An external bone fixation system (100, 200, 300, 400), comprising: a first platform (120, 220, 320, 420) defining an opening and configured to couple to a first bone segment; a second platform (130, 230, 330, 430) defining an opening and configured to couple to a second bone segment; and at least six length-adjustable strut assemblies (110, 210, 310, 410) each including an externally threaded rod portion (12, 212, 312, 412) translatable through an internally threaded strut body portion (5, 205, 305, 405), the externally threaded rod portion (12, 212, 312, 412) of each strut assembly (110, 210, 310, 410) being coupled to one of the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) via a respective joint and the strut body portion (5, 205, 305, 405) of each strut assembly (110, 210, 310, 410) being coupled to the other of the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) via a respective joint; and wherein the strut assemblies (110, 210, 310, 410) are coupled to the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) in pairs of strut assemblies (110, 210, 310, 410) spaced about the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430), and wherein the pairs of strut assemblies (110, 210, 310, 410) each include a first strut assembly (110, 210, 310, 410) coupled to the respective platform (120, 220, 320, 420; 130, 230, 330, 430) via the joint of the externally threaded rod portion (12, 212, 312, 412) thereof and a second strut assembly (110, 210, 310, 410) coupled to the respective platform (120, 220, 320, 420; 130, 230, 330, 430) via the joint of the strut body portion (5, 205, 305, 405) thereof; the external bone fixation system (100, 200, 300, 400) characterized by at least one add-on externally threaded rod portion (13, 213, 313, 413) attachable to one of the externally threaded rod portions (12, 212, 312, 412) when the strut assembly (110, 210, 310, 410) is coupled to the first or second platform (120, 220, 320, 420, 130, 230, 330, 430). a first platform (120, 220, 320, 420) defining an opening and configured to couple to a first bone segment; a second platform (130, 230, 330, 430) defining an opening and configured to couple to a second bone segment; and at least six length-adjustable strut assemblies (110, 210, 310, 410) each including an externally threaded rod portion (12, 212, 312, 412) translatable through an internally threaded strut body portion (5, 205, 305, 405), the externally threaded rod portion (12, 212, 312, 412) of each strut assembly (110, 210, 310, 410) being coupled to one of the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) via a respective joint and the strut body portion (5, 205, 305, 405) of each strut assembly (110, 210, 310, 410) being coupled to the other of the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) via a respective joint; and wherein the strut assemblies (110, 210, 310, 410) are coupled to the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430) in pairs of strut assemblies (110, 210, 310, 410) spaced about the first and second platforms (120, 220, 320, 420; 130, 230, 330, 430), and wherein the pairs of strut assemblies (110, 210, 310, 410) each include a first strut assembly (110, 210, 310, 410) coupled to the respective platform (120, 220, 320, 420; 130, 230, 330, 430) via the joint of the externally threaded rod portion (12, 212, 312, 412) thereof and a second strut assembly (110, 210, 310, 410) coupled to the respective platform (120, 220, 320, 420; 130, 230, 330, 430) via the joint of the strut body portion (5, 205, 305, 405) thereof; the external bone fixation system (100, 200, 300, 400) characterized by at least one add-on externally threaded rod portion (13, 213, 313, 413) attachable to one of the externally threaded rod portions (12, 212, 312, 412) when the strut assembly (110, 210, 310, 410) is coupled to the first or second platform (120, 220, 320, 420, 130, 230, 330, 430).