A resilient external fixator between first and second bone portions includes a spring 11 of axis 12, a body 14, elements 15 for mounting the body to co-operate with the spring, a pin 16 fastened to the first bone and passing through the spring, a second body 22 including a base 122 and a projecting portion 44 that is secured to the base, one end 47 of the helical spring being mounted in co-operation about the projecting portion, and elements 24 for connecting the body with the bone portion O2 and the helical spring. The projecting portion presents a section that increases in continuous manner from its free end 48 until it reaches its end 46, the end 47 of the spring having an inside section that is greater than the section of the free end 48 and less than the cross-section of the end 46.