Abstract
A device for implanting heat deformable fixation elements of different sizes in a bone, comprises a hand piece extending from a proximal end to a distal end and including an internal optical waveguide connected to a laser source and open to the distal end of the hand piece and a light guiding tip extending from a proximal end to a distal end, the proximal end of the light guiding tip being removably mechanically and optically connectable to the distal end of the hand piece and the distal end of the light guiding tip being configured to permit removable attachment of a bone fixation element, the light guiding tip including an optical waveguide, wherein the light guiding tip is configured to control a total radiant energy Q transmitted from the laser source to the bone fixation element
Claims
1. (canceled)
2. A deformable bone fixation element, comprising: a proximal end, and a distal end that is spaced from the proximal end along a distal direction, the distal end configured to be inserted into a bone; and an outer surface that extends from the proximal end to the distal end, wherein the bone fixation element consists entirely of at least one colored polymer that is configured to absorb electromagnetic radiation and convert the electromagnetic radiation to heat such that an entirety of the bone fixation element is configured to soften and deform in response to the electromagnetic radiation.
3. The deformable bone fixation element of claim 2, wherein the at least one colored polymer contains of at least one colored substance that is configured to absorb the electromagnetic radiation.
4. The deformable bone fixation element of claim 3, wherein the at least one colored substance is a chromophore pigment added to the at least one polymer to absorb the electromagnetic radiation and convert the electromagnetic radiation to heat.
5. The deformable bone fixation element of claim 2, wherein the at least one colored polymer is self-colored.
6. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is solid from the proximal end to the distal end.
7. The deformable bone fixation element of claim 2, wherein the distal end of the deformable bone fixation element is pointed.
8. The deformable bone fixation element of claim 2, wherein the at least one colored polymer includes at least one of chlorophyll, carbon black, graphite, fluorescein, methylene blue, indocyanine green, eosine; eosine Y (514 nm), ethyleosine (532 nm), acridine, acridine orange, copper phtalocyanine, chrome-cobalt-aluminum oxide, ferrous ammonium citrate, pyrogallol, logwood extract, chlorophyll-copper complex, D&C blue No. 9, D&C green No. 5, [phtalocyaninate(2-)] copper, D&C blue no. 2, D&C blue no. 6, D&C green no. 6, D&C violet no. 2, and D&C yellow No. 10.
9. The deformable bone fixation element of claim 2, wherein the at least one colored polymer exhibits a molar heat capacity of between 1.6 kJ/kmolK and 2.9 kJ/kmolK.
10. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is configured such that softening of the at least one colored polymer occurs below a warming temperature of 250 C.
11. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is configured such that softening of the at least one colored polymer occurs below a warming temperature of 150 C.
12. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is configured such that softening of the at least one colored polymer occurs below a softening temperature of 100 C.
13. The deformable bone fixation element of claim 2, wherein the at least one colored polymer comprises a thermoplastic material.
14. The deformable bone fixation element of claim 13, wherein the thermoplastic material is chosen from the following groups: poly-alpha-hydroxyester, polyorthoester, polyanhydride, polyphosphazines, poly(propylenefumarate), polyesteramide, polyethylenefumarate, polylactide, polyglycolide, polycaprolacton, trimethylenecarbonate, polydioxanone, polyhydroxybutyrate, as well their copolymers and mixtures thereof.
15. The deformable bone fixation element of claim 2, wherein a volume of the deformable bone fixation element is preferably within a range of about 4 mm.sup.3 to about 400 mm.sup.3.
16. The deformable bone fixation element of claim 2, wherein a surface area of the deformable bone fixation element is within a range of about 2 mm.sup.2 to 240 mm.sup.2.
17. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element defines a pin.
18. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is configured to soften and deform in response to a wavelength of electromagnetic radiation that lies in a range between 260 and 3,000 nm.
19. The deformable bone fixation element of claim 2, wherein the deformable bone fixation element is configured to soften and deform in response to a wavelength of electromagnetic radiation that lies in a visible range and in a near infrared range of up to 1,200 nm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] Several embodiments of the invention will be described in the following by way of example and with reference to the accompanying schematic drawings in which:
[0055] FIG. 1 illustrates a longitudinal section through the hand piece of a first kit according to the invention;
[0056] FIG. 2a illustrates a longitudinal section through a first light guiding tip for the first kit according to the invention;
[0057] FIG. 2b illustrates a longitudinal section through a second light guiding tip for the first kit according to the invention;
[0058] FIG. 2c illustrates a longitudinal section through a third light guiding tip for the first kit according to the invention;
[0059] FIG. 2d illustrates a longitudinal section through a fourth light guiding tip for the first kit according to the invention;
[0060] FIG. 3 illustrates a longitudinal section through the hand piece and a light guiding tip attached thereto of the first embodiment of the kit according to the invention;
[0061] FIG. 4 illustrates a longitudinal section through the hand piece of a second kit according to the invention;
[0062] FIG. 5a illustrates a longitudinal section through a first light guiding tip for the second kit according to the invention;
[0063] FIG. 5b illustrates a longitudinal section through a second light guiding tip for the second kit according to the invention;
[0064] FIG. 5c illustrates a longitudinal section through a third light guiding tip for the second kit according to the invention;
[0065] FIG. 5d illustrates a longitudinal section through a fourth light guiding tip for the second kit according to the invention;
[0066] FIG. 6 illustrates a longitudinal section through the hand piece and a light guiding tip attached thereto of the second embodiment of the kit according to the invention;
[0067] FIG. 7 illustrates a longitudinal section through the hand piece of a third kit according to the invention;
[0068] FIG. 8a illustrates a longitudinal section through a first light guiding tip for the third kit according to the invention;
[0069] FIG. 8b illustrates a longitudinal section through a second light guiding tip for the third kit according to the invention;
[0070] FIG. 8c illustrates a longitudinal section through a third light guiding tip for the third kit according to the invention;
[0071] FIG. 8d illustrates a longitudinal section through a fourth light guiding tip for the third kit according to the invention;
[0072] FIG. 9 illustrates a longitudinal section through the hand piece and a light guiding tip attached thereto of the third embodiment of the kit according to the invention;
[0073] FIG. 10 illustrates a schematic view of the second embodiment of the kit according to the invention;
[0074] FIG. 11 illustrates a schematic view of the third embodiment of the kit according to the invention;
[0075] FIG. 12 illustrates a schematic view of an energy absorbing glass capsule as a variant to the laser light absorbing means of the first embodiment of the kit according to the invention;
[0076] FIG. 13 illustrates the microprocessor and different set-point means according to a first mode of operation according the invention;
[0077] FIG. 14 illustrates the microprocessor and different set-point means according to a second mode of operation according the invention;
[0078] FIG. 15 illustrates the microprocessor and different set-point means according to a third mode of operation according the invention; and
[0079] FIG. 16 shows a table defining different codes of the set-point means according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0080] The present invention is directed to a system and method for the fixation of a bone by implanting a device into the bone, a portion of the device including a material configured to be softened upon application of heat to aid in anchoring the device to the bone. In particular, the present invention is directed to a device comprising one or more bone fixation elements formed of, for example, a biocompatible polymer having material properties (e.g., color, reflective coating, etc.) configured to aid in fixation thereof in a target location of the bone. The exemplary system and method according to the invention also comprises a handpiece configured to guide insertion of the fixation element to a target portion of the bone. The exemplary handpiece is configured to transport laser light from a laser light source provided therein to one or more light guiding tips operably connected thereto. The light guiding tips further guide the laser light to the fixation elements. As will be described in greater detail below, a number of light guiding tips used in a particular application may have a direct correlation to a size of the fixation element, with a greater number of light guiding tips being used for larger fixation elements, as would be understood by those skilled in the art. It is noted, however, that any number of light guiding tips may be used in any application without deviating from the spirit and scope of the invention. Upon application of laser light, the fixation element is heated and softened to conform to a required dimension and/or to bond to one or more biological or implanted structures to ensure proper bone fixation. In one example, the bonding may be performed by melting the biological or implanted structures to one another. The exemplary light source according to the invention is further connected to a timer to control a flow of laser light thereof, as will be described in greater detail later on. That is, once the fixation element is heated, it may conform to a shape of the target region of the bone, including any cracks and crevices, to provide a sufficient holding strength with the bone. It is noted that the term proximal as used herein refers to a direction approaching a physician or other user of the device while the term distal refers to a direction approaching a target treatment area in a patient.
[0081] FIGS. 1-3 depict a kit 1 according to a first exemplary embodiment of the invention, the kit 1 comprising a hand piece 2. The hand piece 2 comprises a laser source 3 optically and mechanically connected to an internal optical waveguide 4. The waveguide 4 is configured to transport laser light emitted by the laser source 3 to a light guiding tip 7 and further includes a timer 10 and a cap 9 coupling the hand piece 2 to the light guiding tip 7. The laser source 3 is configured to emit a constant radiant flux .sub.1. The internal optical waveguide 4 extends from the laser source 3 to a distal end 5 of the hand piece 2. The distal end 5 of the hand piece 2 may be connectable to a proximal end 11 of the light guiding tip 7 by a bayonet or a click connection to optically and coaxially connect the internal optical waveguide 4 to the optical waveguide 12. The hand piece 2 further comprises a trigger button 15 that actuates the timer 10 to activate the laser source 3. The timer 10 is configured with a fixed time period t.sub.F so that the laser source 3 is automatically switched off after expiration of the allowed fixed time period t.sub.F. The cap 9 has a central cavity 16 extending from a distal surface 14 to the distal end 5 of the hand piece 2 so that the proximal end 11 of the light guiding tip 7 can be inserted therethrough.
[0082] FIGS. 2a-2d illustrate a selection of different light guiding tips 7 according to the invention, wherein like elements are referenced with like reference numerals. Each light guiding tip 7, 7, 7, 7 extends from the proximal end 11 to a distal end 13. A fixation element 8 (e.g., a pin) is removably attached to the distal end 13 of the light guiding tip 7. The fixation element 8 may be heated by the laser light until it becomes ductile. Each of the light guiding tips 7, 7, 7, 7 comprise fixation elements 8, 8, 8, 8 with different sizes. The light guiding tips 7, 7, 7 of FIGS. 2a to 2c comprise laser light absorbing means 6 to reduce a radiant flux .sub.1 received from the hand piece 2 to a radiant flux .sub.2<.sub.1 transmitted so that a total radiant energy Q=.sub.2t.sub.F is emitted from the laser source 3 and through the first optical waveguide 4 of the hand piece 2 and the second optical waveguide 12 of the light guiding tips 7 to the fixation element 8. The laser light absorbing means 6 thus permit the radiant flux .sub.2 transmitted to the fixation element 8 to be set with a magnitude adjusted to the volume and/or surface of the fixation element 8. Additionally, when taken in combination with the fixed time period t.sub.F defined by the timer 10, the laser light absorbing means also automatically controls the total radiant energy Q=.sub.2t.sub.F so that no overheating or insufficient softening of the fixation element 8 occurs. FIG. 2d depicts a light guiding tip 7 comprising no laser light absorbing means 6. In this embodiment, the unreduced radiant flux .sub.1 of the laser source 3 is transmitted to the fixation element 8 and the controlled total radiant energy results in Q=.sub.1t.sub.F.
[0083] The laser light absorbing means 6 are provided in the form of elongated sticks 26 which can be attached to fibers of the optical waveguide 12. Specifically, a plurality of the elongated sticks 26 extend distally from the proximal end 11, each having a different length selected to conform to the requirements of a particular procedure. FIGS. 2a-2c depict various combinations of lengths of the elongated sticks 26 according to the invention. It is further noted, however, that any lengths and combinations of the sticks 26 may be employed without deviating from the scope of the invention. The elongated sticks 26 can consist of a metal with a high heat capacity (e.g., aluminum, iron, wax, paraffin or glass). In an alternate embodiment, the elongated sticks 26 can consist of plastic wax. In this embodiment, energy absorption of the light absorbing means 6 may be affected by changing the state of aggregation, e.g., when the plastic wax changes from a solid into a liquid. In another embodiment, the elongated sticks 26 may contain a colored fluid (e.g., water) housed therewithin. In this embodiment, energy transmitted from the laser source 3 through the internal optical waveguide 4 and the fibers of the optical waveguide 12 is absorbed by the colored fluid.
[0084] The fixation elements 8, 8, 8, 8 are provided in the form of pins and are clamped or otherwise attached to the distal end 13 of the light guiding tips 7, 7, 7, 7 and made available to an end-user in this form. When heated, the fixation elements 8, 8, 8, 8 may be easily detached from the light guiding tips 7, 7, 7, 7. It is noted, however, that the fixation elements 8, 8, 8, 8 may be formed with any other shape and dimension without deviating from the scope of the invention.
[0085] FIG. 3 illustrates the hand piece 2 of FIG. 1 with the light guiding tip 7 of FIG. 2b attached thereto. The light guiding tip 7 is centered relative to the hand piece 2 by means of the cap 9. Due to the varying lengths of the elongated sticks 26 of FIG. 2b, a cross-sectional area of the optical waveguide 12 is reduced in a distal direction. It is therefore further noted that the light guiding tip 7 is particularly suitable for fixation elements 8 having different diameters, as those skilled in the art will understand.
[0086] FIGS. 4 to 6 depict a kit 1 according to a first alternate embodiment of the invention, the kit 1 being formed substantially similarly as the kit 1 of FIGS. 1-3, wherein like elements have been referenced with like reference numerals. The kit 1 comprises the hand piece 2 having the laser source 3 optically and mechanically connected to the internal optical waveguide 4. The internal optical waveguide 4 transports laser light emitted by the laser source 3 and a microprocessor 16 electronically connected to a timer 17. In the present embodiment, the laser source 3 is configured to emit a constant radiant flux .sub.1. The internal optical waveguide 4 extends from the laser source 3 to the distal end 5 of the hand piece 2, which may be connected to the proximal end 11 of the light guiding tip 7. The trigger button 15 is provided on the hand piece 2 to actuate the timer 17 and activate the laser source 3.
[0087] The timer 17 is configured as an electronic chip and has a variable time t.sub.V defined and set by a set-point control 14 of the light guiding tip 7. Specifically, the set-point control 14 is configured to control the timer 17 to have a predetermined time period t.sub.V selected to apply a predetermined amount of laser light from the laser source 3, as will be described in greater detail later on. The microprocessor 16 is arranged on the hand piece 2 adjacent to the distal end 5 and comprises a number M of electrical contacts 21 so that the set-point control 14 of the light guiding tip 7 comprising the same number M of electrical contacts 21 may be electrically connected thereto.
[0088] FIGS. 5a-5d illustrate a selection of different light guiding tips 27, 27, 27, 27 according to the invention. Each light guiding tip 27, 27, 27, 27 extends from the proximal end 11 to the distal end 13. Fixation elements 28, 28, 28, 28 are removably attached to the distal ends 13, the fixation elements 28, 28, 28, 28 being configured to be heated by means of the laser light until they become ductile. Each of the light guiding tips 27, 27, 27, 27 is configured to receive a fixation element 28, 28, 28, 28 having a different diameter. Furthermore, each light guiding tip 27, 27, 27, 27 comprises the set-point control 14 electrically connectable to the microprocessor 16 of the hand piece 2 to determine the individual time period t.sub.V for the energy flow of the laser source 3 with respect to the fixation elements 28, 28, 28, 28. The set-point control 14 is described in greater detail below with respect to FIGS. 13 to 16. Each light guiding tip 7 contains a different set-point control 14 that is configured with respect to the volume or surface of the individual fixation element 8.
[0089] FIG. 6 illustrates the hand piece 2 of FIG. 4 with the light guiding tip 27 of FIG. 5d attached thereto. Due to the constant cross-sectional area of the optical waveguide 12 of the light guiding tip 27, the embodiments of FIGS. 4 to 6 are particularly suitable for fixation elements 28, 28, 28, 28 that have the same diameter but different lengths.
[0090] In an operative configuration, the light guiding tip 27 is connected to the hand piece 2 and actuation of the trigger button 15 permits the set-point control 14 to control the timer 17 to activate the laser source 3 for a time period t.sub.V. A total radiant energy Q=.sub.1t.sub.V is then emitted from the laser source 3 through the internal optical waveguide 4 and the optical waveguide 12 to the fixation element 8. The individual time period t.sub.V defined by the set-point control 14 and the constant radiant flux .sub.1 of the laser source 3 permit automatic control of the total radiant energy Q=.sub.1t.sub.V with respect to the fixation element 8 to prevent overheating or insufficient softening of the fixation element 8, as described in greater detail earlier.
[0091] FIGS. 7 to 9 depict a kit 1 according to a third embodiment of the invention, the kit 1 being formed substantially similarly as the kit 1 of FIGS. 1-4, wherein like elements have been referenced with like reference numerals. The kit 1 comprises the hand piece 2 having the laser source 3 optically and mechanically connected to the internal optical waveguide 4. A timer 18 and a microprocessor 16 are electronically connected to the laser source 3. In the present embodiment the laser source 3 is configured to emit a variable radiant flux .sub.V. The timer 18 is configured as an electronic chip and has a constant time period t.sub.F. The microprocessor 16 controls the magnitude of radiant flux .sub.V as defined by the set-point control 14 of the light guiding tip 7 and which depends on the size of the fixation element 8.
[0092] FIGS. 8a to 8d illustrate a selection of different light guiding tips 37, 37, 37, 37. Each light guiding tip 37, 37, 37, 37 extends from the proximal end 11 to the distal end 13 and is removably connectable to one of the fixation elements 38, 38, 38, 38. Furthermore, each light guiding tip 37, 37, 37, 37 comprises the set-point control 14, which are electrically connectable to the microprocessor 16 of the hand piece 2 and determine the individual radiant flux .sub.V transmitted from the laser source 3 to the fixation element 8 via the microprocessor 16. Each light guiding tip 37, 37, 37, 37 contains a different set-point control 14 that is configured with respect to the volume or surface of the individual fixation element 38, 38, 38, 38.
[0093] FIG. 9 illustrates the hand piece 2 of FIG. 7 and the light guiding tip 37 of FIG. 8d attached thereto. Due to the constant cross-sectional area of the optical waveguide 12 of the light guiding tip 37, the embodiment of FIG. 9 is particularly suitable for fixation elements 38 that have the same diameter but different lengths.
[0094] Upon connection of the light guiding tip 37 to the hand piece 2, the set-point control 14 induces the microprocessor 16 to control the magnitude of radiant flux .sub.V. The timer 18 has a fixed time period t.sub.F to activate the laser source 3 so that after actuation of the trigger button 15, a total radiant energy Q=.sub.Vt.sub.F is emitted from the laser source 3 through the internal optical waveguide 4 and the optical waveguide 12 to the fixation element 8. By means of the constant time period t.sub.F defined by the timer 18 and the radiant flux .sub.V defined by the set-point control 14, the total radiant energy Q=.sub.1t.sub.V is automatically controlled so that no overheating or insufficient softening of the fixation element 38 occurs.
[0095] FIG. 10 illustrates an exemplary method of setting the time period t.sub.V of the timer 17 of the kit 1. As described in greater detail hereinafter with reference to FIGS. 13-16, the set-point control 14 of the light guiding tip 7 provides a particular code to the microprocessor 16. The microprocessor 16 then reports a period to the timer 17 on the basis of the code. Actuation of the trigger button 15 then causes the timer 17 to run.
[0096] FIG. 11 illustrates an exemplary method of operation of the kit 1. Specifically, FIG. 11 illustrates how the power of the source of laser 3 of the kit 1 is set. The light guiding tip 7 provides a code to the microprocessor 16 on the basis of the set-point control 14. The microprocessor 16 then reports the power in Watts of the laser source 3 on the basis of the known code. Upon actuating the trigger button 15, the laser source 3 produces energy with power supplied thereto. A simultaneous activation of the constant timer 18 switches off the laser source 3 after the fixed period of time has elapsed.
[0097] FIG. 12 illustrates a variant of the laser light absorbing means 6 used in the kit 1 of FIGS. 1 to 3. In this embodiment, the laser light absorbing means 6 is configured as energy absorbing glass capsule 19 which absorbs the laser light of the laser source 3. A colored fluid 20 (e.g., water) is encased within the glass capsule 19 to absorb the laser light and evaporate. In an exemplary embodiment, the capsule 19 may be embedded within a disposable tip (not shown) configured for removable attachment to the distal end of the hand piece 2, the disposable tip being further configured for removable attachment to a bone fixation element, as described in greater detail with respect to earlier embodiments.
[0098] FIGS. 13 to 15 illustrate the microprocessor 16 electrically connected to the set-point control 14, 14, 14 via a number M=3 of electrical contacts 21 and the grounding 22. The set-point control 14, 14, 14 comprise a code block 23 with a number PM of code pins 24. Each code pin 24 activates one electrical contact 21 by electrically connecting the electrical contact 21 to the grounding 22, as those skilled in the art will understand. The number P and position of the activated code pins 24 defines a particular code, which is turn used to determine the time period t.sub.V or the magnitude of radiant flux .sub.V to the microprocessor 16.
[0099] The table shown in FIG. 16 illustrates the definition of different codes 0 to 7 wherein an inactive electrical contact 21 is by 0 and an activated electrical contact 21 is 1. For example, Code 0 defines that a number P=0 of electrical contacts 21 is activated. Codes 1 to 3 define that a number P=1 of electrical contacts 21 is activated and the position of the activated electrical contacts 21. Codes 4 to 6 define that a number P=2 of electrical contacts 21 is activated and the position of the activated electrical contacts 21. Code 7 defines that a number P=3 of electrical contacts 21 are activated.
[0100] The set-point control 14 illustrated in FIG. 13 defines Code 0 where a number P=0 of electrical contacts 21 is activated. The code block 23 comprises no code pins 24 so that none of electrical contacts 21 is connected to the grounding 22. The set-point control 14 illustrated in FIG. 14 defines Code 1 where the first one of the three electrical contacts 21 is activated. The set point control 14 of FIG. 15 illustrates Code 7 where all three electrical contacts 21 are activated.
[0101] Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, composition of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention.
[0102] It will be appreciated by those skilled in the art that various modifications and alterations of the invention can be made without departing from the broad scope of the appended claims. Some of these have been discussed above and others will be apparent to those skilled in the art.
