An osteotomy navigation tool for trochanteric stem type femoral head replacement

Abstract

The present invention relates to an osteotomy navigation tool for trochanteric stem type artificial femoral head replacement surgery, the osteotomy navigation tool for trochanteric stem type artificial femoral head replacement surgery comprises a positioning rod, a guide piece and a connecting piece, wherein the positioning rod can be inserted into the medullary cavity of the femur to be operated on, the guide piece is installed on the positioning rod and arranged opposite to the positioning rod, when the positioning rod is in a state of being inserted into the medullary cavity of the femur to be operated on, the present invention has the advantages that: by inserting the positioning rod into the medullary cavity of the femur to be operated on, the guide piece arranged opposite to the positioning rod is fitted on the posterior wall of the femur to be operated on, thereby facilitating the pendulum to extend into the first cutting groove and the second cutting groove respectively, and then cutting the corresponding part to be cut on the femur.

Description

Technical Field

[0001] The invention relates to the field of medical surgical tools, in particular to an osteotomy navigation tool for trochanteric stem type artificial femoral head replacement. Background Art

[0002] The femur is the largest long tubular bone in the human body. It can be divided into two ends, namely the middle femoral body and the ends at both ends of the femoral body. The top of the femur is the spherical femoral head. The thinner part below the outer side of the femoral head is the junction of the femoral neck and the femoral body. There is an upward protrusion on the outer side of the greater trochanter, also known as the greater trochanter 102, and the smaller protrusion below the greater trochanter is the lesser trochanter, also known as the lesser trochanter 101. Intertrochanteric fractures of the femur in the elderly are the most common fractures caused by osteoporosis. Artificial hip replacement is one of the means to treat this type of fracture. For example, bone cement hip replacement can enable early movement of the affected hip joint and weight bearing on the bed, avoiding complications caused by long-term bed rest.

[0003] Hip replacement surgery usually involves the following steps:

[0004] After anesthesia, the patient takes the lateral position and adopts the posterolateral approach of the hip joint. The bone block at the attachment point of the gluteus medius muscle at the greater trochanter is retained and turned upward. The femoral head and bone fragments are removed, and the lesser trochanter bone fragments that are difficult to fix are removed or left unfixed. The greater trochanter and lesser trochanter are retained. The osteotomy template is used to perform vertical osteotomy on the medial side of the greater trochanter to the height of the lesser trochanter. The oscillating saw is used to trim the bone at the lesser trochanter perpendicular to the longitudinal axis of the femur on the lesser trochanter plane, retain the cortical bone on the greater trochanter side, and then the knee joint axis is used to locate the anteversion angle and expand the medullary bone in sequence. During the operation, a trochanter-stem artificial femoral head prosthesis is used. A suitable femoral stem is selected. The lower part of the prosthesis neck support is flush with the osteotomy plane, with an anteversion angle of about 15°. After the position is determined, bone cement is filled and the femoral stem is inserted for fixation. After the bone cement hardens, the greater trochanter bone block is fixed to the greater trochanter hole of the prosthesis with an absorbable suture or steel wire, and the iliopsoas muscle attachment point is fixed to the lesser trochanter hole with an absorbable suture. Select a suitable dual-motion head, reposition the hip joint, perform a distraction test to determine whether it is appropriately tight and has no tendency to dislocate, place drainage, and suture the incision layer by layer.

[0005] The most critical step in this operation is the osteotomy of the upper end of the femur, see Figure 1 The existing operation process is to cut the greater trochanter 102 bone fragments by an osteotomy template according to the shape of the implanted prosthesis. The existing osteotomy template is in the form of a sheet, and the following problems may be encountered in the actual operation of the operation:

[0006] 1. It is difficult to place the osteotomy template in the center of the upper end of the femur. It is likely to be placed obliquely, resulting in the greater trochanter section not fitting well with the trochanter stem after osteotomy. Even if the template is placed in line with the central axis of the medullary cavity, it may be biased inward or outward, which will lead to inversion of the prosthesis or excessive removal of greater trochanter bone, which may lead to fracture in severe cases.

[0007] 2. Since the template is placed outside the femur, it is not possible to completely cut along the medial edge of the greater trochanter of the femur during vertical cutting. In addition, due to the instability of the template, the trajectory of the template often forms an angle with the planned cutting path during actual cutting, resulting in excessive or insufficient cutting, which in turn prolongs the operation time and increases surgical trauma.

[0008] 3. The anteversion angle is difficult to control during osteotomy, and the osteotomy needs to be adjusted multiple times, which prolongs the operation time and aggravates the surgical trauma. Often, after multiple osteotomy operations, too much bone in the greater trochanter is removed, which reduces the strength of the gluteus medius attachment point. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide an osteotomy navigation tool for trochanteric stem type artificial femoral head replacement surgery, which does not require hand-holding during cutting and can accurately guide the lower knife.

[0010] The technical solution adopted by the present invention to solve the above technical problems is: the osteotomy navigation tool for trochanteric stem type artificial femoral head replacement comprises

[0011] A positioning rod that can be inserted into the medullary cavity of the femur to be operated on;

[0012] A guide piece is mounted on the positioning rod and arranged opposite to the positioning rod. When the positioning rod is inserted into the intramedullary cavity of the femur to be operated on, the guide piece is located on the rear wall corresponding to the upper end of the femur to be operated on, and the guide piece has a first groove and a second groove for the pendulum to pass through to cut the upper end of the femur. The first groove and the second groove are both arranged to penetrate along the wall thickness direction of the guide piece. The first groove is consistent with the extension direction of the inner edge of the greater trochanter of the femur to be cut, and the second groove is arranged perpendicular to the first groove; and

[0013] The connecting piece is used to install the guide piece on the positioning rod. The connecting piece is arranged between the positioning rod and the guide piece and respectively connects the corresponding ends of the positioning rod and the guide piece.

[0014] In order to further clarify the cutting direction and ensure that the cutting in the two directions will not interfere with each other, preferably, the second groove is arranged below the first groove along the insertion direction of the positioning rod, and the first groove and the second groove are not connected to each other.

[0015] In order to facilitate the selection of a suitable cutting position without moving the entire navigation tool, there are two second cutting grooves, which are arranged side by side and at intervals.

[0016] In order to further ensure the guidance of the pendulum during cutting, preferably, a guide groove for the pendulum to pass through the first cutting groove is opened on the positioning rod at a position corresponding to the first cutting groove.

[0017] In order to further locate the placement angle of the guide member relative to the femur to be operated on, the guide member is also provided with a pointing portion for locating the greater trochanter of the femur to be operated on.

[0018] In order to ensure that the guide member will not deflect again after being placed, as an improvement, a positioning hole is provided on the guide member along the wall thickness direction for the positioning pin used to fix the guide member and the femur to be operated on to pass through.

[0019] In order to ensure that the positioning rod and the guide member are relatively fixed, the corresponding ends of the positioning rod and the guide member are both passed through the connecting member, and corresponding mounting holes for the positioning rod and the guide member to pass through are opened on both sides of the connecting member; the connecting member is also provided with a locking member for limiting the movement of the positioning rod and the guide member relative to the connecting member, and when the positioning rod and the guide member are both installed on the connecting member, the locking member respectively abuts against the positioning rod and the guide member.

[0020] Compared with the prior art, the advantages of the present invention are that the osteotomy navigation tool for trochanter-stem artificial femoral head replacement includes a positioning rod and a guide piece, which is inserted into the medullary cavity of the femur to be operated on through the positioning rod, so that the guide piece arranged opposite to the positioning rod is fitted on the posterior wall of the femur to be operated on, thereby facilitating the pendulum to extend into the first groove and the second groove respectively, and then cut off the corresponding part of the femur to be cut. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the femur after the medullary cavity is cleaned in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the cooperation between the navigation tool and the femur before osteotomy in an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the cooperation between the navigation tool and the femur after osteotomy in an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the overall structure of a navigation tool in an embodiment of the present invention;

[0025] Figure 5 It is a schematic diagram of the decomposition structure of the navigation tool in the embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] like Figures 1 to 5 As shown, it is a preferred embodiment of the present invention. In this embodiment, the osteotomy navigation tool for trochanteric stem type artificial femoral head replacement includes a positioning rod 1 and a guide member 2. The guide member 2 is installed on the positioning rod 1 through a connecting member 3. The corresponding ends of the positioning rod 1 and the guide member 2 are both penetrated on the connecting member 3. The two sides of the connecting member 3 are correspondingly provided with mounting holes 31 for the positioning rod 1 and the guide member 2 to pass through. Of course, there are many ways to connect the positioning rod 1 and the guide rod 2, which are not listed here one by one. The connecting member 3 in this embodiment is also provided with a locking member 4 that limits the relative movement of the positioning rod 1 and the guide member 2 to the connecting member 3. When the positioning rod 1 and the guide member 2 are both installed on the connecting member 3, the locking member 4 is respectively against the positioning rod 1 and the guide member 2.

[0028] In this embodiment, the above-mentioned positioning rod 1 can be inserted into the medullary cavity 100 of the femur to be operated on, and the guide member 2 is arranged opposite to the positioning rod 1 after being installed on the positioning rod 1, and when the positioning rod 1 is in the state of being inserted into the medullary cavity 100 of the femur to be operated on, the guide member 2 is located on the rear wall corresponding to the upper end of the femur to be operated on; the guide member 2 in this embodiment has a first groove 21 and a second groove 22 for the pendulum to pass through and then cut the upper end of the femur, the first groove 21 and the second groove 22 are both arranged along the wall thickness direction of the guide member 2, the first groove 21 is consistent with the extension direction of the inner edge of the greater trochanter of the femur to be cut, the second groove 22 is arranged perpendicular to the first groove 21, the above-mentioned second groove 22 is arranged below the first groove 21 along the insertion direction of the positioning rod 1, and the first groove 21 and the second groove 22 are not connected to each other, such an arrangement of the first groove 21 and the second groove 22 can ensure that the two directions will not interfere with each other during cutting, thereby ensuring the accuracy of the operation. In the present embodiment, there are two second grooves 22, which are arranged side by side and at intervals. The design of the two second grooves 22 can ensure that the insertion position of the pendulum can be accurately selected according to the required cutting position without adjusting the position of the entire navigation tool. At the same time, a guide groove 11 for the pendulum to pass through the first groove 21 is opened on the positioning rod 1 at a position corresponding to the first groove 21.

[0029] In this embodiment, the guide member 2 is also provided with a pointing portion 23 for locating the greater trochanter 102 of the femur to be operated on, and a positioning hole 24 is provided on the guide member 2 along the wall thickness direction for the positioning needle to pass through to fix the guide member 2 and the femur to be operated on.

[0030] The method of using the navigation tool of the present invention is as follows:

[0031] Before the operation, general tracheal anesthesia or epidural anesthesia is used. The patient is in the lateral position and a posterolateral incision is made. After routine disinfection and draping, the skin and subcutaneous tissue are incised, the gluteus maximus and its fascia are incised, the piriformis and other external rotator muscles are incised, and the joint capsule is incised. The intertrochanteric comminuted fracture of the femur can be seen, and the femoral head and femoral neck are removed. Depending on the fracture of the greater trochanter, the greater trochanter is repositioned and fixed to determine the rotation center of the entire femoral head.

[0032] ① According to the specific situation of the fracture, use the smallest femoral medullary cavity file to find the entrance of the medullary cavity 100 at the upper end of the femur, expand the medullary cavity along the axis of the medullary cavity 100, use femoral rasps from thin to thick to expand the medullary cavity, and clean the medullary cavity at the proximal end of the femoral shaft;

[0033] ② Select the positioning rod 1 in the osteotomy navigation tool according to the largest femoral medullary cavity file, and assemble the osteotomy navigation tool with the guide member 2, install the guide member 2 on the positioning rod 1 through the connecting member 3, and lock it with the locking member 4;

[0034] ③ Insert the positioning rod 1 along the medullary cavity. The entire navigation tool moves synchronously with the insertion of the positioning rod 1. The insertion depth of the positioning rod 1 is such that the rotation center of the femoral head of the femoral neck indicator rod is level with the apex of the greater trochanter of the femur.

[0035] ④ Flex the hip 45°, flex the knee 90°, with the sole facing upward, so that the femoral neck indicator rod of the guide member 2 intersects the calf vertically and then rotates forward 15° as the anteversion angle of the artificial femoral head prosthesis, and then fix the guide member 2 to the upper end of the femur through the positioning hole 24 with a positioning pin;

[0036] ⑤ Perform osteotomy in the first notch 21 of the guide member 2 with an oscillating saw, and select one of the two second notches 22 for osteotomy according to the fracture condition of the lesser trochanter, then take out the navigation tool, further trim the osteotomy surface along the osteotomy line, and obtain mutually perpendicular osteotomy surfaces at the upper end of the femur to accommodate the trochanter of the artificial prosthesis;

[0037] ⑥ After proximal medullary expansion, insert the prosthesis stem trial mold and check whether the osteotomy height is correct, that is, whether the center of the femoral head is at the same level as the apex of the greater trochanter. Reset the hip joint to check its tightness and whether there is dislocation in all directions.

[0038] ⑦ Clean the femoral medullary cavity, absorb the moisture, fill it with bone cement, insert the prepared prosthesis stem, and wait until the bone cement is dry. After putting on the prosthesis head, complete the artificial hemihip replacement, and use Kirschner wire tension band to tighten and fix the fracture fragment of the greater trochanter.

Claims

1. An osteotomy navigation tool for trochanteric stem type artificial femoral head replacement, characterized in that: include A positioning rod (1) capable of being inserted into the medullary cavity (100) of the femur to be operated on; as well as A guide member (2) is mounted on the positioning rod (1) and arranged opposite to the positioning rod (1); when the positioning rod (1) is inserted into the intramedullary cavity (100) of the femur to be operated on, the guide member (2) is located on the rear wall corresponding to the upper end of the femur to be operated on, and the guide member (2) has a first groove (21) and a second groove (22) for pendulums to pass through and cut the upper end of the femur; the first groove (21) and the second groove (22) are both arranged to penetrate along the wall thickness direction of the guide member (2); the first groove (21) is in the same extension direction as the inner edge of the greater trochanter of the femur to be cut; and the second groove (22) is arranged perpendicular to the first groove (21); as well as A connecting member (3) is used to mount the guide member (2) on the positioning rod (1); the connecting member (3) is arranged between the positioning rod (1) and the guide member (2) and respectively connects the corresponding ends of the positioning rod (1) and the guide member (2); The second slot (22) is arranged below the first slot (21) along the insertion direction of the positioning rod (1), and the first slot (21) and the second slot (22) are not connected to each other; There are two second grooves (22), and the two second grooves (22) are arranged side by side and at intervals; A guide groove (11) is provided on the positioning rod (1) at a position corresponding to the first groove (21) for the pendulum to pass through the first groove (21); The guide member (2) is also provided with a pointing portion (23) for locating the greater trochanter of the femur (102) to be operated on.

2. The osteotomy navigation tool according to claim 1, characterized in that: The guide member (2) is provided with a positioning hole (24) penetrating along the wall thickness direction for a positioning needle to be passed through for fixing the guide member (2) and the femur to be operated on.

3. The osteotomy navigation tool according to any one of claims 1 to 2, characterized in that: Mounting holes (31) for the positioning rod (1) and the guide member (2) to pass through are correspondingly provided on both sides of the connecting member (3); a locking member (4) for limiting the movement of the positioning rod (1) and the guide member (2) relative to the connecting member (3) is also provided on the connecting member (3); when the positioning rod (1) and the guide member (2) are both installed on the connecting member (3), the locking member (4) respectively abuts against the positioning rod (1) and the guide member (2).

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