The orthosis includes an articulated framework made to be fixed on either side of the knee onto the thigh and lower leg, restraint straps attached to the framework and surrounding the thigh and lower leg leaving the patellar area free. The straps cross and are superimposed on each other on the posterior side next to the skin of the popliteal fossa at the same level as the center of rotation of the knee in order to prevent the anterior part of the tibia sliding forward. Each strap is held in a rigid guide on the lower leg and the thigh, while, where they cross at the popliteal fossa, they are held together by a non stretching sleeve. The first shortest strap is on the outside, as far posteriorly as possible and the last longest strap is on the inside, as far anteriorly as possible next to the skin of the popliteal fossa.
