Rasp handle adapter

Disclosed herein are rasp adapters, rasp systems, and method of use thereof. The rasp adapter can include a body and a retention element. The body can define a body cavity, a handle opening, and a trunnion bore. The retention element can be located within the body cavity and can include a knuckle and a heal. The knuckle can be located proximate to and movable into and out of the trunnion bore. The heal can be located proximate the handle opening. Movement of the retention element due to a force applied to the heal can cause movement of the retention element and movement of the knuckle into the trunnion bore.

FIELD OF THE DISCLOSURE

The present disclosure relates to adapters. Specifically, the present disclosure relates to rasp handle adapters and methods of use thereof.

BACKGROUND

During various surgical procedures, a rasp can be used to prepare a bone to receive an implant. For example, during a hip arthroplasty procedure a stem can be implanted into a femur. However, before the stem can be implanted, a rasp can be used to prepare the femoral canal. The rasp can be removably connected to a rasp handle. By having the rasp be removably connected to the rasp handle, different rasps each having a different size and/or roughness can be connected to the rasp handle.

SUMMARY

Example 1 is a rasp adapter comprising: a body that defines a body cavity, a handle opening, and a trunnion bore; and a retention element located within the body cavity, the retention element including: a knuckle located proximate to and movable into and out of the trunnion bore, and a heal located proximate the handle opening, wherein movement of the retention element due to a force applied to the heal causes movement of the retention element and movement of the knuckle into the trunnion bore.

In Example 2, the subject matter of Example 1 optionally includes wherein the retention element is coupled to the body via a spring.

In Example 3, the subject matter of any one or more of Examples 1-2 optionally include a trunnion protruding from a superior surface of the body, the trunnion defining at least one trunnion notch.

In Example 4, the subject matter of Example 3 optionally includes wherein the trunnion, the retention element, and the body are a monolithic component.

In Example 5, the subject matter of any one or more of Examples 1-4 optionally include a protrusion extending from an inferior surface of the body.

In Example 6, the subject matter of any one or more of Examples 1-5 optionally include a stop located proximate the knuckle.

In Example 7, the subject matter of any one or more of Examples 1-6 optionally include wherein a surface of the body cavity defines an arch structure with an apex proximate the knuckle.

In Example 8, the subject matter of any one or more of Examples 1-7 optionally include wherein the knuckle defines a lead in proximate the trunnion bore.

In Example 9, the subject matter of any one or more of Examples 1-8 optionally include a pin pivotably coupling the retention element to the body.

In Example 10, the subject matter of any one or more of Examples 1-9 optionally include a biasing element located within the body cavity and arranged to bias the knuckle into the trunnion bore.

Example 11 is a rasp adapter comprising: a body having an interior surface that defines a body cavity, a handle opening, and a trunnion bore; a trunnion protruding from a superior surface of the body; a biasing element located within the body cavity; and a retention element located within the body cavity and coupled to the body via the biasing element, the retention element including: a knuckle located proximate to and moveable into and out of the trunnion bore, and a heal located proximate the handle opening, wherein movement of the retention element due to a force applied to the heal causes movement of the retention element and movement of the knuckle into the trunnion bore.

In Example 12, the subject matter of Example 11 optionally includes wherein the biasing element comprises a plurality of spring legs.

In Example 13, the subject matter of any one or more of Examples 11-12 optionally include wherein the trunnion defines at least one trunnion notch.

In Example 14, the subject matter of any one or more of Examples 11-13 optionally include a protrusion extending from an inferior surface of the body.

In Example 15, the subject matter of any one or more of Examples 11-14 optionally include wherein the interior surface of the body cavity defines an arch structure with an apex proximate the knuckle.

In Example 16, the subject matter of any one or more of Examples 11-15 optionally include wherein the knuckle defines a lead in proximate the trunnion bore.

In Example 17, the subject matter of any one or more of Examples 11-16 optionally include wherein the biasing element, the retention element, and the body are a monolithic component.

Example 18 is a rasp system comprising: a handle having a first end that defines a first trunnion bore and a handle pin; and a plurality of adapters, each of the plurality of adapters comprising: a body having an interior surface that defines a body cavity, a handle opening sized to receive the handle pin, and a second trunnion bore; a trunnion protruding from a superior surface of the body, the trunnion defining at least one trunnion notch; a biasing element located within the body cavity; and a retention element located within the body cavity and coupled to the body via the biasing element, the retention element including a knuckle located proximate to and moveable into and out of the second trunnion bore, and a heal located proximate the handle opening, wherein the biasing element of at least one of the plurality of adapters comprises a plurality of spring legs, wherein the knuckle of at least one of the plurality of adapters defines a lead in proximate the second trunnion bore, wherein upon insertion of the handle pin into the handle opening and the trunnion into the first trunnion bore, the handle pin contacts the heal and causes the knuckle to move into the second trunnion bore, wherein a combination of trunnion and second trunnion bore sizes differs for each of the plurality of adapters.

In Example 19, the subject matter of Example 18 optionally includes wherein at least one of the plurality of adapters comprises a protrusion extending from an inferior surface of the body.

In Example 20, the subject matter of any one or more of Examples 18-19 optionally include wherein the interior surface of at least one of the plurality of adapters defines an arch structure with an apex proximate the knuckle.

In Example 21, the rasp adaptor or rasp systems of any one or any combination of Examples 1-20 can optionally be configured such that all elements or options recited are available to use or select from.

DETAILED DESCRIPTION

Rasps, also referred to as broaches, made by different manufactures and/or different generations of rasps from the same manufacturer can have different connection geometries. The different connection geometries can make it difficult and/or impossible to utilize a single rasp handle with the differing rasps. The different connection geometries also can make it difficult and/or impossible to utilize different rasp handles for an individual rasp. For example, a surgeon may prefer to use a particular rasp that has a connection geometry for a first rasp handle, but due to size constraints or familiarity with a particular rasp handle the surgeon may not be able to use the particular rasp handle and may have to use a second rasp handle.

As disclosed herein, a rasp adapter can allow the use of rasps and rasp handles that have different connection geometries. As a result, surgeons that have developed a preference for a particular rasp handle based on their approach and experience, can use different rasps or vice versa. Without the rasp adapters disclosed herein, new rasp handles and/or rasps have to be designed and manufactured mimicking the preferred handle design with a modified connection linkage. Furthermore, surgeons typically require multiple rasp handles to accommodate multiple surgeries occurring in a single day and the asymmetric nature of some handles (i.e. handle designed to access left and right sides of the patient's body). Design and regulatory approval of new rasp handles and rasps can consume a lot of human and financial capital and take upwards of 12 months or longer. Production of each new handle can cost several thousands of dollars as well.

The adapters disclosed herein allow for a simplified component that can be manufactured at a reduced cost and delivery time to allow a single handle to be used with rasps having different connection geometries than the handle. Further, the adapters disclosed herein can allow surgeons to select any of the already existing rasps handles that are available from different manufacturers or generations of rasp handles.

The adapters disclosed herein can include a male post geometry, sometimes referred to as a trunnion, on a superior face that mimics the rasp post designed to mate with the preferred handle. The inferior surface of the adapters can have a complementary female geometry designed to connect to the male rasp post of the preferred rasp and/or stem system. Additionally, the inferior surface can incorporate an anti-rotation feature, such as a tab, peg, or other protrusion that can mimic that of the rasp handle designed to mate with the preferred rasp and/or stem system.

The adapters disclosed herein also can have an integral biasing member, such as a spring feature, that allows for easy assembly and disassembly onto the rasps using only manual forces instead of special fixtures and/or tooling. The biasing element can be designed to stiffen and lock once the rasp handle engages the adapter to prevent the assembly from separating while under working loads during bone preparation (e.g., impaction and retraction).

As disclosed herein, multiple adapters can be used during a single surgery such that multiple rasps sizes can be assembled to expedite to the rasping process. The rasp handle can then be assembled to each rasp/adapter assembly and the bone prepared. Once the final rasp/adapter assembly has been utilized, the surgeon can select to trial off the rasp and thus remove the handle and adapter to allow for the trunnion trials to be installed. At this point the surgeon can disconnect the rasp handle with the rasp/adapter remaining in the canal of the bone (e.g., a femoral canal). The removal of the rasp handle can alleviate the lock allowing the surgeon to manually remove the adapter from the rasp. After successful trialing, the surgeon can replace the adapter and then the rasp handle to remove the rasp from the prepared bone.

Turning now to the figures,FIG.1illustrates proximal portions of rasps100and150in accordance with at least one example of the present disclosure. As shown inFIG.1, rasp100can include a body102and a trunnion104. Trunnion104can extend from a superior surface106and define a notch108. Rasp150can include a body152and a trunnion154. Trunnion154can extend from a superior surface156and define a notch158.

Each of rasps100and150can be from the same manufacturer or different manufacturers. For example, rasp100can be a rasp manufactured by a first manufacturer and rasp150can be a rasp manufactured by a second manufacturer. Rasps100and150can also be manufactured by the same manufacturer but be different generations or designs for rasps.

Because rasps100and150are manufactured by two different manufacturers or are different generations and/or designs, the geometry for connecting rasps100and150to a handle can be different. For example, as shown inFIG.1, the height of trunnions104and154may have a height difference represented by ΔH. Notches108and158can be different as well. For instance, notch108can have a “V” shape that includes two straight portions110and a curved bottom112. Notch158can have a curved structure160of a constant radius, R. The differences in trunnion height and notch structure can prevent rasps100and150from being attachable to a single handle.

FIG.2shows a rasp system200in accordance with at least one example of the present disclosure. Rasp system200can include a handle202, an adapter204, and a rasp206. Rasp206can have a connection geometry similar to that of rasp100or rasp150. As disclosed herein, rasp206has a connection geometry similar to that of rasp150. Handle202can include a lever208that connects to a linkage210. As shown inFIG.2, handle202can include a first end212and a second end214. Adapter204can be connected to first end212and an impaction head216can be connected to second end214. Impaction head216can be removable to allow for customization of handle202and for replacement due to wear and tear over time.

FIG.3shows a detail of adapter204and rasp206connected to handle202. As disclosed herein, movement of lever208can cause movement of linkage210and a lock302so as to secure and release adapter204and rasp206to and from handle202. As shown inFIG.3, adapter204can include a trunnion304that defines a trunnion notch306and is located within a trunnion bore308. In a locked state, a projection310of lock302can rest at least partially in trunnion notch306to secure adapter204to handle202.

Handle202can include a pin312that extends from first end212. Upon pin312entering adapter204, via a handling opening314, pin312can contact a retention element316. For example, pin312can contact a heal318thereby causing a knuckle320to contact notch158thereby securing both adapter204and rasp206to handle202.

FIGS.4A,4B, and4Cshows adapter204in accordance with at least one example of the present disclosure. Adapter204can include a body402that can include a superior surface404, an inferior surface406, and an interior surface410. Trunnion304can extend from superior surface404. The trunnion304can define one or more trunnion notches306. For example, trunnion304can have a length that allows for two trunnion notches to be formed thereby allowing adapter204to accommodate handles that have locks, such as lock302, positioned different distances from a first end of a handle, such as first end212of handle202. Trunnion304can also include a beveled surface414. Beveled surface414can provide a transition to ease inserting adapter204into handle202. For example, beveled surface414can contact lock302in order to cause lock302to move out of trunnion bore308when adapter204is inserted into handle202.

The diameter of trunnion304can be constant and/or can vary. For example, the diameter of trunnion304can be constant as shows inFIGS.4A-4C. the diameter of trunnion304can also vary as a function of distance from superior surface404. For instance, trunnion304can have a slight conical shape.

Trunnion304and body402can be a monolithic component. For example, adapter204can be machined from a solid billet of metal such that trunnion304and body402are one continuous piece of metal. Still consistent with embodiments disclosed herein, trunnion304can be a threaded component that screws into body402. For example, trunnion304can be machined from round stock with a threaded end and body402can include a tapped hole to allow trunnion304to be threaded into body402.

Superior surface404can define handle opening314. The size and shape of handle opening314can vary from one adapter to another. For example, adapter204can be one of a plurality of adapters that are part of a rasp system. Each of the adapters can have handle openings that vary depending on the handle in which they are designed to accommodate. As shown inFIGS.4A and4C, handle opening314can be circular. Still consistent with embodiments disclosed herein, handle opening314can be rectangular, oval shaped, pentagonal shaped, etc. Handle opening314can define a passage from the exterior of adapter204to a cavity416defined by interior surface410. The passage can allow pin312to pass into cavity416and contact heal318of retention element316.

As disclosed herein, retention element316can include heal318and knuckle320. Retention element316can be secured to body402via a biasing element418. Biasing element418can bias knuckle320into trunnion bore420defined by body402. By having biasing element418biased into trunnion bore420, when the trunnion of a rasp, such as trunnion154of rasp206, is inserted into trunnion bore420, knuckle320can move into a notch, such as notch158in trunnion154, to temporarily secure the rasp to adapter204. The biasing force applied by biasing element418can be high enough to secure rasp202to adapter204during general handling by surgeons or other operating room personnel but not so high as to require any special tools or other instruments to secure and/or remove trunnion154from adapter204.

Biasing element418can be comprised of multiple elements. For example, as shown inFIGS.4A-4C, biasing element418can be comprised of a plurality of spring legs422that can be connected together via curved portions430. Other examples of biasing element418can include springs, such as torsional or compression springs.

Interior surface410can include an arched portion proximate retention element318. The arched portion of interior surface410can have an apex that is located proximate retention element318. As described below with respect toFIGS.5A-5E, the arched portion of interior surface410can act as a stop to limit motion of retention element318. In addition to or an in alternative to the arched portion of interior surface410, a tab or other protuberance can extend from interior surface410to limit movement of retention element318when handle202is connected to adapter204.

Adapter204can include a protrusion424that extends from inferior surface406. As disclosed herein, protrusion424can mate with a complementary recess in rasp206. While adapter204is shown and described as having protrusion424and rasp206as having the complementary recess, adapter204can have a complementary recess and rasp206can have a protrusion without departing from contemplated embodiments. Protrusion424can act to prevent rotation of rasp206in adapter204.

As disclosed herein retention element316can include heal318and knuckle320. Knuckle320can include a lead in426. Lead in426can be a beveled portion or other angled surface of knuckle320. Lead in426can allow a trunnion of a rasp, such as trunnion154of rasp206to move retention element316due to contact between the two elements, thereby temporarily moving retention element316out of trunnion bore420. Upon a notch, such as notch158, passing knuckle320, knuckle320can move back into trunnion bore420and contact notch158, thereby temporarily securing rasp206to adapter204. The surface of knuckle320that contact notch158can be contoured to match notch158. For example, notch158has a curved shape so the surface of knuckle320that contacts notch158can be curved as well. Notch108(seeFIG.1) has planar surface110so the surface of knuckle320that contacts notch108can be planar as well.

Adapter204can be manufactured from metals, polymers, ceramics, or any combination thereof. Adapter204can be manufactured via a variety of manufacturing techniques including, but not limited to, machining (CNC or manual), injection molded, overmolding, etc. For example, adapter204can be machined from a single metal billet (i.e. be a monolithic component). Adapter204can also be machined from a metal billet and overmolded with a rubber or other polymer. Various surfaces of adapter204can be overmolded or otherwise coated as well. For example, superior surface404and/or inferior surface406can be coated with a polymer or ceramic to help minimize wear between superior surface404and/or inferior surface406and surfaces of handle202and rasp206.

FIG.4Dshows adapter450in accordance with at least one example of the present disclosure. Adapter450can include a body452that can include a superior surface454, an inferior surface456, and an interior surface458. Trunnion304can extend from superior surface454. Trunnion304can define one or more trunnion notches306and a beveled surface414as disclosed with respect toFIGS.4A-4C.

Adapter450can include a retention element470that can include a heal458and knuckle460. Retention element460can be secured to body402via a biasing element462. Biasing element462can bias knuckle464into trunnion bore420defined by body402. By having biasing element462biased into trunnion bore420, when the trunnion of a rasp, such as trunnion154of rasp206, is inserted into trunnion bore420, knuckle464can move into a notch, such as notch158in trunnion154, to temporarily secure the rasp to adapter204as disclosed herein.

Biasing element462can be comprised of multiple elements. For example, as shown inFIG.4D, biasing element462can be comprised of a plurality of spring legs466connected by arched portions430. Other examples of biasing element462can include springs, such as torsional or compression springs. Spring legs466can be angled relative to the axis of trunnion bore420to provide additional clearance. In addition and as shown inFIG.4D, individual legs of spring legs464can have different lengths relative to one another.

Interior surface468can be flat and retention element460can include an arched portion472proximate interior surface468. Arched portion472can have an apex that is located proximate interior surface468. As described herein, arched portion472and of interior surface468can act as a stop to limit motion of retention element460. Interior surface468can also define a radius474that can act as a stop to limit motion of retention element460via contact with radius474.

In addition to or an in alternative to arched portion472, a tab or other protuberance can extend from retention element460or interior surface468to limit movement of retention element460when handle202is connected to adapter204.

Adapter450can be manufactured from metals, polymers, ceramics, or any combination thereof. Adapter450can be manufactured via a variety of manufacturing techniques including, but not limited to, machining (CNC or manual), injection molded, overmolding, etc. For example, adapter450can be machined from a single metal billet (i.e. be a monolithic component). Adapter450can also be machined from a metal billet and overmolded with a rubber or other polymer. Various surfaces of adapter450can be overmolded or otherwise coated as well. For example, superior surface454and/or inferior surface456can be coated with a polymer or ceramic to help minimize wear between superior surface454and/or inferior surface456and surfaces of handle202and rasp206.

FIGS.5A,5B,5C,5D, and5Eshow method stages for assembling rasp system200in accordance with at least one example of the present disclosure. The method can begin at stage502(FIG.5A) where rasp206can be connected to adapter204. To connect rasp206to adapter204trunnion154can be inserted into trunnion bore420as indicated by arrow504and pin424can be inserted into a recess506located in rasp206as indicated by arrow508. As shown inFIG.5B(stage510), upon trunnion154entering cavity416a beveled surface512of trunnion154can contact lead in416. Upon contacting lead in416trunnion154can cause movement, such as rotation and/or translation, as indicated by arrow514, of retention element316so that knuckle320moves out of trunnion bore420. Upon notch158passing knuckle320, knuckle320can seat into notch158as shown inFIGS.3and5C.

At stage522(FIG.5D.) pin312can seat into handling opening314and protrusion310can be moved into trunnion notch306. Movement of protrusion310and lock302can be caused by movement of level208.

FIG.5Eshows rasp206secured to adapter204, which is in turn secured to handle202. As shown inFIG.5E, pin312resting against heal314can act to constrict movement of retention element316. In addition, the apex of interior surface410also can act to constrict movement of retention element316. As shown inFIG.5E, a downward force (indicated by arrow526) can cause retention element316to move as indicated by arrow528and contact the curved portion or the apex of interior surface410. The contact between knuckle320and interior surface410along with contact of pin312and heal314locks rasp206to adapter204. Stated another way, by constricting movement of retention element316with interior surface410and pin312, knuckle320forms a wedge that secures rasp206to adapter204.

To remove rasp206from adapter204, handle202can be removed so that pin312no longer restricts movement of retention element316. For example, handle202can be removed from adapter204. Once handle202is removed, retention element316is free to move as indicated by arrow530and rasp202can be pulled from adapter204. For instance, as rasp202is pulled from adapter, the surface of knuckle320that contacts notch158can slide along notch158thereby pushing retention element out of trunnion bore420as indicated by arrow530.

NOTES