RU2397736C1 - Hip joint endoprosthesis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to the field of medicine, specifically to traumatology-orthopedics. The endoprosthesis contains a pelvic component, a head, a neck, a trochlear section, a foot with cover enwrapping it, and a supporting platform. The foot conically tapers in the distal part, and along the entire length is equipped with a buttress. The cover is made in the form of a tube from biologically inert, elastically flexible material. Proximal part of the has a smooth sleeve fitted with the collar, under which there are radially arranged holes, below which along the entire length of the tube in the walls there are cross-cutting slit notches at equal distances from each other, which converge at the distal plugged end. The inner tube diametre is less than the outer diametre of the foot and has a buttress corresponding to the foot buttress.

EFFECT: invention provides increase of the foot stability of endoprosthesis in medullary canal of femur.

2 cl; 2 dwg

Description

The invention relates to medicine, specifically to orthopedics traumatology. It is used to replace a deformed or damaged joint injury.

A significant number of endoprosthesis designs are known, but each of them, along with positive qualities, is also characterized by some disadvantages. To date, the problem of implant stability, which arises as a result of a conflict in the metal-bone system, has not been completely solved. In this area, searches continue in different directions: various methods are proposed for both cement and cementless fixation of the endoprosthesis leg in the medullary canal of the femur.

The closest in its technical solution to the claimed device is an endoprosthesis of the hip joint [1]. In this design, a cover made in the form of a "netting" net is placed on the tubular leg. Here, the calculation is made that when the leg is inserted into the bone bed, the cover wedges between the leg and bone tissue, thereby ensuring the fixation of the endoprosthesis. However, this type of fixation cannot be considered reliable enough, since a smooth metal leg can slide along sections of the mesh, which can lead to the danger of instability of the leg.

The invention consists in a combination of essential features sufficient to achieve the desired technical result, consisting in increasing the stability of the leg of the endoprosthesis in the medullary canal of the femur.

The essence of the invention lies in the fact that the hip joint implant contains a pelvic component, a head, a neck, a trochanteric section, a leg with a cover covering it, and a support platform. The leg is tapered tapering in the end section and is equipped with a persistent thread along the entire length. The cover is made in the form of a tube of a biologically inert, elastic material. The proximal part of the tube has a smooth cuff, equipped with a clamp, under which there are radially located holes, below which, through the entire length of the tube, through the slots are made at equal distances from each other through slots, converging at the distal, muffled end. The inner diameter of the tube is smaller than the outer diameter of the leg and has a thread corresponding to the thread of the leg. In the assembled state, the plane of the contacting surfaces of the ears of the clamp and the vertical plane of the axis of the neck coincide, passing through the axis of the legs.

Equipping the endoprosthesis leg with a threaded thread prevents it from cutting into the elastic material of the tube.

The presence of longitudinal slit-like slots in the tube wall provides an increase in its outer diameter when screwing the leg into the body, which has an inner diameter smaller than the outer diameter of the leg, due to the expansion of the slots and provides fixation of the leg in the medullary canal.

The presence of radial holes-compensators in the distal part of the leg prevents the possibility of longitudinal rupture of the tube wall when screwing into the tube legs.

The conical narrowing of the end section of the leg provides a gradual expansion of the tube when the legs are screwed into it.

The presence of a clamp at the proximal end of the tube ensures fixation of the tube-leg connection, allows you to orient the deviation of the neck of the endoprosthesis during its installation.

The use of an elastic material for the manufacture of the tube provides cushioning, eliminating the risk of bone sinking with a metal leg and loss of stability of the endoprosthesis.

The device is shown in the accompanying illustrations in a disassembled form: Fig. 1 shows a leg; Fig. 2 shows a tube in section and with sections.

The device comprises a pelvic component 1, a head 2, a neck 3, a spit section 4, a support pad 5 in the form of a disk, made in the under spit region. Leg 6 is equipped with a persistent thread, its end section is conically narrowed. The cover covering the leg 6 is a tube 7 made of a biologically inert, elastic material. On the tube 7 there are longitudinal slots 8 arranged at equal distances from each other, starting from the radially located holes 9 and converging on the distal, muffled end of the tube 7. The proximal end of the sheath in the form of a tube has a smooth cuff equipped with a collar 10, the ears of which are pulled together the working position of the screw 11. On the inner surface of the proximal end of the tube 7 is a thread that responds to the persistent thread of the legs 6.

The device is used as follows.

One of the commonly accepted surgical approaches exposes the area of the hip joint, excise, during the operation, scar-changed tissues. The head and neck of the thigh are resected. The acetabulum of the pelvis is processed and the pelvic component of the prosthesis is fixed in it. The bone marrow canal of the thigh is processed with a scan under the elastoplastic endoprosthesis tube and the latter is inserted into the canal by free-landing to the stop of the lower edge of the clamp, which is in a relaxed state, in the sawdust of the femur. The case in the form of a tube is installed so that the retrotorsion of the ears of the clamp is equal to the desired neck antetorsia. Screw the leg into the cover until the base plate is in firm contact with the proximal ends of the tube and clamp. Tighten the clamp. The wound is sutured in layers.

Postoperative management is typical for patients undergoing hip replacement surgery.

Information sources

1. RF patent No. 2175533, A61F 2/32, BI 2001, No. 31.

Claims (2)

1. An endoprosthesis of a hip joint containing a pelvic component, a head, a neck, a spit, a leg with a cover covering it, and a support platform, characterized in that the leg is tapered in the end section and is equipped with a persistent thread along the entire length, the cover is made in the form tubes of a biologically inert, elastic material, the proximal part of the tube has a smooth cuff equipped with a clamp, under which there are made radially located holes, below which, for the entire length of the tube, the walls are made at equal sizes melting from each other, through slit-like slots converging at the distal, muffled end, the inner diameter of the tube is smaller than the outer diameter of the legs and has a thread corresponding to the thread of the leg. 2. The endoprosthesis of the hip joint according to claim 1, characterized in that in the assembled state the plane of the contacting surfaces of the ears of the clamp and the vertical plane of the axis of the neck coincide, passing through the axis of the legs.

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