A straight drilling automatic flip haptic type haptic titanium plate implantation device

Abstract

The utility model relates to a straight-drilling automatic loop-turning type looped titanium plate implanting device, which comprises a handle, a loop-turning outer rod, a loop-turning inner rod, a loop-turning button and a looped titanium plate. The loop-turning outer rod is of a hollow tubular structure and is arranged at the head end of the handle and communicated with the handle. A coaxial channel of the loop-turning outer rod is arranged inside the handle. A connecting piece for connecting with an external power source is arranged at the rear end of the handle. The loop-turning inner rod comprises a driving component at the rear end and a top rod fixedly connected with the driving component. An escape opener is arranged at one end of the top rod far away from the driving component. The loop-turning button extends into the coaxial channel through a chute opened on the handle and is fixedly connected with the driving component on the loop-turning inner rod. The front end of the looped titanium plate is set as a drill bit structure for drilling into bone tissue to form a bone tunnel. A plurality of through holes are arranged along the thickness direction of the looped titanium plate. Through the cooperation of each component, the implanting device can integrate the functions of direct drilling and automatic loop-turning, the implanting process is simple, and it is more convenient for minimally invasive operation during the operation.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a direct-drill automatic flipping type titanium plate implantation device with loops. Background Technology

[0002] Joint ligaments are important connective tissues connecting bones, and their main function is to stabilize joints and limit excessive joint movement. Ligaments are easily damaged when subjected to excessive stretching or twisting by external forces. Common sites of injury include the knee, ankle, wrist, fingers, and shoulder joints. Ligament injuries often lead to joint instability, and in severe cases, can even cause joint dislocation or separation, such as acromioclavicular joint dislocation and distal tibiofibular syndesmosis separation. Currently, clinical treatments for acromioclavicular joint dislocation and distal tibiofibular syndesmosis separation mainly include plate and screw fixation and looped plate fixation. Plate and screw fixation is relatively simple to perform and less expensive, but it carries risks of complications such as screw breakage, hook breakage, pain, and limited joint movement, and its biomechanical stability is relatively poor. With the development of medical technology, looped titanium plates, due to their higher strength and better biomechanical characteristics, have become an important means of treating acromioclavicular joint dislocation and distal tibiofibular syndesmosis separation. For example, in 2007, American physician Steven Struer pioneered the application of looped titanium plates in the treatment of acromioclavicular joint dislocation. Looped titanium plates can better maintain joint stability and aid in ligament repair. However, current looped titanium plate implantation techniques still have some shortcomings: Current techniques require pre-drilling holes to create a bone tunnel before inserting a traction wire to guide the plate through the tunnel to the intended position; after the plate passes through the tunnel, it needs to be manually rotated to fit the bone surface, and its position confirmed under fluoroscopy or arthroscopy; traditional open surgery requires guides and traction wire locators for positioning, while arthroscopic surgery requires creating a channel to form a gap, which can easily cause secondary damage to surrounding tissues; current looped titanium plate implantation procedures are complex, requiring multiple steps, increasing surgical time and difficulty. Currently, there is an urgent clinical need for a more minimally invasive and easier-to-operate looped titanium plate implantation technique. This technology allows for the direct drilling of a bone tunnel under C-arm fluoroscopy or CT guidance, requiring no large incisions or only small percutaneous incisions. Simultaneously, a looped titanium plate is inserted into the predetermined position, and its self-contained loop-flipping mechanism automatically flips the plate. Finally, the loop is tightened and knotted or fixed, achieving joint reduction and stability. Furthermore, the device must be able to be removed and re-implanted if loop flipping fails. Therefore, there is a need to develop a looped titanium plate implantation device that integrates direct drilling and automatic loop flipping functions to address the shortcomings of existing technologies, reduce surgical trauma, shorten operation time, lower the incidence of complications, and better help patients recover joint function. Utility Model Content

[0003] The technical problem this invention aims to solve is that existing looped titanium plate implantation devices require pre-drilling holes to form a bone tunnel, then introducing traction wires to guide the titanium plate through the bone tunnel to a predetermined position. After the titanium plate passes through the bone tunnel, it is necessary to manually flip the titanium plate to fit the bone surface. If the flipping fails, it is impossible to adjust and re-flip the plate in time. The implantation process is relatively complicated and requires multiple steps.

[0004] To address the problems existing in the prior art, a direct-drilling automatic flip-loop titanium plate implantation device is disclosed, comprising a handle, an outer flip-loop rod, an inner flip-loop rod, a flip-loop button, and a titanium plate with a loop. The outer flip-loop rod is a hollow tubular structure, located at the head end of the handle and communicating with the handle. The handle contains a coaxial channel for the outer flip-loop rod. The rear end of the handle has a connector for connecting to an external power source. The inner flip-loop rod includes a drive assembly located at the rear end and a top rod fixedly connected to the drive assembly. An escape opening is provided at the end of the top rod away from the drive assembly. The inner rod of the flip-loop is coaxially and movably disposed in the coaxial channel of the handle and the outer rod of the flip-loop. The flip-loop button extends into the coaxial channel through a continuous groove opened along the length and width directions of the handle and is fixedly connected to the drive assembly on the inner rod of the flip-loop. The front end of the looped titanium plate is configured as a drill bit structure for drilling into bone tissue to form a bone tunnel under the drive of the power source. The looped titanium plate has multiple through holes along its thickness direction.

[0005] Furthermore, a spring is fixedly connected to the front end of the drive assembly and sleeved on the outside of the top rod, and the top rod is slidably accommodated inside the outer rod of the flip loop.

[0006] Furthermore, the rear end of the looped titanium plate is slidably disposed inside the flip-loop outer rod, the front end of the flip-loop outer rod is provided with a groove that matches the drill bit at the front end of the looped titanium plate, and the rear end of the flip-loop outer rod is provided with a hole that communicates with its internal hollow tubular structure.

[0007] Furthermore, a groove is provided at the front end of the handle, and a hollow strip hole is provided in the middle of the groove. The hole at the rear end of the flip-loop outer rod is located at the lower end of the hollow strip hole.

[0008] Furthermore, the plurality of through holes include traction through holes, coil through holes, and loop wire through holes. The traction through holes are located close to the drill bit and are provided with traction wires. The coil through holes are located away from the drill bit and are provided with annular coils. The loop wire through holes are provided with loop wires.

[0009] Furthermore, the handle is provided with a wire cavity, and the loop wire and the traction wire on the looped titanium plate extend through the hole at the rear end of the flip-loop outer rod and out of the groove of the handle, and are housed in the wire cavity.

[0010] Furthermore, the escape opening is provided at the end of the escape opening away from the top rod, and the escape opening is used to allow the annular coil to pass through, so as to form a loop structure between the annular coil and the escape opening.

[0011] Furthermore, the annular coil is detachably connected to the escape opening of the top rod.

[0012] Preferably, the escape opening is a rhomboid or irregular polygonal structure.

[0013] Preferably, the looped titanium plate is made of titanium alloy or a magnesium alloy biomaterial that can be absorbed by bone tissue, and the traction wire and the annular coil are made of absorbable material.

[0014] The beneficial effects that the embodiments of this specification may bring include, but are not limited to: (1) The integrated design of the drill bit and the looped titanium plate allows the implantation device to directly drill holes to form a bone tunnel, improving surgical efficiency; (2) Automatic loop turning can be achieved through the cooperation of the push rod, the escape opening device on the push rod, the traction line and the ring coil. The escape opening device at the end of the push rod can be connected to the ring coil on the coil through hole of the looped titanium plate. After the push rod pushes the looped titanium plate out of the bone tunnel, the ring coil is subjected to force at the rear of the push rod and will not detach. After pulling the traction line to rotate the looped titanium plate 90° horizontally, the push rod is pulled back, the escape opening device at the end of the push rod opens, the ring coil detaches, and the entire automatic loop turning is completed. Process; (3) The groove at the front end of the looped outer rod matches the drill bit at the front end of the looped titanium plate, so that the drill bit is stuck in the groove when drilling. As long as the cortical bone is broken, the top rod can be used to push out the looped titanium plate, which can prevent the important soft tissues of the skin and nerves from being broken; (4) If the soft tissue is stuck and the looping is unsuccessful, the escape mouthpiece of the top rod can be opened again, the looped coil can be hooked, the looped titanium plate can be pulled back, and the angle can be changed to release it again until the predetermined surgical effect is achieved; (5) The implantation device of this application can integrate direct drilling and automatic looping functions through the cooperation of various components. The implantation process is simple, more convenient for minimally invasive operation during surgery, reduces collateral damage, saves surgical time, and reduces the incidence of complications. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0016] Figure 1This is a schematic diagram of the overall structure of the straight-drill automatic flip-loop type titanium plate implantation device according to an embodiment of the present utility model;

[0017] Figure 2 This is an exploded view of the straight-drill automatic flip-loop type titanium plate implantation device with loop according to an embodiment of the present invention;

[0018] Figure 3 This is an enlarged schematic diagram of the looped titanium plate according to an embodiment of the present invention;

[0019] Figure 4 This is a plan view of the looped titanium plate according to an embodiment of the present utility model;

[0020] Figure 5 This is a schematic diagram showing the connection between the escape opening and the ring coil in an embodiment of this utility model;

[0021] In the diagram: 1-Handle, 11-Connector, 11-Groove, 111-Hollow strip hole, 12-Cavity, 2-Outer rod of flip-loop, 21-Slot, 22-Hole, 3-Inner rod of flip-loop, 31-Drive assembly, 311-Spring, 32-Top rod, 321-Escape opening device, 3211-Escape opening, 4-Flip-loop button, 5-Titanium plate with loop, 51-Drill bit, 52-Through hole, 521-Traction through hole, 5211-Traction line, 522-Through hole of loop line, 5221-Loop line, 523-Through hole of coil, 5231-Ring coil. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0023] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. In the description of the present invention, it should be understood that the terms "upper," "inner," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein.

[0024] To address the problems existing in the prior art, this application provides a direct-drilling automatic flipping type titanium plate implantation device with loops, specifically, as follows: Figures 1-3 As shown, the direct drilling automatic flipping type titanium plate implantation device includes a handle 1, a flipping outer rod 2, a flipping inner rod 3, a flipping button 4, and a titanium plate with a loop 5. The flipping outer rod 2 is a hollow tubular structure, located at the head end of the handle 1 and communicating with the handle 1. The handle 1 has a coaxial channel for the flipping outer rod 2. The rear end of the handle 1 has a connector for connecting to an external power source. The flipping inner rod 3 includes a drive assembly 31 located at the rear end and a push rod 32 fixedly connected to the drive assembly 31. The push rod 32 is located away from the drive assembly 31. An escape opening 321 is provided at one end of component 31. The inner rod 3 of the flip-loop is coaxially and movably disposed in the coaxial channel of the handle 1 and the outer rod 2 of the flip-loop. The flip-loop button 4 extends into the coaxial channel through a continuous groove opened along the length and width directions of the handle 1 and is fixedly connected to the drive component 31 on the inner rod 3 of the flip-loop. The front end of the titanium plate 5 with loop is configured as a drill bit 51 structure, which is used to drill into the bone tissue to form a bone tunnel under the drive of the power source. The titanium plate 5 with loop has multiple through holes 52 along its thickness direction.

[0025] Understandably, existing technologies require pre-drilling to form a bone tunnel when implanting looped titanium plates. However, the integrated design of the drill bit and looped titanium plate in this application allows the implantation device to directly drill to form a bone tunnel, thus improving surgical efficiency.

[0026] Furthermore, a spring 311 is fixedly connected to the front end of the drive assembly 31 and sleeved on the outside of the top rod 32. The top rod 32 is slidably accommodated inside the flip-loop outer rod 2. When the flip-loop button 4 is pressed, the spring 311 is compressed, and the drive assembly 31 drives the top rod 32 to move forward. When the flip-loop button 4 is released, the elastic deformation restoring force of the spring 311 pushes the drive assembly 31 back, causing the top rod 32 to retract, thereby helping the flip-loop mechanism to reset.

[0027] Furthermore, the rear end of the looped titanium plate 5 is slidably disposed inside the flip-loop outer rod 2. The front end of the flip-loop outer rod 2 is provided with a groove 21 that matches the drill bit 51 at the front end of the looped titanium plate 5, and the rear end of the flip-loop outer rod 2 is provided with a hole 22 that communicates with its internal hollow tubular structure. The design of the groove 21 ensures that the drill bit 51 is stuck in the groove 21 when drilling. Once the cortical bone is broken, the push rod 32 can be used to push out the looped titanium plate 5, which can prevent drilling into the skin and important soft tissues of nerves.

[0028] Furthermore, the multiple through holes 52 include a traction through hole 521, a coil through hole 523, and a loop through hole 522. The traction through hole 521 is located close to the drill bit 51, and a traction wire 5211 is provided on the traction through hole 521. The coil through hole 523 is located away from the drill bit 51, and an annular coil 5231 is provided on the coil through hole 523. A loop wire 5221 is provided on the loop through hole 522.

[0029] Furthermore, a groove 11 is provided at the front end of the handle 1, and a hollow strip-shaped hole 111 is provided in the middle of the groove 11. The hole 22 at the rear end of the flip-loop outer rod 2 is located at the lower end of the hollow strip-shaped hole 111. The alignment design of the hollow strip-shaped hole 111 and the hole 22 of the flip-loop outer rod 2 can guide the correct installation and positioning of the flip-loop outer rod 2 in the handle 1, ensuring that the flip-loop outer rod 2 is coaxial with the handle 1. On the other hand, it can facilitate the passage of the traction line 5211 and the loop line 5221.

[0030] Furthermore, the handle 1 is provided with a suture cavity 12. The looped wire 5221 and the traction wire 5211 on the looped titanium plate 5 pass through the hole 22 at the rear end of the outer rod 2 and extend out of the groove 11 on the handle 1, and are stored in the suture cavity 12. The orderly storage of the cables through the suture cavity 12 can avoid the cables from getting tangled or knotted, and facilitate surgical operations.

[0031] Furthermore, the escape opening 321 is provided with an escape opening 3211 at the end away from the top rod 32. The escape opening 3211 is used to allow the ring coil 5231 to pass through, so as to form a ring structure between the ring coil 5231 and the escape opening 321.

[0032] Furthermore, the toroidal coil 5231 is detachably connected to the escape opening 321 of the top rod 32.

[0033] Understandably, in the prior art, the looped titanium plate needs to pass through the bone tunnel to reach the predetermined position with the help of a traction wire, and the titanium plate needs to be manually flipped to fit the bone. However, this application can achieve automatic loop flipping through the cooperation of the push rod 32, the escape opening device 321 on the push rod 32, the traction wire 5211 and the ring coil 5231. The escape opening device 321 at the end of the push rod 32 can be connected to the ring coil 5231 on the coil through hole 523 of the looped titanium plate 5. After the push rod 32 pushes the looped titanium plate 5 out of the bone tunnel, the ring coil 5231 is subjected to force at the rear of the push rod 32, which will not cause the ring coil 5231 to disengage. After pulling the traction wire 5211 to rotate the looped titanium plate 5 90° horizontally, the push rod 32 is pulled back. The opening of the escape opening device 321 at the end of the push rod 32 opens, the ring coil 5231 disengages, and the entire automatic loop flipping process is completed.

[0034] Preferably, the drill bit 51 structure, which is combined with the front end of the titanium plate 5 with loop, realizes the functions of direct drilling and automatic loop flipping, making the implantation process of the implantation device simple, facilitating minimally invasive operation during surgery, reducing collateral damage, saving surgical time, and reducing the incidence of complications.

[0035] Preferably, the annular coil 5231 is detachably connected to the escape opening device 321 of the push rod 32, so that in the event of soft tissue compression and unsuccessful retraction, the escape opening device 321 of the push rod 32 can be reopened, the annular coil 5231 can be hooked, the looped titanium plate 5 can be pulled back, and the release can be repeated at a different angle until the desired surgical position is achieved.

[0036] Preferably, the escape opening 321 is a rhombus or an irregular polygon structure. The rhombus and irregular polygon angles can be used as temporary fixing points for the ring coil 5231 after it passes through the escape opening 3211. The angles make it difficult for the ring coil 5231 to detach. When the loop is finished and it is necessary to separate the ring coil 5231 from the escape opening 321, it is only necessary to slightly adjust the top rod 32 to adjust the escape opening 321 by an angle, so that the ring coil 5231 can slide out of the escape opening 3211 and detach from the escape opening 321.

[0037] Preferably, the looped titanium plate 5 is made of titanium alloy or magnesium alloy biomaterial that can be absorbed by bone tissue, and the traction wire 5211 and the loop coil 5231 are made of absorbable material. By using absorbable materials, there is no need for a second surgery to remove it after surgery, simplifying the surgical procedure and saving surgical time and costs.

[0038] The usage process of the direct-drill automatic flip-loop type titanium plate implantation device in this embodiment is as follows (taking four through holes in the titanium plate 5 as an example): In the initial state, the traction wire 5211 is set on the traction through hole 521 near the drill bit 51, and the annular coil 5231 is set on the coil through hole 523 away from the drill bit 51. The escape opening device 321 on the top rod 32 and the annular coil 5231 are connected to form a ring structure, and the loop wire 5221 is set in the middle 2. On the loop wire through hole 522, the flip-loop titanium plate 5 is axially slidably set inside the flip-loop outer rod 2. The drill bit 51 is stuck in the slot 21 at the front end of the flip-loop outer rod 2. The traction wire 5211 and the loop wire 5221 pass through the flip-loop outer rod 2, and exit through the hole 22 at the rear end of the flip-loop outer rod 2 and the hollow strip hole 111 of the handle 1. They extend outward through the groove 11 of the handle 1 and are finally stored in the wire cavity 12 on the handle 11. After starting work, the connector at the rear end of the handle 11 is connected. With the external power source activated, the drill bit 51, now locked in slot 21, drills into the bone tissue to form a bone tunnel under the drive of the external power source. Pressing the loop-flipping button 4 compresses the spring 311, causing the drive assembly 31 to move the push rod 32 forward. The push rod 32 pushes the looped titanium plate 5 out of the bone tunnel. Then, pulling the traction line 5211 rotates the looped titanium plate 5 90° horizontally. Releasing the loop-flipping button 4 causes the elastic deformation restoring force of the spring 311 to push the drive assembly 31 back, driving the push rod 32 to move the push rod 32 forward. The rod 32 retracts, the escape opening device 321 at the end of the top rod 32 opens, and the ring coil 5231 disengages, completing the entire automatic looping process. After the looping is completed, the loop line 5221 is tightened, knotted, and then cut, completing joint reduction and fixation. If the looping is unsuccessful, the escape opening device 321 of the top rod 32 is reopened, the ring coil 5231 is hooked, the looped titanium plate 5 is pulled back, and the angle is changed again for release until the predetermined surgical effect is achieved.

[0039] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A straight-drill automatic flipping type titanium plate implantation device with loop, characterized in that, The device includes a handle (1), a flip-loop outer rod (2), a flip-loop inner rod (3), a flip-loop button (4), and a titanium plate with a loop (5). The flip-loop outer rod (2) is a hollow tubular structure. The flip-loop outer rod (2) is located at the head end of the handle (1) and communicates with the handle (1). The handle (1) has a coaxial channel for the flip-loop outer rod (2). The rear end of the handle (1) is provided with a connector for connecting to an external power source. The flip-loop inner rod (3) includes a drive assembly (31) located at the rear end and a top rod (32) fixedly connected to the drive assembly (31). The top rod (32) is located away from the drive assembly (31). An escape opening device (321) is provided at one end of the ), and the inner rod (3) of the loop is coaxially movable in the coaxial channel of the handle (1) and the outer rod (2). The loop button (4) extends into the coaxial channel through a continuous groove opened along the length and width of the handle (1) and is fixedly connected to the drive assembly (31) on the inner rod (3). The front end of the looped titanium plate (5) is set as a drill bit (51) structure, which is used to drill into the bone tissue to form a bone tunnel under the drive of the power source. The looped titanium plate (5) is provided with multiple through holes (52) along its thickness direction.

2. The straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 1, characterized in that, The front end of the drive assembly (31) is fixedly connected to a spring (311) sleeved on the outside of the top rod (32), and the top rod (32) is slidably accommodated inside the flip-loop outer rod (2).

3. The straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 1, characterized in that, The rear end of the looped titanium plate (5) is slidably disposed inside the flip-loop outer rod (2). The front end of the flip-loop outer rod (2) is provided with a groove (21) that matches the drill bit (51) at the front end of the looped titanium plate (5). The rear end of the flip-loop outer rod (2) is provided with a hole (22) that communicates with its internal hollow tubular structure.

4. The straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 3, characterized in that, The handle (1) has a groove (11) at the front end, and a hollow strip hole (111) is provided in the middle of the groove (11). The hole (22) at the rear end of the flip-loop outer rod (2) is located at the lower end of the hollow strip hole (111).

5. The straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 4, characterized in that, The plurality of through holes (52) include a traction through hole (521), a coil through hole (523), and a loop through hole (522). The traction through hole (521) is located close to the drill bit (51) and a traction wire (5211) is provided on the traction through hole (521). The coil through hole (523) is located away from the drill bit (51) and a ring coil (5231) is provided on the coil through hole (523). A loop wire (5221) is provided on the loop through hole (522).

6. The straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 5, characterized in that, The handle (1) is provided with a wire cavity (12). The loop wire (5221) and the traction wire (5211) on the looped titanium plate (5) pass through the hole (22) at the rear end of the flip-loop outer rod (2) and extend out of the groove (11) of the handle (1), and are stored in the wire cavity (12).

7. The straight-drill automatic flipping type titanium plate implantation device with loop according to claim 5, characterized in that, The escape opening (321) is provided with an escape opening (3211) at one end away from the top rod (32). The escape opening (3211) is used to allow the annular coil (5231) to pass through, so as to form a ring structure between the annular coil (5231) and the escape opening (321).

8. The straight-drill automatic flipping type titanium plate implantation device with loop according to claim 7, characterized in that, The annular coil (5231) is detachably connected to the escape opening (321) of the top rod (32).

9. A straight-drill automatic flipping type titanium plate implantation device with loop according to claim 1, characterized in that, The escape opening (321) is a rhomboid or irregular polygonal structure.

10. A straight-drill automatic flipping type titanium plate implantation device with loop as described in claim 5, characterized in that, The material of the looped titanium plate (5) is titanium alloy or magnesium alloy biomaterial that can be absorbed by bone tissue, and the traction wire (5211) and the ring coil (5231) are absorbable materials.

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