Surgical rasp

Abstract

The present disclosure includes a rasp. The rasp includes a handle (102), the handle including a first handle end and a second handle end, the handle including a handle axis (108); and a plurality of elongated segments (110), each of the plurality of elongated segments having a first elongated segment end (112) and a second elongated segment end (114), the first elongated segment end connected to the second handle end, the plurality of elongated segments including an elongated segment axis (116), wherein adjacent elongated segments of the plurality of elongated segments are separated by a gap (118) that extends between the first elongated segment end and the second elongated segment end, wherein the gap is substantially parallel with the elongated segment axis (116).

Description

SURGICAL RASPBACKGROUND OF THE DISCLOSURE

[0001] The present disclosure relates to rasps. More particularly, the present disclosure relates to rasps for preparing bones of various patients to receive a prosthetic implant and to a method for using the same.

[0002] Joint arthroplasty is a surgical procedure for replacing damaged components of a joint with prosthetic components. Such damage may be caused by, for example, traumatic injury or some form of arthritis, such as osteoarthritis.

[0003] For example, the hip joint is formed between the head of the femur and the acetabulum of the pelvis. Therefore, arthroplasty of the hip joint can involve replacing the femoral head with a prosthetic implant, which involves resecting the femoral head along its neck and preparing the intramedullary canal of the femur to receive a prosthetic femoral hip stem.

[0004] Preparation of the intramedullary canal has a significant impact on the arthroplasty procedure. The prepared canal impacts the fit between the prosthetic and the bone itself (for example the femur). For example, if the prepared canal is too large in one or more dimensions, gaps may form between the prosthetic and the intramedullary canal surface, which could cause shifting or rotation of the prosthetic. Also, if the prepared canal is too large in one or more dimensions, or of an incorrect dimension, the prosthetic may be seated too deep within the bone, resulting in an unnatural and / or improper placement of the prosthetic. Conversely, if the prepared canal is too small in one or more dimensions, the prosthetic may not be seated deep enough within the bone, also resulting in an unnatural and / or improper placement of the prosthetic.

[0005] Currently, typical, rigid rasps are used to prepare the intramedullary canals of various bones of every patient. One example of a known, typical, rigid rasp is shown inis a perspective view of a typical, rigid rasp 1, which has a handle 2 and a toothed shaft 4.is a side view of a typical, rigid rasp 1, which has the handle 2 and the toothed shaft 4.

[0006] Typically, a surgeon would hold the handle 2, and slide the toothed shaft 4 into the intramedullary canal of a patient’s bone (for example femur) to contact and scrape against the bone / and or tissue to remove the bone and / or tissue to form a cavity. The cavity created by the rigid rasp 1 is sufficiently sized to fit a shaft of a to be implanted prosthesis.

[0007] The shape of the rigid rasp 1 is designed to substantially correspond with a shaft of the prosthesis, so that during use of the rigid rasp 1, a cavity can be created in the intramedullary canal of a bone of a sufficient size to fit the shaft of the prosthesis. The rigid rasp 1 is typically formed of a single, hard metal material throughout the handle 2 and the shaft 4, which is configured to not bend during use so as the correspondence between the cavity and the prosthetic can be monitored and maintained.

[0008] One deficiency of the typical, rigid rasp 1 is that the rigid rasp cannot bend to accommodate any unique bone characteristics of a specific patient. Additionally, the rigid rasp 1 is limited to formation of a cavity that matches the specific, fixed outer surface of the rigid rasp 1, without allowing for the intramedullary canal of the bone of implantation to guide the formation of the cavity through exertion of varying pressures back onto the rasp.

[0009] Therefore, what is desired is a device that is at least partially flexible, the shape of which can be modified during use preparation of a bone canal for prosthetic implantation.SUMMARY OF THE DISCLOSURE

[0010] In accordance with one or more embodiments, devices and methods are provided.

[0011] In one embodiment an rasp is provided. The rasp comprises a handle, the handle comprising a first handle end and a second handle end, the handle comprising a handle axis; and a plurality of elongated segments, each of the plurality of elongated segments having a first elongated segment end and a second elongated segment end, the first elongated segment end connected to the second handle end, the plurality of elongated segments comprising an elongated segment axis, wherein adjacent elongated segments of the plurality of elongated segments are separated by a gap that extends between the first elongated segment end and the second elongated segment end, wherein the gap is substantially parallel with the elongated segment axis, wherein each of the elongated segments comprises an internal surface and an external surface, wherein at least a portion of the external surface of at least one of the plurality of elongated segments comprises a cutting element, wherein the internal surface of each of the plurality of elongated segments forms a channel.

[0012] The disclosure further relates to a method for forming a cavity in a bone with a rasp of the present disclosure.Brief Description of the Drawings

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure, and, together with the summary given above, and the detailed description of the embodiments below, serve as a further explanation and disclosure to explain and / or illustrate embodiments of the disclosure.

[0014] is a perspective view of a known, prior art rasp;

[0015] is a side view of a known, prior art rasp;

[0016] is a perspective view of a rasp of an embodiment of the present disclosure;

[0017] is a perspective view of a rasp of an embodiment of the present disclosure; and

[0018] is a perspective view of the rasp ofin a portion of a bone.DETAILED DESCRIPTION OF THE DISCLOSURE

[0019] It is noted that the drawings of the present application are provided for illustrative purposes only and, as such, the drawings are not drawn to scale. It is also noted that like and corresponding elements are referred to by like reference numerals.

[0020] In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it will be appreciated by one of ordinary skill in the art that various embodiments of the present application may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present application.

[0021] As used herein, the term “substantially” or “substantial”, is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a surface that is “substantially” flat would either be completely at, or so nearly flat that the effect would be the same as if it were completely flat.

[0022] As used herein, terms defined in the singular are intended to include those terms defined in the plural and vice versa.

[0023] As used in this specification and its appended claims, terms such as “a”, “an” and “the” are not intended to refer to only a singular entity but include the general class of which a specific example may be used for illustration, unless the context dictates otherwise. The terminology herein is used to describe specific embodiments of the disclosure, but their usage does not delimit the disclosure, except as outlined in the claims.

[0024] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weights, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and without limiting the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters describing the broad scope of the disclosure are approximations, the numerical values in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains standard deviations that necessarily result from the errors found in the numerical value's testing measurements.

[0025] Thus, reference herein to any numerical range expressly includes each numerical value (including fractional numbers and whole numbers) encompassed by that range. To illustrate, reference herein to a range of “at least 50” or “at least about 50” includes whole numbers of 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers 50.1, 50.2 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In a further illustration, reference herein to a range of “less than 50” or “less than about 50” includes whole numbers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractional numbers 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc. In yet another illustration, reference herein to a range of from “5 to 10” includes whole numbers of 5, 6, 7, 8, 9, and 10, and fractional numbers 5.1, 5.2, 5.3, 5,4, 5,5, 5.6, 5.7, 5.8, 5.9, etc.

[0026] In the discussion and claims herein, the tern “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. For example, for some elements the term “about” can refer to a variation of ±0.1%, for other elements, the term “about” can refer to a variation of ±1% or ±10%, or any point therein.

[0027] Reference now will be made in detail to embodiments of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment.

[0028] An embodiment of a rasp 100 of the present disclosure is shown inThe rasp 100 comprises a handle 102, the handle comprising a first handle end 104 and a second handle end 106. The handle 102 comprises a handle axis 108. The handle 102 is configured to be held by an operator, such as a surgeon. Alternatively or in addition to being held, the handle 102 can be configured to receive an additional handle, such as a T-handle to provide the opportunity for extra torque. Alternatively or in addition to being held, the handle 102 can be configured to receive torque from a driven source, such as a bone drill, etc.

[0029] The rasp 100 also includes a plurality of elongated segments 110. In this embodiment several elongated segments 110 are shown, in other embodiments two, three, four, five, six, seven, eight, nine, ten or more elongated segments 110 can be included.

[0030] Each of the plurality of elongated segments 110 has a first elongated segment end 112 and a second elongated segment end 114. The plurality of elongated segments 110 comprise an elongated segment axis 116. In some embodiments the elongated segment axis 116 can be a substantially straight line. In the embodiment of the rasp 100 of, the elongated segment axis 116 is a curvilinear axis, which can be of any suitable radius or arc shape.

[0031] The first elongated segment end 112 is connected to the second handle end 106. This connection can be any suitable mechanical connection, such as welding, etc., and / or this connection can be due to a unitary construction of the handle 102 and the plurality of elongated segments 110. This unitary construction can be the result of any suitable manufacturing method, such as a milling method from a single piece of material that forms both the handle 102 and the plurality of elongated segments 110 and / or this unitary construction can be the result of any suitable additive manufacturing (AM) and / or 3D-printing technology. For example, the handle 102 and / or the plurality of elongated segments 110 can be formed according to a suitable electron beam melting (EBM) process and / or a suitable selective laser melting (SLM) process.

[0032] EBM is an additive process for manufacturing and may produce solid or porous material. A powder of the desired material is provided in the desired granulometry. By the EBM process the powders of the desired material are deposited in successive layers at desired positions and in desired sequence (as defined in a preceding modelling step for the porous structure) and made to melt such as to form a coherent, solid body, such as any portion of, or the entirety of, any porous, implantable structure 100 disclosed herein.

[0033] SLM is a manufacturing technique that uses a laser to fuse metallic or non metallic powders, to form a portion, or the entirety of, the handle 102 and / or the plurality of elongated segments 110. The laser selectively fuses powdered material by scanning cross-sections generated from a 3-Dimensional digital description of the portion, or the entirety of, the handle 102 and / or the plurality of elongated segments 110, for example from a programmed computer file, on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness, a new layer of material is applied on top, and the process is repeated until the portion, or the entirety of, the handle 102 and / or the plurality of elongated segments 110 is manufactured to the desired degree.

[0034] As one example of this AM technology, the handle 102 and / or the plurality of elongated segments 110 can be additively manufactured from Ti-6Al-4V extra low interstitial (ELI) powder in an electron beam machine (Arcam EBM Q10 plus).

[0035] The handle 102 and / or the plurality of elongated segments 110 can be formed of any suitable material, such as Ag, Cu, Ni, Fe, Co, Au, Sn, Al, Zr, Li, Mn, Mg, Ti, Ir, Zn, Pt, and Ta, alloys thereof that can include non-metallic elements such as carbon, and combinations thereof.

[0036] Referring again to, adjacent elongated segments 110 of the plurality of elongated segments 110 are separated by a gap 118 that extends between the first elongated segment end 112 and the second elongated segment end 114. The gap 118 is substantially parallel with the elongated segment axis 116. In the embodiment of the rasp 100 of, each of the plurality of elongated segments 110 are also substantially parallel with the elongated segment axis 116.

[0037] Each of the elongated segments 110 comprises an internal surface (not shown) and an external surface 120. A thickness dimension between the internal surface and the external surface 120 can be variable or fixed between the first elongated segment end 112 and the second elongated segment end 114, and can be fixed or varied among each of the plurality of elongated segments 110. For example, a thickness dimension of the elongated segment 110 can be thinner nearer the second elongated segment end 114 as compared to the first elongated segment end 112 to increase elasticity and / or flexibility of the elongated segment 110 in that area.

[0038] In this embodiment shown inthe entire external surface 120 of the plurality of elongated segments 110 comprises a cutting element 122. In other embodiments, one or more of the plurality of elongated segments comprises a cutting element 122. In other embodiments at least a portion of the external surface 120 of at least one of the plurality of elongated segments 110 comprises the cutting element 122. In other embodiments a majority of the external surface 120 of at least one of the plurality of elongated segments 110 comprises the cutting element 122.

[0039] The cutting element 122 can be any suitable structure capable of cutting mammalian bone and / or mammalian tissue. For example, the cutting element 122 can be relatively sharp, pointed teeth to achieve significant bone removal. As another example, the cutting element 122 can be curved, rounded teeth to achieve bone removal, but to a lesser extent than pointed teeth. As another example the cutting element 122 can be an abrasive material and / or a roughened area. In any example, the cutting element 122 can be any suitable shape, size and orientation. In any example, the cutting element 122 can be the same shape / size / orientation throughout the plurality of elongated segments 110, or, different areas of the plurality of elongated segments 110 can include cutting elements 122 of differing shape / size / orientation.

[0040] The cutting element 122 can be formed unitarily with the respective elongated segment 110, and / or the cutting element 122 can be affixed to the external surface 120 in any suitable way.

[0041] The cutting element 122 can also optionally extend onto the handle 102, onto a portion of the second handle end 106, as it does in

[0042] The internal surface of each of the plurality of elongated segments 110 forms a channel 124. Channel 124 can extend wholly or partially between the first elongated segment end 112 and the second elongated segment end 114. The channel 124 is an opening that does not include material.

[0043] The gap 118 is configured so that a width of the gap 118 can be reduced and thereby the channel 124 can be compressed. In some embodiments a single gap 118 can be included, in other embodiments, a plurality of gaps 118 is included that extend between the first elongated segment end 112 and the second elongated segment end 114 of adjacent elongated segments 110 of the plurality of elongated segments 110. The plurality of gaps 118 can include several gaps 118, such as two, three, four, five, six, seven, eight, nine, ten or more gaps 118 can be included.

[0044] The gap 118 shown inis substantially constant width between the first elongated segment end 112 and the second elongated segment end 114. In other embodiments, a width of the gap 118 can vary to be wider or narrower at different pointe between the first elongated segment end 112 and the second elongated segment end 114. This variation can be designed to permit more or less movement of the respective elongated segment 110 and / or more or less compression of the channel 124 in varying locations about the circumference of the plurality of elongated segments 110.

[0045] In some embodiments the channel 124 is compressed along the entire length of the channel 124, in other embodiments a portion of the channel 124 is compressed. Accompanying the compression of the channel 124, each of the plurality of elongated segments 110 is independently configured to bend towards or away from the elongated segment axis 116 in response to a force. This force can be received through contact with a patient’s bone and / or tissue.

[0046] The inclusion of the channel 124, the gap 118 and the plurality of elongated segments 110 forms a rasp 100 (and rasp 200 discussed below) that is automatically more compliant to a patient’s bone shape and / or the patient’s intramedullary canal as compared to the rasp 1 ofandThis compliance is due to the ability of the rasp 100 (and rasp 200 discussed below) to be flexible and / or elastic and / or compress in reaction to forces received by the rasp 100 (and rasp 200 discussed below), whereas the rasp 1 ofandis solid and rigid, causing a lack of ability to be compliant to the specific patient’s bone.

[0047] Another embodiment of the disclosure, rasp 200 ofis now referred to. The rasp 200 is the same or similar in construction, structure and use as compared to rasp 100 discussed above.

[0048] The rasp 200 comprises a handle 202, the handle comprising a first handle end 204 and a second handle end 206. The handle 202 comprises a handle axis 208. The handle 202 is configured to be held by an operator, such as a surgeon. Alternatively or in addition to being held, the handle 202 can be configured to receive an additional handle, such as a T-handle to provide the opportunity for extra torque. Alternatively or in addition to being held, the handle 202 can be configured to receive torque from a driven source, such as a bone drill, etc.

[0049] The rasp 200 also includes a plurality of elongated segments 210. Each of the plurality of elongated segments 210 has a first elongated segment end 212 and a second elongated segment end 214. The first elongated segment end 212 is connected to the second handle end 206.

[0050] The plurality of elongated segments 210 comprise an elongated segment axis 216. In the embodiment of the rasp 200 of, the elongated segment axis 216 is a straight axis and is coaxial, or substantially parallel, with the handle axis 208. In the embodiment of the rasp 200 ofthe plurality of elongated segments 210 are substantially parallel with the elongated segment axis 216.

[0051] Adjacent elongated segments 210 of the plurality of elongated segments 210 are separated by a gap 218 that extends between the first elongated segment end 212 and the second elongated segment end 214. The gap 218 is substantially parallel with the elongated segment axis 216.

[0052] Each of the elongated segments 210 comprises an internal surface (not shown) and an external surface 220. In this embodiment shown inthe majority of the external surface 220 of the plurality of elongated segments 210 comprises a cutting element 222. In other embodiments, one or more of the plurality of elongated segments comprises a cutting element 222. In other embodiments at least a portion of the external surface 220 of at least one of the plurality of elongated segments 210 comprises the cutting element 222. In other embodiments a majority or the entire external surface 220 of at least one of the plurality of elongated segments 210 comprises the cutting element 222. The cutting element 222 can be any suitable structure capable of cutting mammalian bone and / or mammalian tissue, such as the cutting element 122 discussed in reference to rasp 100 above.

[0053] Referring to, the cutting element 222 can also optionally extend onto the handle 202, onto a portion of the second handle end 206, or, the cutting element can optionally extend to a distance away from the first elongated segment end 212, as is shown in

[0054] The internal surface of each of the plurality of elongated segments 210 forms a channel 224. Channel 224 can extend wholly or partially between the first elongated segment end 212 and the second elongated segment end 214. The channel 224 is an opening that does not include material.

[0055] The gap 218 is configured so that a width of the gap 218 can be reduced and thereby the channel 224 can be compressed. The number and the layout of the gap 218 is similar to gap 118 discussed above in reference to rasp 100.

[0056] In, in some embodiments the channel 224 is compressed along the entire length of the channel 224, in other embodiments a portion of the channel 224 is compressed. Accompanying the compression of the channel 224, each of the plurality of elongated segments 210 is independently configured to bend towards or away from the elongated segment axis 216 in response to a force. This force can be received through contact with a patient’s bone and / or tissue, as shown in

[0057] is a perspective view of the rasp 200 ofin a portion of a bone 302 of a patient. In the view of, the rasp 200 has formed a cavity 304 in the bone 302 through a cavity forming method. In this embodiment a bone axis 306 is coaxial, or substantially parallel, with the elongated segment axis 216, in other embodiments, the bone axis 306 and the elongated segment axis 216 can intersect at any suitable angle.

[0058] The method of forming the cavity 304 begins with contacting the bone 302 of the patient with the rasp 200 in a vicinity of an intramedullary canal 308 of the bone 302. For ease of explanation this method is described by referring to rasp 200, but this method can be equally applicable to rasp 100.

[0059] After contacting the bone 302, the rasp 200 is moved vertically, upwards and downwards, with respect to the bone 302 while maintaining a bone 302 cutting force and / or a tissue cutting force of any adjacent tissue and / or bone marrow. During contact and motion of the rasp 200 the cutting element 222 abrades the bone 302 and / or tissue to relatively gradually form the cavity 304, with the cavity 304 configured to substantially match a stem or other portion of a prosthesis.

[0060] During contact and motion of the rasp 200, each of the plurality of elongated segments 210 bends towards or away from the elongated segment axis 216 in response to the bone 302 cutting force and / or the tissue cutting force. This vertical motion of the rasp 200 continues with respect to the bone 302 until the cavity 304 is formed.

[0061] In this method the elongated segment axis 216 is substantially coaxial with the bone axis 306.

[0062] One advantage of the rasps (100 / 200) of the present disclosure is that due to their ability to compress and / or be flexible is that the specific bone being prepared for implantation, for a specific patient, can exert varying pressures back onto the rasp(100 / 200) so that during movement of the rasp (100 / 200) by the surgeon, a more customized cavity can be formed in the specific bone.

[0063] The described embodiments and examples of the present disclosure are intended to be illustrative rather than restrictive and are not intended to represent every embodiment or example of the present disclosure. While the fundamental novel features of the disclosure as applied to various specific embodiments thereof have been shown, described and pointed out, it will also be understood that various omissions, substitutions and changes in the form and details of the devices illustrated and, in their operation, may be made by those skilled in the art without departing from the spirit of the disclosure. For example, it is expressly intended that all combinations of those elements and / or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the disclosure. Moreover, it should be recognized that structures and / or elements and / or method steps shown and / or described in connection with any disclosed form or embodiment of the disclosure may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. Further, various modifications and variations can be made without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.

Claims

A rasp comprising:a handle, the handle comprising a first handle end and a second handle end, the handle comprising a handle axis; anda plurality of elongated segments, each of the plurality of elongated segments having a first elongated segment end and a second elongated segment end, the first elongated segment end connected to the second handle end, the plurality of elongated segments comprising an elongated segment axis,wherein adjacent elongated segments of the plurality of elongated segments are separated by a gap that extends between the first elongated segment end and the second elongated segment end, wherein the gap is substantially parallel with the elongated segment axis, andwherein each of the elongated segments comprises an internal surface and an external surface, wherein at least a portion of the external surface of at least one of the plurality of elongated segments comprises a cutting element, wherein the internal surface of each of the plurality of elongated segments forms a channel.The rasp of claim 1, wherein the gap is configured for compression of at least a portion of the channel.The rasp of claim 1 or claim 2, wherein each of the plurality of elongated segments is independently configured to bend towards or bend away from the elongated segment axis in response to a force.The rasp of any one of claims 1 to 3, further comprising a plurality of gaps that extend between the first elongated segment end and the second elongated segment end of adjacent elongated segments of the plurality of elongated segments.The rasp of any one of claims 1 to 4, wherein the elongated segment axis is a curvilinear axis, and wherein each of the plurality of elongated segments is substantially parallel with the elongated segment axis.The rasp of any one of claims 1 to 5, wherein the elongated segment axis is coaxial with the handle axis and the plurality of elongated segments are substantially parallel with the elongated segment axis.The rasp of any one of claims 1 to 6, wherein a majority of the external surface of each of the plurality of elongated segments comprises the cutting element.The rasp of any one of claims 1 to 6, wherein a portion of the second handle end comprises the cutting element.The rasp of any one of claims 1 to 8, where a gap width of the gap is substantially constant between the first elongated segment end and the second elongated segment end.The rasp of any one of claims 1 to 9, where a gap width of the gap varies between the first elongated segment end and the second elongated segment end.A method of forming a cavity in a bone, the method comprising:contacting the bone with a rasp of any one of claims 1 to 10 in a vicinity of an intramedullary canal of the bone, wherein the bone comprises a bone axis;moving the rasp vertically with respect to the bone while maintaining a bone cutting force and / or a tissue cutting force, wherein each of the plurality of elongated segments bends towards or away from the elongated segment axis in response to the bone cutting force and / or the tissue cutting force; andcontinuing moving the rasp vertically with respect to the bone until a cavity in the bone is formed.The method of claim 11, wherein the elongated segment axis is substantially co axial with the bone axis.

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