years old who underwent ACL anatomical reconstruction between 2010 and 2014. The main outcomes assessed were: level of physical activity (4-point scale), sports participation rate, ACL rerupture defined as documented lesion requiring revision surgery and the numeric pain scale rate (NPSR). Results A total of 83 individuals were included in the study, with a mean age of 31.8 years old and follow-up mean time of 4.2 years after the surgery. A total of 34 patients underwent ACL reconstruction with remnant-preserving technique, and 49 without remnant preservation. No statistically significant difference was found between groups in all outcomes assessed: level of physical activity before the lesion and after the surgery, ACL rerupture rates and postoperative pain level. Subgroup analysis has shown a statistically significant decrease in the activity level in both groups. The most practiced sport was football; 72% of patients in the remnant group have resumed football activity versus 52.6% of the control group. Conclusion Based in these findings, the comparison between ACL reconstruction with remnant preserving technique and remnant resecting technique has shown no differences concerning the return to prelesion activity level.

RESUMEN

BACKGROUND: The agreement for the treatment of proximal humerus fractures is low. Interpretation of exams used for diagnosis can be directly associated with this limitation. This study proposes to compare the agreement between experts and residents in orthopedics for treatment indication of proximal humerus fractures, utilizing 3D-models, holography (augmented reality), x-rays, and tomography as diagnostic methods. METHODS: Twenty orthopedists (ten experts in shoulder and elbow surgery and ten experts in traumatology) and thirty resident physicians in orthopedics evaluated nine fractures of the proximal humerus, randomly distributed as x-rays, tomography, 3D-models and holography, using the Neer and AO / OTA Classifications. After, we evaluated the interobserver agreement between treatment options (conservative, osteosynthesis and arthroplasty) and whether the experience of the evaluators interfered with the results. RESULTS: The interobserver agreement analysis showed the following kappa-values: κ = 0.362 and κ = 0.306 for experts and residents (3D-models); κ = 0.240 and κ = 0.221 (X-ray); κ = 0.233 and κ = 0.123 (Tomography) and κ = 0.321 and κ = 0.160 (Holography), for experts and residents respectively. Moreover, residents and specialists were discordant in the treatment indication using Tomography as a diagnostic method (p = 0.003). The same was not seen for the other diagnostic methods (p > 0.05). CONCLUSIONS: Three-dimensional models showed, overall, the highest interobserver agreement (experts versus residents in orthopedics) for the choice of treatment of proximal humerus fractures compared to X-ray, Tomography, and Holography. Agreement in the choice of treatment among experts that used Tomography and Holography as diagnostic methods were two times higher compared to residents. TRIAL REGISTRATION: Registered in Brazil Platform under no. CAAE 12273519.7.0000.5505.

RESUMEN

Abstract Objectives To analyze the results of anterior cruciate ligament (ACL) reconstruction with remnant-preserving versus remnant-resecting technique, concerning the return to pre-lesion activity level. Methods The present retrospective cohort study has assessed adults > 18 years old who underwent ACL anatomical reconstruction between 2010 and 2014. The main outcomes assessed were: level of physical activity (4-point scale), sports participation rate, ACL rerupture defined as documented lesion requiring revision surgery and the numeric pain scale rate (NPSR). Results A total of 83 individuals were included in the study, with a mean age of 31.8 years old and follow-up mean time of 4.2 years after the surgery. A total of 34 patients underwent ACL reconstruction with remnant-preserving technique, and 49 without remnant preservation. No statistically significant difference was found between groups in all outcomes assessed: level of physical activity before the lesion and after the surgery, ACL rerupture rates and postoperative pain level. Subgroup analysis has shown a statistically significant decrease in the activity level in both groups. The most practiced sport was football; 72% of patients in the remnant group have resumed football activity versus 52.6% of the control group. Conclusion Based in these findings, the comparison between ACL reconstruction with remnant preserving technique and remnant resecting technique has shown no differences concerning the return to prelesion activity level.

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Resumo Objetivo Analisar os resultados da reconstrução do ligamento cruzado anterior (LCA) com preservação do remanescente, comparada à técnica convencional, no retorno do paciente ao nível de atividade física pré-lesão. Métodos Estudo transversal retrospectivo, que avaliou indivíduos adultos submetidos à reconstrução anatômica do LCA no período de 2010 a 2014. Os desfechos analisados foram: nível de atividade física, taxa retorno ao esporte, relesão do LCA definida como lesão documentada que necessite de nova reconstrução ligamentar, e dor pela escala numérica de dor (EVN). Resultados Foram incluídos 83 indivíduos com média de 31,8 anos de idade e seguimento médio de 4,2 anos após a cirurgia, 34 submetidos à reconstrução do LCA com preservação do remanescente, e 49 à convencional. Não houve diferença estatisticamente significativa entre os grupos na frequência de atividade física pré-lesão e pós-operatória, na taxa de relesão do LCA reconstruído e na intensidade da dor no pós-operatório. Na análise intragrupos, houve uma queda estatisticamente significativa na frequência da prática de atividade física pós-operatória para ambos os grupos em comparação ao nível pré-lesão. O tipo de esporte mais praticado foi o futebol, onde 72% pacientes do grupo remanescente retornaram ao esporte comparado a 52,6% do grupo controle; porém, essa diferença não foi estatisticamente significante. Conclusão Não foi possível observar diferenças entre os pacientes submetidos às técnicas cirúrgicas de reconstrução LCA com e sem a preservação do remanescente em relação ao retorno ao esporte, frequência de atividade física e intensidade da dor. Estudos futuros prospectivos são necessários.

Asunto(s)

Humanos , Masculino , Femenino , Dolor , Dolor Postoperatorio , Rotura , Deportes , Ejercicio Físico , Incidencia , Reconstrucción del Ligamento Cruzado Anterior , Volver al Deporte , Lesiones del Ligamento Cruzado Anterior , Fútbol Americano

RESUMEN

BACKGROUND: Anterior cruciate ligament (ACL) repair is increasing in frequency in younger children. Recognition of the normal development of the intercondylar notch is important for successful ACL graft placement, allowing surgeons to better understand the anatomy and risk factors related to ACL tears and its reconstruction. The purpose of this study was to compile normative data on the intercondylar notch in the pediatric population with magnetic resonance imaging (MRI), emphasizing the differences between males and females. METHODS: In this retrospective study, musculoskeletal radiologists evaluated intercondylar notch width, bicondylar distance and notch width index (NWI). A total of 253 MRI examinations (130 males and 123 females between six and 18 years of age) were included. The association between measurements, sex and age was considered. Linear and fractional polynomial regression models were used to evaluate the relationships between measurements. RESULTS: Intercondylar notch width increased up to 10 years of age in females and 11 years of age in males, with relative stabilization up to 13 years in girls and 14 years in boys and a slight reduction in values at subsequent ages. Bicondylar distance showed significant progressive growth with age in both sexes. NWI showed a discrete and homogenous reduction with age in both sexes. CONCLUSION: Intercondylar notch width interrupts its growth around 10-11 years of age, with relative stabilization up to 13-14 years and a slight reduction in dimensions in subsequent ages. This growth pattern resembles the development of the ACL area observed in recent studies.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior/diagnóstico , Ligamento Cruzado Anterior/diagnóstico por imagen , Articulación de la Rodilla/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Modelos Estadísticos , Procedimientos de Cirugía Plástica/métodos , Adolescente , Niño , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo , Programas Informáticos

RESUMEN

OBJECTIVE: The objective of this study was to compare two postero-lateral bundle (PLB) tibial fixation techniques for the reconstruction of the anterior cruciate ligament with double bundle: a technique without the use of an interference screw, preserving the native tibial insertion of the tendons of the gracilis and semitendineous muscles, and a technique with the use of an interference screw and without preserving the insertion of the tendons. METHODS: A comparative study was conducted in cadavers with a universal mechanical test machine. In total, 23 cadaver knees were randomized for tibial fixation of the PLB using the two techniques: Maintaining the tibial insertion of the tendons during reconstruction, without the use of an interference screw (group A, 11 cases); and fixating the graft with an interference screw, without maintaining the insertion of the tendons (group B, 12 cases). A continuous traction was performed (20 mm/min) in the same direction as the produced tunnel, and force (N), elongation (mm), rigidity (N/mm), and tension (N/mm2) were objectively determined in each group. RESULTS: Group A exhibited a maximum force (MF) of 315.4±124.7 N; maximum tension of 13.57±3.65 N/mm2; maximum elongation of 19.73±4.76 mm; force at the limit of proportionality (FLP) of 240.6±144.0 N; and an elongation at the limit of proportionality of 14.37±6.58 mm. Group B exhibited a MF of 195.7±71.8 N; maximum tension of 8.8±3.81 N/mm2; maximum elongation of 15.3±10.73 mm; FLP of 150.1±68.7 N; and an elongation at the limit of proportionality of 6.86±2.42 mm. When comparing the two groups, significant differences were observed in the variables of maximum force (p=0.016), maximum tension (p=0.019), maximum elongation (p=0.007), and elongation at the limit of proportionality (p=0.003). CONCLUSION: The use of the native insertion of the semitendineous and gracilis tendons, without an additional fixation device, presented mechanical superiority over their fixation with interference screws.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirugía , Tornillos Óseos , Tendones Isquiotibiales/cirugía , Músculo Esquelético/trasplante , Procedimientos de Cirugía Plástica/instrumentación , Tibia/cirugía , Fenómenos Biomecánicos , Humanos , Procedimientos de Cirugía Plástica/métodos , Estrés Mecánico

RESUMEN

OBJECTIVE: The objective of this study was to compare two postero-lateral bundle (PLB) tibial fixation techniques for the reconstruction of the anterior cruciate ligament with double bundle: a technique without the use of an interference screw, preserving the native tibial insertion of the tendons of the gracilis and semitendineous muscles, and a technique with the use of an interference screw and without preserving the insertion of the tendons. METHODS: A comparative study was conducted in cadavers with a universal mechanical test machine. In total, 23 cadaver knees were randomized for tibial fixation of the PLB using the two techniques: Maintaining the tibial insertion of the tendons during reconstruction, without the use of an interference screw (group A, 11 cases); and fixating the graft with an interference screw, without maintaining the insertion of the tendons (group B, 12 cases). A continuous traction was performed (20 mm/min) in the same direction as the produced tunnel, and force (N), elongation (mm), rigidity (N/mm), and tension (N/mm2) were objectively determined in each group. RESULTS: Group A exhibited a maximum force (MF) of 315.4±124.7 N; maximum tension of 13.57±3.65 N/mm2; maximum elongation of 19.73±4.76 mm; force at the limit of proportionality (FLP) of 240.6±144.0 N; and an elongation at the limit of proportionality of 14.37±6.58 mm. Group B exhibited a MF of 195.7±71.8 N; maximum tension of 8.8±3.81 N/mm2; maximum elongation of 15.3±10.73 mm; FLP of 150.1±68.7 N; and an elongation at the limit of proportionality of 6.86±2.42 mm. When comparing the two groups, significant differences were observed in the variables of maximum force (p=0.016), maximum tension (p=0.019), maximum elongation (p=0.007), and elongation at the limit of proportionality (p=0.003). CONCLUSION: The use of the native insertion of the semitendineous and gracilis tendons, without an additional fixation device, presented mechanical superiority over their fixation with interference screws.

Asunto(s)

Humanos , Tornillos Óseos , Ligamento Cruzado Anterior/cirugía , Músculo Esquelético/trasplante , Procedimientos de Cirugía Plástica/instrumentación , Tendones Isquiotibiales/cirugía , Lesiones del Ligamento Cruzado Anterior , Estrés Mecánico , Tibia/cirugía , Fenómenos Biomecánicos , Procedimientos de Cirugía Plástica/métodos

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BACKGROUND: The World Health Organization (WHO) estimates that the number of individuals who lose their vision due to retinal degeneration is expected to reach 6 million annually in 2020. The retinal degenerative diseases affect the macula, which is responsible for central and detailed vision. Most macular degeneration, i.e., age-related macular degeneration (AMD) develops in the elderly; however, certain hereditary diseases, such as the Stargardt disease, also affect young people. This degeneration begins with loss of retinal pigmented epithelium (RPE) due to formation of drusen (atrophic) or abnormal vessels (exudative). In wet AMD, numerous drugs are available to successful treat the disease; however, no proven therapy currently is available to treat dry AMD or Stargardt. Since its discovery, human embryonic stem cells (hESCs) have been considered a valuable therapeutic tool. Some evidence has shown that transplantation of RPEs differentiated from hESCs cells can result in recovery of both RPE and photoreceptors and prevent visual loss. METHODS: The human embryonic WA-09 stem cell lineage was cultured under current Good Manufacturing Practices (cGMP) conditions using serum-free media and supplements. The colonies were isolated manually and allowed to spontaneously differentiate into RPE cells. RESULTS: This simple and effective protocol required minimal manipulation and yielded more than 10e8 RPE cells by the end of the differentiation and enrichment processes, with cells exhibiting a cobblestone morphology and displaying cellular markers and a gene expression profile typical of mature RPE cells. Moreover, the differentiated cells displayed phagocytic activity and only a small percentage of the total cells remained positive for the Octamer-binding transcriptions factor 4 (OCT-4) pluripotency cell marker. CONCLUSIONS: These results showed that functional RPE cells can be produced efficiently and suggested the possibility of scaling-up to aim at therapeutic protocols for retinal diseases associated with RPE degeneration.

RESUMEN

PURPOSE: Understanding the pathomechanics of a bicruciate injury (BI) is critical for its correct diagnosis and treatment. The purpose of this biomechanical study aims to quantify the effects of sequential sectioning of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) bundles on knee laxity. METHODS: Twelve cadaveric knees (six matched pairs) were used. Knee laxity measurements consisted of neutral tibial position, anterior-posterior translation, internal-external rotation, and varus-valgus angulation in different conditions: intact, ACL cut, incomplete BI (divided into two groups: anterolateral (AL) bundle intact or posteromedial (PM) bundle intact) and complete bicruciate tear. Data were collected using a Microscribe system at 0°, 30°, 60°, and 90° of knee flexion. RESULTS: In comparison to the intact knees, incomplete BI and complete BI showed a significant increase of total antero-posterior tibial translation. The largest significant increase was observed at 90° of flexion after a complete bicruciate resection (p < 0.001). A threshold difference greater than 15 mm from the intact could be used to identify a complete BI from an incomplete BI evaluating the total antero-posterior translation at 90°. All sectioned states had significant increases compared with the intact condition in internal-external rotation and varus-valgus stability at all tested flexion angles. CONCLUSION: Both incomplete and complete BI led to an important AP translation instability at all angles; however, full extension was the most stable position at all injured models. Total antero-posterior translation at 90° of knee flexion over 15 mm, in comparison to the intact condition, was indicative of a complete BI. Since the appropriate assessment of a combined ACL and PCL lesion remains a challenge, this study intends to assist its diagnosis. As BI's main antero-posterior instability occurred at 90°, a total antero-posterior drawer test is proposed to evaluate BI in the clinical setting. Total antero-posterior translation at 90° > 15 mm, in comparison to the intact condition or the contra-lateral non-injured knee, can be used to identify a complete from an incomplete BI.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior/diagnóstico , Ligamento Cruzado Anterior/cirugía , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla/cirugía , Ligamento Cruzado Posterior/cirugía , Anciano , Lesiones del Ligamento Cruzado Anterior/patología , Lesiones del Ligamento Cruzado Anterior/cirugía , Fenómenos Biomecánicos , Cadáver , Femenino , Humanos , Rodilla/cirugía , Traumatismos de la Rodilla/cirugía , Masculino , Persona de Mediana Edad , Movimiento , Rango del Movimiento Articular , Rotación , Tibia/cirugía , Torque

RESUMEN

PURPOSE: An uncommon technique for bicruciate ligament reconstruction involving simultaneous tensioning of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) grafts with ACL graft fixation first has been pointed out as superior to the "gold-standard" PCL graft fixation first. The purpose of this study was to compare tibiofemoral biomechanics between ACL fixation first and PCL fixation first in a simultaneous tensioning protocol for bicruciate ligament reconstruction. METHODS: 12 fresh-frozen cadaveric knees (six matched pairs) were tested using a custom testing system. Neutral tibial position representing tibiofemoral orientation, anterior-posterior (AP) tibial translation, varus-valgus laxity, and internal-external rotation were measured using a Microscribe 3DLX at 0°, 30°, 60°, and 90° of knee flexion. The following knee conditions were evaluated: intact, bicruciate deficient and following bicruciate reconstruction. A simultaneous tensioning protocol was used for bicruciate reconstruction and PCL fixation first was compared to ACL fixation first. PCL graft fixation was always performed at 90° of flexion and ACL graft fixation was always performed at full extension. RESULTS: ACL fixation first achieved a tibiofemoral orientation closer to the intact knee than PCL fixation first at 90° flexion (1.8 ± 1.6 mm versus 6.1 ± 3.2 mm, p = 0.016). PCL fixation first had a larger decrease in AP translation than ACL fixation first at 30° flexion (64.6 ± 3.5% vs. 58.3 ± 2.4%, p = 0.01). No significant differences were found for varus/valgus, external-internal rotation decrements after bicruciate reconstruction nor for AP translation, varus/valgus and internal/external rotation increase after bicruciate lesion comparing ACL fixation first to PCL fixation first. CONCLUSION: Bicruciate ligament reconstruction using a simultaneous tensioning protocol with ACL fixation first resulted in a closer to normal tibiofemoral orientation. This study will help guide surgeons in decision making for the graft tensioning protocol and fixation sequence in a bicruciate ligament reconstruction. LEVEL OF EVIDENCE: V therapeutic study.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior/cirugía , Ligamento Cruzado Anterior/cirugía , Articulación de la Rodilla/cirugía , Reconstrucción del Ligamento Cruzado Posterior/métodos , Ligamento Cruzado Posterior/cirugía , Anciano , Fenómenos Biomecánicos , Cadáver , Toma de Decisiones , Femenino , Humanos , Rodilla/cirugía , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular , Procedimientos de Cirugía Plástica/métodos , Tibia/cirugía , Trasplantes/cirugía

RESUMEN

The use of Adipose-Derived Stem Cells (ADSC) has been presented as a new alternative for tendon reconstruction. Have been admitted that ADSCs are related to better outcomes when used in tendon healing. This research was designed to apply the potential of ADSCs in tendon healing. Flexor digitorum superficialis tendon lesion was performed on both legs of eleven New Zealand rabbits and them, at the same time, treated as follows: Suture alone (Group III - Suture, n:10), suture associated with ADSC (Group IV - Suture + ADSC, n:10) or without suture (Group II - SHAN, n:2). At four weeks after the tendon surgery, the animal was euthanized, and the tendon evaluated (biomechanically and macroscopically). We used 5 additional New Zealand rabbits in the control group "Group I - Control, n:10". In the macroscopic evaluation, the group with ADSC presented a more homogeneous gross morphology compared with the group III. Biomechanical testing showed a lower ultimate tensile load, stiffness and a higher cross-sectional area in the group III and IV compared with the control group. The group with ADSC showed a greater ultimate tensile load, a larger cross-sectional area and bigger deformation at the ultimate tensile load when compared to the group without ADSC. In general terms, the use of ADSCs in tendon healing have biomechanical advantages compared to the non-use of ADSCs at 4 weeks after surgery. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1281-1286, 2019.

Asunto(s)

Adipocitos/citología , Trasplante de Células Madre , Traumatismos de los Tendones/terapia , Tendones/fisiología , Animales , Fenómenos Biomecánicos , Masculino , Conejos , Regeneración/fisiología , Células Madre/fisiología , Traumatismos de los Tendones/patología , Traumatismos de los Tendones/fisiopatología , Resistencia a la Tracción

RESUMEN

ABSTRACT Objectives: To evaluate the regenerative capacity of gracilis (G) and semitendinosus (ST) tendons, to examine the sensitivity and specificity of signs and symptoms in the assessment of hamstring tendons, and to assess the thickness and insertion site of regenerated tendons. Methods: Thirty sequential knees were subjected to anterior cruciate ligament reconstruction with semitendinosus and gracilis tendons. After surgery, the patients were followed up clinically with physical examination and magnetic resonance imaging (MRI). Results: Overall, 36.66% of the tendons were visible on MRI, whereas 83.33% were palpable. On MRI, the distal insertion site of the regenerated semitendinosus tendon was visible proximal to the landmark of the medial femoral condyle in 28%, at the same level in 16%, and distally in 56% of the cases. Gracilis tendon insertion was visible proximally in 36.66% of cases, at the same level in 10%, and distally in 53.33%. Eleven knees exhibited complete regeneration. Conclusion: Partial or total regeneration of the ST and G tendons was apparent on MRI. Palpation is effective for evaluating regeneration of the ST and G tendons; however, MRI is still the gold standard. ST and G tendons regenerated completely in only a small percentage of patients, limiting reuse as a graft in cases with new ligament injuries of the knee. Level of Evidence II, Prospective comparative study.

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RESUMO Objetivo: Avaliar a capacidade de regeneração dos tendões Grácil e Semitendíneo; Identificar a sensibilidade e especificidade da manobra semiológica para detecção da presença dos tendões isquiotibiais; verificar espessura e região de inserção dos tendões regenerados. Métodos: 30 pacientes foram submetidos à cirurgia para reconstrução do LCA, com retirada dos tendões do semitendíneo e grácil. Após a cirurgia, os pacientes foram acompanhados clinicamente por exame físico e por RM. Resultados: Observou-se que em 36,66% eles se apresentavam visíveis, enquanto 83,33% os tendões estavam palpáveis. Observou-se à RM, quanto a região da inserção distal dos tendões regenerados: Semitendíneos, 28% proximal ao ponto padronizado do MFC, 16% se apresentaram ao nível e 56% distal. Já quanto aos tendões do Grácil, 36,66% apresentavam-se proximais, 10% ao nível e 53,33% distal. Onze tendões do ST e do G tiveram regeneração completa. Conclusões: Ficaram caracterizadas, por RM, as regenerações parciais ou totais dos tendões ST e G;a palpação, é eficaz para avaliar a regeneração dos tendões, porém RM mantem-se como padrão ouro; apenas parte dos pacientes os tendões ST e G se regeneraram de maneira completa, limitando a sua reutilização como enxerto nos casos de nova lesão ligamentar. Nível de Evidência II, Estudo prospectivo comparativo.