A locking cap for a fracture fixation system according to an exemplary aspect of the present disclosure includes, among other things, a cap body that extends along a longitudinal axis between a proximal end and a distal end. An external thread extends around at least a portion of the cap body. A passage extends inside the cap body from the distal end toward the proximal end. An internal thread extends about a periphery of the passage along at least a portion of a length of the passage.