HK40052865B - Ball and cup impactors for implanting a hip prosthesis - Google Patents

Description

Ball and cup impactors for implanting hip prostheses

Case Separation Statement

This application is a divisional application of Chinese patent application No. 201680044079.5, filed on July 15, 2016.

Technical Field

This invention relates to surgical instruments for implanting a reverse hip joint prosthesis into a patient. More specifically, this invention relates to an impactor for implanting an acetabular cup, acetabular ball, and femoral cup.

Related technologies

A reverse hip prosthesis is described in U.S. Patent Nos. 8,313,531B2 and 8,540,779B2. A method for revision surgery with the prosthesis is also described in U.S. Patent No. 8,992,627B2. The disclosures of these three patents are incorporated herein by reference in their entirety.

Summary of the Invention

As described in the aforementioned cited patent, the acetabular cup is attached to the acetabulum by impacting it against the acetabulum, and then further attached using screws if necessary. The acetabular ball is attached to a stem extending from the bottom of the concave surface of the acetabular cup by means of a Morse taper, and the femoral cup is attached to the femoral implant (or femoral stem) by means of a Morse taper. The surgical instrument of the present invention, sometimes referred to herein as a surgical tool, enables the surgeon to impact each of these components of the prosthesis in the optimal position of the acetabular cup and to ensure attachment of the acetabular ball and femoral cup.

Attached Figure Description

Figure 1 is a perspective view of the acetabular cup impactor assembly of the present invention.

Figure 2 is a front view of the acetabular cup impactor assembly.

Figure 3 is a cross-sectional view of Figure 2 showing a portion of the acetabular bone components.

Figure 4 is an exploded view of the acetabular cup impactor assembly.

Figure 5 is a front view of the acetabular cup handle for the acetabular cup impactor assembly.

Figure 6 is a front view of the inner rod used in the acetabular cup impactor assembly.

Figure 7 is a front view of the tilt-forward guide rod used in the acetabular cup impactor assembly.

Figure 8 is a front view of the clamp used in the acetabular cup impactor assembly.

Figure 9 is a front view of the universal handle for the acetabular ball impactor assembly and the femoral cup impactor assembly.

Figure 10 is a perspective view of the acetabular ball impactor assembly, the acetabular ball, and the acetabular cup.

Figure 11 is a front view of Figure 10.

Figure 12 is a cross-sectional view of Figure 11 with additional acetabular elements.

Figure 13 is a front view of the acetabular ball impinger.

Figure 13A is a cross-sectional view of the acetabular ball impinger of Figure 13.

Figure 14 is a front view of the femoral cup impactor assembly.

Figure 15 is a three-dimensional view of the femoral cup impactor.

Figure 16 is a side view of Figure 15.

Figure 17 is a top view of Figure 16.

Figure 18 is a bottom view of Figure 16.

Figure 19 is a front view of the femoral cup impactor assembly and the femoral cup positioned in the femoral implant, which is shown in cross-section.

Figure 20 is a cross-sectional view of Figure 19.

Detailed Implementation

The impactor of the present invention is used for implanting three components of a reverse hip joint prosthesis in a patient. These components are the acetabular cup, the acetabular ball, and the femoral cup.

After the prepared acetabulum receives the acetabular cup, the acetabular cup is positioned in the acetabulum, and the acetabular cup is abutted in the acetabulum using the acetabular cup impactor assembly 1 shown in Figures 1 to 4. Figures 5 to 8 show the components of the acetabular cup impactor assembly 1. Figures 1 to 3 show the acetabular cup 2 associated with assembly 1, and Figure 3 includes a portion of the acetabulum 3.

The acetabular cup impinger assembly 1 includes an acetabular cup handle 4, an inner rod 5, a tilt-forward guide rod 7, and a clamp 8. The acetabular cup handle 4 has an annular channel extending along its length, opening at both the proximal and distal ends of the handle 4. The inner rod 5 has a handle 6 at its proximal end. The guide rod 7 is threaded at its distal end. The acetabular cup handle 4 has a stem 9 and a tilt-forward guide collar 10 rotatably mounted on the stem 9. The tilt-forward guide collar 10, sometimes referred to herein as a rotatable guide 10, has threaded holes indicated as a tilting hole 15 and a tilting hole 16 (see Figure 4). Depending on whether the right or left hip joint is being replaced, the rod 7 is screwed into one of holes 16 and 15. During surgery, when the rod 7 is optimally positioned, the wing screw 11 is tightened to prevent rotation of the guide collar 10. A handle element 12 is attached to the proximal end of the stem 9, and a sleeve 13 is attached to the distal end of the stem 9. Sleeve 13 has a tapered annular interior that narrows proximally. The dimensions of the tapered annular interior of sleeve 13 are designed such that the distal end of the chuck 8 retracts when it is moved into sleeve 13 proximally. Figure 4 shows three chucks 8, each with a different size for a different sized acetabular cup 2. The acetabular cup 2 has a shank 14 protruding from the bottom of its concave surface. The size of the chuck 8 refers to the size of its annular interior portion, which is designed to releasably clamp the proximal end of the shank 14. When the chuck 8 retracts, it clamps the shank 14; when the chuck 8 opens (i.e., without retraction), it releases the shank 14.

In the surgical method of the present invention, the acetabulum 3 is prepared to receive an acetabular cup 2 of appropriate size, and a chuck 8 of suitable size is selected for the cup. An inner rod 5 is inserted to the distal end of the acetabular cup handle 4, and then the chuck 8 is attached to the distal end of the inner rod 5. The chuck 8 is then pushed onto the handle 14 of the acetabular cup 2 and pulled into the sleeve 13, so that the chuck 8 securely clamps the handle 14. This causes the rod 5 to move proximally, leaving space between the handle 6 and the proximal end of the handle element 12. A tilt-forward guide rod 7 is screwed into the hole 16 of the tilt-forward guide collar 10, another tilt-forward guide rod 7 is screwed into the hole 15 (see Figure 4), and the acetabular cup 2 is placed in the acetabulum 3. The screw holes in the cup 2 are then properly aligned in the acetabulum to finally secure the cup to the acetabulum using screws. The tilt-forward guide collar 10 is then rotated until the rod 7 is properly positioned, and then the wing screw 11 is tightened. It should be noted that the guide rod is set at an angle of 45 degrees relative to the rod 9 and an angle of 20 degrees relative to each other. The surgeon uses the rod screwed into hole 16 to set the tilt by keeping the rod parallel to the ground and pointing it toward the patient's shoulder. If the hip joint being replaced is the left, it is pointed toward the left shoulder, and if the hip joint being replaced is the right, it is pointed toward the right shoulder. While setting the tilt, the surgeon then uses rod 7 screwed into hole 15 to set the forward tilt. The choice of which hole 15 to use depends on whether the hip joint being replaced is the right or left, which is obvious to a person skilled in the art based on the disclosure herein. The forward tilt rod is tilted forward at 20 degrees to the tilt rod by oriented toward the same shoulder. The rod is used in this manner with the subsequent surgical procedure, and this properly sets the orientation of the cup 2 to a combined angle of 45 degrees tilt and 20 degrees forward tilt. When the proximal end of handle 6 is struck with a hammer to impact the acetabular cup in the acetabulum, the assembly is held in place by holding handle element 12. Then remove component 1 from the operation location.

Figures 10 through 12 show the acetabular ball impactor assembly, and Figure 13 shows the acetabular ball impactor 20 in a frontal view. The acetabular ball impactor assembly 13 includes the acetabular ball impactor 20 and a universal handle 40 (also see Figure 9). The universal handle 40 includes a rod 41 with a threaded portion 42 at its distal end and a handle element 43 at its proximal end. The acetabular ball impactor 20 has a proximal end and a distal end. As shown in Figure 13A, the proximal end of the acetabular ball impactor 20 has a thread 22, and the distal end has a concave portion 23. The concave portion is shaped like a spherical cross section. The threaded portion 42 is screwed into the thread 22 of the acetabular ball impactor 20.

The acetabular ball impactor 20 is sized to match acetabular balls 21 of different sizes. When a ball 21 is selected, it is placed on the handle 14 of the acetabular cup 2. The appropriately sized acetabular ball impactor 20 is screwed onto the universal handle 40, and the concave side of the acetabular ball impactor 20 is placed on the ball, allowing the ball to be received in the concave side. In this case, appropriate size means that the size of the concave portion of the acetabular ball impactor is designed to receive the acetabular ball. Therefore, the concave side has the shape of a spherical cross section, and its size is the same as or approximately the same as the spherical size of the acetabular ball to be received therein. With the universal handle 40 held in place, wherein the central axis of the handle 14 and the central axis of the rod 41 are in the same or approximately the same straight line (as shown in Figures 11 and 12), the proximal end of the handle element 43 is struck with a hammer so that the acetabular ball 21 is securely attached to the handle 14 by means of a Morse taper.

Figures 15 through 18 show a femoral cup impactor 30. The femoral cup impactor 30 includes a convex portion at its distal end (referred to herein as impactor tip 31) and a threaded portion 32 at its proximal end. The convex portion is spherical. The threaded portion 32 is used for attaching the impactor to a universal handle 40. When the femoral cup impactor 30 is attached to the universal handle 40, this assembly is referred to herein as a femoral cup impactor assembly.

Figures 19 and 20 further illustrate the femoral cup impactor, the femoral cup 50, and the femoral implant 51. The femoral cup 50 has a handle 52, which is sized to fit into the recess 53 of the femoral handle 51 in a Mohs taper relationship.

The femoral cup impactor 30 is sized to match different sizes of femoral cups 50. The femoral cup 50 has a concave portion with a spherical cross-section designed to engage with the acetabular ball 21. When selecting the femoral cup 50, the handle 52 is placed in the recess 53. The appropriately sized acetabular cup impactor is screwed onto the universal handle 40, and the protruding impactor tip 31 is placed in the recess of the femoral cup 50. In this case, appropriate sizing means that the convex surface of the femoral cup impactor is designed to receive the concave portion of the femoral cup. Therefore, the convex surface has a spherical cross-section shape, and its dimensions are the same as or approximately the same as the concave portion of the femoral cup. When the universal handle 40 is held in the proper position, wherein the central axis of the handle 52 is in the same or approximately the same straight line as the central axis of the rod 41 (as shown in Figures 19 and 20), the proximal end of the handle element 43 is struck with a hammer so that the femoral cup 50 is securely attached to the femoral implant 51 by means of the Morse taper.

The surgical instruments of the present invention may be included as part of a surgical kit. The kit may include one or more surgical instruments of the present invention, as well as other surgical instruments and/or implants.

Claims (8)

1. A femoral cup impactor assembly configured to impact a femoral cup into a recess of a femoral implant to attach the femoral cup to the femoral implant, the femoral cup having a concave portion with a spherical cross-section at its proximal end, and the femoral cup having a handle extending from the femoral cup and having a central axis, and the recess of the femoral implant being sized to accommodate the handle, the femoral implant having been implanted into the femur of a patient, the femoral cup impactor assembly comprising: A universal handle, attachable to a femoral cup impactor, the universal handle comprising a rod having a handle at its proximal end and a threaded portion at its distal end, and A femoral cup impactor has a threaded portion at its proximal end, a convex portion at its distal end with a spherical cross-section, and a generally cylindrical intermediate body portion. The threaded portion is sized to receive the threaded portion at the distal end of the rod of a universal handle, and the convex portion is sized to be accommodated within a concave portion of the femoral cup. Physical contact of the femoral cup during impact is limited by contact with the surface of the convex portion, a portion of the generally cylindrical intermediate body portion, and the femoral implant. 2. The femoral cup impactor assembly according to claim 1, wherein: The femoral cup impactor also includes a generally cylindrical intermediate body portion between the proximal and distal ends of the femoral cup impactor, wherein the radius of the generally cylindrical intermediate body portion is greater than the maximum radius of the convex portion disposed at the distal end of the femoral cup impactor. 3. The femoral cup impactor assembly according to claim 1, wherein the handle has a Morse taper. 4. A kit comprising the femoral cup impactor assembly of claim 1, and further comprising: At least the second femoral cup impactor has a convex portion of different dimensions with a spherical cross-section located at its distal end. 5. A kit comprising the femoral cup impactor assembly of claim 1, and the kit further comprising a surgical instrument configured to impact an acetabular cup into a patient's acetabulum, wherein the acetabular cup has a central shank with a Morse taper extending from the bottom of its recessed inner surface, the surgical instrument comprising: A handle having a proximal end and a distal end, a central axis, a sleeve, and an annular channel, the sleeve being concentrically disposed on the distal end of the surgical instrument's handle, and the annular channel extending through the handle of the surgical instrument, the annular channel opening at both the proximal and distal ends of the surgical instrument's handle. A rod having a proximal end and a distal end, and a handle attached to the proximal end of the rod of the surgical instrument, the rod of the surgical instrument being slidably disposed within the annular channel. A chuck, removably attached to the distal end of the lever of the surgical instrument and close to the sleeve, wherein the sleeve has a tapered annular interior that narrows proximally, the tapered annular interior of the sleeve being sized such that when the chuck is moved proximally into the sleeve, the distal end of the chuck retracts and clamps the central shank of the acetabular cup, thereby clamping the acetabular cup solely by means of the central shank. A rotatable guide collar, mounted on the exterior of the handle of the surgical instrument and rotatable about the central axis of the handle, is configured to attach a plurality of guide rods to the rotatable guide collar, wherein each guide rod has a proximal end removably attached to the rotatable guide collar and extends outwardly at an angle relative to the central axis from the proximal end attached to the rotatable guide collar, wherein at least two of the plurality of guide rods are positioned at a 45-degree angle relative to the rod of the surgical instrument and at a 20-degree angle relative to each other when attached to the rotatable guide collar, and the at least two guide rods are oriented to extend distally from the rotatable guide collar, and A wing screw having a portion extending from the rotatable guide collar, wherein rotation of the wing screw prevents movement of the rotatable guide collar and any guide rods attached to the rotatable guide collar relative to the handle of the surgical instrument. 6. The kit of claim 5, wherein the chuck has a chuck interior sized to releasably clamp the proximal end of the center shank, clamping the center shank when the chuck is retracted and releasing the center shank when the chuck is not retracted. 7. The kit according to claim 5, comprising a plurality of clamps. 8. The kit of claim 7, wherein at least two of the plurality of chucks have different sizes.