Rehabilitation training using a single-joint type hybrid assistive limb for the knee after anterior cruciate ligament reconstruction: an initial case report indicating safety and feasibility.

[Purpose] The aim of this report was to describe the safety, feasibility, and efficacy of rehabilitation by knee extension and flexion training using the knee single-joint hybrid assistive limb in a patient after anterior cruciate ligament reconstruction. [Participant and Methods] A 33 year-old male underwent an arthroscopic procedure for anatomic single-bundle anterior cruciate ligament reconstruction with a semitendinosus tendon autograft. Rehabilitation training using the knee single-joint hybrid assistive limb was initiated at postoperative week 18 and repeated weekly for 3 weeks. The patient performed five sets of the knee single-joint hybrid assistive limb-assisted knee-extension-flexion exercises per session at a frequency of 10 exercises/set. [Results] The peak extension torque at all velocities with the limb symmetry index was higher after the hybrid assistive limb intervention (post-intervention) than before using it (pre-intervention). Peak flexion torques at 60°/s and 300°/s of limb symmetry index were higher post-intervention than pre-intervention. The range of motion in extension and flexion improved from -2° (pre-intervention) to -1° (post-intervention) and from 124° to 133°, respectively. The Lysholm score increased from 58 (pre-intervention) to 94 (post-intervention). [Conclusion] The knee single-joint hybrid assistive limb can be used safely for anterior cruciate ligament reconstruction training, without any adverse events. Our results indicate that the knee single-joint hybrid assistive limb training may improve muscle function, effectively overcoming dysfunction.

Análise fotocolorimétrica computadorizada dos efeitos da betametasona intra-articular sobre a concentração de proteoglicanos da matriz cartilaginosa de joelhos leporinos: influência do número de injeções intra-articulares / Computerized photocolorimetric analysis of the effects of intraarticular betamethasone on the proteoglycan concentration of leporine knee cartilage matrix: influence of the number of intraarticular injections

OBJETIVO: Analisar os efeitos da injeção repetida de betametasona na concentração de proteoglicanos da cartilagem articular do joelhos normais de coelhos californianos de ambos os sexos. MÉTODOS: Os animais foram randomizados em oito grupos de dez animais cada. Três grupos controle (injeção ou não de solução salina isotônica) e cinco grupos de estudo - doses terapêuticas, repetidas ou não, de betametasona injetadas no joelho direito de cada coelho, com intervalos semanais. Após oito dias da última injeção prevista, cortes histológicos da cartilagem das áreas de apoio dos platôs tibiais foram corados com hematoxilina e eosina para análise por microscopia óptica, e com safranina O para a pesquisa da quantidade de proteoglicanos. A intensidade da coloração da safranina O foi quantificada em aparelho de histomorfometria, composto por microscópio Olympus BX 50 e microcomputador com software Image Pro-plus 4.5Ò. RESULTADOS: Não houve diferenças nos animais que tiveram seus joelhos injetados com betametasona uma, duas e quatro vezes quando comparados com os grupos controle. Nos animais que receberam seis e oito aplicações a intensidade da coloração com safranina O reduziu-se significativamente (p < 0,05) quando comparada tanto com grupos controle quanto com os outros de estudo. CONCLUSÃO: Foi possível demonstrar redução da concentração de proteoglicanos na matriz cartilaginosa articular dependente do efeito deletério cumulativo das repetidas injeções intra-articulares de betametasona.

OBJECTIVE: To study the effects of repeated injections of betamethasone on proteoglycan concentration in the articular cartilage of normal knees of Californian rabbits of both sexes. METHODS: Eighty animals were randomly divided into eight groups of ten animals each. Three control groups (saline solution injected or not) and five study groups - therapeutical doses, repeated or not, of betamethasone injected into the right knee of each animal at weekly intervals. After eight days from the last injection, sections of articular cartilage from tibial plateaus collected from weight-bearing surfaces were stained with hematoxylin and eosin for light microscopy analysis and with safranin O for the proteoglycan content assay. The staining intensity of safranin O was quantified by histomorphometry using an Olympus BX 50 microscope and a microcomputer with the Image Pro-plus 4.5Ò software. RESULTS: Animals receiving one, two and four betamethasone injections showed no differences when compared to normal controls. Animals receiving six and eight injections had a significant decrease in safranin O staining intensity (p < 0.05) as compared to the control groups and the other study groups. CONCLUSION: A decrease in the concentration of articular cartilage proteoglycans dependent on repeated betamethasone injection was effectively demonstrated.