Patent Description:
After removal of a large area of a skull of a patient due to trauma or operation, cranioplasty needs to be carried out to repair the defect area in the skull using an artificial bone plate to cover the defect area of the skull. The artificial bone plate provides proper protection for the vulnerable brain tissue and prevents sequelae.

A conventional artificial bone plate used in cranioplasty is cut by machining from a chunk of material; to be precise, a chunk of metal or polymer is cut into the shape of the removed bone of the skull, and then the machined artificial bone plate is fixed to the skull by surgery.

However, the surface of the skull is curved, and therefore a great amount of material needs to be removed during the machining process, which causes a waste of material and time.

To overcome the shortcomings, the present invention provides an assembleable artificial bone plate and an artificial bone plate unit to mitigate or obviate the aforementioned problems.

The main objective of the present invention is to provide an assembleable artificial bone plate and artificial bone plate units that save material and take less time to manufacture.

An artificial bone plate unit of a first configuration comprises a plate body, multiple connecting pins and multiple connecting holes. The plate body has two main surfaces and a peripheral surface. The peripheral surface is connected between the two main surfaces. The connecting pins are formed on the plate body and arranged along the peripheral surface on the plate body. The connecting holes are formed in the plate body and arranged along the peripheral surface on the plate body. The connecting holes correspond in shape to the connecting pins. Multiple drug cavities are formed in the artificial bone plate unit. Multiple drug-releasing openings are formed on the artificial bone plate unit, and each of the drug-releasing openings is connected to a respective one of the drug cavities. A maximum area of a cross section of each of the drug cavities is greater than an area of a corresponding one of the drug-releasing openings; and a normal direction of the cross section of each of the drug cavities is parallel to an opening direction of the corresponding drug-releasing opening.

The assembleable artificial bone plate is bendable and comprises multiple aforementioned artificial bone plate units. The artificial bone plate units are connected using the connecting pins and the connecting holes.

By designing the artificial bone plate units each having the connecting pins and the connecting holes formed on/in the plate body and arranged along the peripheral surface, the artificial bone plate units can be connected with each other using the connecting pins and the connecting holes located in the edge to form a larger piece of an assembleable artificial bone plate. An artificial bone plate for the patient is produced by connecting multiple said artificial bone plate units of the present invention to form a larger piece of the assembleable artificial bone plate, and then bend the assembleable artificial bone plate to make its shape correspond to a shape of a defect area of a skull. In this case, a waste of expensive medical grade material due to machining is prevented, and also the time it takes to produce the artificial bone plate is shorter.

Moreover, with the drug cavities and the drug-releasing openings, the bone plate unit is capable of facilitating wound healing by slowly releasing drugs after a surgery. To be precise, the drugs can be filled in the drug cavities before the surgery, and then the drugs will be slowly released through the drug-releasing openings after the bone plate unit is placed inside a human body.

In addition, three USA patent publications, which are No. <CIT>, No. <CIT>, and No. <CIT>, have respectively disclosed an artificial bone plate unit.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

With reference to <FIG>, an artificial bone plate unit in accordance with the present invention comprises a plate body, multiple connecting pins <NUM> multiple connecting holes <NUM>, multiple drug cavities <NUM>, and multiple drug-releasing openings <NUM>. The plate body has two main surfaces <NUM>, a peripheral surface <NUM>, multiple connecting pins <NUM> and multiple connecting holes <NUM>. The peripheral surface <NUM> is connected between the two main surfaces <NUM>.

The connecting pins <NUM> and the connecting holes <NUM> are formed on the plate body and arranged along the peripheral surface <NUM> on the plate body. The connecting holes <NUM> correspond in shape to the connecting pins <NUM>, which means two artificial bone plate units in accordance with the present invention can be assembled together by engaging one of the connecting pins <NUM> of one plate unit with one of the connecting holes <NUM> of the other plate unit.

The drug cavities <NUM> (as shown in <FIG>) are formed in the artificial bone plate unit. The drug-releasing openings <NUM> are formed on the artificial bone plate unit, and each of the drug-releasing openings <NUM> is connected to a respective one of the drug cavities <NUM> such that drugs can be prefilled in the drug cavities <NUM> before surgery, and then drugs in the drug cavities <NUM> will be slowly released after the artificial bone plate unit is placed inside a human body.

In the preferred embodiment, the drug cavities <NUM> are formed in the plate body and the connecting pins <NUM>; the drug-releasing openings <NUM> are formed on the two main surfaces <NUM>, the peripheral surface <NUM>, and all outer surfaces of the connecting pins <NUM>; that is, the drug-releasing openings <NUM> and the drug cavities <NUM> are disposed on all outer surfaces of the artificial bone plate unit. In another preferred embodiment, the drug-releasing openings <NUM> and the drug cavities <NUM> are disposed only on the plate body. The drug cavities <NUM> and the drug-releasing openings <NUM> are preferably formed together by etching.

Moreover, the artificial bone plate unit preferably has multiple drug-releasing channels <NUM>. Each of the drug-releasing channels <NUM> connects a respective one of the drug-releasing openings <NUM> and a respective one of the drug cavities <NUM>; that is, the drug-releasing openings <NUM> and the drug cavities <NUM> are connected via the drug-releasing channels <NUM>. In another preferred embodiment, the drug-releasing channels <NUM> are omitted, and the drug-releasing openings <NUM> and the drug cavities <NUM> are directly connected.

With reference to <FIG>, detailed dimensions and shapes of the drug cavities <NUM> are further explained using cross section and longitudinal section of the drug cavities <NUM>. A normal direction of the cross section of each of the drug cavities <NUM> is parallel to an opening direction of the corresponding drug-releasing opening <NUM>, while a normal direction of the longitudinal section of each of the drug cavities is perpendicular to an opening direction of the corresponding drug-releasing opening <NUM>.

A maximum area of the cross section of each of the drug cavities <NUM> is greater than an area of a corresponding one of the drug-releasing openings <NUM>. As a result, drug in the drug cavity <NUM> will be released slowly for a longer period of time due to the relatively small drug-releasing opening <NUM>. Shape of a longitudinal section of each of the drug cavities <NUM> is a circle (as shown in <FIG>), an ellipse (as shown in <FIG>), or an ovoid.

With reference to <FIG>, in another preferred embodiment, the area of the cross section of each of the drug cavities <NUM> increases as a cutting plane X-X of the cross section moves away from the corresponding drug-releasing opening <NUM>. In this particular embodiment, the shape of the longitudinal section of each of the drug cavities <NUM> is preferably a triangle.

With reference to <FIG> and <FIG>, the connecting pins <NUM> and the connecting holes <NUM> are preferably formed on the peripheral surface <NUM> of the plate body, and therefore when multiple said artificial bone plate units are assembled together to form an assembleable artificial bone plate, a surface of the assembleable artificial bone plate is substantially smooth as edges of the plate bodies do not protrude therefrom. However, positions of the connecting pins <NUM> and the connecting holes <NUM> are not limited by the abovementioned, as long as the connecting pins <NUM> and the connecting holes <NUM> are arranged along the peripheral surface <NUM> on/in the plate body, which means the connecting pins <NUM> and the connecting holes <NUM> only have to surround or be arranged along the peripheral surface <NUM>, and do not have to be located on the peripheral surface <NUM>. To be precise, the connecting pins <NUM> and the connecting holes <NUM> can be formed on the peripheral surface <NUM> as shown in <FIG>, or the connecting pins 30F and the connecting holes 40F can be formed on the main surface 10F and located adjacent to an edge of the peripheral face 20F as shown in <FIG>.

The plate body in a preferred embodiment is a six-sided polygon, and to be precise, the plate body is a regular hexagon, such that the six connecting faces <NUM> are formed on the peripheral surface <NUM>. A number of the connecting pins <NUM> is six, and each of the six connecting pins <NUM> is formed on a respective one of the six connecting faces. A number of the connecting holes <NUM> is six, and each of the six connecting holes <NUM> is formed in a respective one of the six connecting faces <NUM>.

In another preferred embodiment, the plate body can be an N-sided polygon other than hexagon, where N is an integer greater than <NUM>. When the plate body is the N-sided polygon other than hexagon, a number of the connecting faces <NUM>, the number of the connecting pins <NUM>, and the number of the connecting holes <NUM> are N. Each of the N connecting pins <NUM> is formed on a respective one of the N connecting faces <NUM>, and each of the N connecting holes <NUM> is formed in a respective one of the N connecting faces <NUM>. In other words, each side of the N-sided polygonal plate body has a connecting pin <NUM> and a connecting hole <NUM>.

Moreover, a number of the connecting pin <NUM> on each connecting face <NUM> and a number of the connecting hole <NUM> on each connecting face <NUM> are not limited to one. For example, in a second embodiment in accordance with the present invention (as shown in <FIG>), some connecting faces 21A have two connecting pins 30A but no connecting hole 40A, while other connecting faces 21A have two connecting holes 40A but no connecting pins 30A.

A shape of the connecting pin <NUM> is cylindrical, while the connecting hole <NUM> is a round recess, which corresponds to the shape of the connecting pin <NUM>. However, the shapes of the connecting pin <NUM> and connecting hole <NUM> are not limited to the abovementioned, and can be of other shapes depending on the application. For example, the connecting pin 30B can be a quadrilateral prism as shown in <FIG>, while the connecting hole 40B is a square hole; or the connecting pin 30C can be a triangular prism as shown in <FIG>, while the connecting hole 40C is a triangular hole; or the connecting pin 30D can be a pentagonal prism as shown in <FIG>, while the connecting hole 40D is a pentagonal hole.

In another preferred embodiment, a round connecting ball 50E is connected to the tip of the connecting pin 30E (as shown in <FIG>), and a diameter of the connecting ball 50E is greater than a diameter of the connecting pin 30E. A round connecting cavity 60E is formed in a bottom of the round connecting hole 40E, and a diameter of the connecting cavity 60E corresponds to the diameter of the connecting ball 50E. In this case, when connecting two of the artificial bone plate units, the connecting ball 50E can be pressed through the connecting hole 40E and forcing a diameter of the connecting hole 40E to expand elastically, and finally the connecting ball 50E is pressed through the connecting hole 40E and engages with the connecting cavity 60E. A strength of the connection between said two artificial bone plate units is further enhanced to prevent separation when the two artificial bone plate units are pulled in opposite directions respectively.

With reference to <FIG> and <FIG>, a seventh embodiment of an artificial bone plate unit in accordance with the present invention is substantially similar to the first embodiment, but the difference is that multiple drug pins <NUM> are formed on one of the main surfaces <NUM> of the plate body. Each of the drug pins <NUM> has one of the drug cavities <NUM> formed in the drug pin and one of the drug-releasing openings <NUM> formed on a distal end of the drug pin <NUM> and connected to the corresponding drug cavity <NUM>. The drug pins <NUM> are preferably micro tubes formed by special chemical procedures, and are preferably intensely arranged the main surface <NUM>.

With reference to <FIG>, an assembleable artificial bone plate in accordance with the present invention is bendable. The assembleable artificial bone plate comprises multiple said artificial bone plate units P. The artificial bone plate units P are connected to each other. Among any two of the artificial bone plate units P that are connected to each other, at least one of the connecting pins <NUM> on one of said two artificial bone plate units P is mounted inside the at least one of the connecting holes <NUM> in the other one of said two artificial bone plate units P. In a preferred embodiment, the assembleable artificial bone plate is formed by having the artificial bone plate units P connected to each other through the connecting pins <NUM> and the connecting holes <NUM> located on the peripheral surface <NUM>, and the artificial bone plate units P are in accordance with the first embodiment of the present invention, but an assembleable artificial bone plate can also be formed by the artificial bone plate units of another embodiment.

With reference to <FIG> and <FIG>, an eighth embodiment of the artificial bone plate unit in accordance with the present invention is substantially similar to the first embodiment mentioned above, but the connecting pins 30F and the connecting holes 40F are formed in different positions.

The connecting pins 30F are formed on one of the two main surfaces 10F. The connecting holes 40F are formed through the two main surfaces 10F of the artificial bone plate unit. In a preferred embodiment, multiple screw holes 11F are formed through the two main surfaces 10F, and the screw holes 11F are arranged along the peripheral face 20F of the plate body. However, positions of the screw holes 11F are not limited by abovementioned positions, and the plate body may optionally have no screw holes 11F.

In a preferred embodiment, the plate body is polygonal, such that multiple corner portions 22F are formed on the peripheral surface 20F. Each of the connecting pins 30F is disposed adjacent to one of the corner portions 22F, and each of the connecting holes 40F is disposed adjacent to one of the corner portions 22F. To be precise, the plate body is a six-sided polygon, and the corner portions 22F are located adjacent to the corner positions of the polygonal plate body. However, positions of the connecting pins 30F and the connecting holes 40F are not limited by abovementioned positions. For example, the connecting pins 30F and the connecting holes 40F can be located in the middle of two of the adjacent corner portions 22F.

In a preferred embodiment, the plate body is an N-sided polygon, such that the peripheral surface 20F comprises N connecting faces 21F. A sum of a number of the connecting pins 30F and a number of the connecting holes 40F is N. To be precise, N is six, and the plate body is hexagonal, such that the peripheral surface 20F comprises N connecting faces 21F. Three connecting pins 30F and three connecting holes 40F are formed on the plate body, making the sum of the number of the connecting pins 30F and the number of the connecting holes 40F be six, through which a polygonal plate body can be securely connected to an adjacent polygonal plate body. However, the sum of the number of the connecting pins 30F and the number of the connecting holes 40F is not limited by the abovementioned. For example, the sum of the number of the connecting pins 30F and the number of the connecting holes 40F in the polygonal plate body can be twelve.

With reference to <FIG> and <FIG>, an ninth embodiment of the artificial bone plate unit is substantially similar to the eighth embodiment mentioned above, but the connecting pins <NUM> are formed on a respective one of the two main surfaces <NUM>. The connecting pins <NUM> can be located symmetrically on the two main surfaces <NUM>, which means all connecting pins <NUM> are formed through the plate body; the connecting pins <NUM> can also be located asymmetrically, which means some of the connecting pins <NUM> are formed through the plate body, while the remaining connecting pins <NUM> are only formed on either side of the plate body.

A distance between the two main surfaces 10F is defined as a thickness of the plate body. The thickness of the plate body in the aforementioned eighth and ninth embodiments of the artificial bone plate unit is less than <NUM>, but the thickness of the plate body in the embodiment wherein the connecting pins 30F and the connecting holes 40F are formed on the main surface 10F is not limited by abovementioned as long as the plate body can be deformed when bended to satisfy the need of a surgical repair.

In all the abovementioned embodiments of the artificial bone plate unit, the artificial bone plate unit can be made of a material with good biocompatibility and mechanical strength, such as titanium, Ti-6Al-4V, <NUM> stainless steel or polyether ether ketone (PEEK). The artificial bone plate unit can also be made of aluminum for reduced weight and cost. Moreover, all the abovementioned embodiments of the artificial bone plate unit comprise the drug cavities <NUM> and the drug-releasing openings <NUM> for releasing the drugs.

With reference to <FIG>, a second embodiment of the assembleable artificial bone plate is substantially similar to the first embodiment mentioned above, but the difference is that the connecting pins and the connecting holes are formed on the main surfaces of the artificial bone plate units, and therefore the edges of the artificial bone plate units are overlapped. Three different embodiments of the artificial bone plate units are present in said assembleable artificial bone plate: the artificial bone plate unit P1 corresponds to the ninth embodiment as shown in <FIG>; the artificial bone plate unit P2 corresponds to the eighth embodiment as shown in <FIG>; the artificial bone plate unit P3 is substantially similar to the eighth embodiment mentioned above, but a length of one of the connecting pins P4 is longer than the other connecting pins in order to connect the artificial bone plate unit P2.

To use the present invention, first connect several artificial bone plate units together to form a larger piece of the assembleable artificial bone plate, and then bend the assembleable artificial bone plate to make the shape of the assembleable artificial bone plate correspond to the shape of a defect area of a skull.

When the assembleable artificial bone plate is of the second embodiment (as shown <FIG>), the edge of the assembleable artificial bone plate overlaps with the surface of the skull, and screws can be used to fasten the assembleable artificial bone plate to the skull through the screw holes on the artificial bone plate units.

Claim 1:
An artificial bone plate unit (P) comprising:
a plate body having
two main surfaces (<NUM>);
a peripheral surface (<NUM>) connected between the two main surfaces (<NUM>);
multiple connecting pins (<NUM>) formed on the plate body and arranged along the peripheral surface (<NUM>) on the plate body;
multiple connecting holes (<NUM>) formed in the plate body and arranged along the peripheral surface (<NUM>) in the plate body; the connecting holes (<NUM>) corresponding in shape to the connecting pins (<NUM>);
characterized in that
multiple drug cavities (<NUM>) are formed in the artificial bone plate unit (P); and
multiple drug-releasing openings (<NUM>) are formed on the artificial bone plate unit (P); each of the drug-releasing openings (<NUM>) is connected to a respective one of the drug cavities (<NUM>);
a maximum area of a cross section of each of the drug cavities (<NUM>) is greater than an area of a corresponding one of the drug-releasing openings (<NUM>); and
a normal direction of the cross section of each of the drug cavities (<NUM>) is parallel to an opening direction of the corresponding drug-releasing opening (<NUM>).