DETENT PIN SYSTEM FOR REPAIR ARTHRODESIS IN HEEL BONE FRACTURES Russian patent published in 2009 - IPC A61B17/56 A61F2/42 

FIELD: medicine.

SUBSTANCE: system consists of pin (1), number of calcaneostragaloid screws (2), guide (3), guide tubes, a drill, a depth gauge, a cannuled screw-driver, a wide-band impactor, a restraint drill, a reference angle pin and the other elements used within the system. Pin (1) represents a cylinder with a taper point; its blunt end is provided with threaded hole (12) and groove (13) to hold inserting or applicator guide (33). Besides, the pin is provided with two lateral edges (14) and two through holes (15 and 16) being partially threaded and related at the angle 10° to a horizontal. Screws (2) are cannuled (22) to be directed through the guide tubes. Screws (2) are threaded (21) at the distal end to be fixed in a spongy layer of ankle bone. The screw end is self-perforated and self-tapping. The screw head is threaded to be fixed in pin (1) with a hexagonal joint to the screw-driver to insert the screws thus ensuring more effective screwing down (2). Guide (3) consists of main support (31) containing surface guide hole (32) with extrinsic geometry of pin (1) to be inserted with applicator guide (33). From below, the guide is extended with two holes (36). Besides, it is provided with handle (38) attached to pickup elements (37), fastened to a spike pre-mounted in ankle bone, and applied as a reference axis and a support to control the pin (1) position with holder (39) provided on the end of handle (38). The guide tubes are two in number, except for a trocar tip to direct properly the various tools used to prepare the seat for calcaneostragaloid screws (2) and to position thereof. The other elements used within the system are the depth gauge for screw length metering (2), the cannuled screw-driver for inserting screws (2), the wide-band impactor for pin (1), a restraint drill for pin (1) seat preparation, and a reference angle pin for guide (3) support.

EFFECT: healing the damaged joint to be repaired, as far as possible posterior foot to avoid such other accompanying complications, as pressure increase syndrome in anatomic cavity, reflex sympathetic dystrophy, foot cushion syndrome, tarsal and peroneal canal syndrome evidently relieved owing to fracture reposition.

5 cl, 5 dwg