SU1242148A1 - Spine distractor - Google Patents

Description

The invention relates to medical technology, namely to devices for the surgical treatment of spinal curvatures.

The aim of the invention is to prevent injury to the spinal cord in the process of correcting its curvature by avoiding excessive efforts during rotation of the spinal column.

FIG. 1 shows a spinal distractor, side view in cross section; in fig. 2 — node I in FIG. one; in fig. 3 is a view A of FIG. 2; in fig. 4, node II in FIG. one; in fig. 5 view B in FIG. four.

The distractor contains a threaded rod 1 associated with two hooks 2 and 3 installed at the ends of the latter, and a mechanism for spreading hooks, including coupling halves 4 and 5 mating to each other with ratchet teeth 6 and 7 at the ends. One of the coupling half 4 is installed on the smooth end of the rod 1, and the other half coupling 5 - in the cavity of the first hook 2. The smooth end of the rod 1 with the coupling half 4 is placed in the cavity of the first hook 2, and the opposite threaded end of the rod 1 and the second hook 3, having threaded channel under the rod, form a screw pair. The thread in the connection of the rod 1 with the second hook 3 has a triangular profile with an angle of 90-130 °, and the braking torque of the threaded connection of the rod 1 with the second hook 3 exceeds the braking moment of the coupled coupling halves 4 and 5 1.3-1.7 times .

The distractor works as follows.

When fixing the hooks for the vertebral arches under the load of the corrected vertebral column, the teeth 6 of the coupling half 4 at the end of the rod 1 are engaged with the teeth 7 of the coupling half 5 of the first hook 2 and, due to the geometry of the teeth, perform the function of a ratchet mechanism. In this case, it is possible to periodically rotate the rod 1 only in one direction relative to each of the hooks, since the braking torque of the threaded connection of the rod with the second hook exceeds the braking moment of the coupled coupling halves 1.3-1.7 times.

The rotation of the vertebral column in one direction is accompanied by rotation of the rod 1 relative to the first hook 2, and when rotating the spine in the opposite direction, the teeth of the coupling half 4 and 5 are

in engagement and rotation of the rod relative to the second hook 3 increases the distance between the hooks 2 and 3.

When treating scoliosis in children and adolescents on an operating table under general anesthesia after accessing the intact upper and lower vertebrae intact, hooks 2 and 3 are attached to the arms of intact vertebrae. Then the threaded part of the rod 1 is screwed into the upper hook 3, the opposite part of the rod with the coupling half 4 is inserted into the cavity of the hook 2 before the coupling of the teeth of the coupling half. Using a spanner key, the rod is rotated, the upper hook 3 is screwed along rod 1 until the necessary degree of spinal distraction is created and its scoliotic deformity is corrected.

In the postoperative period, after recovery from anesthesia, the patient, under the supervision of a physician, performs rotational movements in the spine by 15–20 ° to the right and left sides until the scoliotic curvature is completely corrected, but does not cause the first signs of overgrowth of the spinal cord elements to be controlled by the patient and the doctor and nerve conductors. In order to prevent the loss of correction of the growing spinal column every 5-7 days during massages and physical therapy, the patient performs 2-5 fold rotational movements of the spine, thus supporting the correction and training of the muscular corset. When the necessary correction is achieved, the rotational movements in the spine are reduced, which excludes the possibility of damage to the spine and spinal cord elements by the distracter.

The proposed spinal distractor allows you to create and maintain the necessary degree of spinal correction in the postoperative period without additional surgical interventions, reduces trauma to the patient's biological tissues and prevents the development of atrophy and hypodynamic disorders associated with prolonged external immobilization while reducing the distraction efforts of the device during the growth of the spinal column. The number of repeated operations required is reduced by 2-4 times. In addition, early rehabilitation of sick children and adolescents reduces the treatment time by 2-6 times and reduces disability by 70-80%.

fig4

FIG. five

Claims (1)

) A SPINE DISTRACTOR, comprising a threaded rod connected to two hooks at its ends, and a hook extension mechanism, including interconnected half-couplings with ratchet teeth at the ends, characterized in that, in order to prevent injury to the spine during correction of its curvature, one of the coupling halves is installed at the end of the rod, and the other coupling half is installed in the cavity of the first of the hooks, the thread in the connection of the rod with the second hook has a triangular profile with an angle at the apex of 90-130 °, while the torus moment the possibility of a threaded connection of the rod with the second hook exceeds the braking moment of the mating coupling halves by 1.3-1.7 times.