WO1996019943A1

WO1996019943A1 - Medical instrument for reducing or reconstructing fractured or deformed facial bones

Info

Publication number: WO1996019943A1
Application number: PCT/KR1995/000174
Authority: WO
Inventors: Yong Oock Kim
Original assignee: Yong Oock Kim
Priority date: 1994-12-28
Filing date: 1995-12-27
Publication date: 1996-07-04
Also published as: KR960020961A; KR0139944B1; AU4316896A

Abstract

A medical instrument for reducing or reconstructing fractured or congenitally and posttraumatically deformed facial bones three dimensionally is disclosed. The above medical instrument tightly attaches to a human head outside the skin in order to reduce or reconstruct a fractured or deformed facial bone. The medical instrument thus neither requires complex surgical operations nor the use of foreign substances during the reduction or reconstruction of the fractured or deformed facial bones. Therefore, the medical instrument leaves no scar on the skin, causes neither infection nor ill effects due to the existence of foreign substances. The instrument comprises means (1) for tightly attaching the instrument to a cranial bone (51) said attaching means (1) being screwed to a mastoid area of temporal bone (52) of cranium; means (3) for holding displaced bone segments of a fractured or deformed facial bone thus reducing or reconstructing the facial bone, said holding means (3) being screwed to the displaced bone segments in order to hold the bone segments in their original places thus reducing or reconstructing the facial bone three dimensionally; and means (2) for connecting the attaching and holding means (1, 3) together and adjusting the position of said holding means (3) in order to arrange the holding means (3) on the skin above the bone segments of the facial bone.

Description

MEDICAL INSTRUMENT FOR REDUCING OR RECONSTRUCTING FRACTURED OR DEFORMED FACIAL BONES

TECHNICAL FIELD

The present invention relates in general to a medical instrument for reducing or reconstructing fractured or deformed facial bones three dimensionally. The medical instrument of this invention tightly attaches to a human head outside the skin, thus easily reducing or reconstructing the fractured or deformed facial bones without making an incision on the skin nor leaving any remarkable scars.

BACKGROUND ART

In the prior art, when a long bone such as a humerus or femur is simply fractured, the displaced bone segments are reduced prior to either forming a cast or fixating the bone segments using a fixation means. It is easy to fixate the fractured bone using a cast or fixation means after reducing the bone segments or performing an operation for positioning the bone segments in their original places in the event of simple or comminuted fracture of a long bone such as a humerus or femur. When a fractured long bone is reduced and completely united, many scars may be left on the skin due to operations for implanting fixation wires and/or metal plates inside the skin and for removing the wires and/or plates from the human body after the fractured bones are completely united together. However, the scars are not shown as they are hidden by clothes so the scars do not cause embarrassment by others. However, fractured craniofacial membranous bones, particularly facial bones, cannot be reduced and united using a typical cast or fixation means, which has been used for reduction and fixation of the humerus or femur, due to the eyes, nose and ears of the head. In this regard, the fractured cranial bones or facial bones have been typically reduced and fixed through an open bone reduction operation. However, such an open bone reduction operation has a problem in that it leaves remarkable scars on the incised parts of the face thus causing embarrassment to the patient when facing with other people.

In order to reduce and fix the displaced bone segments of a fractured facial bone in the prior art, an incision is made on the facial or head skin about the fractured facial bone. After the incision to the facial or head skin is made, the collapsing, projecting or displaced bone segments (hereinbelow, referred to simply as "bone segments") are combined with portions (hereinbelow, referred to as "unaffected portions ") of the facial bone, not affected by the shock, using interosseous wiring, mini and micro-plate and screw system. The bone segments of the fractured facial bone can be thus reduced and fixed. However, the above method for reducing and fixating the bone segments of the fractured facial bone has a problem in that it is very difficult to precisely array the bone segments relative to the fixating bone since this method uses one point reduction. The fractured points are reduced and fixed step by step, not simultaneous reduction of all the fractured points. After reduction and complete bone union between the bone segments of the fractured facial bone, the interosseous wiring, mini and micro-plate system and screws must be removed from the united facial bone in some cases. In order to remove the interosseous wiring, mini and micro-plate system and screws after uniting the bone segments of the fractured facial bone, the facial skin or head skin has to be incised again. This lengthens the time of treatment and requires additional plastic surgical operation for removing the scars. When the interosseous wiring, mini and micro-plate system and screws are left on the bone segments of the facial bone, they can be a possible cause of infection.

When a facial bone is either congenitally deformed or deformed by an external trauma, the deformed facial bone has been typically reconstructed by either of the following two manners. That is, the facial bone deformity may be reconstructed by osteotomy with bone graft or lengthening the deformed bone. In order to reconstruct the facial bone deformity with osteotomy and bone graft, the reconstructed bone segments must be retained using interosseous wiring and mini and micro-plate system until the bone segments are tightly united together after the reconstructing operation. And, the facial bone deformity can be reconstructed by lengthening the deformed bone theoretically, but there is no reports except mandible. Above first method has several problems, it leaves scars on the skin, and may cause an infection due to the inserted synthetic material, and may produce ill effects such as absorption of the transplanted autogenous bone graft. In accordance with recent medical memoirs, the facial bone deformities may be reconstructed through a bone lengthening procedure instead of using the above methods. However, any facial bone lengthener which can be appropriately used for reconstructing the facial bone deformity has not yet been proposed except mandible. DISCLOSURE OF INVENTION

It is, therefore, an object of the present invention to provide a medical instrument for reduction and fixation or reconstruction of fractured or deformed facial bones in which the above problems can be overcome and which tightly attaches to a human head outside the skin in order to reduce, fix, correct and lengthen a fractured and deformed facial bone three dimensionally. The above medical instrument either does not require any surgical operations for incising the skin or minimizes the extent of incision, thus either requiring no plastic operation that removes incision of the skin or can reduce the scale of such a plastic operation.

It is another object of the present invention to provide a medical instrument for reduction or reconstruction of fractured or deformed facial bones which uses neither the interosseous wiring nor the mini and micro-plate system for reconstructing the posttraumatic or congenital facial bone deformity, thus requiring no surgical operation for removing the interosseous wiring and mini and micro-plate system. The above medical instrument reconstructs a deformed facial bone through a bone lengthening procedure with neither inserting a synthetic material nor transplanting an autogenous bone graft, thus neither requiring any plastic surgery for removing scars from the skin nor causing infection or ill effects.

In order to accomplish the above objects, the present invention provides a medical instrument for reduction or reconstruction of facial bones comprising an attaching unit which is tightly screwed to a mastoid area of the temporal bone of cranium, thus tightly attaching the medical instrument to a cranial bone. The above medical instrument also has a bone segment holding unit adapted for holding displaced bone segments of a fractured or deformed facial bone, thus reducing or reconstructing the facial bone. The above holding unit is screwed to the displaced bone segments in order to hold the bone segments in their original places thus reducing or reconstructing the facial bone. The above attaching and holding units are coupled together by a longitudinal arm unit. The above arm unit also adjusts the position of the holding unit relative to the attaching unit in order to arrange the holding unit on the skin above the displaced bone segments of the facial bone.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is an exploded perspective view showing the construction of a medical instrument in accordance with an embodiment of the present invention;

Fig. 2 is a front view of the medical instrument of Fig. 1;

Fig. 3 is a plan view of the medical instrument of Fig. 1, showing a lateral turning motion of an arm unit of the instrument;

Fig. 4 is a front view of the medical instrument of Fig. 1, showing a vertical turning motion of the arm unit and different positions of a fixing plate of an attaching unit of the above instrument;

Figs. 5A to 5D are views showing the operational motions of the units of the above medical instrument, in which:

Fig. 5A is a view showing a turning motion of a bone segment holding unit pivoted to the arm unit; Fig. 5B is a view showing the lateral turning motion of the arm unit for adjusting the position of the holding unit;

Fig. 5C is a sectional view showing a motion of the attaching unit for adjusting the gap between front and back plates of the attaching unit; and

Fig. 5D is a view showing a turning motion of a length adjusting screw for adjusting the length of the arm unit;

Fig. 6 is a sectional view of an attaching unit of the medical instrument having a ball joint between the fixing and back plates in accordance with another embodiment of the present invention; and

Fig. 7 is a view showing the medical instrument of the present invention attached to the left-handed side of a cranial bone in order to reduce and fix or reconstruct a fractured or deformed facial bone.

MODE(S) OF CARRYING OUT THE INVENTION

Figs. 1 to 3 show a medical instrument in accordance with an embodiment of the present invention. As shown in these drawings, the medical instrument of the invention generally comprises three parts, that is, an attaching unit 1, a bone segment holding unit 3, and an arm unit 2. The attaching unit 1 is screwed to the mastoid area of the temporal bone of a human head. The unit 1 is thus fixed to the mastoid area of the temporal bone and tightly attaches the medical instrument to the cranium (skull). The bone segment holding unit 3 holds and fixes the displaced bone segments of a fractured or deformed facial bone in their original places until the bone segments of the facial bone are completely united together. The arm unit 2 connects the attaching and holding units 1 and 3 together, thus assembling the units 1 and 3 into the medical instrument. The above arm unit 2 also adjusts the position of the holding unit 3 in order to move the holding unit 3 on the skin above the displaced bone segments.

The above attaching unit 1 includes a fixing plate

11 with an opening. The above fixing plate 11 is fixed to the mastoid area of the temporal bone outside the skin by a plurality of fixing screwed pins 15, thus tightly attaching the instrument to the human skull. The above unit 1 also includes a back plate 12 which is coupled to the fixing plate 11. The back plate 12 has an internally threaded boss which is fitted in the opening of the fixing plate 11. When coupling the back plate 12 to the fixing plate 11, the internally threaded boss of the back plate

12 is received in the opening of the fixing plate 11 prior to fixing the position of the back plate 12 relative to the fixing plate 11 by tightening a plurality of fixing bolts 17. An externally threaded gap adjusting bolt 13 engages with the internally threaded boss of the back plate 12. The above gap adjusting bolt 13 can thus advance toward or retract from the fixing plate 12. A center protrusion 19 axially extends from the outside end of the above bolt 13. The above protrusion 19 has a center hole for receiving an L-wrench when it is required to adjust the gap between the front and back plates 14 and 12 or the height of the attaching unit 1 as will be described later herein. A front plate 14 is coupled to the protrusion 19 of the bolt 13. A plurality of fixing bolts 18 are fixed to the front plate 14 after passing the back plate 12, thus preventing the front plate 14 from rotating relative to the back plate 12. The above front plate 14 includes a worm 26. The worm 26 gears into a worm gear 25 of a first arm 21 of the arm unit 2 which will be described hereinbelow.

The arm unit 2 has a link motion. The above link motion includes the first arm 21 which is pivotally fitted over the protrusion 19 of the gap adjusting bolt 13. One end of the above first arm 21 has the worm gear 25 which gears into the worm 26 of the front plate 14 of the attaching unit 1. The first arm 21 is thus turned up or down about the protrusion 19 in accordance with the rotating motion of the worm 26. That is, the first arm 21 can be turned to vertically move the holding unit 3 in order to arrange the unit 3 on the skin above the bone segments of the fractured or deformed facial bone. An intermediate arm 22 is pivotally coupled to the other end of the first arm 21 at one end thereof by a first pivot bolt 41. The arm 22 is thus laterally rotatable about the pivot bolt 41. The other end of the above intermediate arm 22 is pivotally coupled to one end of a second arm 23 by a second pivot bolt 42. The above second arm 23 is laterally rotatable about the pivot bolt 42 and has an internally threaded guide plate 28. The arm unit 2 also includes a longitudinal slide arm 24 which has a longitudinal guide slot 29. The guide slot 29 of the above arm 24 slidably receives the guide plate 28 of the second arm 23. The above slide arm 24 has a worm 35 on one end thereof. A length adjusting screw 27 is axially set in the slide arm 24 and axially penetrates the guide plate 28 received in the guide slot 29. The head of the above screw 27 is exposed outside the slide arm 24. The above screw 27 can be thus handled outside the slide arm 24 in order to adjust the length of the arm unit 2.

The above bone segment holding unit 3 has an upper plate 31 whose one end is pivotally coupled to the slide arm 24 by a third pivot bolt 43. The upper plate 31 has a worm gar 36 which gears into the worm 35 of the slide arm 24. The above upper plate 31, which can be laterally turned about the slide arm 24, also has at least one groove 34 for holding a bone segment holding pin 33. The holding unit 3 also includes a lower plate 32. The lower plate 32 is assembled with the upper plate 31 by a fixing bolt 44, thus forming the holding unit 3. The above lower plate 32 has at least one groove 34' at a position corresponding to the groove 34 of the upper plate 31. When the upper and lower plates 31 and 32 are assembled into the holding unit 3 by the bolt 44, the grooves 34 and 34' form a hole for holding the pin 33. The above pin 33, which is held by the pin holding hole formed by the grooves 34 and 34' of the plates 31 and 32, holds a bone segment of the fractured or deformed facial bone in its original place.

In the above medical instrument, each of the fixing and holding pins 15 and 33 has a sharpened screw tip 33' as shown in the circled portion of Fig. 1. As the screw tip 33' of each pin 15, 33 has a length shorter than the thickness of the cranial bone, the screw tip 33' cannot penetrate entire depth of the craniofacial bone. In addition, a notch mark is formed on each rotating or reciprocating part of the above medical instrument in order to precisely check the rotating angle or reciprocating distance of each rotating or reciprocating part. As described above, the attaching unit 1 of the medical instrument according to the primary embodiment of the invention comprises several parts, that is, the fixing plate 11, back plate 12, gap adjusting bolt 13 and front plate 14. However, it should be understood that the above unit 1 may essentially consist of a thickened fixing plate 11 with the worm 26 in which the worm 26 gears into the worm gear 25 of the arm unit 2. That is, the gap adjusting bolt 13 may be removed from the attaching unit 1. In addition, the number of parts of the above unit 1 may be increased in order to more precisely adjust the positions of the back and front plates 12 and 14 relative to the fixing plate 11 of the unit 1. That is, the fixing and back plate 11 and 12 of the attaching unit 1 may be coupled together by a ball joint 50 as shown in Fig. 6. In this case, the back and front plates 12 and 14 can freely rotate relative to the fixing plate 11 in every direction.

In the primary embodiment, the first, intermediate and second arms 21, 22 and 23 and length adjusting screw 27 are assembled into the link motion of the arm unit 2. However, the above arms 21, 22 and 23 may be integrated into a single body which is bent at a predetermined inclination angle. The above integrated single body of the unit 2 in turn is coupled to the slide arm 24, thus forming the arm unit 2. Alternatively, the link motion of the above arm unit 2 may comprise the first and second arms 21 and 23 which are pivotally coupled together without using the intermediate arm 22. In the same manner, it should be understood that there exist various different configurations of the holding unit 3 which hold the pin 33 while yielding the same result as that described for the primary embodiment without affecting the functioning of this invention.

That is, the pin 33 may be directly held by a bolt. The above pin holding grooves 34 and 34' of the plates 31 and 32 may have circular or rectangular cross-sections in order to provide extra space for placing the pin 33 when holding the pin 33. When the grooves 34 and 34' has the rectangular cross-section, the holding part of the above pin 33 has a rectangular cross-section corresponding to the configuration of the grooves 34 and 34'. In this case, it is preferable to give uneven contact surfaces to the shank of the pin 33, thereby allowing the pin 33 to be more tightly held by the assembled plates 31 and 32.

The operational effect of the above medical instrument will be described hereinbelow. As shown in the drawings, the fixing pins 15 of the fixing plate 11 screw into the mastoid area 52' of the temporal bone 52 of a cranial bone 51. The fixing pins 15 are, thereafter, fixed by the stop bolts 16, thus tightly attaching the fixing plate 11 to the temporal bone 52. The worm 26 of the front plate 14 in the above state may rotate in order to adjust the holding unit 3 in accordance with the position of the fractured part of the facial bone. In accordance with a rotating motion of the above worm 26, the worm gear 25 of the first arm 21 rotates to turn the first arm 21 about the protrusion 19 of the gap adjusting bolt 13 up or down. The position of the arm unit 2 relative to the attaching unit 1 can be thus adjusted. Thereafter, the length adjusting screw 27 engaging with the slide arm 24 of the arm unit 2 is handled outside the slide arm 24 thereby adjusting the length of the arm unit 2. In this case, the angles of the first, intermediate and second arms 21, 22 and 23 of the above arm unit 2 are appropriately adjusted at the same time. When it is required to adjust the gap between the back and front plates 12 and 14 of the attaching unit 1, an L-wrench is inserted into the center hole of the gap adjusting bolt's protrusion 19 prior to turning the bolt 13. The gap between the plates 12 and 14 is thus adjusted. Of course, it should be understood that the order of adjusting the moving parts of the medical instrument may be changed. In addition, the moving parts of the medical instrument may be repeatedly adjusted. It is preferable to adjust both the inclination angle of the arm unit 2 and the gap between the plates 11 and 14 of the attaching unit 1 prior to attaching the fixing plate 11 to the temporal bone 52.

Thereafter, the pin 33 screws into the bone segments of the fractured facial bone 9 prior to adjusting the position of the upper plate 31 of the holding unit 3 by rotating the worm gear 36. The pin 33 screwing into the bone segments is in turn received in the holding grooves 34 and 34' of the plates 31 and 32. Thereafter, the plates 31 and 32 are assembled together by the bolt 44, thus tightly holding the pin 33.

After the pin 33 is held by the holding unit 3 of the medical instrument, the length adjusting screw 27, gap adjusting bolt 13 and worm 26 are appropriately controlled in order to move the pin 33 along with the bone segment, thereby returning the bone segment to its original position. The bone segment thus recovers its original position in the fractured facial bone three dimensionally.

When the above medical instrument requires to be removed from the cranial bone 51 after the bone segments are completely united together, the bolt 44 is loosened in order to separate the pin 33 from the holding unit 3. In addition, the stop bolts 16 of the fixing plate 11 are loosened to allow the fixing pins 15 to be released. The fixing pins 15 in the above state are separated from the temporal bone. The medical instrument in the above state can be separated from the cranial bone 51. After separating the medical instrument from the cranial bone 51, the pins 15 and 33 are removed from the cranial bone 51.

When the above medical instrument attaches to the other side or the right-handed side of the cranium, the fixing plate 11 is turned inside out and screwed to the mastoid area of the temporal bone of the cranium.

When using the above reconstruction medical instrument in a bone lengthening procedure for reconstructing a deformed facial bone, the moving parts of the reconstructing medical instrument such as the gap adjusting bolt 13, worm 26 and length adjusting screw 27 are appropriately handled after reconstructing the facial bone in the same manner as described for the reduction and fixation of the fractured facial bone. In the above state, the moving parts of the reconstructing medical instrument are handled at appropriate time intervals in order to lengthen the deformed facial bone by a predetermined length in a desired bone lengthening direction. After lengthening the deformed facial bone, the medical instrument is fixed until the bone lengthening is completely accomplished and consolidated. The above instrument is removed from the cranial bone after the reconstructed facial bone is completely united in the same manner as described for the reduction of a fractured facial bone.

As described above, the present invention provides a medical instrument for reducing or reconstructing fractured or deformed facial bones three dimensionally. The above medical instrument simply attaches to a cranial bone outside the skin in order to reduce and fix the displaced bone segments of a fractured facial bone without performing any surgical operations for fixating the displaced bone segments using interosseous wiring, mini and micro-plate system and screws. In this regard, the medical instrument of this invention does not require a surgical operation for removing the interosseous wiring, mini and micro-plate system and screws after the bone segments are completely united together. The above medical instrument thus leaves no scar or small scars on the skin in the event of reduction and bone union of the fractured facial bones.

In addition, the above medical instrument is effectively used for reconstructing a posttraumatic or congenital facial bone deformity through a bone lengthening procedure. During the bone lengthening procedure for the facial bone, the above medical instrument simply attaches to a mastoid area of cranial bone outside the skin with neither performing a surgical operation nor using synthetic material or autogenous bone graft. That is, the above medical instrument simply reconstructs the facial bone deformity without performing any complex operations for cutting the deformed facial bone and fixating the bone segments of the facial bone using interosseous wiring, mini and micro-plate system and screws. In accordance with the above medical instrument, it is not required to insert a synthetic material or transplant an autogenous bone graft while reconstructing the facial bone deformity. In this regard, the medical instrument of this invention leaves no scar or small scars on the skin, thus requiring no additional plastic operation for removing the incision scars on the skin. In addition, the above medical instrument used for reconstruction of a facial bone deformity neither causes infection due to the inserted synthetic material nor produces ill effects such as absorption of the transplanted autogenous bone graft.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A medical instrument for reducing or reconstructing fractured or congenitally and posttraumatically deformed facial bones three dimensionally comprising: means for tightly attaching the instrument to a cranial bone, said attaching means being screwed to a mastoid area of temporal bone of cranium; means for holding displaced bone segments of a fractured or deformed facial bone thus reducing or reconstructing the facial bone, said holding means being screwed to the displaced bone segments in order to hold the bone segments in their original places thus reducing or reconstructing the facial bone three dimensionally; and means for connecting the attaching and holding means together and adjusting the position of said holding means in order to arrange the holding means on the skin above the bone segments of the facial bone.

2. The medical instrument according to claim 1, wherein said attaching means comprises: a fixing plate screwed to the mastoid area of temporal bone of cranium by a fixing pin; a back plate coupled to said fixing plate; and a front plate movably coupled to said back plate in order to selectively move toward or from the back plate thereby adjusting a gap between said front and back plates, said front plate having a rotatable worm, said worm gearing into a worm gear of said connecting means in order to selectively turn said connecting means relative to the attaching means.

3. The medical instrument according to claim 2, wherein said attaching means further comprises: a gap adjusting bolt movably screwing in the back plate and adapted for adjusting the gap between the front and back plates, said gap adjusting bolt having a center protrusion for pivotally coupling both the front plate and the connecting means to said back plate.

4. The medical instrument according to claim 1, wherein said connecting means comprises: a link motion pivotally coupled to said attaching means and having a worm gear gearing into a worm of said attaching means thereby being turned up or down by a rotating motion of said worm, said link motion also having a guide plate; a longitudinal slide arm having an axial guide slot and a worm, said guide slot being adapted for movably receiving said guide plate of the link motion; and a longitudinal length adjusting screw adapted for adjusting the length of said connecting means, said length adjusting screw being axially set in the slide arm and axially penetrating the guide plate of the link motion received in the guide slot of the slide arm.

5. The medical instrument according to claim 4, wherein said link motion comprises: a first arm pivotally coupled to said attaching means, one end of said first arm having the worm gear gearing into the worm of the attaching means thereby being turned up or down relative to the attaching means by the rotating motion of said worm; an intermediate arm pivotally coupled to the other end of said first arm at one end thereof, thus being laterally turned relative to the first arm; and a second arm pivotally coupled to the other end of said intermediate arm in order to be laterally turned relative to the intermediate arm, said second arm having said guide plate movably coupled to the said slide arm by the length adjusting screw.

6. The medical instrument according to claim 1, wherein said holding means comprises: an upper plate pivotally coupled to said connecting means, said upper plate having a worm gear and at least one lateral groove, said worm gear gearing into a worm of a slide arm of said connecting means; a lower plate fixed to said upper plate, said lower plate having at least one lateral groove cooperating with said lateral groove of the upper plate in order to form a pin fixing hole; and a bone segment holding pin tightly held by the pin fixing hole and adapted for holding a displaced bone segment of the fractured or deformed facial bone in its original place.

7. The medical instrument according to claim 2 or 6, wherein each of said fixing and holding pins has a sharpened screw tip having a length shorter than a thickness of said cranial bone.

8. The medical instrument according to any one of claims 1 to 6, wherein a notch mark is formed on each rotating or reciprocating part of said medical instrument in order to precisely check a rotating angle or reciprocating distance of the part.

9. The medical instrument according to claim 1 or 2, wherein a ball joint is provided between the fixing and back plates thus allowing the front and back plates to freely rotate relative to the fixing plate in every directions.