An angle limitation system for an orthopedic brace comprising: a hinge assembly (18a, 18b) rotatably receiving an upper strut (14a, 14b) and a lower strut (16a, 16b) and having a hinge plate and a hinge assembly cap; an extension angle limit element removably insertable in an anterior port between the hinge plate and hinge assembly cap, said extension angle limit element having a body with limiting surfaces adapted to engage mating faces indented in anterior edges of the upper and lower strut; a flexion angle limit element removably insertable in a posterior port between the hinge plate and hinge assembly cap, said flexion angle limit element having a body with limiting surfaces adapted to engage mating faces indented in posterior edges of the upper and lower strut; and, engagement mechanisms adapted to releasably secure the flexion angle limit element in the posterior port and the engagement angle limit element in the anterior port; characterised in that the engagement mechanisms comprise a resilient lever (74,88) extending from each body, said resilient lever engaged in a mating channel (76, 90) in the hinge assembly cap to prevent extraction of the body from the respective anterior or posterior port, the hinge assembly cap having apertures each extending through the hinge assembly cap into the associated mating channel said apertures being configured to receive tool inserted to engage the resilient lever whereby depression of the lever by the tool disengages the lever from the mating channel. a hinge assembly (18a, 18b) rotatably receiving an upper strut (14a, 14b) and a lower strut (16a, 16b) and having a hinge plate and a hinge assembly cap; an extension angle limit element removably insertable in an anterior port between the hinge plate and hinge assembly cap, said extension angle limit element having a body with limiting surfaces adapted to engage mating faces indented in anterior edges of the upper and lower strut; a flexion angle limit element removably insertable in a posterior port between the hinge plate and hinge assembly cap, said flexion angle limit element having a body with limiting surfaces adapted to engage mating faces indented in posterior edges of the upper and lower strut; and, engagement mechanisms adapted to releasably secure the flexion angle limit element in the posterior port and the engagement angle limit element in the anterior port; characterised in that the engagement mechanisms comprise a resilient lever (74,88) extending from each body, said resilient lever engaged in a mating channel (76, 90) in the hinge assembly cap to prevent extraction of the body from the respective anterior or posterior port, the hinge assembly cap having apertures each extending through the hinge assembly cap into the associated mating channel said apertures being configured to receive tool inserted to engage the resilient lever whereby depression of the lever by the tool disengages the lever from the mating channel. from each body, said resilient lever engaged in a mating channel (76, 90) in the hinge assembly cap to prevent extraction of the body from the respective anterior or posterior port, the hinge assembly cap having apertures each extending through the hinge assembly cap into the associated mating channel said apertures being configured to receive tool inserted to engage the resilient lever whereby depression of the lever by the tool disengages the lever from the mating channel.