Método de ensaio biomecânico para análise da isometricidade na reconstrução do ligamento patelofemoral medial

Abstract

Objective: To present a biomechanical device for evaluating medial patellofemoral ligament (MPFL) reconstruction and its isometricity. Methods: An accessible biomechanical method that allowed application of physiological and non-physiological forces to the knee using a mechanical arm and application of weights and counterweights was developed, so as to enable many different evaluations and have a very accurate measurement system for distances between different structures, for analysis on experiments. This article describes the assembly of this system, and suggests some practical applications. Six cadaver knees were studied. The knees were prepared in a testing machine developed at the Biomechanics Laboratory of IOT--HCFMUSP, which allowed dynamic evaluation of patellar behavior, with quantification of patellar lateralization beRev Bras Ortop. 2012;47(5):598-605

Double Bundle Medial Patellofemoral Ligament Reconstruction

“…The two ends of the graft were sutured separately by the anchors. The first bundle, considered as the inferior straight bundle, was set at 30° of flexion; and subsequently, the superior oblique bundle was set at 60° of flexion [7,15,24]. The required tension was checked by the mobility of the patella, which can reach glide approximately 2 quadrants.…”

“…Thus, reconstruction of the two bands could increase the stability during the first flexion angles around 30°. The function of the MPFL at greater angles requires more elucidative studies [8][9][10][11][12][13][14][15].…”

Reconstrução do ligamento patelofemoral medial com o terço medial do tendão patelar no tratamento da instabilidade recidivante da patela: resultados a médio e longo prazo

“…Para tensionamento final do enxerto, optou-se pela fixação femoral com o joelho entre 45 e 60º de flexão, por ser mais fácil o controle da centralização da patela na tróclea femoral. Esta posição também foi recomendada por Sadigursky et al (139) , na sua análise biomecânica realizada com o mesmo tipo de enxerto do TP, e por outros estudos clínicos e biomecânicos com diferentes tipos de enxertos (42,84,94,104,(140)(141)(142) . E, apesar de seguir os princípios da referida técnica, o autor preferiu não realizar a sutura do enxerto junto ao músculo VMO, conforme a descrição original, visto a inconstante presença de conexão entre este músculo e o LPFM conforme relatado por Steensen et al (65) em 2004 e corroborado posteriormente por Placella et al (68) .…”