What is the Donjoy Drytex Playmaker Knee Brace? superb sports & skiing hinged knee brace for ACL knee ligament injuries & cartilage tears. Has hi tech hinge system that can be locked at 9 different ranges of knee bend. When can I use it? For instability of the knee following partial or complete tears of the ACL (Anterior Cruciate Ligament). Donjoy recommend that this brace is used for mild instability. For moderate to severe instability Donjoy recommend the Donjoy Armor with Fourcepoint Knee Brace or the Donjoy Legend Knee Brace. The lightweight polyester-nylon weave Drytex fabric with pull on sleeve design eliminates neoprene allergies & improves comfort, making the Donjoy Drytex Playmaker ideal for sports & skiing use. Which size do I need? Measure around the thigh, 15cm (6") above the centre of the knee. If measurements indicate two different sizes, choose the larger size. This product can be used on either the left or the right knee. X-Small 33-39cm (13-15.5") Small 39-47cm (15.5-18.5") Medium 47-53cm (18.5-21") Large 53-60cm (21-23.5") X-Large 60-67cm (23.5-26.5") XX-Large 67-75cm (26.5-29.5") How does it work? The Polycentric hinge reproduces normal knee joint movement & increases the amount of knee stability. Also features the Donjoy Four Points of Leverage™ system which restores knee joint stability by preventing movement of the shin in relation to the thigh. A simple pin system within the hinge allows knee range of motion to be set at 0, 10, 20, 30, 40, 45, 60, 75 & 90 degrees of knee motion using a screwdriver. This makes it the brace of choice if you want to block specific knee movements to provide protection. It reduces the forces on the Anterior Cruciate Ligament (ACL), which provides stability & protection during rehab or following ACL surgery.