HIP JOINT ENDOPROSTHESIS PEDICLE Russian patent published in 2006 - IPC A61F2/32 

FIELD: medical engineering.

SUBSTANCE: device according to the first embodiment has axial canal, rod enclosed therein, slit windows as a set of slits longitudinally arranged in tiers having leaflets inside. The pedicle is tube of constant cross-section having plug on upper end and solid sharp lower end. Free ends of vertically arranged leaflets are directed upward in the upper pedicle segment and downward in the lower one. Leaflet ends have riffling on external surface. The leaflets are arranged at an angle of 120° on the external surface both in upper and lower segments. Leaflets belonging to upper and lower tier have 60° displacement relative to each other. The rod, resting on axial bearing of mating conic shape, is axially rotatable in pedicle cavity. Upper rod end has square cross-section and its upper and lower segments have threads of different orientation and bear threaded bushings with mating threads of different orientation and ring-shaped protrusions of triangular cross-section on their surfaces engageable with bevels available on thickened internal surfaces of end leaflet segments. Longitudinal slots engageable with anti-rotation pins built-in onto tube wall are available on bushing surfaces. The second embodiment has axial canal, rod enclosed therein, slit windows as a set of slits longitudinally arranged in tiers having leaflets inside. The pedicle is tube of constant cross-section having plug on upper end and solid sharp lower end. Slit windows are arranged on vertical axes along pedicle surface both in the upper and lower segment and displaced relative to each other at an angle of 120°. The windows belonging lower tier are displaced relative to each other at an angle of 60°. Upper pedicle segment has flat leaflets of free narrowing drop-shaped ends. The leaflets are mounted in slits with narrowed part edges along circular pedicle contour. The narrowed parts are directed upwards. The leaflets belonging lower pedicle part are directed with their narrowed parts downwards. Wide leaflet bases are rotatable about the axles fixed in pedicle wall and arranged in perpendicular to longitudinal leaflet axes. The rod is rotatable and placed in the pedicle cavity along its axis. It is supported by axial bearing of mating conic shape. Upper rod end has square cross-section. Its upper and lower segments have worms threaded in different orientation. The worms are engageable with end face surfaces of the wide leaflet bases manufactured as worm wheel segments and making worm-and-worm pairs with corresponding axle segments. The third embodiment has axial canal, rod enclosed therein, slit windows as a set of longitudinal slits arranged in tiers having leaflets mounted inside. Flat drop-shaped leaflets have wide bases. The pedicle is tube of constant cross-section having plug on upper end and solid sharp lower end. The slit windows are displaced relative to each other at an angle of 120° on the external pedicle surface both in its upper and lower segments. The windows belonging lower tier are displaced relative to each other at an angle of 60°. Upper rod end has square cross-section and the upper and lower rod segments have threads of different orientation. The upper and lower rod segments have bushings having mating threads. U-shaped sockets are available on bushing surfaces. Wide leaflet bases are rotatable about the axles fixed in U-shaped socket walls in perpendicular relation with longitudinal leaflet axes. The sockets and leaflets are mounted in the slits. The leaflets are turned with their narrowed portions upward in the upper pedicle segment and downward with their narrowed portions in the lower segment. Twisting springs are mounted between leaflets and one of socket walls. One spring end is fixed in leaflet and the other one in socket wall. The rod is rotatable and placed in the pedicle cavity thrusting against axial bearing of mating conic shape.

EFFECT: improved treatment results; high fixation stability in medullary canal.

4 cl, 3 dwg