EXTERNAL FIXATOR

Abstract

An external fixator includes at least four half rings having ledged areas on each end providing connections to form full rings, each half ring includes rod holes provided at intervals parallel to the axis of the ring and channel slots between the rod holes and the outer edge of the ring; at least four connectors to fix the half rings to each other through the connection holes; at least three threaded rods having same diameter as that of the rod holes and fit into the rod holes; nuts which fix the rods to the half rings; at least one Kirschner wire to fix the bones and soft tissues; at least two wire fixation bolts passing through the rod holes to fix the Kirschner wire at both ends to the half rings.

Description

TECHNICAL FIELD

The present invention relates to an Ilizarov external fixator which is used in orthopedic surgeries such as repair of segmental fractures, correction of congenital or developmental deformities, and limb lengthening.

BACKGROUND

External fixators are used in orthopedics to stabilize and align bones and soft tissues. The Ilizarov external fixator stabilizes limbs by passing the Kirschner wires, which are fixed to an external frame, typically a ring, through bones transversely, fixing them in place.

In the Ilizarov external fixator, each set of half rings is placed around the site needed to be stabilized, and then assembled into a full ring. The threaded rods are passed through the holes at regular intervals on the rings and secured by means of nuts from the bottom and the top of the rings. Thus a cage like structure is formed along the limb by the rings and the rods. To adjust the position of the rings relative to each other, the nuts are loosened and the rings moved along the axis of the threaded rods. After establishing the desired position of the rings, the nuts are retightened. The wires which are passed through tissues and bone are fixed to the rings via wire fixation bolts.

In currently existing Ilizarov external fixators, there is a large amount of discomfort and pain subjected on the patient as well as difficulty in mounting the fixture due to the form of engagement of the rods to the rings. Besides bending over the wires may also pose a risk of infection for both the surgeon and the patient.

It is therefore necessary to develop an external fixator which minimizes the amount of pain and discomfort a patient is subjected to and can be more easily applied by a surgeon.

United States patent document no. U.S. Pat. No. 7,226,449B2, another application known in the state of the art, discloses an Ilizarov external fixator used in orthopedic treatments. The rods of the external fixator are comprised of two parts connected by a mechanism in order to easily adjust the distance between the rings.

SUMMARY

The objective of the present invention is to provide an external fixator which is used for repairing segmental fractures, bone infections, correcting congenital or developmental deformities, and limb lengthening.

The objective of the present invention is to provide an external fixator wherein the rings and rods can be positioned with minimal effort by a surgeon and minimal pain and discomfort to a patient.

The objective of the present invention is to provide an external fixator wherein the rings and rods can be positioned with minimal effort by a surgeon and minimal pain and discomfort to a patient.

The objective of the present invention is to provide an external fixator wherein the Kirschner wires can be bent over safely to minimize the risk of infection.

BRIEF DESCRIPTION OF THE DRAWINGS

An external fixator developed to fulfill the objective of the present invention is illustrated in the accompanying figures wherein:

FIG. 1 is a perspective view of the external fixator.

FIG. 2 is a perspective view of the rods.

FIG. 3 is a perspective view of the half ring.

FIG. 4 is a perspective view of connected half rings.

The components shown in the figures are each given reference numbers as follows:

• • 1. External fixator
  • 2. Half ring
  • 3. Connector
  • 4. Rod
  • 5. Nut
  • 6. Kirschner wire
  • 7. Wire fixation bolt
  • 8. Apparatus

DETAILED DESCRIPTION OF THE EMBODIMENTS

An external fixator (1) used in orthopedics comprises

• • at least four half rings (2) which have ledged areas on each end that provide connections to form full rings wherein each half ring comprises rod holes at certain intervals parallel to the axis of the ring, and channel slots between the rod holes and outer edge of the ring wherein the channel slots are narrower than the rod holes,
  • at least four connectors (bolts and nuts) (3) which fix the half rings to each other through the connection holes located on the ledges areas of the half rings (2),
  • at least three threaded rods (4), which have the same diameter with those of the rod holes and fit into the rod holes, and which are in the form of bars that are trimmed longitudinally from two opposite sides of the diameter so as to be equal to the width of the channel slots,
  • nuts (5) which fix the rods (4) to the half rings (2),
  • at least one Kirschner wire (6) to fix the bones and soft tissues,
  • at least two wire fixation bolts (7) which are passed through the rod holes to fix the Kirschner wire (6) at both ends to the half rings (2).

The half rings (2) form two full rings that are aligned approximately to proximodistal axis at the bottom and the top as such in an external fixator (1), which is to encircle the site needed to be stabilized. Each rod (4) is fitted into the rod hole by passing through the channel slot, and after being rotated 90 degrees, it is ensured that it will not get dislocated from the channel slot and is fixed to the half rings (2) via the nuts (5). Distance between the rings can be adjusted by loosening the nuts (4).

The Kirschner wire (6), which is passed through the bones and soft tissues, is fixed by wire fixation bolts (7) from both ends thereof and connected to the rings. The sharp ends of the Kirschner wire (6) are usually bent over to avoid injury.

In a preferred embodiment of the invention, to bend the ends of the Kirschner wire (6), an apparatus (8) is used, whose one end holds the wire and the other end has a handle to easily bend. This way, inward/outward migration of the wire are prevented and both the surgeon and the patient are protected from injury.

Claims

1. An external fixator used in orthopedics, comprising: at least one Kirschner wire to fix bones and soft tissues;at least four half rings having ledged areas on each end for provide connections to form full rings and rod holes at intervals parallel to an axis of each half ring,at least four connectors to fix the at least four half rings to each other through connection holes,at least three threaded rods,nuts to fix the at least three threaded rods to the at least four half rings,at least two wire fixation bolts passing through the rod holes to fix the Kirschner wire at both ends to the at least four half rings, anda channel slot is provided between the rod holes and an outer edge of the each half ring, wherein, the channel slot is narrower than the rod holes.

2. (canceled)

3. The external fixator according to claim 1, each threaded rod has a same diameter as that of the rod holes and fits into the rod holes, and the each threaded rod is trimmed longitudinally from the two opposite sides of the diameter so as to have the diameter equal to a width of the channel slot.

4. (canceled)