WO1999025265A1

WO1999025265A1 - Stable dynamic axial fixator

Info

Publication number: WO1999025265A1
Application number: PCT/TR1998/000018
Authority: WO
Inventors: Haci Kutlu
Original assignee: Haci Kutlu
Priority date: 1997-11-17
Filing date: 1998-08-05
Publication date: 1999-05-27
Also published as: AU8822198A; TR199701377A3; TR199701377A2

Abstract

Stable Dynamic Axial Fixator is a ball-socket type, monoarticulated which can be cancelled for the stability, external fixator used in orthopaedic and traumatological surgery. This fixator was designed for a new and unique application technique which increases the stability and also minimise the need of X-ray usage. The additional advantages were superposition of fixator on X-ray image was minimised, the risk of loosening of the pin was also minised by decreasing the weight, and hospitalisation time was reduced. To increase the stability of the articulation, 'body contact of the clamp' was achieved at the final position of the application and also the surgeon can cancel the articulation (if not need) by sliding the clamp on the articulation globe (13). Secondly to increase the stability the height of the eccentric pin was reduced. By this way the load arm can be shortened, thus the surgeon can fix the articulation globe (13) with more force, which increases the stability. The polyplanar clamp can fix the fragments in different combination and in different angle without using articulation. Also it can translate the fragments of the bone. By the means of new distraction-compressing unit the surgeon and the patient can easily distract or compress the fragments of the bone only by turing the extension nut (7) in one direction up click sound was heard. No other work is needed to stabilise or anything else. So adaptation time of the patient and the hospitalisation time was reduced.

Description

STΑBLE DYNAMIC .AXXAL FIXATOR

This invention is related to an external fixator in type of removable ball-socket articulated dynamic axial fixator used in treatments of fractured, deformed and shortness of long bones in the branches of Orthopaedics and traumatology of the field of medicine.

External fixators used in medicine are classified in several major groups. Sub-groups where that invention falls, and some examples of works under patent belonging to such groups are as follows:

a-Inarticulated: Orthofix External Fixer

b-Double-articulated ball-socket type: Orthofix External Fixator

c-Double articulated hinged type: Wagner External Fixator, Howmedica monotube External Fixator

In fixators of this type, generally there are clamp parts which would hold both epiphysis separately, two articulation pieces adapted to clamps which provide redressing and adaptation of fracture, body illustrating the length of device and elongation rate thereof, distraction units ensuring extension and shortening.

As distraction units achieve extension and shortening actions in the body as an unit annexed to body, and in the manufacture of this unit certain metal alloys being used with higher resistance and higher density but having less perviousness against X-rays, renders more difficult to fix the articulation by X-ray film. For these reasons, excessive use of X-ray device is required to be able to do articulation fixation, and thus, both patient and doctor are being exposed to X rays more. Anyhow, the risk of fractured reposition loss is still higher due to insufficient articulation fixation. In addition thereto, super-position event is more frequently encountered in X-ray films.

As annexed unit which has been mounted over body and which provides the modification of body length through fitting its parts one into another, could change the length with the help of the keys and by exercising force, this process which renders difficulties of patient's use, cause of delay fcr adaptation of the patient to device, ana extends the time cf staying in hospital.

Controlled dynamization could not be achieved due to device length could be changed by the rate cf force applied to distraction unit, and the risk of progression in shortness is increased consequently.

Usage cf devices in sizes more than one is necessary due to amount of distraction-ccmpressicn is limited. Weights of annexed devices and additional unit lead to loosening of nails during usage.

Articulation angle in existing fixators is maximum 22° and fixator is not sufficiently functional in fractured repositioning due to insufficiency of articulation angle.

In this connection, purpose of this invention is to provide the fixator which would be used in treatments of fractured, deformed and shortness cf long bones at orthopaedics and traumatology being effective to fix the bone in a straight and stable manner until the completion of welding, and being capable of doing angularity and controlled dynamization, if needed, further its being functional as much as possible, having enough spaciousness for articulation movement and high modularity, stable, would not cause any reposition loss during application and within time; light, hygienic, pervious for X-rays in sufficient degree, capable fcr easy application, smoothly acceptable by patient and easily usable.

Fixator which is developed for attaining the objectives of this invention is shown in enclosed illustrations which reflect following c-tlooks;

Figure 1- Articulation fixation by using fixator on fractured bond.

Figure 2- Complete section of polyplanar clamped fixator.

Figure 3- Complete section of monoplanar clamped fixator.

Figure 4- A view from a section of polyplanar clamp and articulation globe.

Figure 5- A view from a section monoplanar clamp and of clamp cover.

Figure 6- A view of removable articulation from a section.

Figure 7- A section of distraction unit.

Figure 8- A view of sliding clamp cover.

Parts in figures have been numbered one by one, and the descriptions corresponding to these numbers are given below:

(1) Monoplanar Clamp Cover (2) Body cf Monoplanar Clamp Cover

(3) Bolt

(4) Pin

(5) Extension bolt

(6) Press spring

(7) Extension nut

(8) Ball

(9) Segment

(10) Tightening cleat

(12) Tightening nut

(13) Articulation globe

(14) Polyplanar clamp body

(15) Eccentric Pin

(16) Polyplanar Clamp Bottom Cover

(17) Polyplanar Clamp Intermediary part

(18) Polyplanar Clamp Upper Cover

(19) Derotation Pin

Figure 1 is the outlook of fixator in the position where polyplanar clamps have been fixed on bone through its special nails (Figure 4).

As is seen in Figures 2 and 3, fixator body (10) is telescopic, and works also by moving within extension belt (5). It is possible to use the body in large, middle and small sizes by selecting extension bolts in different longitudes. Polyplanar clamp, as is seen in Figures 2 and 4, is composed of two bolts (3), polyplanar clamp body (14), polyplanar clamp bottom cover (16), polyplanar clamp intermediary part (17) and polyplanar clamp upper cover (18), and is allowed to place nails in different plans and various combinations. Fixator with inarticulated polyplanar clamp could be used in bones having a broad clinging surface (like metaphase), angularity of fractured and translation thereof could also be corrected through this clamp.

Monoplanar clamp as seen in Figures 2, 3 and 5, containing Monoplanar Clamp cover (1), Monoplanar clamp body (2) and 2 bolts (3) ensures the placement of nail in single plan, and could be used articulated or inarticulated manner according to requirements .

Figure 6 illustrates removable articulation. When needed, by loosening bolt on the clamp (3) space between clamp and tightening nut is broadened, and by turning eccentric pin (15) tightening cleat (11) is loosened and the globe (15, is become idled. Thus, clamp could be given such angularity around a circle of 360° to a direction up to 30° from the center, so the angle of articulation is being increased and therefore device becomes more functional. In order to fix in desired angle, firstly tightening nut (12) is tightened for taking in the slack of articulation. Thereafter, eccentric pin (15) is tightened with "L-alian" wrench by maximum force. Then, clamp is made to be slided en the body of globe (13) until taking in the slack of articulation, and thus clamp body is leaned against tightening nut. In this way, load is being transferred directly to the body and articulation could be removed or insufficiency position of articulation in angular fixation could be eliminated. Through taking in the slack of articulation by tightening nut and reducing of height of eccentric pin (15) down to maximum 0.5 mm load arm is shortened, more tightening of globe is ensured, and stability is increased by sliding of eccentric in the course of time with a counter-screw applied to eccentric. Distraction- compression share has also been increased by removal of articulation. 3y the grace of removalableness of articulation, problem of reduction loss due to articulation insufficiency is also eliminated and furthermore, stability is increased. Removableness of articulation causes also to ease production and cost decrease as well. Thus, "removable ball-socket type articulated external fixators" has been added to external fixators as a new sub-group. This method could be used in both clamps.

Figure 2 is an outlook of distraction unit. Distraction unit consisting of extension bolt (5), pressing spring '6), extension nut (7), ball (8), segment (9) and derotation pin (19) is placed within body. Therefore, annexed unit which was using for the same purpose has been removed, and in this way, perviousness cf device for X-rays is increased and radioscopy process becomes easier. At the same time, the risk of loosening in nails is also reduced along with decrease of super-position risk and the weight of device. If extension nut (7) is turned clockwise one tour, then the system is being extended 1.2 mm. Meanwhile, spring ball is seated into its three separate sockets with equal intervals placed onto extension nut with a "click" sound, an warns the user, as well as ensures rotation stability. Here, each "click" sound corresponds 0.4 mm. For compression, these steps would be repeated vice versa. So, by presenting easiness in use, adaptation of patient becomes easier.

Figure 8 is an outlook of sliding clamp cover. Monoplanar clamp cover (1) is slided towards outside by loosening external bolt (3) fcr smooth application of nail to the bone. After fractured reduction is achieved, external screw is tightened. After internal nail is placed into the bone, cover (1) is locked by being slided. This practice provides easiness in technical usage. In Figure 1, the locked position of sliding clamp cover and the area of movement of cover with the help cf bolt hole design could be seen.

Invention could reliably be used in long bones of extremities. As device has been designed in a modularly structure and could be produced in different sizes, suitable fixator is selected as to the kind, location and length of bone. If articulated fixator is preferred, articulation in flat bones is hold firstly straight and closed, distraction-compression share is adjusted. Long bone is rather taken to traction. Nails at both farthest ends of fixator will be placed intc bone at 90° under sterile conditions. Thus, fractured re-position in front- rear plan is being ensured. In second step, nail is placed at the same plan with first nail and parallel thereto into the hole nearest fractured or farthest hole from previous nail. If while placing the nail, central line of bone is not balanced, fractured bone is pulled downward or upward, and central line is so matched. Same process is applied to opposite side and fractured ends are being reposed in lateral plan. When necessary, third nails are placed into center part in the same plan and parallel to others. Newness in clamp cover is ensured to ease such application.

After both clamps are applied in the same manner, fractured state is controlled by radioscopy or X-ray. If any angularity is observed, then articulation is opened and correction is made. Distraction-compression rate is adjusted and fixator is locked.

Claims

1) The polyplanar clamp can fix the fragments in different combination and in different angle without using articulation. Also it can translate the fragments of the bone. The polyplanar clamp consists of two bolts (3), polyplanar clamp body (14), polyplanar clamp bottom cover (16), polyplanar clamp intermediary oart (17) and polyplanar clamp upper cover (18).

2) To increase the stability of the fixator, the articulation unit can be cancelled (if not need) or the clamp can be seated on the body at the final angle of the application through sliding the clamp over articulation globe (13), seating on tightening nut (12) and thus the load can be transferred to the body.

3) Since the death space of the articulation can be closed by tightening nut (12) the height of the eccentric pin (15) can be reduced down to 0.5 mm. By this way the load arm can be shortened, thus the surgeon can fix the articulation globe (13) with more force which increase the stability.

4) Distraction-compressing unit consisting of extension bolt (5), pressing spring (6), extension nut (7), ball (8), segment (9) and de-rotation pin (19) and taking place in the body, working by seating of ball (8) in sockets with equal intervals on extension nut through movement of extension nut (7) towards one direction around extension bolt (5), each socket causing to proceed as long as corresponding to 0.4 mm and warning the user with a "click" sound, and ensuring extending and shortening cf the body. By the means of this unit the surgeon and the patient can easily district or compress the fragments of the bone only by turning the extension nut (7) in one direction up to click sound to be heart. No other work is needed to stabilise or anything else.

5) Our fixator has unique and easy application technique. For that reason monoplanar clamp cover (1) can be slided towards outside by loosening of external bolt (3) for easy application of internal nail to the bone. After the reposition of the fragments external bolt is tightened and internal nail is placed and again the cover (1) is slided internally and the cover is locked.