RU2390318C1 - Femoral prosthesis - Google Patents

Abstract

FIELD: medicine. ^ SUBSTANCE: invention concerns medicine. Prosthesis comprises a cotyloid cavity, a spherical head, a neck and a leg. A proximal part of the neck and the cotyloid cavity represents sphere sections. The head is placed between the sphere sections to perform free rotation about all the axes. The head and contacting sphere sections are equipped with grooves. On sphere sections, the grooves are located on meridians converging in tanks on their poles. Face parts of the cotyloid cavity and the proximal part of the neck are connected by a casing made of an elastic corrugated tube forming a tight cavity filled with a biologically inert liquid with viscometric characteristics corresponding to those of the synovial fluid. The grooves on the head are located on parallels, meridians and in parallel to meridians. The meridian grooves converge on the head poles in the spherical tanks; the same tanks are located in crosslines of meridian and parallel grooves. In the head centre, there is a spherical cavity wherefrom the channels opening in the tanks on the head poles and in the crosslines of the grooves diverge. ^ EFFECT: invention provides improved functional qualities due to considerably decreased friction factor and increased wear resistance of the device components. ^ 4 dwg

Description

The invention relates to medicine, specifically to orthopedics traumatology. It is used to replace a pathologically altered, destroyed, as a result of trauma or orthopedic disease, hip joint.

Known devices whose designs suggest the possibility of reducing friction of the elements of the joint. These include the hip joint endoprosthesis [1], in which the diaphyseal shank is equipped with a spherical-shaped thrust bearing at the proximal end and the spherical head installed in it is immersed in the spherical bowl of the acetabulum with the possibility of rotation of the head around all orthogonal axes. However, a significant area of the contact surface of the sphere with two spherical recesses enclosing it causes increased friction. Known hip joint endoprosthesis [2], in which a spherical head immersed in spherical formations receives lubrication, which significantly reduces the friction of moving parts, contributing to increased wear resistance. In this device, the concave surfaces of the proximal neck and acetabulum are equipped with grooves located along the meridians, converging in tanks at the poles. On the surface of the head, grooves are arranged in parallel, and the end sections of the acetabulum and the proximal neck are interconnected by an elastic corrugated tube, forming a sealed cavity filled with lubricating fluid. However, in this design, the lubrication of the rubbing surfaces does not reach the required degree.

The essence of the claimed invention lies in the combination of essential features sufficient to achieve the desired technical result, namely, to increase the functional qualities of the device due to a significant decrease in the coefficient of friction and increase the wear resistance of the parts of the device.

This essence consists in the fact that the hip joint implant contains an acetabulum, a spherical head, a neck and a leg. The proximal neck and acetabulum are made in the form of parts of a sphere, the head is placed between them with the possibility of free rotation around all axes. In this case, the head and the parts of the sphere contacting it are equipped with grooves; on the parts of the sphere they are located along the meridians converging in tanks at their poles. The end sections of the acetabulum and the proximal neck are connected by a sheath of elastic corrugated tube forming a sealed cavity filled with a biologically inert liquid viscometric corresponding to the synovial. The grooves on the head are located along the parallels, meridians and parallel to the meridians. Meridial grooves converge at the poles of the head in tanks of a spherical shape, the same tanks are located at the crossings of the meridional, running parallel to the meridional, and parallel grooves. A spherical cavity is made in the center of the head, from which channels diverging in rays open in tanks at the poles of the head and in the grooves of the grooves.

The presence of a spherical cavity in the center of the head increases the amount of lubricating fluid, which is especially important when the device is operating for a long time.

The presence of channels diverging in rays from the center of the head to its periphery increases the intensity of circulation of the lubricating fluid.

The presence of tanks on the surface of the head, not only at the poles, but also in the grooves of the grooves (additional tanks, compared with the prototype), not only increases the intensity of circulation of the lubricating fluid, but also reduces the contact area of the rubbing surfaces.

The device is shown in the attached drawings. Figure 1 shows its General view, figure 2 is a groove in section, figure 3 is a longitudinal section of the head, figure 4 is a three-dimensional image of the contacting parts spaced in space (with sections).

The endoprosthesis contains an acetabulum 1 in the form of a sphere, a head 2 in the form of a ball, a leg 3, which is expanded in the proximal section 4 and structurally made similar to the acetabulum 1 in the form of a spherical recess 5. The diameter of the recess is equal to the diameter of the acetabulum 1 and head 2. All three adjacent surfaces have grooves, and on the concave surfaces of the acetabulum 1 and neck 4, the grooves 6 are located along the meridians converging in the tanks 7 at their poles. On the surface of head 2, the grooves are located in parallel to 8, meridians 9, and also parallel to the meridians - 10, meridional grooves converge at the poles of head 2 in tanks 11 of a spherical shape, the same tanks are located: at the crossings of the meridional and parallel grooves, and parallel grooves. In the center of the head, a spherical cavity 12 is made, from which the channels 13 diverge, opening in tanks 11 at the poles of the head at the crosshairs of the slots. The end sections of the acetabulum 1 and the proximal neck 4 are connected by a cover 14 of an elastic corrugated tube forming an airtight cavity 15 filled with a biologically inert liquid viscometric corresponding to the synovial.

The device is used as follows.

The endoprosthesis of the size required for the patient is selected. Surgical intervention to replace a pathologically altered joint is carried out typically by excision of scar-modified capsules and paraarticular tissues, resection of the head, followed by the installation of an endoprosthesis.

Postoperative management of patients is typical for patients undergoing hip replacement.

Information sources

1. Auth. testimonial. No. 1659042, A61F 2/32, BI, 1991, No. 24.

2. RF patent No. 2201173, A61F 2/32, BIPM, 2003, No. 9.

Claims (1)

An endoprosthesis of the hip joint containing the acetabulum, spherical head, neck and leg, in which the proximal neck and acetabulum are made in the form of parts of a sphere, the head is placed between them with the possibility of free rotation around all axes, while the head and parts of the sphere contact with it equipped with grooves, on parts of the sphere they are located along the meridians converging in tanks at their poles, and the end sections of the acetabulum and the proximal section of the neck are connected by a sheath of elastic corrugated tube, forming an airtight cavity filled with a biologically inert fluid viscometric corresponding to synovial, characterized in that the grooves on the head are parallel, meridian and parallel to the meridians, the meridional grooves converge on the poles of the head in tanks of a spherical shape, the same tanks are located at the intersections of the meridional and parallel crossings and them and parallel grooves, in the center of the head a spherical cavity is made, from which channels diverging by rays open in tanks on the poles x heads and grooves at the crosshairs.

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