RU2236185C2 - Device for elongating nerve trunks - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has driving mechanism and traction unit enclosed in casing. The casing and cover are of cylindrical shape. The driving mechanism has two castellated rims. The castellated rims are rigidly connected with slides. The slides are diametrically arranged. The rims have skewed teeth set in opposition with a shift equal to half-width of tooth base and with some space between teeth tops in the same rim and skewed sides of teeth of another rim. The shifts allow equal-arm balance beam moving between them. The beam is a rod mounted on axle in perpendicular thereto. The axle is mounted in thrust bearing with one end on the casing bottom and in socket on the cover bottom with its other end. The socket depth allows longitudinal displacements to take place. Balance beam arms overlay rim diameter. Traction unit is mounted on the lower part of the axle as reel fixed on its nave with flexible tie-rod. The tie-rod protrudes outside through an opening in casing. Spiral compression spring is arranged between the reel and lower rim. The ring holds coupled rims in upper position. The coupled rims are axially movable along the axle on guides. The guides are mounted on internal surface of the casing. The cover enveloping the casing has ring-shaped supporting member on the inner surface. The supporting member is engageable with the upper rim and slot on the lateral surface of the casing. Ears with holes are available on the casing bottom.

EFFECT: improved comfortable conditions for patients; high accuracy in bringing the central and peripheral nerve ends close.

2 dwg

Description

The invention relates to medicine and is used in traumatology-orthopedics, neurosurgery, reconstructive surgery in the treatment of defects of nerve trunks.

There are a number of analogues of the proposed device, including the “Distraction apparatus for lengthening nerve trunks” [1], which contains rings with spokes connected by threaded rods with a traction unit mounted on them with rods in the form of ligatures, mounted on movable brackets in coaxial threaded hooks.

The disadvantages of this device are the bulkiness of the traction system and the risk of infection of soft tissues at the exit points through the skin of traction ligatures and knitting needles.

Closest to the claimed in its technical solution is the “Device for lengthening nerve trunks” [2], considered as a prototype. In this design, the ratchet wheel, driven into rotation by the reciprocating movement of the flat spring, transmits the movement to the threaded shaft, which converts the rotational movement into the translational movement of the threaded rod, which carries the elongating nerve through the ligature.

The disadvantages of the prototype include the absence of a button protruding above the surface of the device, since palpation through the skin and soft tissue of the end of the flat spring is difficult.

The essence of the invention lies in the combination of distinctive features sufficient to obtain the desired technical result, namely, increasing comfort for the patient and the ability to accurately approximate the central and peripheral ends of the nerve.

The essence of the invention lies in the fact that the device for lengthening the nerve trunks containing the drive mechanism and the traction unit located in the housing, characterized in that the housing and the cover are cylindrical, the drive mechanism is made in the form of two rigidly connected runners located diametrically, crowned crowns with one-sided chamfered teeth installed counterclockwise with a half-width shift of the tooth base and with gaps between the tops of the teeth of one crown and the beveled sides of the teeth of the other crown full-time to move the ends of an equal-arm rocker in them, made in the form of a rod, perpendicularly mounted on an axis installed by one end in a thrust bearing placed on the bottom of the body, the other end - in a socket located on the bottom of the cover and having a depth that provides longitudinal movement of the cover along the axis , while the arms of the rocker arm overlap the diameter of the crowns, and in the lower section of the axis there is a traction assembly made in the form of a coil with a flexible rod fixed to its hub, brought out through the hole in the housing, between the lower rim and the coil contain a spiral compression spring that holds paired rims in the upper position, mounted with the possibility of axial displacements along the axis along the guides made on the inner surface of the housing, the lid covering the housing is equipped on the inner surface with an annular contact in contact with the upper rim and groove on the side surface under the derotation protrusion on the outer surface of the housing, the housing in the lower section is equipped with ears with holes.

The use of two rigidly connected counterclosed crown rims with unilaterally beveled teeth provides movement in a predetermined direction of the beam mounted between them, whose shoulders overlap the diameter of the rims.

The presence of flat rails of a staple shape guarantees the necessary clearance for moving the beam between the crowns, and the movement of the runners along the guides eliminates the rotation of the crowns around the axis.

Securing the rocker arm on an axis rotating in the thrust bearing and the lid seat, with the simultaneous exclusion of the rotation of the crowns, allows translational translation of the lid into the rotational motion of the axis with a coil mounted on it.

The installation of crowns with a shift, relative to each other, at half the width of the tooth base, ensures uniform movement of the rocker arm.

The presence of a nest of a certain depth in the bottom of the lid, a groove under the derotation protrusion on its outer surface, a corresponding protrusion on the side surface of the housing, as well as a compression spring mounted on the axis between the paired crown crowns and the coil, provide reciprocating movements along the axis. An annular stop at the bottom of the cover serves to evenly transmit pressure to subsequent links.

The cylindrical body, the cover of which is a button, allows the patient to easily detect the device under the skin and independently perform distraction during the day, after a number of manipulations (clicks) pre-determined by the doctor necessary to bring the ends of the nerve together and the total time the mechanism is in the patient’s body.

The device is shown in figure 1 and figure 2. In Fig. 1, the device is shown in a disassembled form without flexible traction, where for convenience of examination the paired crowns are conventionally removed from the axis, and sectoral cutouts are made in the lid, upper crown and body; figure 2 is a General view of the device in cross section.

The device comprises a cylindrical body 1 with a protrusion 2 on the outer surface and a cylindrical cover 3 with an open groove 4 on the side surface under the protrusion 2 of the housing 1. At the bottom of the housing 1 there is a thrust bearing 5. In the thrust bearing 5 there is an axis 6 with a coil 7 and a rocker mounted on it. 8. The beam 8 is placed in the gap between two, rigidly connected to each other, crown crowns 9 having opposing, one-sided bevel teeth 10 and 11. The crowns are interconnected by diametrically arranged flat, staple-shaped, floor with holes installed with the possibility of vertical movement along the guide grooves 13, made on the inner surface of the housing 1. Between the coil 7 and the crown crowns 9, a compression spring 14 is installed, the end of the flexible rod 15 is fixed on the hub of the coil 7, which is led out through the hole 16 in the housing 1 out. The upper end of the axis 6 is placed with the possibility of rotation and axial movements in the cylindrical socket 17 of the cover 3.

In the bottom of the housing 1 there are ears with holes 18 under the bone screws for attaching the device to the bone.

The device is used as follows.

ширины зуба - до вертикального контура верхнего венца. При снятии давления с кнопки вертикальный контур зубьев 10 верхнего венца за счет разжатия пружины доводит коромысло до скоса зубьев 11 нижнего венца и этим скосом поворачивает коромысло еще на

ширины зуба. Этот цикл повторяется необходимое количество раз.Skeletonize a segment of a limb segment on which an elongation of a nerve is performed. In this case, the distance from the skeletonized area to the end of the nerve should be equal to the required elongation. A device with a free coil and a flexible traction of the required length fixed on it is fixed with bone screws to the skeletonized portion of the bone. The free end of the traction is sutured to an elongated nerve. The wound is sutured in layers so that the suture is outside the projection of the device located in the soft tissues. Subsequently, the patient independently, a certain number of times a day, presses “fully” on the housing cover 1, which rises under the skin cover, which ensures that the gear screws 9 move downward and the rocker arm 8 is engaged in the rotational movement. The pressure on the button is transmitted to the gear crowns, which with their skids 12 along the grooves of the housing 13, compress the spring 14. At the same time, the rocker 8, originally located in the cavity between the teeth 11 of the lower crown, is “delivered” by the vertical contour of these teeth to the bevel of the teeth 10 ver his crown, and trapped by it, rotates

tooth width - to the vertical contour of the upper crown. When releasing pressure from the button, the vertical contour of the teeth 10 of the upper rim due to the release of the spring brings the beam to the bevel of the teeth 11 of the lower rim and this bevel rotates the beam again

tooth width. This cycle is repeated as many times as necessary.

Since the rocker arm 8 and the coil 7 are rigidly mounted on the axis 6, the rotation of the rocker arm rotates the coil, on which the flexible rod 15 is wound, pulling along the elongated end of the nerve.

Sources of information

(1) Auth. testimonial. No. 1598995, A 61 B 17/60, BI No. 38, 1990

(2) Patent No. 2161918, A 61 B 17/60, 17/04, BI No. 2, 2001.

Claims (1)

A device for lengthening nerve trunks containing a drive mechanism and a traction unit located in the housing, characterized in that the housing and the cover are cylindrical in shape, the drive mechanism is made in the form of two rigidly connected runners, diametrically disposed, crowned crowns with one-sided bevel teeth mounted counterclockwise with a shift of half the width of the tooth base and with gaps between the tops of the teeth of one crown and the beveled sides of the teeth of the other crown, sufficient to move the ends of rocker arm, made in the form of a rod, perpendicularly mounted on an axis mounted at one end in a thrust bearing placed on the bottom of the housing, the other end - in a nest located at the bottom of the cover and having a depth that provides longitudinal movement of the cover along the axis, while the cover is made in in the form of a button for detection under the skin, the arms of the rocker arm overlap the diameter of the crowns, and in the lower part of the axis there is a traction unit made in the form of a coil with a flexible rod fixed to its hub, brought out through an opening into the housing outward, between the lower rim and the coil there is a spiral compression spring holding the paired rims in the upper position, mounted with the possibility of movement along the axis along the guides made on the inner surface of the housing, the cover covering the housing is equipped on the inner surface with an annular contact in contact with the upper rim and a groove on the side surface under the derotation protrusion on the outer surface of the housing, with ears with holes made in the bottom of the housing.

Images