Patent Application
20240207067
The present disclosure relates generally to orthopaedic instruments, and particularly to orthopaedic instruments for use in a direct anterior approach hip replacement surgical procedure.
Joint arthroplasty is a well-known surgical procedure by which a diseased and/or damaged natural joint is replaced by a prosthetic joint. The prosthetic joint may include a prosthesis that is implanted into one or more of the patient's bones. Many hip prostheses include a femoral prosthesis that is implanted into a patient's femur. A femoral prosthesis typically includes an elongated stem component that is cemented in the medullary canal of the patient's femur and a spherically-shaped head component that bears against the patient's acetabulum or a prosthetic replacement acetabular cup.
Some hip replacement procedures are performed using a direct anterior approach. When using the direct anterior approach, the surgeon does not have line-of-sight access to the intramedullary canal of the patient's femur. This limited access and visibility makes it difficult for the surgeon to install certain components, such as cemented femoral stem components, using instruments designed for other approaches (e.g., a posterior approach).
According to one aspect, an orthopaedic surgical instrument for implanting a cemented femoral stem component during a direct anterior approach orthopaedic hip replacement surgical procedure on a patient's femur includes a stem insertion instrument. The stem insertion instrument includes a handle positioned on a proximal end of the stem insertion instrument and an insertion prong positioned on a distal end of the stem insertion instrument. The insertion prong is sized and shaped to be received into an insertion aperture formed in a lateral shoulder of the femoral stem component. The insertion instrument also includes an elongated shaft extending distally away from the handle to the insertion prong and a depth stop rotatably secured to the elongated shaft. The depth stop includes a guide arm extending away from the elongated shaft.
In an embodiment, the depth stop includes a hub rotatably coupled to the elongated shaft and an extension arm extending distally away from the hub and transitioning to an elbow. In such an embodiment, the guide arm extends away from the elbow.
In an embodiment, the insertion prong extends in the superior/inferior direction, and the elongated shaft is angled in the medial direction relative to the insertion prong.
In another embodiment, a longitudinal axis of the insertion prong and a longitudinal axis of the elongated shaft define an offset angle, with such an offset angle being between 15-45 degrees.
In yet another embodiment, a longitudinal axis of the insertion prong and a longitudinal axis of the guide arm define a guide angle, with such a guide angle being between 40-45 degrees.
In an embodiment, the depth stop includes a second guide arm extending away from the elongated shaft from an opposite side of the elongated shaft as the other guide arm. In such an embodiment, the two guide arms may rotate relative to the elongated shaft independently of one another.
According to another aspect, an orthopaedic surgical system for use in a direct anterior approach orthopaedic hip replacement surgical procedure on a patient's femur includes a cemented femoral stem component and a stem insertion instrument. The cemented femoral stem component includes a proximal body that has a lateral shoulder. The lateral shoulder has an insertion aperture formed therein. The femoral stem component also include an elongated neck extending medially from the proximal body, and a tapered stem extending inferiorly away from proximal body. The stem insertion instrument includes a handle positioned on a proximal end of the stem insertion instrument, and an insertion prong positioned on a distal end of the stem insertion instrument. The insertion prong is sized and shaped to be received into the insertion aperture formed in the lateral shoulder of the femoral stem component. The insertion instrument also includes an elongated shaft extending distally away from the handle to the insertion prong, and a depth stop rotatably secured to the elongated shaft. The depth stop includes a guide arm extending away from the elongated shaft. When the insertion prong of the stem insertion instrument is positioned in the insertion aperture of the femoral stem component the depth stop is rotatable between a guide position in which the guide arm is positioned in contact with the femoral stem component, and an access position in which the guide arm is spaced apart from the femoral stem component.
In an embodiment, the guide arm is positioned in contact with an anterior side of the femoral stem component when the depth stop is positioned in its guide position.
In an embodiment, the guide arm is positioned in contact with an anterior side of the proximal body of the femoral stem component when the depth stop is positioned in its guide position.
In an embodiment, the depth stop includes a hub rotatably coupled to the elongated shaft and an extension arm extending distally away from the hub and transitioning to an elbow. In such an embodiment, the guide arm extends away from the elbow.
In an embodiment, the insertion prong extends in the superior/inferior direction, and the elongated shaft is angled in the medial direction relative to the insertion prong.
In another embodiment, a longitudinal axis of the insertion prong and a longitudinal axis of the elongated shaft define an offset angle, with such an offset angle being between 15-45 degrees.
In yet another embodiment, a longitudinal axis of the insertion prong and a longitudinal axis of the guide arm define an guide angle, with such a guide angle being between 40-45 degrees.
In an embodiment, the depth stop includes a second guide arm extending away from the elongated shaft from an opposite side of the elongated shaft as the other guide arm. In such an embodiment, when the insertion prong of the stem insertion instrument is positioned in the insertion aperture of the femoral stem component and the depth stop is positioned in its guide position, the first guide arm is positioned in contact with a first side of the femoral stem component and the second guide arm is positioned in contact with a second, opposite side of the femoral stem component. In a more specific example of such an embodiment, when the insertion prong of the stem insertion instrument is positioned in the insertion aperture of the femoral stem component and the depth stop is positioned in its guide position, the first guide arm is positioned in contact with an anterior side of the femoral stem component and the second guide arm is positioned in contact with a posterior side of the femoral stem component.
In an embodiment, the two guide arms may rotate relative to the elongated shaft independently of one another.
According to another aspect, a method of installing a cemented femoral stem component during performance of a direct anterior approach orthopaedic hip replacement surgical procedure on a patient's femur includes surgically-preparing a proximal end of the patient's femur so as to create a resected planar surface. An insertion prong of an insertion instrument is inserted into an insertion aperture formed in a lateral shoulder of the femoral stem component so as to secure the femoral stem component to the insertion instrument. A guide arm of the insertion instrument is rotated into contact with the secured femoral stem component. A distal end of the femoral stem component is then advanced through the surgically-prepared proximal end of the patient's femur and into an intramedullary canal of the patient's femur. The femoral stem component is then further advanced until the guide arm of the insertion instrument engages the resected planar surface of the surgically-prepared proximal end of the patient's femur.
In an embodiment, the guide arm of the insertion instrument is rotated into contact with an anterior surface of the secured femoral stem component.
In another embodiment, an anterior guide arm of the insertion instrument is rotated into contact with an anterior surface of the secured femoral stem component, and a posterior guide arm of the insertion instrument is rotated into contact with a posterior surface of the secured femoral stem component.
The guide arm may be rotated out of contact with the femoral stem component subsequent to engagement of the guide arm of the insertion instrument with the resected planar surface of the surgically-prepared proximal end of the patient's femur.
In an embodiment, the femoral stem component is unsecured from the insertion instrument subsequent to engagement of the guide arm of the insertion instrument with the resected planar surface of the surgically-prepared proximal end of the patient's femur, and thereafter the insertion prong of the insertion instrument is advanced proximally out of the intramedullary canal of the patient's femur.
The detailed description particularly refers to the following figures, in which:
While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Terms representing anatomical references, such as anterior, posterior, medial, lateral, superior, inferior, etcetera, may be used throughout the specification in reference to the orthopaedic implants or prostheses and surgical instruments described herein as well as in reference to the patient's natural anatomy. Such terms have well-understood meanings in both the study of anatomy and the field of orthopedics. Use of such anatomical reference terms in the written description and claims is intended to be consistent with their well-understood meanings unless noted otherwise.
Referring to
As shown in
A proximal body 18 defines the midsection of the femoral stem component 14. As such, the elongated neck 16 extends superiorly and medially away from the proximal body 30, with the tapered trunnion being formed in the superior/medial end of the neck 16—i.e., opposite the end that mates with the proximal body 18. A tapered stem 20 extends inferiorly away from the opposite end of the proximal body 18. The tapered stem 20 has a rounded distal end 22 that defines the inferior-most surface of the femoral stem component 14. As can be seen in
In the illustrative embodiment described herein, the femoral stem component 14 is embodied as a cemented femoral stem—i.e., a stem that is installed with the use of bone cement. As such, the femoral stem component 14 is embodied as a monolithic metal structure. The femoral stem component 14 may be constructed with an implant-grade biocompatible metal, although other materials may also be used. Examples of such metals include cobalt, including cobalt alloys such as a cobalt chrome alloy, and stainless steel.
As can be seen in
An elongated shaft 44 extends distally away from the center of the handle 30 towards the distal end 38 of the insertion instrument 12. The handle 30, the elongated shaft 44, and the insertion prong 40 may be integrally formed with one another, or may be provided as separate components welded or otherwise secured to one another.
To facilitate a direct anterior approach hip arthroplasty, the elongated shaft 44 is angled in the medial direction relative to the insertion prong 40. Specifically, as can be best seen in
As can be seen in
The depth stop 50 includes a hub 62. The hub 62 has a bore 64 extending therethrough. In such a way, the hub 62 is received onto the shaft 44 thereby rotatably coupling the guide arm 52 to the elongated shaft 44. An extension arm 66 extends outwardly and distally from the hub 62 and transitions to an elbow 68. The guide arm 52 extends away from the elbow 68. Thus, rotation of the hub 62 relative to the shaft 44 causes rotation of the guide arm 52. Such a feature allows the depth stop 50 to be used to control the depth at which the femoral stem component 14 is installed, yet have the ability to move the depth stop 50 out of the surgeon's line of sight if the surgeon needs to visualize into the prepared bone to, for example, assess the position of the femoral stem component 14 within a cement mantle introduced into the bone. Specifically, the depth stop 50 is rotatable between a guide position in which the guide arm 52 is positioned in contact with the anterior side 26 the femoral stem component 14 (see
As can be seen in
In use, the orthopaedic surgical system 10 may be used by a surgeon to install the cemented femoral stem component 14 in the intramedullary canal 104 of a patient's femur 106 during a direct anterior approach hip replacement surgical procedure. Prior to installation of the femoral stem component 14, the surgeon performs a number of pre-operative and intra-operative surgical steps to prepare the patient's femur 106 to receive the femoral stem component 14. For example, the surgeon uses a bone saw to surgically resect the patient's natural femoral head and create a surgically-prepared proximal end 108 of the patient's femur 106 that includes, amongst other features, a resected planar surface 102. The surgeon also assembles and installs a number of trial components and trials the fit and function of the components to be installed before implanting the femoral stem component 14. Immediately prior to installation of the femoral stem component 14, the surgeon injects pressurized bone cement into the intramedullary canal 104 of the patient's femur 106. Once bone cement has been injected into the intramedullary canal 104 of the patient's femur 106, the surgeon installs the femoral stem component 14 before the bone cement sets (i.e., partially or completely hardens).
To do so, the surgeon first selects a femoral stem component 14 having the desired size from the various available sizes. The surgeon then installs the insertion instrument 12 to the selected femoral stem component 14. As such, the surgeon first positions the hub 62 of the instrument's depth stop at a location along the elongated shaft 44 at a depth mark 72 corresponding to the desired depth at which the femoral stem component 14 is to be implanted based on the surgeon's pre-operative and intra-operative analysis. Thereafter, the surgeon inserts the insertion prong 40 of the instrument 12 into the stem component's insertion aperture 24 (as shown in
Once the insertion instrument 12 is secured to the femoral stem component 14 with its depth stop 50 positioned in its guide position, as shown in
The surgeon continues to advance the handle 30 (and hence the femoral stem component 14) distally into the intramedullary canal 104 of the patient's femur 106 until the depth stop 50 engages bone. In particular, the surgeon continues to advance the femoral stem component 14 until the distal-most planar surface 56 of the guide arm 52 (see
Once the femoral stem component 14 has reached the desired depth, the surgeon then assesses if the femoral stem component 14 is properly positioned (e.g., centered) in the intramedullary canal 104. In order to do so, the surgeon may rotate the depth stop 50 to its access position in which the guide arm 52 is spaced apart from the anterior side 26 of the femoral stem component 14 (see
If the surgeon is satisfied with the fit of the femoral stem component 14 within the intramedullary canal 104, the surgeon pulls or otherwise urges the handle 30 in a direction away from the femoral stem component 14 while preventing movement of the femoral stem component 14 thereby releasing the instrument's insertion prong 40 from the stem component's insertion aperture 24. Once released in such a manner, the surgeon removes the insertion instrument 12 from the surgically-prepared proximal end 108 of the patient's femur. Thereafter, the surgeon performs the remaining steps in the surgical procedure.
As shown in
As shown in
As shown in
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
There are a plurality of advantages of the present disclosure arising from the various features of the method, apparatus, and system described herein. It will be noted that alternative embodiments of the method, apparatus, and system of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the method, apparatus, and system that incorporate one or more of the features of the present invention and fall within the spirit and scope of the present disclosure as defined by the appended claims.
