EP4676353A1

EP4676353A1 - Surgical instruments, reamer sets and surgical methods

Info

Publication number: EP4676353A1
Application number: EP24710375.7A
Authority: EP
Inventors: James Anderson; Michael Reeve
Original assignee: DePuy Ireland ULC
Current assignee: DePuy Ireland ULC
Priority date: 2023-03-08
Filing date: 2024-03-07
Publication date: 2026-01-14
Also published as: WO2024184440A1; AU2024233671A1; GB202303421D0; JP2026510030A; CN120813310A

Abstract

A set of surgical instruments adapted for cutting bone and tissue material for the preparation of a surgical site to receive a prosthesis. The set includes a plurality of distal reamers including subsets with differing diameter and common axial lengths and corresponding sets of proximal reamers of differing diameters and common axial lengths. A fully modular instrument cutting assembly is provided to allow conversion intra- operatively between different implant types.

Description

SURGICAL INSTRUMENTS, REAMER SETS AND SURGICAL METHODS

Field

This disclosure relates to surgical instruments, sets incorporating such surgical instruments and surgical methods using such instruments. The disclosure particularly but not exclusively concerns reaming/cutting instruments and specifically surgical site preparation reaming instruments.

Background

Orthopaedic surgeons must develop openings or cavities in long bones for a variety of reasons including fracture fixation and the implantation of stem-based prostheses. Stems are used in prosthetic joint implants to anchor the prosthesis in a bone cavity. The bone receiving the stem is typically prepared by drilling a hole and creating an opening sized and contoured to receive the implant stem. Typically for joint reconstruction, the stem is inserted into the cavity within the bone and a joint bearing part (head) provided at or coupled to the stem, extends outwardly for coupling to a receiving socket or other region to complete the joint.

To prepare a bone, such as a femur, reamers are often used. Different types and/or sizes of surgical implant may be appropriate to a particular surgical issue or site and it may be necessary to change surgical plans. This can often necessitate large numbers of instrument trays as surgical implants typically come with their own sets of reamers and often sets of different types of reamers. Additionally, the same reamer may be used to ream to a variety of different depths depending on the size of the stem being implanted. Large number of reamers represent undesirably large instrument inventories that must be maintained.

A reamer generally includes a rotating reamer bearing cutting formations, such as flutes, a body by which the surgeon can hold the instrument and a coupling for connection to a rotational drive source which is often a power tool but can also be manual. Often, the reamer can be removed from the instrument so that a different sized reamer can be used, for example because of the size of the patient or in order to progressively increase the size of the cavity to match the size of a planned prosthesis. Hence, a releasable attachment mechanism is often provided to allow the reamer to be replaceably attached to the remainder of the reamer instrument so that different sized reamers can be used.

During a hip replacement procedure, it is generally necessary to provide the surgeon with a certain degree of flexibility in the selection of a prosthesis. In particular, the anatomy of the bone into which the prosthesis is to be implanted may vary somewhat from patient to patient. Integral or monobloc protheses include a head (or head mount), stem and neck that are formed integrally. Typically there may be a range of different sized prostheses from which a surgeon can select to match a patient’s femur size. For example, a patient's femur may be relatively long or relatively short thereby requiring use of a femoral prosthesis which includes a stem that is relatively long or short, respectively. Moreover, in certain cases, such as when use of a relatively long stem length is required, the stem must also be bowed in order to conform to the anatomy of the patient's femur. A modular prosthesis is constructed in modular form so the individual components can be selected to fit the needs of a patient's anatomy. For example, a typical modular prosthesis includes a proximal body component that can be assembled to any one of numerous distal stem components. Such a design allows the distal stem component to be selected and thereafter implanted in the patient's bone at a position which conforms to the patient's anatomy while also allowing for a degree of independent positioning of the proximal body component.

Accordingly, it would be beneficial to reduce the number of surgical instruments and/or sets of surgical reamers that are required. Additionally, it would be beneficial to allow greater interchangeability between different types of implant during surgery and in response to an assessment by a surgery that a second different implant or implant type may be more suited than a first intended implant. It would be advantageous if such interchangeability could be achieved via a minimised number of surgical instruments and in particular bone preparation reamers.

Summary

It is an objective of the present concept to provide a set of surgical instruments and in particular reamers for preparing a surgical site with increased compatibility and interchangeability between different surgical instruments/reamers of the present set. Such a configuration is advantageous such that a surgical site may be prepared via the combined use of a plurality of instruments/reamers of the present set in a variety of different combinations. It is a further specific objective to provide a set of surgical instruments/reamers that are adapted to be used in any combination and in particular combinations that may be interchanged during a surgical procedure to prepare a surgical site to receive an implant of different types and/or sizes. It is a further specific objective to provide a set of instruments/reamers in which the instruments may be used with an intention to prepare a surgical site to receive a first type of implant whilst allowing the same surgical site as prepared to be suitable for receiving a different second type of implant without the need for a complete repreparation of the site.

It is a further specific objective to provide a set of surgical instruments having different groups of instruments/reamers where the groups may be combined and used interchangeably to prepare a surgical site to receive at least an implant of a first type and an implant of a second type. It is a further specific objective to provide a set of surgical reamers organised into groups including distal and proximal reamers with interchangeable compatibility between different groups of distal and proximal reamers.

The objectives are achieved via a set of surgical instruments and in particular reamers that are organised into groups of proximal reamers and distal reamers. Each group of reamers comprises an array of reamers of the same common length but differing in diameter. Such a configuration is provided for both distal and proximal reamer groups with each group optionally provided at a tray.

In particular, the present set of surgical instruments/reamers is designed to be modular via the respective axial lengths and diameters of distal and proximal ends of respective cutting portions of each of the reamers. That is, the present modular set of reamers includes groups of fixed length but variable diameter cutting portions such that the diameters of any one of the distal and proximal ends of the reamers of the different groups match, overlap and/or are the same across all, some or a plurality of different groups. The present modular construction of the set of surgical instruments/reamers allows a surgeon to identify an implant to match a patient and in particular a patient femur with regard to length and in particular gauge and then to identify a group of distal reamers needed to prepare the bone site as an initial step. The present modular set further enables a surgeon to select one or a plurality of different groups of proximal reamers firstly to prepare the bone site as an intermediate or final stage whilst also allowing a surgeon to interchange to a different implant depending upon the state or condition of a patient’s bone and/or the surgical site. Specifically, the present concept provides such interchangeability without a need to undertake further/additional distal reaming and to finish preparing the surgical site via the use of one or more reamers from the selected group of proximal reamers identified to match and be appropriate for a second type of surgical implant identified by the surgeon.

According to a first aspect of the present concept there is provided a set of surgical reamers comprising: a plurality of distal reamers each having a cutting portion extending between a distal tip and a proximal end, the distal reamers including at least a first group with differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length by a modular increment value; a plurality of proximal reamers each having a cutting portion extending between a distal end and a proximal end, the proximal reamers including at least a first group with differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length of the proximal reamers by said modular increment value; the distal and proximal reamers configured such that proximal ends of the first group of distal reamers are positionable adjacent the distal ends of the first and second groups of proximal reamers and the distal ends of the second group of proximal reamers are positionable adjacent the proximal ends of the first and second groups of distal reamers such that respective combined axial lengths of the cutting portions of the first group of proximal reamers plus the first group of distal reamers; the second group of proximal reamers plus the first group of distal reamers, and the second group of proximal reamers plus the second group of distal reamers differ from one another by at least one said modular increment value.

Reference herein to a modular increment value encompasses a qualitative and quantitative axial length measured between two spatially separate axial positions. The modular increment value may be a fixed integer or decimal. The modular increment may be measured from an axial end of any one of the cutting portions described herein with such ends of the cutting portions including a distal cutting tip and proximal and distal ends.

Optionally, a diameter of the distal end of the cutting portion of at least one of the first group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the first group of distal reamers; a diameter of the distal end of the cutting portion of at least one of the second group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the first group of distal reamers; and a diameter of the distal end of the cutting portion of at least one of the second group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the second group of distal reamers. Optionally, the distal reamers comprise an increase in diameter according to a tapered profile between the distal tip and the proximal end of each respective cutting portion. Optionally, the proximal reamers comprise an increase in diameter according to a tapered profile between the distal end and the proximal end of each respective cutting portion.

Optionally, the respective cutting portions comprise flutes extending at least axially and/or circumferentially along each respective cutting portion.

Optionally, the set of surgical reamers comprise at least three groups of distal reamers comprising the first group, the second group and a third group of differing diameter and common axial length that is greater than the axial length of the second group of distal reamers by said modular increment value. Optionally, the set of surgical reamers comprise at least three groups of proximal reamers comprising the first group, the second group and a third group of differing diameter and common axial length, each of the reamers within the third group comprising a cutting portion having a uniform diameter extending axially between the distal and proximal ends of each cutting portion. Optionally, the distal reamers further comprise a fourth group and a fifth group each respective group having a plurality of reamers with differing diameters and respective common axial lengths wherein: the fourth group of reamers each comprise a cutting portion having an axial length that is greater than the axial length of the cutting portion of each of the reamers of the third group by said modular increment value; and the fifth group of reamers each comprise a cutting portion having an axial length that is greater than the axial length of the cutting portion of each of the reamers of the fourth group by said modular increment value.

Optionally, a diameter of the distal end of the cutting portion of at least one of the third group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the fourth group and/or the fifth group of distal reamers. Optionally, a diameter of the distal end of the cutting portion of at least one of the reamers of the third group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the reamers of the third group of distal reamers. Optionally, an axial length of the cutting portion of each of the reamers of the third group of proximal reamers is equal to or approximately equal to the axial length of the cutting portion of reamers of the second group of proximal reamers wherein a diameter of the cutting portions of the second group of proximal reamers increases according to a tapered profile from the distal ends to the proximal ends of each respective cutting portion.

Optionally, each of the groups of proximal and distal reamers comprise in a range 2 to 16, 4 to 14, 4 to 12 or 8 to 12 reamers of different diameter. Optionally, a diameter of the proximal ends of the respective cutting portions of the distal reamers is in a range 10 to 24 mm or 12 to 22 mm. Optionally, a diameter of the distal ends of the respective cutting portions of the proximal reamers is in a range 10 to 24 mm or 12 to 22 mm. Optionally, an axial length of the reamers of the second group of proximal reamers is in a range 80 to 110 mm, 85 to 105 mm or 90 to 100 mm. Optionally, an axial length of the reamers of the first group of distal reamers is in a range 125 to 155 mm, 130 to 150 mm or 135 to 145 mm. Optionally, an axial length of the reamers of the first group of proximal reamers is in a range 30 to 60 mm, 35 to 55 mm or 40 to 50 mm. Optionally, an axial length of the reamers of the second group of distal reamers is in a range 175 to 205 mm, 180 to 200 mm or 185 to 195 mm. Optionally, the modular increment value is in a range 20 to 75 mm, 25 to 70 mm, 30 to 65 mm, 35 to 65 mm, 40 to 60 mm, or 45 to 55 mm.

According to a further aspect of the present concept there is provided surgical apparatus to prepare a bone site to receive an implant comprising: a set of surgical reamers as claimed in any preceding claim; and a first implant having a stem, a neck and a head or head mount connected to the shaft via the neck, the implant having a pre-defined gauge value corresponding to a diameter at a pre-defined axial position on the stem; wherein at least one reamer of at least one of the first and second group of distal reamers comprise a cutting portion having a gauge value corresponding to a diameter at a pre-defined axial position on the cutting portion being equal to the gauge value of the implant to provide at least one gauge matched distal reamer.

Optionally, the pre-defined axial position on the cutting portion of the distal reamer is at the proximal end of the cutting portion. Optionally, with the implant positioned side-by-side to the matched distal reamer and with the cutting portion and the stem aligned parallel or nearly parallel and a distal tip of the stem coaxially aligned with the distal tip of the cutting portion of the distal reamer, an axial separation distance between an axial position at a centre of the head and the proximal end of the cutting portion is a pre-defined set distance.

Optionally, a second implant having a stem, a neck and a head or head mount connected to the shaft via the neck, the implant having a pre-defined gauge value corresponding to a diameter at a pre-defined axial position on the stem; wherein at least one reamer of at least one of the first and second group of distal reamers comprise a cutting portion having a gauge value corresponding to a diameter at a pre-defined axial position on the cutting portion being equal to the gauge value of the implant to provide at least one gauge matched distal reamer; wherein an axial length of the second implant is greater than the first implant and the second gauge matched distal reamer comprises an axial length greater than that of the first gauge matched distal reamer.

Optionally, the pre-defined axial position on the cutting portion of the distal reamer is at the proximal end of the cutting portion.

Optionally, with the implant positioned side-by-side to the at least one gauge matched distal reamer and with the cutting portion and the stem aligned parallel or nearly parallel and a distal tip of the stem coaxially aligned with the distal tip of the cutting portion of the distal reamer, an axial separation distance between an axial position at a centre of the head and the proximal end of the cutting portion is a pre-defined set distance.

According to a further aspect of the present concept there is provided a surgical method of preparing a surgical site and implanting an implant comprising: selecting a distal reamer from the first and second group of distal reamers according to claim 1 by matching a predefined gauge value of an implant to be implanted with a pre-defined gauge value of one of the distal reamers of the first and second groups; cutting material from a distal location at a surgical site of a patient using the selected gauge matched distal reamer; selecting a proximal reamer from one of the first and second groups of proximal reamers based on an axial length and/or the gauge value of the implant to be implanted such that a combined axial length of the cutting portions of the selected distal and proximal reamers is less than an axial length of the implant measured between a distal tip of a stem of the implant and a centre point of a head of the implant; cutting material from a proximal location of the surgical site using the selected proximal reamer; and implanting the implant at the surgical site in the patient.

Optionally, after the step of cutting material using the distal reamer, assessing a state or condition of the material at the surgical site and selecting one of the first, second or third group of proximal reamers prior to the step of cutting material with the selected proximal reamer.

Optionally, if a proximal reamer is selected from group one or two, the implant to be implanted is a unitary body implant; or if a proximal reamer is selected from group three of the proximal reamers, the implant is a modular implant having a proximal body (neck to mount a head) that is detachably mountable to the distal stem; such that the selected distal reamer is configured for sequential use to cut material at the surgical site with either the first and second or the third group of proximal reamers.

According to a further aspect of the present concept there is provided a set of surgical reamers comprising: a plurality of distal reamers each having a cutting portion extending between a distal tip and a proximal end, the distal reamers including at least a first group or differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length; a plurality of proximal reamers each having a cutting portion extending between a distal end and a proximal end, the proximal reamers including at least a first group with differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length of the proximal reamers.

Preferably, the distal and proximal reamers are configured such that proximal ends of the first group of distal reamers are positionable adjacent the distal ends of the first and second groups of proximal reamers and the distal ends of the second group of proximal reamers are positionable adjacent the proximal ends of the first and second groups of distal reamers.

Preferably, the combined axial lengths of the cutting portions of: the first group of proximal reamers plus the first group of distal reamers; the second group of proximal reamers plus the first group of distal reamers, and the second group of proximal reamers plus the second group of distal reamers differ from one another by at least one said modular increment value.

According to a further aspect the disclosure provides a set of surgical instruments, the set comprising two or more first type surgical instruments, the first type surgical instruments may comprise: a proximal end and a distal end; and/or one or more cutting elements provided by a distal portion between the proximal end and the distal end; and/or a location having a location diameter, the location may be intermediate the proximal end and the distal end; wherein at least two of the first type surgical instruments may further comprise: having a different extent between the proximal end and the distal end to each other; and/or the location having the location diameter having the same diameter as each other; and/or the location having the location diameter having the same distance relative to the proximal end of the first type of surgical instrument as each other.

Optionally, three and/or four and/or all of the first type surgical instruments in the set may have a different extent between the proximal end and the distal end to each other.

Optionally, three and/or four and/or all of the first type surgical instruments in the set may have the location (pre-defined axial position) having a diameter that is the same as each other. Optionally, three and/or four and/or all of the first type surgical instruments in the set may have the location having the location diameter having the same distance relative to the proximal end of the first type of surgical instrument as each other.

Optionally, the first type surgical instruments may be a reamer. The first type surgical instrument may be a distal reamer. The first type of surgical instrument may be provided with a tapering portion, for instance in a distal portion. The tapering portion may be a full taper. The one or more cutting elements may be provided in a tapering portion. The one or more cutting portions may extend distally and/or radially, for instance in an inclined manner. The proximal end may be provided with a mounting element. The mounting element, in use, may connect the first type surgical instrument to a drive instrument. The mounting element, in use, may interact with, for instance receive, a second type of surgical tool, for instance a different type of reamer. The mounting element may be a shaft or stem. The mounting element may have a mounting element diameter. The mounting diameter may be less than the location diameter and/or less than an internal bore diameter of a second type of surgical tool.

Optionally, one or more or all of the first type instruments may have a mounting element with the same extent proximally to distally. The distal end may be provided with an increased taper portion. Optionally, the location may be a cross-sectional location through the surgical instrument, for instance perpendicular to the axis of the surgical instrument. The location may be a gauge location. The location diameter may be the maximum diameter at the location. The location diameter may be the minimum diameter at the location. The location diameter may be the average diameter around the perimeter of the location. Optionally, the distal portion providing the one or more cutting elements may extend distally of the location for one or more or all of the first type surgical instruments. The distal portion providing the one or more cutting elements may extend proximally of the location for at least one or two of the first type surgical instruments. The distal portion providing the one or more cutting elements may extend distally and proximally of the location for at least one or two of the first type surgical instruments. The distal portion providing the one or more cutting elements may not extend proximally of the location for at least one or two of the first type cutting elements. The set of surgical instruments of a first type may be provided together with one or more types of surgical implant. Where the set of surgical instruments of a first type is provided together with one or more types of surgical implant, the location having the diameter that is the same as each other may have the same distance relative to a head portion of the surgical implant, for instance the head centre. This type of surgical implant may be a modular surgical implant. Optionally, where the set of surgical instruments of a first type is provided together with one or more types of surgical implant, the location having the diameter that is the same as each other may have the same distance relative to the proximal end of the surgical implant as the start of the flutes on the surgical implant, for instance the head centre. This type of surgical implant may be a unitary or monoblock surgical implant.

The set of surgical instruments of a first type may be provided together with one or more sets of surgical instruments of a second type.

The further aspect of the disclosure may include any of the features, options or possibilities set out elsewhere in this specification, including in the other aspects.

According to a further aspect the disclosure provides a set of surgical instruments, the set comprising two or more first type surgical instruments, the first type surgical instruments may comprise: a proximal end and a distal end; and/or one or more cutting elements provided by a cutting portion provided between the proximal end and the distal end, the cutting portion may have a proximal limit; wherein at least two of the first type surgical instruments may further comprise: having a different extent between the proximal end and the distal end to each other; and/or the proximal limit of the cutting portion having the same distance relative to the proximal end of the first type of surgical instrument as each other.

Optionally, the cutting portion may have a distal limit at the distal end of the surgical instrument. Optionally, at least two of the first type surgical instruments may further comprise: having a different extent between the proximal end and the distal end to each other; the location having the diameter the same as each other; and the location having the location diameter having the same distance relative to the proximal end of the first type of surgical instrument as each other. Optionally, two or more of the first type surgical instruments may have a first same distance for the proximal limit of the cutting portion. Two or more of the first type surgical instruments may have a second same distance for the proximal limit of the cutting portion. The first same distance may be less than the second same distance. Where the two or more first type surgical instrument have the location, the first same distance may be proximal of the location. Where the two or more first type surgical instrument have the location, the second same distance may be coincident with the location.

Optionally, three and/or four and/or all of the first type surgical instruments in the set may have a different extent between the proximal end and the distal end to each other. Three and/or four and/or all of the first type surgical instruments in the set may have a location having a location diameter having the same diameter as each other. Optionally, three and/or four and/or all of the first type surgical instruments in the set may have a location having a location diameter having the same distance relative to the proximal end of the first type of surgical instrument as each other.

Optionally, two or more of the second type surgical instruments may have a first same distance for the proximal limit of the cutting portion to the distal limit of the cutting portion. Two or more of the first type surgical instruments may have a second same distance for the proximal limit of the cutting portion to the distal limit of the cutting portion. The first same distance may be less than the second same distance.

According to a further aspect the disclosure provides a surgical method, the method may comprise: providing a set of surgical instruments of the first type according one aspect of the invention as described and claimed here; and/or selecting a first surgical instrument of the first type from the set of instruments; and/or cutting material from a surgical site of a patient using the first surgical instrument; and/or providing a first type of surgical implant and a second type of surgical implant; and/or providing two sets of surgical instruments of a second type, the first of the two sets being different from the second of the two sets in terms of one or more physical characteristics of the surgical instruments; and/or making an assessment to use either the first type of surgical implant or the second type of surgical implant for the patient; and/or if the first type of surgical implant is to be used then also selecting for use the first set of surgical instruments of the second type; and/or if the second type of surgical implant is to be used then also selecting for use the second set of surgical instrument of the second type; and/or using at least one of the second set of surgical instruments on the patient; and/or implanting the selected surgical implant in the patient. The first type of surgical implant may be a non-customisable implant. The first type of surgical implant may be a unitary or monoblock implant.

Optionally, the second type of surgical implant may be a customisable implant. The second type of surgical implant may be a modular implant. The second type of implant may include a separate distal stem portion and separate proximal stem and head portion. A plurality of different characteristic distal stem portions and/or proximal stem and head portions may be provided, for instance to make a selection from.

Optionally, the first type of surgical implant and/or the second type of surgical implant may differ in terms of differences in profile and/or proximal to distal extent, and/or differences in the lateral extent of the head section and/or inclination of the head section and/or profile of the head section and/or flutes (including their profile and/or start location and/or end location and/or inclination) and/or the formation of the surgical implant from a single element or from two or more connected together elements (including modular implants where a stem part and a head part are connected and are selected from a wide variety of different stem parts and/or head parts).

The first set of the second type surgical instruments may be a reamer. The first set of the second type surgical instrument may be a proximal reamer. The first set of the second type of surgical instrument may be provided with a tapering portion, for instance in a distal portion. The tapering portion may be a partial taper. The first set of the second type of surgical instrument may be provided with a conical portion. Optionally, the first set of the second type instruments may comprise one or more cutting elements may be provided in a tapering portion or conical portion. The one or more cutting portions may extend distally and/or radially, for instance in an inclined manner.

Optionally, the first set of the second type instruments may comprise a proximal end may be provided with a mounting element. The mounting element, in use, may connect the second type surgical instrument to a drive instrument. The mounting element may be a shaft or stem. The mounting element may have a mounting element diameter. The mounting diameter may be less than the location diameter. Optionally, one or more or all of the first set of the second type instruments may have a mounting element with the same extent proximally to distally. Optionally, the first set of the second type instruments may be provided with a planar distal end, for instance perpendicular to the axis of the instrument.

The second set of the second type surgical instruments may be a reamer. The second set of the second type surgical instrument may be a proximal reamer. The second set of the second type of surgical instrument may be provided with a non-tapering portion, for instance in a distal portion. The non-tapering portion may be a cylindrical portion.

The second set of the second type instruments may comprise one or more cutting elements that may be provided in a cylindrical portion. The one or more cutting portions may extend distally and/or radially, for instance in an inclined manner. Optionally, the second set of the second type instruments may comprise a proximal end may be provided with a mounting element. The mounting element, in use, may connect the second type surgical instrument to a drive instrument. The mounting element may be a shaft or stem. The mounting element may have a mounting element diameter. The mounting diameter may be less than the location diameter.

Optionally, one or more or all of the second set of the second type instruments may have a mounting element with the same extent proximally to distally. Optionally, the second set of the second type instruments may be provided with a planar distal end, for instance perpendicular to the axis of the instrument. Optionally, the second type instruments may have a proximal to distal extent less than the proximal to location extent of the first type instruments.

Optionally, the sets of second type instruments may include, for the first set and/or the second set, two or more instruments with a first proximal to distal extent for the cutting elements which is the same. The sets of second type instruments may include, for the first set and/or the second set, two or more instruments with a second proximal to distal extent for the cutting elements which is the same. The first proximal to distal extent may be less than the second proximal to distal extent. According to a further aspect the disclosure provides a surgical method, the method may comprise providing a set of surgical instruments of the first type according to an aspect of the invention as described and claimed herein; and/or selecting a first surgical instrument of the first type from the set of instruments; and/or cutting material from a surgical site of a patient using the first surgical instrument; and/or providing a first type of surgical implant and a second type of surgical implant; and/or providing two sets of surgical instruments of a second type, the first of the two sets being different from the second of the two sets in terms of one or more physical characteristics of the surgical instruments; and/or making an assessment to use either the first type of surgical implant or the second type of surgical implant for the patient; and/or if the first type of surgical implant is to be used then also selecting for use the first set of surgical instruments of the second type; and/or if the second type of surgical implant is to be used then also selecting for use the second set of surgical instrument of the second type; and/or using at least one of the second set of surgical instruments on the patient; and/or implanting the selected surgical implant in the patient.

Optionally, the first and/or second type of surgical implant may be a customisable implant. The first and/or second type of surgical implant may be a modular implant. The first and/or second type of implant may include a separate distal stem portion and separate proximal stem and head portion. A plurality of different characteristic distal stem portions and/or proximal stem and head portions may be provided, for instance to make a selection from.

Brief description of drawings

A specific implementation of the present subject matter will now be described, by way of example only, and with reference to the accompanying drawings in which:

Figure 1 A is a plan view of a tray of distal reamers having respective cutting portions of different diameter and having a first common length according to a specific implementation; Figure IB is a plan view of a tray of distal reamers having respective cutting portions of different diameter and having a second common length according to a specific implementation for preparation of a bone site to receive unitary body implant;

Figure 1C is a plan view of a tray of distal reamers having respective cutting portions of different diameter and a third common length according to a specific implementation for preparation of a bone site to receive unitary body implant;

Figure 2A is a plan view of a proximal reamers having respective cutting portions of different diameter and a first common length according to a specific implementation for preparation of a bone site to receive unitary body implant;

Figure 2B is a plan view of proximal reamers having respective cutting portions of different diameter and a second common length according to a specific implementation for preparation of a bone site to receive unitary body implant;

Figure 2C is a plan view of proximal reamers having respective cutting portions of different diameter and a first common length according to a specific implementation to receive a modular implant formed from a plurality of separate components;

Figure 3A is a side view of a distal reamer of a first set corresponding to figure 1 A;

Figure 3B is a side view of a proximal reamer of the set corresponding to figure 2B having a tapered cutting portion with a relatively short length;

Figure 3C is a side view of a proximal reamer of the set corresponding to figure 2A having a tapered cutting portion with a relatively long cutting length;

Figure 3D is a side view of a proximal reamer of the set corresponding to figure 2C having a conical cutting portion with a relatively long cutting length; Figure 4 is a schematic illustration of hip joint arthroplasty in which a unitary body implant is inserted into a pre-prepared surgical site at a bone of a patient;

Figure 5 is a schematic illustration of hip joint arthroplasty in which a modular implant is inserted into a pre-prepared surgical site at a bone of a patient;

Figure 6 is a schematic illustration of an initial bone preparation stage involving distal reaming of a femoral canal;

Figure 7 is a schematic illustration of a further stage of a hip arthroplasty procedure involving attachment of a proximal reamer to the proximal end of a distal reamer;

Figure 8 is a schematic illustration of an assembled combined reaming device of figure 7 with the proximal reamer mounted proximally to a distal reamer and inserted within the femoral canal;

Figure 9A is a front view of a unitary body integrated hip implant;

Figure 9B is a side view of the implant of figure 9A;

Figure 10 illustrates schematically axially combined assemblies of proximal and distal reamers having different axial length combinations suitable for preparing a bone site to receive a prosthesis of desired axial length to match a patient’s anatomical profile;

Figure 11 illustrates schematically an interchangeable map of the various component parts of the present concept enabling preparation of a surgical site to receive a prosthesis using proximal and distal reamers according to a specific implementation of the present concept.

Detailed description

The present concept provides a fully modular interchangeable set of surgical site preparation instruments and in particular a collection of distal and proximal reamers configured specifically for bone site preparation suitable for arthroplasty. Additionally, the present set of instruments enable convenient and efficient interchange ‘ in-procedure between intended implantation of an integrated (monoblock) implant and a modular implant via common distal reaming site preparation. In particular, the present set of instruments comprises distal reamers of varying lengths and gauge (diameter) configurations adapted for both monoblock and modular prosthesis implantation. The present set of instruments comprise at least a first type of proximal reamer and a second type of proximal reamer, each configured specifically for monoblock or modular prosthesis.

Referring to figure 1 A, an instrument tray 10 comprises a set of distal reamers 13a. In particular, tray 10 comprises eleven reamers 13a of the same axial length but with each reamer 13a comprising a different diameter. Each reamer 13a comprises a cutting portion 60 extending between a distal tip 15 and a proximal end 14. Cutting portion 60 comprises a decreasing diameter between end 14 and tip 15 according to a tapered profile. Each of the reamers 13a comprises cutting flutes 17 extending helically over the cutting portion 60 between tip 15 and end 14. A shaft 16 projects proximally from proximal end 14 and is adapted for connection to a driving tool (not shown). According to the specific implementation, reamers 13a within set 10 vary in maximum diameter between 12 to 22mm. With each reamer 13a having a length of 140mm.

Referring to figure IB, a second instrument tray 11 comprises a plurality (eleven) of proximal reamers 13b, each comprising the same configuration, features and function of the reamers 13a of figure 1 A. However, reamers 13b comprise a longer axial length, of 190mm, relative to reamers 13a. Reamers 13b comprise a maximum diameter of 12 to 22m. A further tray of instruments 12 according to figure 1C also includes a plurality (eleven) of distal reamers 13c provided with a cutting portions 60 and with the same features and function of reamers 13a described referring to figures 1 A and IB. However, an axial length of the respective cutting portions 60 of reamers 13c is less than that of reamers 13a and 13b, being 120mm. Accordingly, the different sets of distal reamers 10, 11, 12 may be utilised to prepare a surgical site to receive implants of different lengths. A set of proximal reamers 18 is provided at a further tray, with the tray comprising thirteen reamers 25a. Each of the proximal reamers 25a comprises a cutting portion 22 extending between a distal end 23 and a proximal end 24. A shaft 21 projects proximally from proximal end 24 and is adapted for connection to the same driving tool (not shown) attachable to distal reamers 13a to 13c. Each of the reamers 25a and in particular the respective cutting portions 22 comprise the same axial length but differ in maximum diameter in a range 12 to 22mm. A further set (eleven) of proximal reamers 19 is illustrated in figure 2B mounted within a further tray. Proximal reamers 25b comprise the same features and function described referring to figure 2A including in particular cutting portions 22, shafts 21 and respective cutting portion terminal/distal ends 23, 24. Both sets of proximal reamers 25a, 25b comprise respective cutting portions 22 that are tapered to decrease in diameter between proximal end 24 and distal end 23. Via the array of different diameters and the number of distal and proximal reamers provided, an overlap is provided between the size of the respective diameters of the proximal ends 24 of the proximal reamers 25a, 25b and the diameters of the proximal ends 14 of the distal reamers 13a to 13c. Such a configuration enables a surgeon to select an appropriate proximal reamer from the set 18, 19 of the desired maximum diameter and axial length to work cooperatively at a surgical site with one or more selected distal reamers of the sets 10, 11 and 12. Sets of distal reamers 10, 11 and 12 and proximal reamers 18 and 19 via the respective tapered diameter profiles are adapted for preparing a surgical site to receive a monoblock (integrated) implant.

Referring to figure 2C, a further set 20 of proximal reamers is provided at a further tray. In particular, the set 20 includes thirteen proximal reamers 26 having respective cutting portions 22 defined by terminal ends 23, 24 that share the majority of the features and function of the reamers 25a of figure 2A. However, according to the further set 20, reamers 26 and in particular cutting portions 22 comprise a uniform diameter between proximal ends 24 and distal ends 23. In particular, cutting portions 22 of reamers 26 are generally conical. However, all reamers 25a, 25b and 25c at the respective cutting portions 22 comprise cutting flutes similar to the flutes 17 of the distal reamers 13a to 13c. The proximal reamer set 20 is accordingly configured for surgical preparation to receive a modular prosthesis in which a stem is separate from and attachable to a neck having a head mount/trunnion to mount a femoral head component for mating within an acetabular cup. Proximal reamer set 20, sets 18 and 19 are adapted for cooperative cutting and coaxial mounting with any one and a combination of the plurality of distal reamers 13a, 13b and 13c. Accordingly, the respective diameters of the cutting portions 22 at distal ends 23 corresponds to the respective diameters of at least some of the respective diameters of the proximal ends 14 of the cutting portions 60 of reamers 13a to 13c. Advantageously, if during a surgical procedure a surgeon, having assessed the surgical site and in particular the status of bone and/or tissue, may change the surgical procedure from intended implantation of a monoblock implant to a modular implant. Such a situation may be required where the tissue and/or bone is to be preserved to a greater extent and cutting minimised. This conversion intra-operatively to a modular implant provides greater adjustability for surgeons during complex and unpredictable procedures. As will be appreciated, surgeons prioritise conservation of remaining bone and the minimisation of operating time to reduce blood loss and anaesthetic exposure. Monoblock implants are typically preferred for enhanced bone contact and reduced operating time. However, modular implants are beneficial for maximised bone preservation in femurs with more severe defects. Such decisions and assessments can be made during surgery and therefore the present instrument set enables surgeons to optimise the aforementioned considerations for the wellbeing and best possible outcome for the patient.

Figures 3A to 3D are side illustrations of the distal and proximal reamers 13, 25b, 25a and 26. Referring to figure 3 A, shaft 16 comprises one or more features 28 facilitating attachment to the drive tool (not shown). Similarly, each of the proximal reamers 25b, 25a, 26, comprises corresponding features 28 for connection directly or indirectly to the driving tool. Each of the proximal reamers 25b, 25a, 26 comprise an internal bore 41 dimensioned to receive shaft 16. Accordingly, each of the proximal reamers 25b, 25a, 26 may be mounted coaxially at the proximal end of the distal reamers 13 so as to form an axial stack or assembly. The proximal reamer, as assembled with the distal reamer, may then be driven via a drive tool. Additionally, the present proximal reamers 25b, 25a, 26 may be used independently and separately from distal reamers 13 as required by a surgeon. Cutting flutes 17, 27 extend the full axial length of each respective cutting portion 60, 22 and are preferably helical between the axial ends. However, as will be appreciated further embodiments may comprise different configurations of cutting elements including blades, ribs, grooves and the like.

Referring to figure 4, a femur 29 may be prepared via the sequential reaming of a femoral canal 29a using the distal reamers 13 followed by the proximal reamers 25a, 25b or 26 to prepare an implant site cavity 30 adapted to receive implant 31. Implant 31 comprises a stem 32, a neck 33 and a trunnion (head mount) 34 to mount a head (as will be appreciated). Referring to figure 5, the as-prepared cavity 30 may be adapted via the use of proximal reamers 26 so as to receive, in the alternative, a modular implant 35. Implant 35 also comprises a stem 32 insertable within the pre-prepared femoral canal 29a whilst further comprising a modular shoulder 37 mountable onto a spigot 36. A neck 38 extends from shoulder 37 and terminates at head trunnion 39.

Referring to figure 6, an initial stage of a surgical procedure to prepare femur 29 to receive either of the implants 31 or 35, involves an initial distal reaming using an appropriately selected plurality of distal reamers from the appropriate set 10, 11 or 12. Specifically, the selected distal reamer is matched in axial length and diameter to the axial length, diameter and specifically the gauge of the implant 31 or 35. Typically, three to six distal reamers 13 of any one set 10, 11 or 12 may be used during the initial distal reaming stage starting with a smaller diameter reamer and finishing with a largest diameter reamer, of a particular set/tray, that is gauge-matched to the implant 31 or 35. A drive mount 40 is attachable to the distal reamer shaft 16 for connection with to the drive tool (not shown).

Referring to figure 7, a further stage of the procedure involves proximal reaming via selected proximal reamers of the sets 18, 19 or 20. If a decision is taken to proceed with monoblock implant 31, 3 to 6 proximal reamers (for example three to six) may be selected of differing diameter from one of the sets 18 or 19 to work cooperatively to remove bone of the femoral canal 29a. In particular, proximal reamer 25b is mounted onto axial coupling 40b (being an extension of shaft 16) that is insertable and received within bore 41 extending axially within proximal reamer 25. The assembled proximal and distal reamer combination is illustrated in figure 8. If the decision is taken to proceed with modular implant 35, the proximal reamers 26 of appropriate diameter may be used in place of reamers 25a, 25b.

As indicated, during a procedure, a surgeon will select a first distal reamer from the set of distal reamers, use that first distal reamer to expand the channel and then withdraw the first distal reamer, before repeating the process with a second larger diameter reamer. Further increased diameter reamers may be used until the surgeon achieves the desired diameter and profile channel. Typically, “cortical chatter” will indicate to the surgeon when the desired bone preparation point has been reached. During the distal reaming stage, the surgeon is generally able to establish whether the seating location prepared for the stem of the surgical implant is a predictable one. That is, when the actual implant is inserted, the implant will sit in the desired position within the femur and thus relative to the joint position. The stem will be axially stable during subsequent stages and use. In such a case, the surgeon will proceed with the planned use of a first type of surgical implant. A monoblock surgical implant may be used as the first type of surgical implant, with all of the stem portion defined by a singular element.

As indicated, in some situations, for patients with poor bone quality, the bone will not give sufficient bite or support to the stem and implant, the surgeon may determine that there is a need to use an alternative type of implant. Returning to the procedure if the first type of surgical implant is to be used (monoblock), then the procedure continues with the selection of a proximal reamer. Typically, a first diameter of proximal reamer, is selected. The reamer blades are provided at the distal end and a mounting location at the proximal end. As shown in Figure 7, the proximal reamer is mounted on a drive instrument and is then inserted over the proximal end of the last distal reamer used. The proximal end of the last distal reamer is received in a bore inside the proximal reamer. As seen in Figure 8, abutment of the proximal end of the distal reamer with the proximal end inner surface of the bore of the proximal reamer controls the position of the proximal reamer distally. The proximal reamer is then used to remove further material from the proximal part of the channel in the femur. Again, the process may be repeated with increased external diameter proximal reamers from within the set to increase the proximal channel diameter or profile generally. Once the preparation of the site has been completed, then the surgical implant of the first type can be inserted into the final position. If during or at the end of the distal reaming stages, the surgeon determined that the site in the patient was not stable enough for the first type of surgical implant, then the possibility of swapping to a different type applies. However, the sets of reamers provided for the different types of implant are quite different in length, profiles along those lengths and general form. Hence, the surgeon might be faced with the need to open and use an increased number of reamer sets, particularly distal reamers, and/or to conduct further preparatory work in the femur for the different type of implant. These steps potentially add surgical time, cost and complexity. In the disclosure, selective design of the different implant types across their different sizes, and particularly careful design of the reamer sets means that the give reamer sets are more versatile and there is better interchangeability between the instrument types.

Referring to figures 9A and 9B, each of the implants 31, 35 comprise a pre-defined gauge value corresponding to a diameter at an axial length position 42. Axial length position 42 is pre-set in the axial direction by a separation distance D from a central region/point of head trunnion 34. Different sized and dimensioned implants 31 are overlaid illustratively such that a first size 43 comprises the same axial position 42 of the gauge location relative to an implant 31 of greater length 44 and a further size 45 of yet longer length. The present set of instruments is adapted specifically to provide a modular set of components including distal and proximal reamers in which the distal and proximal components may be interchanged to suit the different sizes 43, 44 and 45 whilst adhering to the pre-defined separation distance D and axial gauge location 42.

The modular configuration of the present instrument is illustrated in figure 10. In particular, each combination of distal and proximal reamers of the present concept comprises a pre-defined gauge value G that is co-aligned axially at the same separation distance D of the head centre point as defined for the implant 31 referring to figures 9A and 9B. As illustrated, the gauge location G of distal reamers 13a, 13b and 13d (also mounting proximal reamers 25a) are coaligned at the proximal end 14 of the respective cutting portions 60. The combination of proximal reamer 25b (of shorter axial length than reamer 25a) with distal reamer 13a comprises a gauge location G at an approximate midlength position along the cutting portion 60. Additionally, according to a further configuration and pairing of distal reamer 13c with proximal reamer 25b, gauge location G is positioned towards distal tip 15.

The proximal ends 24 of all the assembled proximal reamers 25a, 25b (when paired with different sized distal reamers 13a, 13b, 13c, 13d) are all coaxially aligned at a pre-defined separation distance A relative to head centre position that, in part, also defines separation distance D of the gauge location. According to the present configuration, distance A is 50mm according to a specific configuration. Separation distance B corresponds to the axial length of each respective cutting portion 22 of proximal reamers 25 and separation C corresponds to the axial length of cutting portion 60 of distal reamers 13b. Referring to figure 10, axial length H is the separation distance between proximal end 14 and distal tip 15 of the cutting portion of distal reamer 13c; axial length K is the separation distance between proximal end 24 and distal end 23 of the cutting portion of proximal reamer 13c; axial length I is the separation distance between proximal end 14 and distal tip 15 of the cutting portion of distal reamer 13a; axial length J is the separation distance between proximal end 14 and distal tip 15 of the cutting portion of distal reamer 13d.

The present modular construction and reamer/implant interchangeability and compatibility is achieved via a common/uniform increment of the respective axial lengths of the cutting portions of the various proximal and/or distal reamers described herein. In particular and referring further to figure 10, the differences between all respective length K and B; H and I; C and J is equal. Put another way, the total increase in length of the combined cutting portions of reamers 25a and 13d relative to that of reamers 25a and 13b is equal to the increase in combined length of the combined cutting portions of reamers 25a and 13b relative to the relative to that of reamers 25a and 13a, which is equal to the total increase in length of the combined cutting portions of reamers 25a and 13a relative to that of reamers 25b and 13a, which is equal to the total increase in length of the combined cutting portions of reamers 25b and 13a relative to that of reamers 25b and 13c. As the implant length increases, the length of reamer is required to increase, distal to the gauge location. However, as the tapered part of the distal reamers extends proximally of the gauge location, it means that a common second type (proximal reamer) can be used for a first implant length and a common second type (proximal reamer) can also be used for a second different implant length, thereby reducing the number of distal reamers that are required.

As described, the present set of surgical instruments via the modular configuration of the respective axial lengths and diameters of the respective cutting portions in addition to the range of diameters within each set, provides conversion intra-operatively between different implant types and/or sizes to minimise conservation of bone and operation time. In addition, the present surgical instruments set via the array of different length and diameter profiles of the individual sets of reaming instruments, minimise the total number of cutting instruments that form the kit by utilising common cutters suitable for surgical site preparation independently of the type of implant. As indicated, this is provided in-part, by a common gauge location G at the respective cutting portions of the cutting instruments to correspond to the gauge location of an implant. This is achieved via a modular and/or common/uniform size difference between the various distal and/or proximal reamers. That is, the size of the various sets of distal and/or proximal reamers differs from one another by the same/common qualitative modular amount. This provides reamers with cutting portions having different lengths whilst each reamer of each/all set(s) comprises the same axial position G corresponding to the gauge location. This interchangeability and modularity may be best illustrated in figure 10 via the pairing of proximal reamers 25a with each of the different distal reamers 13a, 13b. Whilst not illustrated, if the decision is taken to change from monoblock implantation (figure 4) to the modular implant (figure 5) proximal reamers 26 would be used in place of reamers 25a at their respective pairing with distal reamers 13a, 13b or 13d for example.

The interchangeability according to the present concept is further illustrated schematically in figure 11. In particular, the present set of instruments includes a monoblock core set of reamers 50 that, in turn, comprise sub-sets including short/standard proximal reamers 51 and long/extra long (XL) proximal reamers 52. The short/standard proximal reamers 51 (corresponding to reamer set 19) may be used cooperatively with short distal reamers 53 or standard/long distal reamers 54 (corresponding to distal reamer sets 12, 10 and 11, respectively). The long/XL proximal reamers 52 are configured for cooperative use with the standard/long distal reamers 54 and a further set of XL distal reamers 55.

The instruments further comprise a modular core of reamers 56 including specifically a sub-set of modular proximal reamers 57 (corresponding to proximal reamer set 20). As indicated, modular proximal reamers 57 differ from the monoblock proximal reamers 51, 52 via the configuration of the cutting portions being cylindrical versus frusto-conical, respectively. Modular proximal reamers 57 are adaptable for interchange and use with an array of different sized distal reamers including standard/long distal reamers 54, XL distal reamers 55, XXL distal reamers 58 and XXXL distal reamers 59.

The various reamers herein of at least a first type and the second type are provided in a series of different lengths, considered proximally to distally. Examples include, three different lengths STD, Long and X-Long for each of the different reamers sets. The number of different lengths can be less or greater than three and in a number of the other embodiments described, four different lengths are provided. These different length configurations may be provided for both distal and proximal reamer types. Thus there may be a first type with a length STD, one with a length Long and one with a length X-Long. There may also be a second type with the same length STD, one with the same length Long and one with the same length X-Long.

As indicated, the gauge location is defined for each of the different types and different lengths STD, Long, X-Long, XXL, XXXL. At the gauge location, the diameter of the surgical implant is the same in each case. In this disclosure, for each of the different types of surgical implant, the gauge location is provided at the same location. For each of the different lengths STD, Long, X-Long, XXL, and XXXL, the gauge location is also provided at the same location. The gauge location may be defined as being in the same location when aligned in the manner shown in Figure 9A, 9B and 10 . For instance, the gauge location may be in the same location by it being provided at the given distance D, = distally, from the centre of head trunnion 34. Between the gauge location and the proximal end of the stem section, each of the different lengths, STD, Long, X-Long, etc may be provided with a proximal stem section which corresponds in diameter and/or other profile characteristics across the different lengths STD, Long, X-Long etc. Between the gauge location and the proximal end of the stem section, each of the different types of surgical implant may be provided with a proximal stem section which corresponds in diameter and/or other profile characteristics across the different lengths STD, Long, X- Long etc.

Distally to the gauge location, the different lengths may have different diameters and/or other profile characteristics to one another. For instance, each may have an increased taper portion approaching the distal end and/or each may have a different length distal stem section. Distally to the gauge location, two or more of the different lengths may have a common profile for an initial section. Distally to the gauge location, each of the different lengths may have the same diameters and/or other profile characteristics of that length. As well as the above-mentioned differences in profile and/or proximal to distal extent, there may be other differences between the types of surgical implant and/or the characteristics of the different sets of reamers. For instance, regarding an implant, there may be differences in the lateral extent of the head section and/or inclination of the head section and/or profile of the head section and/or flutes (including their profile and/or start location and/or end location and/or inclination) and/or the formation of the surgical implant from a single element or from two or more connected together elements (including modular implants where a stem part and a head part are connected and are selected from a wide variety of different stem parts and/or head parts).

As described here, the gauge position is at the same fixed distance from the proximal end, the centre of the head section, of the implant in each case. It is also a consistent distance from the proximal end of the mounting element of the second type surgical instrument shown. This is a slightly reduced distance, around 10-15mm reduced compared with the proximal end of the head section. The gauge position is also a consistent distance from the proximal end of the mounting element of the first type surgical instrument (obscured by and received within the internal bore of the second type). As indicated, because the gauge location is constant for all the surgical instruments and implants as described herein, the same distal reamers can be used for the distal reaming for either implant type.

Significantly, the taper and the cutting area (tapered or cylindrical) of the proximal reamers are maximised by minimising the proximal cylinder length. This may be 50mm +/- 10%. The proximal cylinder length is the same across all of the lengths used. Thus, the disclosure offers the surgeon the possibility of fully swapping to the second type of surgical implant, after the distal reaming stages, without the need for further distal reaming or other preparatory steps.

In terms of the sets of reamers needed overall, the reamer design allows the surgeon to select, for instance in pre-operative planning the likely size of implant that will be needed to fit the femur of the patient. In use, irrespective of which of the different types of surgical implant end up being used, the a first reamer tray may be opened and distal reamers from it will be used. The surgeon will decide partway through the overall procedure whether to continue with the planned use of the first monoblock type of surgical implant or whether to switch to the second/modular type. If the first type is still to be used, then only a second tray of proximal reamers will be opened and used; further trays will remain unopened and unused. If the swap to the second/modular type is to be made, then only the will the tray 20 with the different type of proximal reamers 26 will be opened and used; the second tray will remain unopened and unused.

An example of how the reamers may overlap in their roles in a more partial sense, but still with similar benefits, is also to be seen in Figure 11. Each block in Figure 11 may represent a tray. For example, the St/L Distal Reamers tray and the XL Distal Reamers tray can both be used in the distal reaming stages and yet allow the surgeon to readily chose between use of the Monobloc Core tray as the first intended type of implant to be used or swap to the Modular Core tray if the second type of implant is needed. If the Monobloc Core tray is to be used, then the L/XL Proximal Reamers tray would be used. If the swap to the Modular Core tray is to be made, then the Mod. Proximal Reamers tray is used. The overlap in reamer configurations is partial as the Short Distal Reamers tray would lead to the Monobloc Core tray use (further reaming could be an option to move to the Modular Core tray use), but still only require the use of the Sh/St Proximal Reamers tray to achieve the proximal reaming stages. Similarly, the XXL Distal Reamers tray would lead to the Modular Core tray use, but the Mod Proximal Reamer tray would be all that is needed if the XXL Distal Reamers tray or XXXL Distal Reamers tray is used for the distal reaming stages.

Unless defined otherwise all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently described subject matter pertains.

Where a range of values is provided, for example, concentration ranges, percentage ranges, or ratio ranges, it is understood that each intervening value, to the tenth of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the described subject matter. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and such embodiments are also encompassed within the described subject matter, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the described subject matter.

It should be understood that the terms "a" and "an" as used above and elsewhere herein refer to "one or more" of the enumerated components. It will be clear to one of ordinary skill in the art that the use of the singular includes the plural unless specifically stated otherwise. Therefore, the terms “a,” “an” and “at least one” are used interchangeably in this application.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as size, weight, reaction conditions and so forth used in the specification and claims are to the understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present subject matter. At the very least, and not as an attempt to limit 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.

Throughout the application, descriptions of various embodiments use "comprising" language; however, it will be understood by one of skill in the art, that in some instances, an embodiment can alternatively be described using the language "consisting essentially of or "consisting of."

The present subject matter being thus described, it will be apparent that the same may be modified or varied in many ways. Such modifications and variations are not to be regarded as a departure from the spirit and scope of the present subject matter, and all such modifications and variations are intended to be included within the scope of the following claims.

Claims

1. A set of surgical reamers comprising: a plurality of distal reamers each having a cutting portion extending between a distal tip and a proximal end, the distal reamers including at least a first group of differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length by a modular increment value; a plurality of proximal reamers each having a cutting portion extending between a distal end and a proximal end, the proximal reamers including at least a first group with differing diameter and common first axial length and a second group with differing diameter and common second axial length greater than the first axial length of the proximal reamers by said modular increment value; the distal and proximal reamers configured such that proximal ends of the first group of distal reamers are positionable adjacent the distal ends of the first and second groups of proximal reamers and the distal ends of the second group of proximal reamers are positionable adjacent the proximal ends of the first and second groups of distal reamers such that respective combined axial lengths of the cutting portions of: the first group of proximal reamers plus the first group of distal reamers; the second group of proximal reamers plus the first group of distal reamers, and the second group of proximal reamers plus the second group of distal reamers differ from one another by at least one said modular increment value.

2. The set as claimed in claim 1 wherein: a diameter of the distal end of the cutting portion of at least one of the first group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the first group of distal reamers; a diameter of the distal end of the cutting portion of at least one of the second group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the first group of distal reamers; and a diameter of the distal end of the cutting portion of at least one of the second group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the second group of distal reamers.

3. The set as claimed in claims 1 or 2 wherein the distal reamers comprise an increase in diameter according to a tapered profile between the distal tip and the proximal end of each respective cutting portion.

4. The set as claimed in any preceding claim wherein the proximal reamers comprise an increase in diameter according to a tapered profile between the distal end and the proximal end of each respective cutting portion.

5. The set as claimed in any preceding claim wherein the respective cutting portions comprise flutes extending at least axially and/or circumferentially along each respective cutting portion.

6. The set as claimed in any preceding claim wherein the set of surgical reamers comprise at least three groups of distal reamers comprising the first group, the second group and a third group of differing diameter and common axial length that is greater than the axial length of the second group of distal reamers by said modular increment value.

7. The set as claimed in any preceding claim wherein the set of surgical reamers comprise at least three groups of proximal reamers comprising the first group, the second group and a third group of differing diameter and common axial length, each of the reamers within the third group comprising a cutting portion having a uniform diameter extending axially between the distal and proximal ends of each cutting portion.

8. The set as claimed in claim 7 wherein the distal reamers further comprise a fourth group and a fifth group each respective group having a plurality of reamers with differing diameters and respective common axial lengths wherein: the fourth group of reamers each comprise a cutting portion having an axial length that is greater than the axial length of the cutting portion of each of the reamers of the third group by said modular increment value; and the fifth group of reamers each comprise a cutting portion having an axial length that is greater than the axial length of the cutting portion of each of the reamers of the fourth group by said modular increment value.

9. The set as claimed in claim 8 wherein a diameter of the distal end of the cutting portion of at least one of the third group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the fourth group and/or the fifth group of distal reamers.

10. The set as claimed in claims 6 and 7 wherein a diameter of the distal end of the cutting portion of at least one of the reamers of the third group of proximal reamers is equal to or approximately equal to a diameter of the proximal end of the cutting portion of at least one of the reamers of the third group of distal reamers.

11. The set as claimed in claim 7 wherein an axial length of the cutting portion of each of the reamers of the third group of proximal reamers is equal to or approximately equal to the axial length of the cutting portion of reamers of the second group of proximal reamers wherein a diameter of the cutting portions of the second group of proximal reamers increases according to a tapered profile from the distal ends to the proximal ends of each respective cutting portion.

12. The set as claimed in any preceding claim wherein each of the groups of proximal and distal reamers comprise in a range 2 to 16, 4 to 14, 4 to 12 or 8 to 12 reamers of different diameter.

13. The set as claimed in any preceding claim wherein a diameter of the proximal ends of the respective cutting portions of the distal reamers is in a range 10 to 24 mm or 12 to 22 mm.

14. The set as claimed in any preceding claim wherein a diameter of the distal ends of the respective cutting portions of the proximal reamers is in a range 10 to 24 mm or 12 to 22 mm.

15. The set as claimed in any preceding claim wherein an axial length of the reamers of the second group of proximal reamers is in a range 80 to 110 mm, 85 to 105 mm or 90 to 100 mm.

16. The set as claimed in any preceding claim wherein an axial length of the reamers of the first group of distal reamers is in a range 125 to 155 mm, 130 to 150 mm or 135 to 145 mm.

17. The set as claimed in any preceding claim wherein an axial length of the reamers of the first group of proximal reamers is in a range 30 to 60 mm, 35 to 55 mm or 40 to 50 mm.

18. The set as claimed in any preceding claim wherein an axial length of the reamers of the second group of distal reamers is in a range 175 to 205 mm, 180 to 200 mm or 185 to 195 mm.

19. The set as claimed in any preceding claim wherein the modular increment value is in a range 35 to 65 mm, 40 to 60 mm or 45 to 55 mm.

20. Surgical apparatus to prepare a bone site to receive an implant comprising: a set of surgical reamers as claimed in any preceding claim; and a first implant having a stem, a neck and a head or head mount connected to the shaft via the neck, the implant having a pre-defined gauge value corresponding to a diameter at a pre-defined axial position on the stem; wherein at least one reamer of at least one of the first and second group of distal reamers comprise a cutting portion having a gauge value corresponding to a diameter at a pre-defined axial position on the cutting portion being equal to the gauge value of the implant to provide at least one gauge matched distal reamer.

21. The apparatus as claimed in claim 20 wherein the pre-defined axial position on the cutting portion of the distal reamer is at the proximal end of the cutting portion.

22. The apparatus as claimed in claim 20 wherein with the implant positioned side- by-side to the matched distal reamer and with the cutting portion and the stem aligned parallel or nearly parallel and a distal tip of the stem coaxially aligned with the distal tip of the cutting portion of the distal reamer, an axial separation distance between an axial position at a centre of the head and the proximal end of the cutting portion is a pre-defined set distance.

23. The apparatus as claimed in claim 22 comprising: a second implant having a stem, a neck and a head or head mount connected to the shaft via the neck, the implant having a pre-defined gauge value corresponding to a diameter at a pre-defined axial position on the stem; wherein at least one reamer of at least one of the first and second group of distal reamers comprise a cutting portion having a gauge value corresponding to a diameter at a pre-defined axial position on the cutting portion being equal to the gauge value of the implant to provide at least one gauge matched distal reamer; wherein an axial length of the second implant is greater than the first implant and the second gauge matched distal reamer comprises an axial length greater than that of the first gauge matched distal reamer.

24. The apparatus as claimed in claim 23 wherein the pre-defined axial position on the cutting portion of the distal reamer is at the proximal end of the cutting portion.

25. The apparatus as claimed in claim 24 wherein with the implant positioned side- by-side to at least one gauge matched distal reamer and with the cutting portion and the stem aligned parallel or nearly parallel and a distal tip of the stem coaxially aligned with the distal tip of the cutting portion of the distal reamer, an axial separation distance between an axial position at a centre of the head and the proximal end of the cutting portion is a pre-defined set distance.

26. A surgical method of preparing a surgical site and implanting an implant comprising: selecting a distal reamer from the first and second group of distal reamers according to claim 1 by matching a pre-defined gauge value of an implant to be implanted with a pre-defined gauge value of one of the distal reamers of the first and second groups; cutting material from a distal location at a surgical site of a patient using the selected gauge matched distal reamer; selecting a proximal reamer from one of the first and second groups of proximal reamers based on an axial length and/or the gauge value of the implant to be implanted such that a combined axial length of the cutting portions of the selected distal and proximal reamers is less than an axial length of the implant measured between a distal tip of a stem of the implant and a centre point of a head of the implant; cutting material from a proximal location of the surgical site using the selected proximal reamer; and implanting the implant at the surgical site in the patient.

27. The method as claimed in claim 26 when dependent on claim 7 wherein after the step of cutting material using the distal reamer, assessing a state or condition of the material at the surgical site and selecting one of the first, second or third group of proximal reamers prior to the step of cutting material with the selected proximal reamer.

28. The method as claimed in claim 27 wherein: if a proximal reamer is selected from group one or two, the implant to be implanted is a unitary body implant; or if a proximal reamer is selected from group three of the proximal reamers, the implant is a modular implant having a head that is detachably mountable to the stem; such that the selected distal reamer is configured for sequential use to cut material at the surgical site with either the first and second or the third group of proximal reamers.