INTRAMEDULLARY TELESCOPIC PIN Russian patent published in 2010 - IPC A61B17/72 

FIELD: medicine.

SUBSTANCE: intramedullary telescopic pin contains a hollow cylinder and a retractable rod and clickworks with face falling of ratchet teeth mounted therein. The cylinder and the rod are provided with locking holes to block the cylinder and the rod respectively to proximal and distal fragments after osteotomy. The hollow cylinder has a female thread and a longitudinal rectangular groove which is located along a cylinder axis. The retractable rod is formed by a threaded bushing, a distractor and a stop sleeve. End faces of the threaded bushing have the opposed ratchet teeth and joined with the ratchet teeth of the distractor and the stop sleeve to form control and stop clickworks respectively. The distractor, threaded bushing and stop sleeve are fastened by a fixing bolt which is spring-assisted through the stop sleeve and threaded bushing with respect to the distractor, passed through the holes of the stop sleeve and threaded bushing, and fixed in a blind hole formed in the distractor. The threaded bushing of the clickworks is connected with a cylinder cavity by a threaded connection for unidirectional motions of the retractable rod concerning the cylinder. On the stop sleeve, there is a rectangular flange perpendicular to the axis, located in longitudinal a groove of the cylinder, movable in the longitudinal direction, and has a width equal to that of the groove to prevent rotary motions. The distractor is provided with a five-sided flange arranged in the groove of the cylinder, movable transversally and forms a rotation angle setting mechanism with the groove. The five-sided flange has four lateral faces, two of which are parallel and located across the groove and shaped after equivalent isosceles trapezes, and two other are inclined lateral sides and form with the lateral face of the groove an angle equal to a sector angle of the clickworks, wherein each tooth is located. The thickness of a wall of the cylinder case makes 1/3 of the external diametre of the cylinder.

EFFECT: invention provides transformation of angular rotary-recurrent extremity motions to step translation of the retractable rod concerning the cylinder, high accuracy of the planned regenerate transport, improved conditions for formation and change of the bone regenerate and cutting time of regenerate hardening to bone density, reduced trauma of soft tissues and cutting time of treatment of the patients.

2 cl, 6 dwg