An angle limitation system for an orthopedic brace employs a hinge assembly rotatably receiving an upper strut and a lower strut and having a hinge plate and a hinge assembly cap. An extension angle limit element is removably insertable in an anterior port between the hinge plate and hinge assembly cap. The extension angle limit element has a body with limiting surfaces adapted to engage mating faces indented in the anterior edges of the upper and lower strut. A flexion angle limit element is removably insertable in a posterior port between the hinge plate and hinge assembly cap. The flexion angle limit element has a body with limiting surfaces adapted to engage mating faces indented in the posterior edges of the upper and lower strut. Engagement mechanisms are adapted to releasably secure the flexion angle limit element in the posterior port and the engagement angle limit element in the anterior port.