Elastic external fixator between first and second bone portions (O1, O2), comprising: * a helical spring (11) defined according to a first axis (12), * a first body (14), * first means (15 ) for cooperatively mounting said first body (14) with said helical spring (11), * a first pin (16) suitable for being fixed on said first bone portion (O1), said first pin (16) being oblong in shape defined according to a second axis (17), said helical spring being able to rotate with respect to said first body around the first axis (12), and by which the first pin (16) crosses said helical spring (11), * means (19) for mounting said first pin (16) in cooperation with said first body (14) so that said second axis (17) makes with the first axis (12) a non-zero angle, * a second body (22) that it comprises a base (122) and a projecting part (44) integral, by one (46) of its ends, to said base (122), is one (47) of the ends of the helical spring (11) mounted cooperatively around said protruding part (44), and * means (24) for joining said second body (22) with said second bone portion (O2) and said helical spring (11), characterized in that this protruding part (44) has a relatively continuous increasing cross-section from its free end (48) to its end (46) integral with said base (122), having one ( 47) of the ends of said helical spring an inner cross section superior to the cross section of the free end (48) of said protruding part and inferior to the cross section of the end (46) of said protruding part integral to said base (122) .Fijador externo elástico entre unas primera y segunda porciones de hueso (O1, O2), que comprende: * un resorte helicoidal (11) definido según un primer eje (12), * un primer cuerpo (14), * unos primeros medios (15) para montar en cooperación dicho primer cuerpo (14) con dicho resorte helicoidal (11), * un primer pasador (16) apto para ser fijado sobre dicha primera porción de hueso (O1), siendo dicho primer pasador (16) de forma oblonga definida según
