The optimized tourniquet versus no tourniquet in total knee arthroplasty. Analysis of muscle injury, functional recovery, and knee strength.

Background: Tourniquet is widely used in total knee replacement surgery because it reduces intraoperative hemorrhage and provides a comfortable surgical area for the surgeon. It's possible that its use could lead to impaired postoperative functional and motor recovery, as well as local and systemic complications. Our goal was to compare the outcomes of total knee replacement without ischemia using an optimized protocol, consisting of tourniquet inflation before skin incision and deflation after cementing, with a pressure of one hundred millimeters above systolic blood pressure and without postoperative articular suction drains.). We believed that tourniquet effectively would result in no additional muscle damage and no functional or knee strength impairment compared to no tourniquet. Methods: In a prospective and randomized study, 60 patients with osteoarthritis were evaluated for total knee replacement, divided in two groups: 'without tourniquet' and 'optimized tourniquet'. Outcomes were mean creatine phosphokinase levels, Knee Society Score and knee isokinetic strength. Data were considered significant when p < 0.05. Results: Creatine phosphokinase levels and functional score were similar between groups. There were no differences between groups regarding knee extension strength on the operated limbs, although the knee flexors' peak torque in the operated limb in the optimized tourniquet group was significantly higher at 6 months relative to preoperative and 3 months assessments. Conclusions: The optimized tourniquet protocol use in total knee replacement combines the benefits of tourniquet use without compromising functional recovery and without additional muscle damage and strength deficits compared to surgery without its use.

Effect of Spinal Correction Surgery on Lower Limb Strength in Idiopathic Adolescent Scoliosis / Efeito da cirurgia de correção da coluna vertebral na força dos membros inferiores na escoliose idiopática do adolescente

Abstract Objectives To analyze the lower limb strength in both untreated and surgically treated adolescent idiopathic scoliosis (AIS) patients and examine its correlation with the distance covered in a six-minute walking test (6MWT). Methods A total of 88 participants (n = 30 pre-surgery AIS patients, n = 30 postsurgical AIS patients, and n = 28 control) underwent a 6MWT and a muscle strength assessment. The lower limb strength was measured at the knee joint using the knee extension (KE) and knee flexion (KF) peak torque (PT) measurements. Results The control group covered a greater distance in the TC6 compared to both the pre-surgical (534 ± 67 m) and post-surgical (541 ± 69 m) groups, with a distance of 612 ± 70 m (p < 0.001). No differences were observed in KE PT (pre: 2.1 ± 0.63, post: 2.1 ± 0.7, control: 2.2 ± 0.7 Nm.kg-1, p = 0.67) or KF PT (pre: 1.0 ± 0.3, post: 1.1 ± 0.3, control: 1.1 ± 0.5 Nm.kg-1, p = 0.46). A moderate positive correlation was observed between KE PT and 6MWT distance (r = 0.53, p < 0.001), as well as a low positive correlation for KF PT (r = 0.37, p = 0.003) with 6MWT distance. Conclusion This study highlights the importance of lower limb maximal strength in the functionality of AIS patients. Our findings suggest that exercise programs aimed at enhancing lower limb strength, especially the KE, could improve the walking capacity of AIS patients. These results provide useful information for designing purposeful exercise programs for AIS patients with walking deficits.

Resumo Objetivos Analisar a força dos membros inferiores em pacientes com escoliose idiopática do adolescente (EIA) submetidos ou não ao tratamento cirúrgico e examinar sua correlação com a distância percorrida em um teste de caminhada de seis minutos (TC6). Métodos Um total de 88 participantes (n = 30 pacientes com EIA pré-operatório, n = 30 pacientes com EIA pós-operatório e n = 28 controles) foram submetidos ao 6MWT e à avaliação da força muscular. A força dos membros inferiores foi medida na articulação do joelho usando os valores de pico de torque (PT) de extensão do joelho (EJ) e flexão do joelho (FJ). Resultados O grupo controle percorreu uma distância maior no TC6 em comparação aos grupos pré-operatório (534 ± 67 m) e pós-operatório (541 ± 69 m), com distância de 612 ± 70 m (p < 0,001). Não foram observadas diferenças em PT EJ (pré: 2,1 ± 0,63, pós: 2,1 ±0,7, controle: 2,2±0,7 Nm.kg-1, p = 0,67) ou PT FJ (pré: 1,0±0,3, pós: 1,1 ±0,3, controle: 1,1 ±0,5 Nm.kg-1, p = 0,46). Houve uma correlação positiva moderada entre PT EJ e a distância do TC6 (r = 0,53, p<0,001), assim como uma correlação positiva baixa entre PT FJ (r = 0,37, p = 0,003) e a distância do TC6. Conclusão Este estudo destaca a importância da força máxima dos membros inferiores na funcionalidade de pacientes com EIA. Nossos achados sugerem que programas de exercícios destinados a aumentar a força dos membros inferiores, especialmente de EJ, podem melhorar a capacidade de caminhada de pacientes com EIA. Esses resultados fornecem informações úteis para o projeto de programas de exercícios intencionais para pacientes com EIA e déficits de marcha.

Effect of fatigue on explosive strength and muscle architecture of the vastus lateralis / Efecto de la fatiga sobre la fuerza explosiva y la arquitectura muscular del vasto lateral / Efeito da fadiga na força explosiva e arquitetura muscular do vasto lateral

ABSTRACT Introduction: There has been little research on changes in rate of torque development (RTD) and muscle architecture. This study evaluated the effect of fatigue on RTD and muscle architecture of the vastus lateralis (VL). Methods: Seventeen volunteers (25.5 ± 6.2 years; 177.2 ± 12.9 cm; 76.4 ± 13.1 kg) underwent isokinetic knee extension assessment at 30°/s to obtain the peak torque (PT-ISK), before and after a set of intermittent maximal voluntary isometric contractions (MVIC) (15 reps - 3 s contraction, 3 s rest) used to promote muscle fatigue, monitored by the median frequency (MDF) of the electromyography from the VL, rectus femoris and vastus medialis muscles. Before and after the fatigue protocol, ultrasound images of the VL were obtained to measure muscle thickness (MT), fascicle length (FL), and fascicle angle (FA). The peak isometric torque (PT-ISM) and the RTDs in 50 ms windows were calculated for each MVIC. The RTDs were reported as absolute values and normalized by the PT-ISM. Results: Fatigue was confirmed due to significant reductions in MDF in all three muscles. After the fatigue protocol, the PT-ISK was reduced from 239.0±47.91 to 177.3±34.96 Nm, and the PT-MVIC was reduced from 269.5±45.63 to 220.49±46.94 Nm. All the RTD absolute values presented significant change after the fatigue protocol. However, the normalized RTD did not demonstrate any significant differences. No significant differences were found in the muscle architecture of the VL. Conclusions: The reduction in explosive strength occurred concomitantly with the reduction in maximum strength, as evidenced by the lack of changes in normalized TDT. Level of Evidence III.

RESUMEN Introducción: Los cambios en la tasa de desarrollo del torque (TDT) y la arquitectura muscular causada por la fatiga son temas poco investigados. Esta investigación evaluó el efecto de la fatiga en la TDT y la arquitectura muscular del vasto lateral (VL). Métodos: 17 voluntarios (25.5 ± 6.2 años; 177.2 ± 12.9 cm; 76.4 ± 13.1 kg) se sometieron a una evaluación isocinética de la extensión de la rodilla a 30º/s para obtener el pico de torque (PT-ISK), antes y después de una serie de contracciones voluntarias máximas intermitentes (CVIM) (15 repeticiones - contracción 3 s, intervalo 3 s) utilizadas para causar fatiga muscular, monitoreadas por la frecuencia media (FMD) de la electromiografía VL, recto femoral y vasta medial. Antes y después del protocolo de fatiga, se obtuvieron imágenes de ultrasonido VL para medir el grosor muscular, la longitud del fascículo y el ángulo del fascículo. Se calculó el par isométrico máximo (PT-ISM) y las TDT en ventanas de 50 ms para cada CVIM. Las DTT se calcularon en valores absolutos y se normalizaron mediante PT-ISM. Resultados: la fatiga se confirmó por reducciones significativas en la fiebre aftosa de los tres músculos. Después de la fatiga, el PT-ISK se redujo de 239.0 ± 47.91 a 177.3 ± 34.96 Nm, y el PT-CVIM de 269.5 ± 45.63 a 220.49 ± 46.94 Nm. Todos los valores absolutos de TDT fueron significativamente diferentes después del protocolo de fatiga. Sin embargo, las TDT normalizadas no mostraron diferencias significativas. No se observaron diferencias significativas en la arquitectura muscular de la LV. Conclusiones: La reducción en la capacidad explosiva ocurrió simultáneamente con la reducción en la fuerza máxima, evidenciada por la falta de cambios en la TDT normalizada. Nível de evidencia III.

RESUMO Introdução: Alterações na taxa de desenvolvimento de torque (TDT) e arquitetura muscular causadas pela fadiga são temas pouco investigados. Esta pesquisa avaliou o efeito da fadiga na TDT e arquitetura muscular do vasto lateral (VL). Métodos: Dezessete voluntários (25,5 ± 6,2 anos; 177,2 ± 12,9 cm; 76,4 ± 13,1 kg) realizaram avaliação isocinética de extensão do joelho em 30º/s para obtenção do pico de torque (PT-ISK) antes e após uma série de contrações voluntárias isométricas máximas (CVIM) intermitentes (15 reps - 3 s contração, 3 s intervalo) utilizadas para causar fadiga muscular, monitoradas pela frequência mediana (FMD) da eletromiografia do VL, reto femoral e vasto medial. Antes e após o protocolo de fadiga, imagens de ultrassonografia do VL foram obtidas para mensuração da espessura muscular, comprimento de fascículo e ângulo do fascículo. O pico de torque isométrico (PT-ISM) e TDTs em janelas de 50 ms foram calculados para cada CVIM. As TDTs foram calculadas em valores absolutos e normalizadas pelo PT-ISM. Resultados: A fadiga foi confirmada devido a reduções significativas da FMD dos três músculos. Após a fadiga, o PT-ISK foi reduzido de 239,0 ± 47,91 para 177,3 ± 34,96 Nm, e o PT-CVIM de 269,5 ± 45,63 para 220,49 ± 46,94 Nm. Todos os valores de TDT absolutos apresentaram-se significativamente diferentes após o protocolo de fadiga. Contudo, as TDTs normalizadas não demonstraram diferença significativa. Não foram observadas diferenças significativas na arquitetura muscular do VL. Conclusões: A redução da capacidade explosiva ocorreu de maneira concomitante com a redução da força máxima evidenciada pela falta de alterações na TDT normalizada. Nível de Evidência III.

Cardiorespiratory function of patients with adolescent idiopathic scoliosis / Função cardiorrespiratória de pacientes com escoliose idiopática do adolescente / Función cardiorrespiratoria de pacientes con escoliosis idiopática del adolescente

ABSTRACT Objective: Adolescent idiopathic scoliosis (AIS) is a spinal deformity that can cause cardiorespiratory dysfunction, contributing to decreases in tolerance for aerobic exercise (TAE) and in functionality. The objective is to assess the TAE and lung capacity of patients who underwent corrective AIS surgery in the pre- (PRE) and postoperative (POST) periods. Methods: Sixty individuals, PRE (n=30, age: 18.5±2.4 years) and POST (n=30, age: 24.5±4.5 years), participated in the study. The forced vital capacity (FVC), the forced expiratory volume in the first second (FEV1) and the FEV1/FVC ratio, as well as the maximum inspiratory and expiratory pressure were verified. The TAE was assessed by the distance travelled in the 6-minute walk test (6MWT), together with blood pressure, heart rate, respiratory rate and peripheral oxygen saturation measured at the beginning and at the end of the test. Results: A mild restrictive pattern in lung function and reduced expiratory muscle strength were observed in both groups, but with no difference between the PRE and POST groups. No difference was found between the PRE (534±67.1 m) and POST (541± 69.5 m) groups for the distance travelled in the 6MWT, though both were below the predicted percentage (82.8±10.0% and 84.8±10.9%, respectively). Hemodynamic and respiratory changes caused by the 6MWT were observed, except for the peripheral oxygen saturation. Conclusion: The results suggest that even after surgical correction, patients with AIS continue to have low TAE. Level of evidence III; Therapeutics Study - Investigation of Treatment Results / Case-control study.

RESUMO Objetivo: A escoliose idiopática do adolescente (EIA) é uma deformidade da coluna que pode ocasionar disfunções cardiorrespiratórias, contribuindo para a diminuição da tolerância ao exercício aeróbio (TEA) e da funcionalidade. O objetivo é avaliar a TEA e a capacidade pulmonar em pacientes no pré (PRÉ) e pós-operatório (PÓS) de correção da EIA. Métodos: Participaram 60 indivíduos PRÉ (n = 30, idade: 18,5 ± 2,4 anos) e PÓS (n = 30, idade: 24,5 ± 4,5 anos). A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1) e a razão VEF1/CVF, assim como as pressões inspiratória e expiratória máximas, foram verificados. A TEA foi avaliada pela distância percorrida no teste de caminhada de 6 minutos (TC6), acompanhado de medidas de pressão arterial, frequência cardíaca, frequência respiratória e saturação periférica de oxigênio no início e no final do teste. Resultados: Um padrão restritivo leve na função pulmonar e força da musculatura expiratória reduzida foram observados em ambos os grupos, mas sem diferença entre PRÉ e PÓS. Não foi encontrada diferença entre PRÉ (534 ± 67,1 m) e PÓS (541 ± 69,5 m) para a distância percorrida no TC6, abaixo do predito para ambos os grupos (82,8 ± 10,0% e 84,8 ± 10,9%, respectivamente). Foram observadas alterações hemodinâmicas e respiratórias provocadas pelo TC6, exceto para a saturação periférica de oxigênio. Conclusões: Os resultados sugerem que mesmo após a correção cirúrgica os pacientes com EIA continuam apresentando baixa TEA. Nível de evidência III; Estudos terapêuticos - Investigação dos Resultados do Tratamento / Estudo de caso-controle.

RESUMEN Objetivo: La escoliosis idiopática del adolescente (EIA) es una deformidad de la columna que puede causar disfunciones cardiorrespiratorias, contribuyendo para la disminución de la tolerancia al ejercicio aeróbico (TEA) y de la funcionalidad. El objetivo es evaluar la TEA y la capacidad pulmonar en pacientes en el pre (PRE) y postoperatorio (POS) de corrección de la EIA. Métodos: Participaron 60 individuos PRE (n=30, edad: 18,5±2,4 años) y POS (n=30, edad: 24,5±4,5 años). Fueron verificadas la capacidad vital forzada (CVF), el volumen espiratorio forzado en el primer segundo (VEF1) y la razón VEF1/CVF, así como las presiones inspiratoria y espiratoria máximas. La TEA fue evaluada por la distancia recorrida en el test de caminata de 6 minutos (TC6), acompañado de mediciones de presión arterial, frecuencia cardíaca, frecuencia respiratoria y saturación de oxígeno al inicio y al final del test. Resultados: Fueron observados un patrón restrictivo leve y fuerza muscular espiratoria reducida en ambos grupos, pero sin diferencia entre PRE y POS. No fue encontrada diferencia entre PRE (534 ± 67,1 m) y POS (541 ± 69,5 m) para la distancia recorrida en el TC6, por debajo de los predicho para ambos grupos (82,8 ± 10,0% y 84,8 ± 10,9%, respectivamente). Se observaron alteraciones hemodinámicas y respiratorias provocadas por el TC6, excepto para la saturación periférica de oxígeno. Conclusiones: Los resultados sugieren que incluso después de la corrección quirúrgica, los pacientes con EIA continúan presentando baja TEA. Nivel de evidencia III; Estudios Terapéuticos - Investigación de los Resultados del Tratamiento / Estudio de caso-control.

Bodyweight distribution between limbs, muscle strength, and proprioception in traumatic transtibial amputees: a cross-sectional study.

OBJECTIVES: To evaluate how transtibial amputation (TT) affects bodyweight distribution, voluntary knee joint position sense (JPS), and quadriceps (QUA) and hamstrings (HAM) strength in prosthetized patients. METHODS: Only TT patients who had been prosthetized for more than one year were included, and an age-paired able-bodied group was used as control. The participants stood on force plates with their eyes open to measure bodyweight distribution between the limbs. Knee voluntary JPS was assessed by actively reproducing a set of given arbitrary joint angles using a video analysis approach, and QUA and HAM strength were assessed isometrically with a hand-held dynamometer. RESULTS: Sixteen TT subjects (age: 39.4±4.8 years) and sixteen age-paired control subjects (age: 38.4±4.3 years) participated in the study. The amputees supported their bodyweight majorly on the sound limb (54.8±8.3%, p<0.001). The proprioceptive performance was similar between the amputated (absolute error (AE): 2.2±1.6°, variable error (VE): 1.9±1.6°, constant error (CE): -0.7±2.0°) and non-amputated limbs (AE: 2.6±0.9°, VE: 2.1±0.9°, CE: 0.02±2.3°), and was not different from that of control subjects (AE: 2.0±0.9°, VE: 1.4±0.4°, CE: -1.1±1.7°). There was a considerable weakness of the QUA and HAM in the amputated limb compared with the sound limb and control subjects (p<0.001 both). CONCLUSIONS: The asymmetric bodyweight distribution in the transtibial amputees was not accompanied by a reduction in knee proprioception. There was significant weakness in the amputated limb, which could be a potential issue when designing rehabilitation programs.

Bodyweight distribution between limbs, muscle strength, and proprioception in traumatic transtibial amputees: a cross-sectional study

OBJECTIVES: To evaluate how transtibial amputation (TT) affects bodyweight distribution, voluntary knee joint position sense (JPS), and quadriceps (QUA) and hamstrings (HAM) strength in prosthetized patients. METHODS: Only TT patients who had been prosthetized for more than one year were included, and an age-paired able-bodied group was used as control. The participants stood on force plates with their eyes open to measure bodyweight distribution between the limbs. Knee voluntary JPS was assessed by actively reproducing a set of given arbitrary joint angles using a video analysis approach, and QUA and HAM strength were assessed isometrically with a hand-held dynamometer. RESULTS: Sixteen TT subjects (age: 39.4±4.8 years) and sixteen age-paired control subjects (age: 38.4±4.3 years) participated in the study. The amputees supported their bodyweight majorly on the sound limb (54.8±8.3%, p<0.001). The proprioceptive performance was similar between the amputated (absolute error (AE): 2.2±1.6°, variable error (VE): 1.9±1.6°, constant error (CE): -0.7±2.0°) and non-amputated limbs (AE: 2.6±0.9°, VE: 2.1±0.9°, CE: 0.02±2.3°), and was not different from that of control subjects (AE: 2.0±0.9°, VE: 1.4±0.4°, CE: -1.1±1.7°). There was a considerable weakness of the QUA and HAM in the amputated limb compared with the sound limb and control subjects (p<0.001 both). CONCLUSIONS: The asymmetric bodyweight distribution in the transtibial amputees was not accompanied by a reduction in knee proprioception. There was significant weakness in the amputated limb, which could be a potential issue when designing rehabilitation programs.