The compressive orthosis comprises a leg portion (16) in a compressive knit suitable for delivering degressive therapeutic retention. The compressive knit comprises a net type knit knitted with a weft thread (22) of elastic material, advantageously in combination with at least one background thread (24, 26, 28), likewise in elastic material, and of smaller weight than the weft thread. The assembly forms a deformable array of substantially hexagonal cells (30) which, on being deformed, present greater elastic return force in the horizontal direction (H) than in the vertical direction (V).