SURGICAL DISTRACTOR AND METHODS OF MANUFACTURE AND USE

Abstract

Surgical instruments, such as distractors and methods of manufacture are provided for maintaining a displacement of bone determined to be necessary by a surgeon. For instance, a surgical distractor may include a first holder section, a second holder section, a first displacement element, a second displacement element, a positioning element, and a rotatable component having an opening. The second holder section may be coupled to the first holder section using one or more coupling elements coupled to both the first holder section and the second holder section. The first displacement element and the positioning element may be positioned on the first holder section and the second displacement element and the rotatable opening may be positioned on the second holder section configured to engage the first displacement element.

Claims

1. A surgical distractor comprising: a first holder section; a second holder section coupled to the first holder section using one or more coupling elements coupled to both the first holder section and the second holder section; a first displacement element positioned on the first holder section; a second displacement element positioned on the second holder section configured to engage the first displacement element; a positioning element positioned on the first holder section; and a rotatable component having an opening and positioned on the second holder section.

2. The surgical distractor of claim 1, wherein the coupling elements form a four-bar linkage that is releasably lockable by a releasable fixation screw.

3. The surgical distractor of claim 1, wherein the one or more coupling elements comprises a first bar coupled to the first and second holder sections.

4. The surgical distractor of claim 2, wherein the one or more coupling elements comprises the second bar coupled to the first holder section, the second holder sections, and the first bar.

5. The surgical distractor of claim 1, wherein the first displacement element comprises a pawl and the second displacement element comprises a rack with teeth.

6. A surgical distractor comprising: a handle; one or more coupling elements that form a four-bar linkage actuated by the handle; a tissue-engaging element projecting away from and coupled to the four-bar linkage; and a rotating component having an opening arranged on a portion of the tissue-engaging element.

7. The distractor of claim 6, further comprising a ratchet mechanism configured to maintain a position of the four-bar linkage.

8. The distractor of claim 6, wherein the rotating member further comprises a pin component.

9. The distractor of claim 6, wherein the handle section comprises scissor-style handles.

10. The distractor of claim 6, wherein the handle section comprises plier-style handles.

11. The distractor of claim 6, further comprising a movable member configured to control a position of the tissue-engaging element relative to the rotating component.

12. The distractor of claim 6, further comprising a movable member configured to be moved such that a position of a four-bar linkage is controlled.

13. A method of distracting tissue during surgery comprising: making an initial incision at a target area of a patient; creating an osteotomy proximate to the target area; positioning a wire an intramedullary canal of a proximal portion of a metatarsal of the patient; positioning a distractor comprising a four-bar linkage actuated by a handle with a guide and a locking member operatively coupled to the four-bar linkage and proximate the target area such that the wire is positioned in the guide; engaging the locking member such that the position wire is reversibly fixed relative to the medical instrument; moving at least a first holder section away from a second holder section to a desired position; and engaging a locking mechanism to secure the four-bar linkage in a desired position such that a desired displacement is maintained without further intervention of a member of the surgical team.

14. The method of claim 13, wherein moving the first holder section allows the osteotomy to be distracted such that the desired displacement of tissues is achieved.

15. The method of claim 13, wherein the locking mechanism comprises a ratchet.

16. The method of claim 13, further comprising fixing at least a portion of tissue near the target area.

17. The method of claim 13, further comprising fixing at least a portion of tissue near proximal end of metatarsal.

18. A distractor comprising: a tissue-engaging portion positioned on a first holder section configured to engage a patient's target area; a rotatable component having an opening configured to engage a positioning element and positioned on a second holder section; a first link positioned on the first holder section; and a second link positioned on the second holder section configured to engage the first link element; wherein the first and second links are configured to engage such that a predetermined distance is maintained between the positioning element and the rotatable component.

19. A medical distractor comprising: a tissue-engaging portion positioned on a first holder section; a rotatable component having an opening and positioned on a second holder section; a first link positioned on the first holder section; and a second link pivotally coupled to the first link and positioned on the second holder section configured to engage the first link; wherein the first and second displacement elements are configured to engage such that a predetermined distance is maintained between the tissue-engaging portion and the rotatable component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and other features and advantages of the apparatuses and methods described herein will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiments, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:

[0029] FIG. 1 depicts a perspective a view of a foot that has undergone a surgical procedure involving displacement of bone and subsequent fixation of the displaced bone;

[0030] FIG. 2 is a drawn representation of a typical radiograph image of a foot as viewed during a surgical procedure involving displacement of bone;

[0031] FIG. 3A depicts a perspective view of an elevator used to displace tissue, such as bone, during surgery;

[0032] FIG. 3B depicts a perspective view of another surgical elevator used to displace tissue, such as bone, during surgery;

[0033] FIG. 4 depicts an image of bones in the foot and a Burr positioned along a desired plane;

[0034] FIG. 5 depicts a plan view of a distractor of one embodiment of the invention in a pre-distraction configuration;

[0035] FIG. 6 depicts a plan view of the distractor as shown in FIG. 5, but in a post-distraction configuration;

[0036] FIG. 7 depicts an enlarged view of a handle portion and a ratchet mechanism of the distractor as shown in FIG. 5;

[0037] FIG. 8 depicts an enlarged view of a distractor portion and coupling elements of the distractor as shown in FIG. 5;

[0038] FIG. 9 depicts an enlarged view of the distractor portion and coupling elements of the distractor as shown in FIG. 5, but in a post-distraction configuration;

[0039] FIG. 10 depicts a perspective view of a distractor of one embodiment of the invention in a pre-distraction configuration coupled to an elongated member;

[0040] FIG. 11 depicts a perspective view of the distractor as shown in FIG. 10, but in a post-distraction configuration coupled to the elongated member; and

[0041] FIG. 12 depicts an enlarged view of coupling elements of the distractor as shown in FIG. 10, but in a slightly distracted distraction configuration.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0042] This description of the embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

[0043] Disclosed embodiments include a distractor for use in orthopedic surgery. Distractors may be used to position tissue, such as bone. Use of a distractor may allow a surgical team, and in particular, a surgeon to maintain a predetermined displacement of tissues while simultaneously conducting additional procedures such as drilling and inserting screws. More specifically, a distractor may be capable of maintaining a selected displacement between tissues, by separating the bones and then locking the linkage using a screw, without requiring a surgeon or other team member to hold the distractor after placement and thereby allowing the surgeon and team members to freely position other instruments and/or devices related to the surgical procedure.

[0044] Bones and/or portions thereof may be positioned relative to one another in a predetermined configuration to correct a problem area. In particular, hallux valgus deformities may be corrected using a Chevron Osteotomy. Corrective positioning may be achieved after one or more bones or portions thereof are displaced and then held in place by fasteners. Referring to FIG. 1, corrective positioning is achieved after a portion of the metatarsal bone 6 is displaced a displacement distance 12, 14 and then held in place by fasteners, e.g., screws 16. Displacement 12, 14 is maintained throughout such a procedure to allow proper positioning of securing elements, such as screws.

[0045] Displacement 20 of a portion of metatarsal bone 26 is represented in a drawing depicting an X-ray image 18 of FIG. 2 using conventional elevator 24. Images of elevators 28, 30 used in conventional procedures are shown in FIGS. 3A-3B.

[0046] Referring to FIG. 4, foot 32 with burr 34 may be aligned to desired potential planes 36, 38 for an osteotomy, according to known procedures. Generally, a burr should be positioned perpendicular to a plane extending along the first metatarsal and angled at a 20 degree angle as shown in FIG. 4.

[0047] Distractors of the invention as described herein are shown in FIGS. 5-12 for use in various surgical procedures. Referring to FIG. 5, distractor 40 in a pre-distraction configuration includes sections 62, 64 that are divided into handle portion 42, coupling portion 44, and engaging portion 46. Handle portion 42 includes openings 48, 58 and ratchet mechanism 50. Ratchet mechanism 50 includes displacement elements, including pawl 54 and rack 52. As depicted, section 64 includes pawl 54 and section 62 includes rack 52. In some embodiments, pawl 54 and rack 52 may be configured to releasably engage each other. For example, pawl and rack may include engaging members such as teeth.

[0048] Coupling portion 44 includes coupling elements 56. Coupling elements 56 may be fasteners as shown in FIG. 5. Fasteners may include, but are not limited to, screws, rivets, pins, bolts, other known fasteners in the art and combinations thereof. Coupling elements 56 may include elongated member 60 as shown in FIG. 5. Elongated members 60 may be formed such that they can be coupled together by coupling elements 56 and to both sections 62, 64 of the distractor device 40. In some embodiments, coupling portion 44 has been formed using a closed-chain movable linkage, such as a four-bar linkage, with advantageous results.

[0049] Engaging portion 46 may include tissue-engaging portion 68 and fixation portion 70. Fixation portion 70 may include opening 72, locking member 74 and rotating member 76. As shown in FIG. 5, rotating member 76 includes opening 72 and locking member 74 in the form of set screw. In some embodiments, the locking member or set screw 74 may communicate with the opening 72. For example, a set screw may extend through the rotating member and potentially into the opening. Tissue-engaging portion 68 may have a geometry selected by a surgical team based on the procedure to be performed, the anatomy of a patient, and/or other reasons determined by the surgical team, such as tip 66 of engaging portion 46.

[0050] Distractor 40 is shown in FIG. 6 in a post-distraction position. Sections 62, 64 of distractor 40 are separated as they would be during use. This capability to separate allows the distractor 40 to provide the predetermined displacement distance during use. Corrective positioning may be achieved after the distractor 40 is positioned proximate a target area. Tissue-engaging portion 68 is configured to engage with a target area during a surgical procedure. In some embodiments, a distractor may have a tissue-engaging portion with a geometry selected based on a surgical procedure, an anatomy of a patient, and/or other desired properties as determined by a surgeon or a member of a surgical team. In some embodiments, a distractor 40 may be maintained in a post-distraction position, maintaining a selected displacement between tissues, by separating the bones and then locking the linkage using a screw 74, without requiring a surgeon or other team member to hold the distractor after placement.

[0051] As shown in FIG. 6, coupling portion 44 includes coupling elements 56 and elongated members 60. Elongated members 60 are pivotally coupled to one another and to both sections 62, 64 of the distractor device 40. Sections 62, 64 includes openings 78 in which coupling elements 56 are positioned. Coupling elements 56 may be moved in the openings 78 to control positioning of the elongated members 60 and thereby of the opposing sections 62, 64 of the distractor 40. Openings 78 may be used to control movement of the sections 62, 64 of the distractor 40. For example, openings may guide elongated members due to the position of fasteners within the openings. Openings 78 may have a geometry selected based on a path that the openings 78, fasteners 56, and/or elongated members 56 allow sections 62, 64 of the distractor 40 to travel. These may be selected based on the type of procedure, the anatomy of the patient and/or other requirements of the surgical team.

[0052] FIG. 7 depicts a partial view of distractor 40 in a pre-distraction mode that includes sections 62, 64 pivotally coupled together by fastener 56. Distractor 40 includes handle portion 42 and part of coupling portion 44. Handle portion 42 includes openings 48, 58 and ratchet mechanism 116. Ratchet mechanism 50 includes displacement locking elements, including pawl 54 and rack 52. Section 64 includes pawl 54 and section 62 includes rack 52 having teeth 80 arranged and oriented so as to operatively engage pawl 54. Pawl 54 and rack 52 may be configured to releasably engage each other. In some instances, rack 52 may be formed integrally with section 62. Portions of pawl 54 may be secured to section 64 using fasteners. At least one fastener (shown as 82) may allow pawl 54 to rotate and engage rack 52.

[0053] Referring to FIG. 8, engaging portion 46 includes tissue-engaging portion 68 and first fixation portion 84a. Tissue-engaging portion 68 includes radiused surface defined on first fixation portion 84a. In some embodiments, the tissue-engaging portion 68 may include a surface that is configured to engage a target area of a patient. For example, a tissue-engaging portion may include a radiused surface on a first fixation portion shaped like a cup to engage a bunion deformity on a patient's foot. In some instances, the tissue-engaging portion 68 may have a surface on first fixation portion 84a shaped to engage a lateral side surface of a patient's foot or a portion thereof. For example, a tissue-engaging portion may have a surface on a first fixation portion shaped to engage a lateral aspect of a calcaneal tuberosity.

[0054] A second fixation portion 84b may include opening 72, locking mechanism 74, rotating member 76, and member 88 positioned in slot 86. Member 88 may be moved within slot 86 such that it allows or inhibits rotation of the rotating member 76. In this manner, the opening 72 in the rotating member 76 may be positioned as desired with respect to a target area. Further, rotating member 76 may include opening 72 and set screw 74. For example, a set screw may extend through a rotating member and potentially into an opening. As shown in FIG. 9, set screw 74 threadingly engages opening 72 so as to press an outer surface of wire 90 positioned within opening 72. For example, a screw set a engages wire such that a distractor is fixed during use. In particular, the set screw 74 may clamp any element placed in the opening 72, such as a k-wire 92, to inhibit and/or prevent movement of the distractor 40 relative to any element during use. For example, a set screw that communicates with an opening may prevent or inhibit movement of a distractor relative to a wire in an opening.

[0055] The slot 86 may allow the rotating member 76 to rotate as needed to allow for a desired positioning of the distractor 40 and/or elements coupled to the distractor 40. For example, a desired positioning of wires may be achieved after a distractor is positioned due to the possible rotation of a rotating member, as well as the positioning of a wire in an opening. In some instances, the degree of rotation may be limited to a predetermined range based on the requirements of use.

[0056] Referring to FIG. 10, a distractor 140 is arranged in pre-distraction mode having elongated member 192 positioned in opening 172, as required by the surgical procedure, the surgical team, and/or the anatomy of the patient. Elongated member 192 may be movable within opening 172 so long as set screw 174 has not yet been secured against a portion of it. Rotating member 176 has been rotated such that the elongated member 192 is positioned at a desired angle relative to a plane extending through the distractor 140.

[0057] Referring to FIG. 11, distractor 140 is shown in a position which allows for a displacement of tissue to be maintained. Rotating member 176 is rotatable as the distractor 140 is moved into a position that allows for displacement of tissue. For example, as a distractor is moved into position, a rotating member rotates such that angulation of, e.g., a metatarsal, is positioned as required by the surgeon. A ratchet mechanism 150 is used to lock the distractor 140 in a surgeon desired position. In some embodiments, for example, a surgeon may separate the bones and then lock the linkage, so as to maintain the bone separation selected, using a screw set (e.g., a thumb screw, set screw 174, etc.). Engaging the ratchet mechanism 150 may allow the surgeon and/or other members of the surgical team to take hands off distractor 140, when in the locked position, during the surgical procedure to do other tasks related to the surgical procedure. As shown, rotating member 176 may be rotated as distractor 140 is moved into a position that allows for displacement of tissue.

[0058] Referring to FIG. 12, elongated strut members 160 are in a position where distractor 140 may be slightly distracted. Elongated strut members 160 act as coupling elements along with fasteners 156a, 156b so as to couple the elongated strut members 160 to sections 162, 164 to form a four-bar linkage, such that the elongated strut members 160 may move when a screw set (not pictured here) is released. Fasteners 156a are positioned within slots 178 such that they are allowed to slide along slots 178 such that sections 162, 164 are moved in manner that will allow sections 144a, 144b to be maintained in a substantially parallel configuration relative to each other during movement. For example, fasteners 156a, 156b may move along slots 178 to ensure that sections 144a, 144b, as shown in FIG. 12, are parallel.

[0059] Referring once again to FIG. 11, the elongated strut members 160 may allow the distractor 140 to move such that planes running through a midline of the patient engaging portions of distractor 140 are substantially parallel to one another. In some embodiments, the distractor 140 includes an attachment mechanism for a vertical Kirchner wire (“k-wire”) 192 or some other elongate straight slender rod to be used as a physical visual reference and/or positioning element. One embodiment includes wire 192 (e.g., Kirchner wire) for aligning the distractor 140 with respect to the patient and/or providing a visual check. FIGS. 9-11 illustrate an embodiment in which the Kirchner wire 92, 192 is positioned in opening 72, 172 of rotating member 76, 176 of distractor 40, 140.

[0060] Bone engaging portions may have a geometry selected by a surgical team based on the procedure to be performed, the anatomy of a patient, and/or other reasons determined by the surgical team. For example, as shown in FIG. 11, bone engaging portion 168 has a geometry selected to engage with a bunion deformity, lateral calcaneal tuberosity, and/or outer surface of a foot.

[0061] Elongated members as disclosed herein above may couple separate sections of a distractor together. Sections of the distractor may be formed as separate elements and coupled together. For example, sections of a distractor may be coupled using a combination of fasteners such as screws, rivets, pins, bolts, other known fasteners in the art and/or elongated members such as struts, bars, etc. As shown in FIG. 11, sections 162, 164 of distractor 140 are coupled to one another by fastener 156d. Further, elongated strut members 160 are coupled to sections 162, 164 using fasteners 156a, 156b. Elongated strut members 160 are coupled to each other by fastener 156c. Openings in sections may be positioned to control movement of the sections relative to each other such that planes running through a midline of the engaging portions are substantially parallel to each other.

[0062] Materials for the body sections may include radiolucent materials. Body sections may include composites, thermoplastics, including, but not limited to, polycarbonate (PC), polyethylene (PE), methyl methacrylate (MMA), polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK), acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyamide, such as nylon, other plastics known in the art, and combinations thereof. In particular, materials may be selected that are capable of being used in additive manufacturing, such as 3D printing, selective laser sintering (SLS), and/or injection molding, for example polyamides, such as nylon or ceramics. In some embodiments, materials used in an instrument may be selected for specific properties desired in a particular instrument or location in the instrument such as magnetism, surface roughness, reflectivity, refractivity, radiolucency, radiopacity, strength, compatibility with in vivo placement, etc.

[0063] A surgical procedure utilizing embodiments of a distractor 40, 140 begins with the distraction of tissue during surgery after an initial incision at a target area of a patient. The surgeon creates an osteotomy of the metatarsal, proximate to the target area. The surgeon then positions a wire in an intramedullary canal of a proximal portion of a metatarsal of the patient. The distractor 40, 140, with a guide and a locking member 74, 174 (i.e., set screw) is then positioned proximate the target area such that the wire is positioned in the guide of the distractor 40, 140. The locking member 74, 174 is turned until it engages the wire 92, 192 positioned in the guide such that the wire 92, 192 is not capable of sliding within the guide due to the frictional engagement between the screw 74, 174 and the wire 92, 192. Essentially, the locking member 74, 174 is used to reversibly fix the position wire 92, 192 relative to the distractor 40, 140. Holder sections 62, 64, 162, 164 are moved such that the desired position of the tissue-engaging portion 68, 168 is achieved. Thus, the locking mechanism 74, 174 secures the distractor 40, 140 in a desired position such that a desired displacement was maintained without further adjustment by the surgeon. When the locking mechanism 74, 174 secures the distractor 40, 140 in the desired position, so as to maintain the bone separation selected, the surgeon's hands free-up to do other tasks related to the surgical procedure. For example, the surgical procedure disclosed herein utilizing a distractor 40, 140 for a Chevron Osteotomy may be used to correct a hallux valgus deformities. A stab incision first placed over the dorso-medial aspect of the proximal edge of the ‘flare’ of the medial eminence. The incision is placed such that it avoids the dorso-medial cutaneous nerve to the Hallux.

[0064] Once the incision is made, a distractor 40, 140 is used to carefully create a working area for a burr (not shown). The space is created over the dorsal surface of M1, but not on the plantar surface, as this may risk damage to the blood supply of the M1 head. An osteotomy is created with the burr, e.g., the dorsal aspect of the osteotomy is created using a 2×20 mm burr placed into the stab incision portal and onto the exposed bone surface. Once the burr exits the lateral cortex of the metatarsal, a portion of the burr is rotated and lifted so that the burr cuts dorsally. The plantar limb is created by placing the burr back into the original bi-cortical position. Then, under controlled power, the burr is translated plantarly and simultaneously a hand piece is rotated dorsally and/or laterally (so the burr moves in a plantar medial direction) until the burr exited the medial cortex. After completing the plantar osteotomy, a hand piece is positioned dorsal to the hallux to ensure the burr has fully exited the medial cortex of the metatarsal. Once the cut is complete (confirmed by the motion at the osteotomy site), the metatarsal head is displaced along its defined plane.

[0065] Displacement of the bone is achieved by placing a wire 92, 192 through the existing portal. A distractor 40, 140 is then applied over wire 92, 192 and actuated to leverage the distal fragments laterally. In particular, distractor 40, 140 is positioned such that the tissue-engaging portion 68, 168 and fixation portion 70, 84a, 84b are proximate the target area such that the wire 92, 192 is positioned in the guide; engaging the locking member 74, 174 such that the position wire 92, 192 is reversibly fixed relative to the medical instrument fixation portion 70, 84a, 84b. Once in this position, a first holder section 62, 162 is moved away from a second holder section 64, 164 to a desired position. Once in the desired position, a locking member 74, 174 is rotated to secure the distractor 40, 140 in the desired position such that a desired bone displacement is maintained without further intervention by the surgeon, freeing the surgeon's hands to do other tasks related to the surgical procedure.

[0066] To avoid fracturing the medial cortex of the proximal fragment, the wire 92, 192 is inserted sufficiently deeply into the diaphysis. Elevation of the metatarsal head is avoided by ensuring that the distractor 40, 140 remains directly over the medial eminence during displacement. A 1.4 mm diameter k-wire is placed proximate the medial aspect of the first metatarsal and a second k-wire having a 0.9 mm diameter is placed until the tip of the k-wire is positioned proximate to the osteotomy. The osteotomy is then fixed internally with two (2) cannulated screws. Once the lateralization and plantarization are achieved, the k-wires are driven into the metatarsal head. The k-wires are positioned such that the proximal/lateral 1.4 mm k-wire sat in the lateral half of the metatarsal head and the distal/medial 0.9 mm wire sat in the medial half of the metatarsal head. Both the 1.4 mm and 0.9 mm k-wires are placed such that they do not breach the MTP Joint.