WO2018102879A1

WO2018102879A1 - A boot arrangement and method for determining leg length discrepancy intra-operatively and post-operatively for hip surgery using said boot arrangement

Info

Publication number: WO2018102879A1
Application number: PCT/AU2017/051352
Authority: WO
Inventors: Jonathan Peter CABOT
Original assignee: Cabot Jonathan Peter
Priority date: 2016-12-09
Filing date: 2017-12-08
Publication date: 2018-06-14

Abstract

A boot arrangement for determination of leg length discrepancy intra-operatively and post-operatively for hip surgery having a boot that includes an ankle and/or heel aperture to provide access for a surgeon to engage a bony feature around the ankle and/or heel of a patient wearing the boot such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the ankle or heel of each leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

Description

A BOOT ARRANGEMENT AND METHOD FOR DETERMINING LEG LENGTH DISCREPANCY INTRA-OPERATIVELY AND POST-OPERATIVELY FOR HIP

SURGERY USING SAID BOOT ARRANGMENT

FIELD OF THE INVENTION

[001 ] This invention relates to a simple and unique arrangement and method for being able to determine leg length discrepancy of a patient undergoing hip surgery and more particularly a method and arrangement that will allow both intra-operative and post-operative determination of any leg length discrepancy of the patient undergoing hip surgery, by allowing the surgeon access to bony landmarks that generally would be inaccessible using conventional equipment and apparatus used in carrying out hip surgery.

BACKGROUND ART DISCUSSION

[002] Generally hip surgery, wherein the ball and socket of the hip joint are replaced with artificial implants, requires that the patient's foot be placed within a boot that is connected to a traction device so that when the patient lies upon a surgical table during the hip replacement surgery, the traction device is designed to pull on the patient's leg to open up the hip joint.

[003] When the hip joint is surgically opened, various surgical procedures

undertaken by the surgeon on both the thigh bone and the socket of the pelvis allows part of the existing bone structure of the patient's hip to be replaced with artificial implants including a metal plate positioned within the open socket of the pelvis and a ball placed on top of the thigh bone.

[004] Depending on the positioning and size of the artificial implants introduced into both the thigh bone and the socket of the pelvis, will have a direct determination on the length of the legs of the patient undergoing hip surgery.

[005] While it is paramount that the artificial implant of the ball and socket to complete the hip replacement provide stability, in that there should be no subsequent dislocation of the artificial ball mounted to the thigh bone from the socket of the pelvis, this stability of the artificial implants cannot be done at the expense of inadvertently making the length of one leg of the patient discrepant with the other leg of the patient after the hip surgery is completed.

[006] As the surgeon endeavours to reach that requisite stability between the artificial implants of the ball and socket through the appropriate size selection of the implants and/or bone resection, she or he must be continually observant to the potential of altering the length of the patient's leg.

[007] Once the surgeon feels that there is stability between the artificial implants used in the hip replacement, it would be therefore be advantageous while still intra- operatively completing the hip surgery when the incision is still open to also make sure that there is no discrepancy in the lengths of the legs of the patient.

[008] One way in which surgeons conveniently determine leg length discrepancy is to rely upon bony landmarks in the foot where, for example, a surgeon could compare the ankle bones of each of the patients legs when appropriately aligned and extended by placing his or her thumbs directly over each ankle or thereabouts seeing if the thumbs are at an even level.

[009] Nonetheless a problem with hip replacement surgery that relies upon the boot connected to the traction device introduced above, is that as the foot of the patient is encapsulated within a boot that is often also padded, it no longer becomes possible for the surgeon to access these bony features on each foot such as in and around the ankle or heel to make the alignment comparison between the thumbs and/or fingers of the surgeon to establish whether leg length discrepancies exist for the patient.

[010] Accordingly it would be particularly advantageous if it is was possible to, for the most part, rely upon conventional surgical instrumentation, apparatus and techniques for hip replacement surgery that requires a boot connected to the traction device, but still allow the surgeon the opportunity of being able to access bony features upon the foot, normally inaccessible and encapsulated in the boot. [01 1 ] As it stands presently, surgeon's selection of the size of the implants in order to improve the artificial ball and socket stability, may adversely affect the length of one leg to the other of the patient and without a non-intrusive way of conveniently measuring leg length using conventional hip replacement surgery apparatus, should the surgeon want to determine whether leg lengths are in fact symmetric he or she will need to wait until the hip joint is surgically closed so that the patient can be appropriately repositioned for more conventional leg length measuring.

[012] Unfortunately, carrying out leg measurements post-operatively means that if leg length discrepancy is established then the patient is often left with no other choice but to undergo further hip replacement surgery or be restricted from being able to carry out certain activities to prevent problems that may arise from the discrepancy between the length of one leg with the other, if the integrity of the artificial implants of the hip replacement are to be maintained.

[013] It is therefore an object of this invention to make available an arrangement and method for being able to conveniently and simply determine leg length discrepancy both intra-operatively and post-operatively, while the hip joint remains surgically opened for the surgeon by providing access to bony features of the foot of the patient, albeit conventional hip replacement equipment and techniques are being employed, thereby allowing the surgeon the ability to utilise these bony features within the foot of each of the legs of the patient in order to determine if there is any discrepancy in the lengths of the legs of the patient undergoing hip surgery.

[014] Further objects and advantages of the invention will become apparent from a complete reading of the following specification.

SUMMARY OF THE INVENTION

[015] In one form of the invention there is provided a boot arrangement when used for determination of leg length discrepancy intra-operatively and post-operatively for hip surgery, said boot arrangement including: [016] a boot, said boot adapted to receive a foot of a patient undergoing hip surgery wherein the boot is fastenable to a traction device configured to pull on a patient's leg, in which the foot of said patient's leg has been received in said boot, so as to open a hip joint between a thigh bone and a socket of a pelvis of the patient undergoing hip surgery;

[017] said boot including an ankle aperture providing access for at least one hand digit of a surgeon undertaking the hip surgery upon the patient, so as to engage a bony feature on or around an ankle of the patient such that said engagement with the bony feature on or around the ankle of the or each hand digit of the surgeon provides an ability of the surgeon to align a corresponding hand digit or digits of the surgeon upon a bony feature on or around the ankle of another leg of the patient undergoing hip surgery such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the ankle of the leg and the other leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

[018] In preference the hand digit is a thumb.

[019] In preference the bony feature on or around the ankle includes a medial malleolus at a side of the ankle, wherein thumbs on each hand of the surgeon undertaking the hip surgery are able to access the medial malleolus through the ankle aperture of the boot for aligning of the thumbs to provides a determination of leg length discrepancies.

[020] In a further form of the invention there is provided a boot arrangement when used for determination of leg length discrepancy intra-operatively and postoperatively for hip surgery, said boot arrangement including:

[021 ] a boot, said boot adapted to receive a foot of a patient undergoing hip surgery wherein the boot is fastenable to a traction device configured to pull on a patient's leg, in which the foot of said patient's leg has been received in said boot, so as to open a hip joint between a thigh bone and a socket of a pelvis of the patient undergoing hip surgery; [022] said boot including an heel aperture providing access for at least one hand digit of a surgeon undertaking the hip surgery upon the patient, so as to engage a bony feature on or around an heel of the patient such that said engagement with the bony feature on or around the heel of the or each hand digit of the surgeon provides an ability of the surgeon to align a corresponding hand digit or digits of the surgeon upon a bony feature on or around the heel of another leg of the patient undergoing hip surgery such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the heel of the leg and the other leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

[023] In preference the hand digit for access to a bony feature on or around the heel is a finger, fingers and/or thumb.

[024] In preference the bony feature accessible through the heel aperture is the heel bone or a calcaneus of the foot.

[025] In a further form of the invention the boot adapted to receive the foot of the patient undergoing hip surgery, wherein the boot is fastenable to a traction device, includes both the ankle aperture providing access for at least one hand digit of the surgeon undertaking the hip surgery upon the patient to engage a bony feature on or around the ankle, and the heel aperture providing access for at least one hand digit of the surgeon undertaking the hip surgery upon the patient to engage a bony feature on or about the heel of the patient undergoing hip surgery.

[026] Advantageously, this invention has been able to rely upon, for the most part, existing surgical techniques, instrumentation and apparatus that notably includes a boot that secures the patient's foot therein wherein the boot is then fastened to a traction device which is importantly responsible to pull on the leg of the patient so as to assist in opening up the hip joint so that when the patient is surgically opened the top of the thigh bone and the socket of the pelvis can be shaped so that the artificial implants can be appropriately introduced as a stable hip joint replacement. [027] Advantageously for this invention, as the boot that engages to the

conventional traction device includes the ankle aperture, heel aperture or both, this means that while the hip joint remains surgically opened, as the surgeon makes the selection and adjustment of the artificial implants to maximize stability during surgery, the surgeon is still able to determine whether the leg lengths remain symmetric by way of not being inhibited from accessing bony features on or around the ankle, heel or both, so that the thumbs and/or fingers on the respective hands of the surgeon can be used on these bony features to make sure that there are no leg length

discrepancies of the patient resulting from the hip surgery.

[028] If the artificial implants introduced into the hip joint during surgery have altered the leg length of the patient, then as the surgeon has the ability to make the simple determination of any leg length discrepancy through the access available via the ankle, heel or both apertures of the boot, then the problem can be identified while the hip joint is still surgically opened, so replacement of larger/smaller or longer/shorter implants in the bone associated with the hip joint can be made to rectify the problem while the hip surgery is still ongoing.

[029] Hence the unique and inventive way of introducing the ankle, heel or both apertures into the boot prevents post-operative leg length discrepancies to the patient which avoids the patient having to undergo subsequent hip surgery or be restricted from undertaking certain activities to prevent problems with artificial implants used in the hip replacement.

[030] In preference the boot arrangement includes a second boot, wherein the second boot is adapted to receive a foot of another leg of the patient undergoing hip surgery wherein the second boot is fastenable to a traction device, wherein the traction device is configurable to pull on the patient's another leg to open a hip joint between a thigh bone and a socket of the pelvis of the another leg of the patient undergoing hip surgery, wherein said second boot includes an ankle aperture

eatable about an ankle area of the foot of the another leg of the patient, a heel aperture eatable about a heel area of the foot of the another leg of the patient or both an ankle aperture and a heel aperture beatable respectively about an ankle area and heel area of the foot of the another leg of the patient. [031 ] In preference the arrangement further includes a cushion member, wherein the cushion member is positionable around a crotch of the patient while the patient is lying on a surgical table undergoing the hip surgery, wherein the cushion member includes a cushioning position for cushioning and stability of the patient during the hip surgery and a non-cushioning position, wherein the non-cushioning position is characterised by allowing the leg and the another leg of the patient to be drawn together without substantial impact upon said cushion member.

[032] In preference, in one embodiment of the invention the cushion member in the non cushioning position is adapted to be retracted away from the crotch area of the patient undergoing hip surgery when the surgeon requires to make a determination of leg length discrepancy during hip surgery by bringing the respective legs of the patient together without impacting upon the cushion member.

[033] In an alternative embodiment of the invention the cushion member in the cushioning position includes a main body having a width longer than said cushion lenght so that the cushion member is adapted to be rotatable such that when then patient undergoing hip surgery requires cushioning to the crotch, the body structure of the cushion member is rotatable to provide for a broad length of the cushion member engagement with the crotch area of the patient and wherein when the legs of the patient are to be drawn together for a determination on leg length discrepancy of the patient while the hip joint remains surgically opened during the hip surgery, the cushion member is rotatable to configure the shorter width of the cushion member between the legs of the patient, to allow the respective legs of the patient to be drawn together without substantial impact upon the cushion member.

[034] In preference the arrangement further includes a resilient sheath or film across the openings of the ankle aperture, heel aperture or both the ankle and heel apertures.

[035] In preference the resilient sheath or film is transparent.

[036] While the resilient sheath or film across the ankle and/or heel aperture openings provides an environmental barrier to maintain a sterile environment, there is no impact or impedance upon the fingers or thumbs of the surgeon as the surgeon seeks to engage the respective bony features on or around the ankle or the heel.

[037] In order now to describe the invention in greater detail a series of preferred embodiments will be presented with the assistance of the following illustrations and accompanying text.

BRIEF DESCRIPTION OF THE DRAWINGS

[038] Figures 1 a, 1 b and 1 c show a perspective, side and front views of the boot of the arrangement for determining leg length discrepancy intra-operatively and postoperatively for hip surgery in a preferred embodiment of this invention.

[039] Figures 2a, 2b and 2c show schematic representations of the use of the arrangement for this invention in a preferred embodiment as the surgeon determines leg length discrepancy while the hip joint remains surgically opened during hip surgery.

[040] Figures 3a and 3b show a further preferred embodiment of the invention schematically utilising an alternative cushion member.

DETAILED DESCRIPTION OF THE DRAWINGS

[041 ] Referring to the drawings now in greater detail wherein the arrangement includes a boot shown generally as (10).

[042] The boot includes the main body structure (12).

[043] The main body structure (12) encloses padding (19) to comfortably rest the foot of the patient within the boot wherein the boot (10) is fastenable through fastening straps (20).

[044] In this preferred embodiment the boot (10) includes a general access opening (18) where the toes of the foot (not shown) of the patient are extendable out therefrom if required. [045] For the most part these features just introduced in relation to the boot (10) are conventional features used as part of the standard traction boot required during hip replacement surgery.

[046] What makes this boot (10) significantly different and advantageous over prior art boots used in hip replacement surgery is that the boot (10) includes additional openings, which in this preferred embodiment, include both the ankle aperture (13) providing for open access area (14) and the heel aperture (15) providing for open access area (16).

[047] While the preferred embodiment includes the two apertures, that being the ankle aperture (13) and the heel aperture (15), other preferred embodiments may require just one of these respective aperture (13) and (15) openings.

[048] As seen in the schematic representations shown both in Figures 2a, 2b and 2c and 3a and 3b, the boot (10) has been received upon the foot of both legs (26), (28) of the patient (22) undergoing hip surgery.

[049] While the preferred embodiment shows the boot (10) being received upon each foot (27), (29) of the legs (26), (28) of the patient undergoing hip surgery, in many instances involving hip replacement surgery there is not the requirement to place both legs of the patient undergoing hip surgery connected to the traction device.

[050] Hence while the Figures 2a, 2b, 2c, 3a and 3b show the arrangement wherein the boot is received upon the foot (27), (29) of both legs (26) and (28) of the patient (22) undergoing hip surgery, the invention in its broadest sense is not restricted to the requirement of having the boot (10) upon both feet of the patient (27), (29) of both legs (26) and (28) of the patient (22) undergoing hip surgery. In many instances the boot (10) may only be applied to a single foot of the patient.

[051 ] The boot (10) includes block type feature (17) which generically represents a structural member which allows the boot (10) to engage with the traction device shown generally as (32) in Figures 2a, 2b and 2c. [052] As noted, the structural member (17) which allows the mounting of the boot (10) to the traction device (32) is away from the heel section of the boot (10) which thereby allows the boot (10) to include the heel aperture (15) providing for the opening (16) which would allow the fingers and/or thumbs of the surgeon undertaking the hip surgery to engage that heel area in order to access the relevant bony features on or around the heel which can assist the surgeon in making comparisons by aligning fingers and/or thumbs of the surgeon up to establish leg length discrepancy of the patient, albeit the hip joint remains surgically opened.

[053] The applicant also wishes to advise that the actual means and mechanism of mounting the boot (10) to the traction device (32) does not form part of this invention per se, nor the actual operation of the traction device, which as introduced above in the general description of the summary of the invention, is responsible for providing the pull on the leg of the patient so as to open up the hip joint which then becomes accessible once the joint is surgically opened.

[054] The purpose of this invention is to allow surgeons to perform hip replacement surgery using, for the most part, conventional techniques, instrumentation and apparatus, however by uniquely introducing the ankle aperture (13) and/or the heel aperture (15) to the boot (10) this means that despite the fact that the hip joint is surgically opened, the surgeon will still be able to utilise those conventional leg length discrepancies means of placing hand digits directly over bony features around the ankle or heel to carry out the leg length measurement.

[055] In Figures 2a, 2b and 2c, the patient (22) rests upon a surgical table (24), the legs (26) and (28) of the patient (22) are both stabilized by a cushioning member (30) around the crotch area (32) of the patient (22).

[056] Feet (27) and (29) of legs (26) and (28) of the patient (22) have been received into respective boots (10), while not shown in Figures 2, 2b and 2c, the patient (22) is considered to be currently undergoing hip surgery and the hip joint is surgically opened however the surgeon (34) wishes to make a determination as to whether or not there is any leg length discrepancy, perhaps after concluding initially that the appropriate artificial implants of the ball and socket are stable. [057] In order to make this determination intra-operatively, the surgeon (34) shown by way of arrows (37) and (37) in Figures 2b and 2c is able to bring the legs (26) and (28) of the patient (22) together.

[058] In the embodiment shown in Figures 2a, 2b and 2c the cushioning member (30) is a retractable device.

[059] Therefore in Figure 2a the cushion member (30) is configured around the crotch area (32) of the patient (22) to provide the requisite comfort and stability to the patient (22) as they lie upon the surgical table (24).

[060] When the surgeon (34) is required to make a determination on leg length discrepancy, the cushion member (30) shown by way of arrow (35) can be retracted away as best seen in Figure 2b.

[061 ] With the cushion member (30) is in the retracted positioning there is no impact upon the legs (26) and (28) of the patient (22) as they are drawn together thereby allowing the surgeon to comfortably grasp the legs (26) and (28) of the patient (22) and pull them generally straight.

[062] As best seen in Figure 2c the surgeon (34) places his or her hands (36) and (38) on opposing boots (10) wherein the respective thumbs (40) and (42) on each of the hands (36) and (38) of the surgeon (34) are able to access the bony features around the ankle bones through the opening (14) provided for by the ankle aperture (13) of the boot (10).

[063] Accordingly the surgeon (34) is able to compare the ankle bones, notably the medial malleolus at the side of the ankle by placing thumbs (40) and (42) of the hands (36) and (38) of the surgeon directly over this bony feature on each foot (29) and (27) to see if the thumbs (40) and (42) are at an even level, thereby providing a determination if there is any discrepancy between the leg lengths (26) and (28) of the patient (22).

[064] While Figures 2a, 2b and 2c for the most part illustrate the surgeon (34) accessing the ankle aperture (13) of the boot (10) through the access opening (14), in alternative embodiments the heel aperture (15) and the associated opening (16) can be utilised by the surgeon (34) in order to access various bony features within the foot around the heel which can be used to establish the existence, or lack thereof, of any leg length discrepancies of the patient (22).

[065] Figures 3a and 3b illustrate an alternative embodiment of the cushion member (30) as shown in Figures 2a to 2c.

[066] In Figures 3a and 3b the cushion member is referenced as (50).

[067] The body structure of the cushion member (50) in Figures 3a and 3b is such that when the patient requires the cushion member (50) to provide cushion stability around the crotch area (32) of the patient (22), the broad length as shown in Figure 3a is longer than the width shown in Figure 3b when the cushion member (50) is rotated shown by way of arrow (52).

[068] Effectively Figure 3a shows the cushion member (50) in the cushioning position and when the surgeon is required to bring the legs (26) and (28) of the patient (22) together, shown by way of arrows (54) and (56) in Figure 3b, so that the thumbs (40) and (42) of the hands (36) and (38) of the surgeon (34) can be aligned, as in the case of Figure 2c, the legs (26) and (28) of the patient (22) come together without any substantial impact or poor orientation caused by the cushion member (50).

Claims

1 . A boot arrangement when used for determination of leg length discrepancy intra- operatively and post-operatively for hip surgery, said boot arrangement including: a boot, said boot adapted to receive a foot of a patient undergoing hip surgery wherein the boot is fastenable to a traction device configured to pull on a patient's leg, in which the foot of said patient's leg has been received in said boot, so as to open a hip joint between a thigh bone and a socket of a pelvis of the patient undergoing hip surgery; said boot including an ankle aperture providing access for at least one hand digit of a surgeon undertaking the hip surgery upon the patient, so as to engage a bony feature on or around an ankle of the patient such that said engagement with the bony feature on or around the ankle of the or each hand digit of the surgeon provides an ability of the surgeon to align a corresponding hand digit or digits of the surgeon upon a bony feature on or around the ankle of another leg of the patient undergoing hip surgery such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the ankle of the leg and the another leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

2. The boot arrangement of claim 1 wherein the hand digit is a thumb.

3. The boot arrangement of claim 2 wherein the bony feature on or around the ankle includes a medial malleolus at a side of the ankle, wherein the thumb of the surgeon undertaking the hip surgery is able to access the medial malleolus through the ankle aperture of the boot .

4. A boot arrangement when used for determination of leg length discrepancy intra- operatively and post-operatively for hip surgery, said boot arrangement including: a boot, said boot adapted to receive a foot of a patient undergoing hip surgery wherein the boot is fastenable to a traction device configured to pull on a patient's leg, in which the foot of said patient's leg has been received in said boot, so as to open a hip joint between a thigh bone and a socket of a pelvis of the patient undergoing hip surgery; said boot including a heel aperture providing access for at least one hand digit of a surgeon undertaking the hip surgery upon the patient, so as to engage a bony feature on or around a heel of the patient such that said engagement with the bony feature on or around the heel of the or each hand digit of the surgeon provides an ability of the surgeon to align a corresponding hand digit or digits of the surgeon upon a bony feature on or around the heel of another leg of the patient undergoing hip surgery such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the heel of the leg and the another leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

5. The boot arrangement of claim 1 wherein the hand digit for access to a bony feature on or around the heel is a finger, fingers and/or thumb.

6. The boot arrangement of claim 5 wherein the bony feature accessible through the heel aperture is a heel bone or a calcaneus of the foot.

7. The boot arrangement of claim 1 wherein the boot further includes a heel aperture providing access for at least one hand digit of the surgeon undertaking the hip surgery upon the patient, so as to engage a bony feature on or around a heel of the patient such that said engagement with the bony feature on or around the heel of the or each hand digit of the surgeon provides an ability of the surgeon to align a corresponding hand digit or digits of the surgeon upon a bony feature on or around the heel of another leg of the patient undergoing hip surgery such that the aligning of the or each hand digit of the hands of the surgeon upon the respective bony features on or around the heel of the leg and the another leg of the patient enables a determination of length discrepancy between legs of the patient undergoing hip surgery.

8. The boot arrangement of claim 1 or claim 7 wherein the boot arrangement further includes a second boot, wherein the second boot is adapted to receive a foot of another leg of the patient undergoing hip surgery wherein the second boot is fastenable to a traction device, wherein the traction device is configurable to pull on the patient's another leg to open a hip joint between a thigh bone and a socket of the pelvis of the another leg of the patient undergoing hip surgery, wherein said second boot includes an ankle aperture eatable about an ankle area of the foot of the another leg of the patient, a heel aperture locatable about a heel area of the foot of the another leg of the patient or both an ankle aperture and a heel aperture locatable respectively about an ankle area and heel area of the foot of the another leg of the patient.

9. The boot arrangement of claim 8 further including a cushion member, wherein the cushion member is positionable around a crotch area of the patient while the patient is lying on a surgical table undergoing the hip surgery, wherein the cushion member includes a cushioning position for cushioning and stability of the patient during the hip surgery and a non-cushioning position, wherein the non-cushioning position is characterised by allowing the leg and the another leg of the patient to be drawn together without substantial impact upon said cushion member.

10. The boot arrangement of claim 9 wherein the cushion member in the non cushioning position is adapted to be retracted away from the crotch area of the patient undergoing hip surgery when the surgeon requires to make a determination of leg length discrepancy during hip surgery.

1 1 . The boot arrangement of claim 9 wherein the cushion member in the cushioning position includes a main body having a width longer than said cushion main body length.

12. The boot arrangement of claim 1 1 wherein the cushion member is rotatable.

13. The boot arrangement of claim 1 wherein the cushion member includes a resilient sheath or film across the ankle aperture.

14. The boot arrangement of claim 4 wherein the cushion member includes a resilient sheath or film across the heel aperture.

15. The boot arrangement of claim 13 or claim 14 wherein the resilient sheath or film is transparent.