HIP JOINT ENDOPROSTHESIS Russian patent published in 2009 - IPC A61F2/32 

FIELD: medicine; orthopaedics and traumatology.

SUBSTANCE: endoprosthesis comprises a hip component, a head, a neck, a trochanteric portion, a leg with an axial canal, with stepped windows on the lateral surface comprising notches and provided with spring-loaded petals. The latter is covered with grooved faces while being pulled out and provided with a shaft arranged in said canal. Endoprosthesis is equipped with a guide disk with a shaft-hole and latching springs, a support ball and three-flange thrusters with faces to interact with internal surfaces of the petals. The leg has a uniform cross-section. It is provided with a distally dead end and pointed portion, its bottom comprises a partially hemispherical hollow. The stepped windows are perpendicular to the leg axis. Within each step, the windows are inclined at the angle 120 degrees to each other and step-biased at the angle 60 degrees. Internal surfaces of the petals are concave and congruous to external surfaces of said thrusters and variable cross-section: their thickness is decreased at the ends, while thicker bottoms are split lengthwise and forked. The guide disk is attached to internal surface of the leg. The shaft is provided with an axial faceted blind key hole in a proximal end face. Its proximal portion contains a fixed ratchet gear to interact with said for latching springs. Its distal end accommodates a partially hemispherical hollow. The shaft is rotatable in the guide disk of the case. The thrusters are fixed on the shaft between the disk and the distal end of the shaft. External surfaces of the thrusters interact with internal surfaces of the petals. The hollows are opposite and used to mount the support ball. The trochanteric portion of the leg is supplied with a key hole.

EFFECT: improved leg fixation stability ensured by higher contact area between leg fixation elements and bone tissue of femur.

2 cl, 5 dwg