Levine A M, Drennan J C
J Bone Joint Surg Am. 1982 Oct;64(8):1158-63.
The metaphyseal-diaphyseal angle is the angle created by the intersection of a line through the transverse plane of the proximal tibial metaphysis with a line perpendicular to the long axis of the tibial diaphysis. This angle represents the degree of deformity of the proximal end of the tibia in a patient with clinical bowleg deformity and permits early differentiation between infantile tibia vara and physiological bowleg, before the appearance of the radiographic changes of tibia vara. In twenty-nine of thirty affected extremities with an initial metaphyseal-diaphyseal angle of more than 11.0 degrees, radiographic changes of tibia vara later developed. However, only three of fifty-eight extremities with a metaphyseal-diapyseal angle of 11.0 degrees or less had any of the diagnostic changes. In addition, the ratio of the metaphyseal-diaphyseal angle (proximal tibial metaphyseal deformity) to the tibiofemoral angle (deformity of the entire extremity) showed that approximately 60 per cent of the deformity in tibia vara originates in the proximal metaphysis, whereas only 20 per cent of the deformity in physiological bowing originates there. The metaphyseal-diaphyseal angle allows accurate early diagnosis of bowleg deformity, as well as accurate assessment of its progression.
干骺端-骨干角是由一条穿过胫骨近端干骺端横平面的线与一条垂直于胫骨干长轴的线相交形成的角度。这个角度代表了临床膝内翻畸形患者胫骨近端的畸形程度，并且在胫骨内翻的影像学改变出现之前，能够早期区分婴儿型胫骨内翻和生理性膝内翻。在最初干骺端-骨干角大于11.0度的30个受累肢体中，有29个后来出现了胫骨内翻的影像学改变。然而，在58个干骺端-骨干角为11.0度或更小的肢体中，只有3个出现了任何诊断性改变。此外，干骺端-骨干角（胫骨近端干骺端畸形）与胫股角（整个肢体的畸形）的比值显示，胫骨内翻中约60%的畸形起源于近端干骺端，而生理性膝内翻中只有20%的畸形起源于此。干骺端-骨干角能够准确地早期诊断膝内翻畸形，并准确评估其进展情况。
