A telescopic strut for use with an external fixator includes a tube and a rod, especially a threaded rod being in threaded engagement with the tube. The tube comprises at least one hole for accommodating a ball, the ball having the spherical shape for engagement with the threaded rod. A sleeve is provided on the portion of the tube comprising the hole. The sleeve comprises a non-spherical inner cross-section. The greater diameter of the sleeve has a dimension which is at least the sum of the outer diameter of the threaded rod plus the diameter of an accommodating ball for allowing direct axial movement of the threaded rod against the tube in such a rotational position of the sleeve. The lesser diameter has a dimension to place the ball within the threaded rod for allowing a rotational movement of the threaded rod against the tube.