JP3439811B2 - Acetabular reconstruction shell for hip prosthesis - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention aims at restoring the function of a hip joint whose joint function has decreased due to various diseases such as osteoarthritis and rheumatism. The present invention relates to an acetabular reconstruction shell used for hip replacement, pelvic osteotomy, and revision of the same. 2. Description of the Related Art As shown in FIG. 3, a hip joint is a ball-shaped femoral head A at the proximal end side of a femur L, which receives the bone head A and supports a load applied to a lower leg. It is a joint composed of the acetabular lid P. [0003] In a normal hip joint, the femoral head A and the acetabular cap P maintain their joint functions at an appropriate position balanced with soft tissues such as muscles and ligaments, and perform complicated movements of the lower limbs. Support. However, the hip joint loses the function of the joint sliding surface between the femoral head A and the acetabular lid P. P cannot fully receive the femoral head A, and
If the original joint function is lost due to a disease such as hip dislocation, which dislocates and forms a joint in an inappropriate position, it causes pain accompanying lower limb movement and decreases the range of motion, This can hinder the daily life of the person. [0005] As a conventional treatment method for a hip joint whose joint function has been reduced due to such a disease, a femoral head A and an acetabular cap P constituting the hip joint are attached to the femur L as shown in FIG. There is a total hip arthroplasty in which the stem LS inserted into the acetabular part and the acetabular lid component SO are screwed to the side of the acetabular lid part P or fixed by means of fixation with bone cement. However, if such treatment is necessary and the acetabular cap P is deformed or destroyed so that the acetabular cap component SO cannot be installed, the resected femoral head A bone fragment collected from A is transplanted into an incision site of the divided acetabular cap P, or the acetabular cap P is divided and partially resected, and the divided bone is directly fixed using screws. Thus, the acetabular component SO can be installed, and thereafter, the acetabular component SO is installed in the acetabular component P. [0007] However, in the conventional hip arthroplasty involving the above-mentioned bone division, when the acetabular component SO is installed with screws, the screws for fixing the bones are hindered. Or the amount of remaining bone is small, the space in which the screw for fixing the acetabular component SO can be screwed is extremely limited, and therefore, it must be fixed with a small number of screws. Especially in the early postoperative period, in addition to insufficient fixation to the bone, it takes a long time to fuse the divided bones.On the other hand, the acetabular component with bone cement When installing the SO, it takes time for the divided bones to heal, and it is necessary to keep the osteosynthesis at rest for a long period of time. Put a heavy burden on the elderly. In addition, since the acetabular component SO is installed with a small number of screws, even if the bones are fused, the fixing force with the bones is insufficient, and loosening between the bones occurs gradually, and the replacement is performed. Was forced to do so. [0009] In order to solve the above problems, the present invention comprises an acetabular body for fixing to an acetabulum, and a peripheral portion of the body. The present invention provides a acetabular lid reconstruction shell for a metal hip prosthesis, comprising a flange portion for fixing bolts and a plate portion having a thickness of 0.4 to 2 mm extending outward for fixing assistance. I do. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an acetabular reconstruction shell (hereinafter abbreviated as “shell”) 1 of the present embodiment.
To secure the acetabular acetabular portion P, together comprising a body portion k of the acetabulum shape and extends outwardly for flanges F ₁ and fixation assisting the bolt secured to edge portions of the main body portion k It has two plate portions F ₂ and F ₂ . A plurality of small-diameter holes N are formed in the outer edge portion of the main body k, and as a selective and auxiliary fixing means,
Metal wires, nylon threads, and the like can be used. Furthermore, the above-mentioned main body k, is provided with a device holding screw holes H _2, upon mounting the shell 1, in the instrument holding hole H _2, not shown with the corresponding screw to the tip The shell 1 can be easily held at a predetermined position by attaching the special holding device. FIG. 2 shows the manner in which the shell 1 of this embodiment is used. The outer diameter of the main body portion k corresponds to the size of the acetabular to which the shell 1 is fixed, and as shown in FIG. Φ30-80 to accommodate hip acetabulum component SO
On the order, also, to the main body portion k, a plurality of set screw mounting hole H ₁ is drilled having a countersunk portion on the inside of the main body portion k so as to screw attachment Hiroshihoneusufuta P. The set screw mounting hole H ₁ is preferably formed slightly larger so that the screwing direction of the screw S can be selected according to the form of the acetabular cap P. [0015] Note that the above-mentioned flange portion F ₁ are formed two set screws mounting hole H _1, in particular, the less the residual bone mass for bone split, can act from the inside of the main body portion k If the number of screw S is small, the flange portion F _1, is brought into contact with the higher part edge of the residual bone mass often hip acetabular portion P, by the action of the screw S from the set screw mounting hole H ₁ The fixing force between the shell 1 and the bone is increased. The plate portion F ₂ can be easily bent by using a simple tool. When the shell 1 is fixed to the acetabular lid portion P during the operation, the distal end portion of the plate portion F ₂ can be bent. Is bent into a hook shape, and a hook portion is embedded in a narrow groove D formed in the bone as shown in FIG. It is used so that it can be hooked so as to hold the loose edge portion and engage with it. By doing so, the divided bone is supported or held around, and a strong connection between the shell 1 and the bone is made possible, and the divided bones are closely attached and supported. It is possible,
Healing of bones can be accelerated. The material of the shell 1 thus constructed is a metal material which is stable in the living body and has no harmful effect, for example, stainless steel, cobalt chromium alloy, pure titanium,
Materials such as titanium alloys are suitable, the outer surface and bone paired contact surface of the flange portion F ₁ of the main body portion k in contact with the bone, expect further adherence of the bone, biological apatite Coating active material or spray metal, or
Irregularities may be provided to achieve mechanical engagement with bone by grooves, protrusions, beads, or the like. Further, when the acetabular component is fixed via the bone cement, the inner surface of the main body k is coated with PMMA and a silane agent in advance to enhance the fixation of the bone cement and the shell 1. It may be. The plate portion F ₂ has a diameter of 0.4 mm so that the distal end portion can be deformed and worked during the operation.
It is preferable that the thickness is about 2 mm. This thickness is 0.
If it is smaller than 2 mm, the strength of the plate portion F ₁ is insufficient,
Since the bone is easily deformed by the load, the bone supporting force is insufficient. On the other hand, if it is larger than 2 mm, intraoperative deformation and processing may be difficult. As described above, the shell according to the present invention has a flange portion for screwing at the periphery of the acetabular body, so that the shell is screwed by bone division or the like. Even in the case where the region that can be formed is limited, it is possible to apply a screw to the high-order edge of the acetabular lid portion having a large amount of remaining bone, and furthermore, to make the shell metal, By providing a 0.4 to 2 mm thick plate extending outward at the edge, the plate can be deformed during surgery.
It can be processed and bent into a hook shape so as to catch on the bone, and as a result, the fixing force with the bone is large. Therefore,
Because the divided bones can be made to adhere to each other and supported, treatment is fast, there is no gap between the bones,
It can be stably implanted for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an acetabular reconstruction shell according to an embodiment of the present invention;
(A) is a side view, (b) is a plan view. FIG. 2 is a perspective view showing a state in which the acetabular reconstruction shell of FIG. 1 is installed at a hip joint site. FIG. 3 is a schematic perspective view showing a form of a hip joint. FIG. 4 is a perspective view showing a hip prosthesis installed in a conventional total hip arthroplasty. [Description of Signs] 1 (For acetabular reconstruction) Shell k Main body H ₁ Set screw mounting hole H ₂ Instrument holding screw hole N Small diameter hole F ₁ Flange F ₂ Plate S Screw A Femoral head P Hip bone Acetabular part L femur LS stem SO acetabular component D slot

────────────────────────────────────────────────── (5) References US Pat. No. 4,377,716 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61F 2/34 WPI (DIALOG)

Claims (1)

(57) Claims 1. An acetabular main body is provided for fixing to an acetabular lid, and a flange portion for fixing bolts and a fixing portion are provided at a peripheral portion of the main body. An acetabular reconstruction shell for a metal hip prosthesis, comprising a 0.4 to 2 mm thick plate extending outward for assistance.