AU2004100977A4

AU2004100977A4 - Distractable body augmenter capable of being planted through a pedicle for vertebral body reconstruction

Info

Publication number: AU2004100977A4
Application number: AU2004100977A
Authority: AU
Inventors: Kung-Chia Li
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-17
Filing date: 2004-11-17
Publication date: 2004-12-09
Anticipated expiration: 2012-11-17

Description

559071P JOM:MN P/00/009 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

INNOVATION SPECIFICATION FOR AN INVENTION ENTITLED Invention Title: Name of Applicant: Address for Service: DISTRACTABLE BODY AUGMENTER CAPABLE OF BEING PLANTED THROUGH A PEDICLE FOR VERTEBRAL BODY RECONSTRUCTION KUNG-CHIA LI COLLISON CO 117 King William Street, Adelaide, S.A. 5000 The invention is described in the following statement: DISTRACTABLE BODY AUGMENTER CAPABLE OF BEING PLANTED THROUGH A PEDICLE FOR VERTEBRAL BODY 0

RECONSTRUCTION

t"- BACKGROUND OF THE INVENTION 1. Field of the invention SThe present invention relates to a distractable body augmenter capable of being planted through a pedicle for vertebral body reconstruction, more particularly one, which is used for treatment of vertebral burst fractures, and vertebral compression fractures.

2. Brief Description of the Prior Art Vertebral body fractures including acute burst fracture or chronic compression fracture with kyphosis were treated in various ways.

Acute burst fracture can be treated conservatively, surgical posterior instrumentation, or even anterior bone graft and posterior instrumentation. However, conservative treatment is limited to those with neural intact, non-osteoporosis, good compliance to wear brace and less kyphosis. Posterior instrumentation alone is easy and simple but may lead to 20% implant failure. However, combining anterior and posterior approaches proved to have mechanical advantages, but surgery itself is a suffering to elder patients. The best way to those not good for conservative treatment will be posterior approach with functions of anterior approach simultaneously.

O

C In chronic osteoporotic compression fractures may induce lots of z morbilities including chronic back pain, GI dysfunction, decreased pulmonary vital capacity, and feasible new compression fractures. The various methods including surgical instrumentation, vertebral augmentation with cement, kyphoplasty etc. The techniques improved and results become better recently. However, instrumentation may induce decreased spine ROM, implant failure, and adjacent segment disease. The cement either in augmentation or kyphoplasty may induce cement disease. The kyphosis correction is not perfect in kyphoplasty especially the chronic cases with anterior partial or fully fusion. The body augmenter tried to correct the collapsed vertebral body and lead to union with bone graft either combined short posterior instrumentation or cement techniques.

SUMMARY OF THE INVENTION It is a main object of the present invention to provide a body augmenter, which can be planted into an osteoporosis-effected vertebra from a pedicle of the vertebra, for helping maintain or restore normal position and size of the vertebra.

Through the vertebral pedicle, a device, fit the pedicle anatomy, was created to reconstruct the fractured or collapsed vertebral body.

S- 'Through the pedicle, the augmenter, fitting the pedicle anatomy, was (c-l created to reconstruct the fractured or collapsed vertebral body. The augmenter includes a lower block, an upper block fitted in, and longitudinally displaceable relative to the lower block, and a prop bar, which is inserted between the upper and the lower blocks for changing the height of the augmenter after the upper and the lower blocks have Sbeen planted in a vertebra via a planting tunnel on a pedicle of the Svertebra. After the body augmenter is planted in a vertebra, harvested autogenous bone or artificial bone is injected into the vertebra such that the space in the vertebra are filled with the injected bone, and the body augmenter is securely fixed in positiion. The fractured body was reduced and maintained by the augmenter until the bone growth and fracture union.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood by referring to the accompanying drawings, wherein: Fig. 1 is an exploded perspective view of the first embodiment of a body augmenter for vertebral body reconstruction, Fig. 2 is a view of the first embodiment of a body augmenter for vertebral body reconstruction, planted in a vertebra, Fig. 3 is a view of the first embodiment of a body augmenter for vertebral body reconstruction, used in another way, ,i Fig. 4 is an exploded perspective view of the second embodiment 0 o of a body augmenter for vertebral body reconstruction, Fig. 5 is a view of the second embodiment of a body augmenter for vertebral body reconstruction, planted in a vertebra, t Fig. 6 is an exploded perspective view of the third embodiment of Sa body augmenter for vertebral body reconstruction, and SFig. 7 is a view of the third embodiment of a body augmenter for vertebral body reconstruction, planted in a vertebra.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Fig. 1, a first embodiment of a distractable body augmenter for vertebral body reconstruction in the present invention includes an upper planted block 1, a lower planted block 2, and a prop bar 3.

Both the upper and the lower planted blocks 1 and 2 have rough surfaces with small bumps all over. The upper planted block 1 has an uppermost portion 11, an insertion portion 12 projecting down from a lower side of the uppermost portion 11, and a base 14 joined to a rear end of the insertion portion 12. The insertion portion 12 has longitudinal fitting trenches 13 on two sides of front end and rear end thereof, and a screw hole 15 on the front end. The base 14 has a convexly curved outer side.

C The lower planted block 2 has two lengthways extending lateral portions 24, a holding cavity 21 between the lateral portions 24, an inverted T shaped gap 22 at a front end thereof, and an U-shaped gap 23 at a rear end; the gaps 22 and 23 communicate with the holding cavity 21, and oppose each other.

SThe prop bar 3 has a screw hole 31 on a front end thereof, to Swhich a tool can be connected to help planting. And, the prop bar 3 of c- the present embodiment is in the shape of a wedge.

Referring to Fig. 2, to plant the body augmenter into a vertebra 4, first a planting tunnel 42 is formed on a pedicle 41 of the vertebra 4.

Second, a planting tool (not shown) is screwed into the screw hole 15 of the upper planted block 1, and the upper planted block 1 is inserted in the holding cavity 21 of the lower planted block 2 at the insertion portion 12 thereof with the front and the rear ends, which have the fitting trenches 13 on two sides, being fitted in the gaps 22 and 23 of the lower planted block 2. Then, the upper and the lower planted blocks 1 and 2 together are planted in the vertebra 4 through the planting tunnel 42 with the help of the planting tool, and the planting tool is removed from the upper planted block 1, and the prop bar 3 is inserted in between the insertion portion 12 and a bottom of the lower planted block 2 with the help of another tool (not shown), which is screwed in the screw hole 31; thus, the height of the present augmenter increases, and the vertebra 4 is enlarged in longitudinal direction. Finally, harvested autogenous bone or artificial bone is injected into the vertebra 4 through the planting hole 41 0 such that both the hollow area of the body augmenter and the space r between the body augmenter and the vertebra 4 are filled with the injected bone, and the body augmenter is secured in position.

r Referring to Fig. 3, if it is necessary, a screw system 5 can be O applied to both of the vertebras next to the vertebra 4 for helping Sincrease stability of the spine after planting of the body augmenter of the present invention.

The dimension of the body augmenter is decided according to the vertical cross-section and the height of the pedicle 41 of the vertebra 4; the vertical cross-section of the pedicle 41 is close to a rectangle, and somewhat oval, and the distance from an upper end to a lower end of the pedicle 41 is larger than that from a rear end to a front end; the ratio of the height of pedicle 41 to the height of the vertebra 4 is between 0.5 and 0.6. Therefore, the augmenter can be made with a size near to the pedicle 41 so that at least 50% to 60 of the vertebra 4 is reconstructed.

Consequently, 70 %to 80 of the vertebra 4 will be reconstructed when the augmenter is combined with the rest of the vertebra 4. Furthermore, the height of the body augmenter will be changed up to 30 by means of changing the thickness of the prop bar 3, and in turns, the vertebra 4 can nearly recover the original size, which it had before the fracture.

Therefore, with the help of the augmenter, the vertebra 4 can be restored to the original position.

C, Referring to Fig. 4, which is an exploded perspective view of a z second embodiment of an augmenter for vertebral body reconstruction, insertion portion 12 of upper planted block 1 is formed with a concavely curved side on a lower end thereof, and raised lines 16 spaced apart on othe concavely curved side thereof while lower planted block 2 is formed Swith a concavely curved portion on an upper side of a bottom thereof, Sand raised lines 25 spaced apart on the concavely curved portion thereof.

And, a prop element 6, which has threads thereon like a screw, is screwed along the raised lines 16 and 25 into between the concavely curved side of the insertion portion 12 of the upper planted block 1 and the concavely curved portion of the lower planted block 2 to keep the planted blocks 1 and 2 in desired position relative to each other, as shown in Fig. Referring to Fig. 6, which is an exploded perspective view of the third embodiment of an augmenter for vertebral body reconstruction, prop bar 3 is further formed with a downwards projecting extension portion 32 at a front end thereof while several holes 26 are formed on the front end of the lower insertion block 2. Thus, another tool can be connected with the holes 26 to help the augmenter planted in the vertebra 4, and the front ends of the upper and the lower planted blocks 1 and 2 will be co-planar in the vertebra 4, as shown in Fig. 7.

From the above description, it can be easily understood that the body augmenter of the present invention has advantages as followings: 1. The body augmenter is planted in a collapsed vertebra via the z pedicle of a vertebra instead of via the thoracic or abdominal cavity of the patient therefore the operation is relatively safe, and mechanical strength of the vertebra is increased.

2. The body augmenter can be used alone on a collapsed vertebra without the need for operation being done on other healthy vertebras Snear to the collapsed vertebra, which operation will cause the other healthy vertebras to lose the freedom to move.

3. Because the body augmenter has a rough surface with small bumps all over, after the planting tunnel 42 is filled with harvested autogenous bone graft or artificial bone, the bone will be more firmly connected with the body augmenter, and the connection of the bone sponge bone of the vertebra with the harvested autogenous bone graft (or artificial bone) will be more stable.

4. By means of inserting a wedge-shaped bar with suitable size in between the upper and the lower planted blocks 1 and 2, the body augmenter will be enlarged to a suitable height for supporting the vertebra in a desired position.

Claims

1. A distractable body augmenter capable of being planted through a pedicle of a vertebra for vertebral body reconstruction, comprising an upper planted block; the upper planted block having an insertion portion projecting down from a lower side of an uppermost Sportion thereof; the upper planted block having a screw hole on a front end thereof; a lower planted block fitted on the upper planted block; the lower planted block having a holding cavity between two lateral portions thereof; the upper planted block being fitted in the holding cavity at the insertion portion thereof; and a prop bar having a connecting hole on a front end thereof; the prop bar being inserted between a lower end of the insertion portion and an upper side of a bottom of the lower planted block for causing longitudinal displacement of the upper and the lower planted blocks after the planted blocks together have been planted in a vertebra via a planting tunnel of a pedicle of the vertebra.

2. The distractable body augmenter as claimed in claim 1, wherein the prop bar is formed with a wedge-shape.

3. The distractable body augmenter as claimed in claim 1, wherein the upper planted block has a plurality of spaced apart raised lines on a lower concavely curved side of the insertion portion thereof, and the lower planted block has a plurality of spaced apart raised lines on a concavely curved portion thereof, which face the spaced apart raised 0 lines of the upper planted block, while the prop bar is formed with screw threads thereon, and screwed along the spaced apart raised lines of the upper and the lower planted blocks.