A surgical cable tensioning system, comprising: a reaction frame (10; 62); a sliding platform (12; 104) within said reaction frame (10; 62), said platform being arranged to move linearly within said reaction frame along a first axis (14; 106); a clam-type cleat (16; 72; 108) attached to said sliding platform (12; 104), said clam-type cleat comprising: one or more V-shaped grooves, each of which comprises two arrays (22a, 22b) of opposing ridges that converge to form the V-shape, each of said V-shaped grooves having a longitudinal axis which is approximately parallel to said first axis and adapted to receive a length of cable (28; 66; 70, 72; 183) such that said received length of cable lies along an axis approximately parallel to said longitudinal axis of said one or more grooves, the ridges of each groove being tilted relative to an axis perpendicular to said longitudinal axis such that said length of cable (28; 66; 70, 72; 183) is progressively captured between the ridges of said opposing arrays (22a, 22b) as it settles toward the bottom of said V-shaped groove when moved in a first direction relative to said cleat (16; 72; 108), and such that said length of cable is disengaged from said cleat (16; 72; 108) by relaxing the axial force on the length of cable and moving the length of cable in a direction opposite said first direction; a threading assist device comprising at least one channel, each channel having a longitudinal axis which is approximately parallel to said first axis and adapted to receive a length of cable (28; 66; 70, 72; 183); and a linear tension mechanism (150, 152) coupled to said sliding platform (12; 104) and arranged to pull said sliding platform (12; 104) toward the proximal end of said reaction frame (10; 62) when actuated, characterized in that the surgical cable tensioning system further comprises a wrist joint which couples said threading assist device to the distal end of said reaction frame (10; 62) such that the distal end of said threading assist device can pivot up and down around a wrist joint axis which is perpendicular to said first axis. a reaction frame (10; 62); a sliding platform (12; 104) within said reaction frame (10; 62), said platform being arranged to move linearly within said reaction frame along a first axis (14; 106); a clam-type cleat (16; 72; 108) attached to said sliding platform (12; 104), said clam-type cleat comprising: one or more V-shaped grooves, each of which comprises two arrays (22a, 22b) of opposing ridges that converge to form the V-shape, each of said V-shaped grooves having a longitudinal axis which is approximately parallel to said first axis and adapted to receive a length of cable (28; 66; 70, 72; 183) such that said received length of cable lies along an axis approximately parallel to said longitudinal axis of said one or more grooves, the ridges of each groove being tilted relative to an axis perpendicular to said longitudinal axis such that said length of cable (28; 66; 70, 72; 183) is progressively captured between the ridges of said opposing arrays (22a, 22b) as it settles toward the bottom of said V-shaped groove when moved in a first direction relative to said cleat (16; 72; 108), and such that said length of cable is disengaged from said cleat (16; 72; 108) by relaxing the axial force on the length of cable and moving the length of cable in a direction opposite said first direction; one or more V-shaped grooves, each of which comprises two arrays (22a, 22b) of opposing ridges that converge to form the V-shape, each of said V-shaped grooves having a longitudinal axis which is approximately parallel to said first axis and adapted to receive a length of cable (28; 66; 70, 72; 183) such that said received length of cable lies along an axis approximately parallel to said longitudinal axis of said one or more grooves, the ridges of each groove being tilted relative to an axis perpendicular to said longitudinal axis such that said length of cable (28; 66; 70, 72; 183) is progressively captured between the ridges of said opposing arrays (22a, 22b) as it settles toward the bottom of said V-shaped groove when moved in a first direction relative to said cleat (16; 72; 108), and such that said length of cable is disengaged from said cleat (16; 72; 108) by relaxing the axial force on the length of cable and moving the length of cable in a direction opposite said first direction; a threading assist device comprising at least one channel, each channel having a longitudinal axis which is approximately parallel to said first axis and adapted to receive a length of cable (28; 66; 70, 72; 183); and a linear tension mechanism (150, 152) coupled to said sliding platform (12; 104) and arranged to pull said sliding platform (12; 104) toward the proximal end of said reaction frame (10; 62) when actuated, characterized in that the surgical cable tensioning system further comprises a wrist joint which couples said threading assist device to the distal end of said reaction frame (10; 62) such that the distal end of said threading assist device can pivot up and down around a wrist joint axis which is perpendicular to said first axis.