Femoral stem taking-out forceps

Abstract

The utility model discloses a pair of femoral stem taking-out forceps, which belongs to the technical field of medical instruments and comprises an upper forceps arm, a lower forceps arm and a movable block, the lower side of the front end of the upper forceps arm is hinged to the upper side of the rear end of the movable block, an upper jaw is fixedly arranged at the front end of the upper forceps arm, and the front end of the lower forceps arm is hinged to the lower side of the rear end of the movable block. A lower jaw is arranged at the front end of the movable block; the opposite end faces of the upper jaw and the lower jaw are provided with an upper groove and a lower groove which are used for containing a femoral stem conical head to be taken out respectively. The front end of the upper groove and the front end of the lower groove are provided with an upper boss and a lower boss respectively, wherein the upper boss and the lower boss can be matched with a femoral stem neck to hook a femoral stem when the femoral stem conical head is clamped by the upper jaw and the lower jaw. The femoral stem taking-out clamp further comprises a distraction locking device used for keeping the upper clamp arm and the lower clamp arm in a distraction state so as to clamp a femoral stem conical head. The femoral stem taking-out clamp is good in matching effect, easy and convenient to operate and capable of taking out the femoral stem efficiently and firmly.

Description

Technical Field

[0001] The utility model relates to the technical field of medical instruments, in particular to a femoral stem removal forceps. Background Art

[0002] After 30 years of clinical practice, total hip replacement has become a reliable treatment method that has been fully recognized. With the development of society, the indications of total hip replacement have been expanded to elderly and young patients, and the demand for postoperative revision surgery has also increased. Compared with the initial hip replacement, hip revision surgery is more difficult, especially how to remove the femoral stem efficiently and securely, which has always been a difficulty and pain point in the medical community.

[0003] Under the influence of factors such as early prosthesis design and installation, the femoral stem removal process is prone to prosthesis breakage and peri-prosthesis fractures, causing secondary injuries to patients. Therefore, a femoral stem removal instrument is generally used to remove the femoral stem. However, existing femoral stem removal instruments are generally occlusal. For example, invention patent application CN102579168A discloses a universal femoral stem extractor, utility model patent CN214549757U discloses a femoral stem removal instrument, and utility model patent CN205459225U discloses an occlusal femoral stem removal instrument assembly. The above-mentioned femoral stem removal instruments are all used to occlude the femoral stem cone head. The part of the femoral stem removal instrument used to occlude the femoral stem cone head is adapted to the cone head of the femoral stem of standard specifications, and it is actually difficult to achieve complete adaptation. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a femoral stem removal forceps which has good adaptation effect, is easy to operate and can remove the femoral stem efficiently and firmly.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] A femoral stem removal forceps, comprising an upper forceps arm, a lower forceps arm and a movable block, wherein:

[0007] The front lower side of the upper clamp arm is hinged to the rear upper side of the movable block, the front end of the upper clamp arm is fixed with an upper jaw, the front end of the lower clamp arm is hinged to the rear lower side of the movable block, and the front end of the movable block is provided with a lower jaw;

[0008] An upper groove and a lower groove are respectively provided on the opposite end surfaces of the upper jaw and the lower jaw for accommodating the femoral stem cone to be removed, and an upper boss and a lower boss are respectively provided at the front ends of the upper groove and the lower groove for cooperating with the neck of the femoral stem to hook the femoral stem when the upper jaw and the lower jaw clamp the femoral stem cone.

[0009] The femoral stem extraction forceps also include a distraction locking device for keeping the upper forceps arm and the lower forceps arm in a distraction state to clamp the femoral stem cone head.

[0010] Furthermore, a lug is provided at the lower front end of the movable block, and a receiving groove is provided at the rear of the lower jaw, and the lug is hinged in the receiving groove.

[0011] Furthermore, the upper front end of the movable block is fixedly connected to the lower jaw, an upper liner is provided in the upper groove, a lower liner is provided in the lower groove, and an upper accommodating groove and a lower accommodating groove are respectively provided on opposite end surfaces of the upper liner and the lower liner;

[0012] An upper elastic member capable of enabling the upper liner to move up and down in the upper groove is provided between the upper liner and the bottom wall of the upper groove, and a lower elastic member capable of enabling the lower liner to move up and down in the lower groove is provided between the lower liner and the bottom wall of the lower groove.

[0013] Furthermore, an upper guide column is provided on the upper surface of the upper liner, an upper guide hole matching with the upper guide column is provided on the bottom wall of the upper groove, and the upper elastic member is an upper spring sleeved on the upper guide column;

[0014] And / or, a lower guide column is provided on the lower surface of the lower lining, a lower guide hole matching with the lower guide column is provided on the bottom wall of the lower groove, and the lower elastic member is a lower spring sleeved on the lower guide column.

[0015] Furthermore, the lower end surface of the upper jaw is provided with upper fixing strips on both sides of the upper groove for preventing the upper lining from falling out;

[0016] And / or, the upper end surface of the lower jaw is provided with lower fixing strips on both sides of the lower groove for preventing the lower lining from falling out.

[0017] Furthermore, a connecting rod sliding groove extending along the length direction of the upper clamp arm is provided on the rear lower side of the upper clamp arm, and the expansion and locking device includes a connecting rod located between the upper clamp arm and the lower clamp arm, the lower end of the connecting rod is hinged to the middle part of the lower clamp arm, and the upper end of the connecting rod is slidably connected in the connecting rod sliding groove. The expansion and locking device also includes a locking member located on the upper clamp arm and used to lock the upper end of the connecting rod in the connecting rod sliding groove.

[0018] Furthermore, the rear end of the upper clamp arm is provided with a threaded hole connected to the connecting rod sliding groove, the locking piece is an adjusting bolt threadedly connected to the threaded hole, the front end of the adjusting bolt is provided with a supporting portion for abutting against the upper end of the connecting rod, and the rear of the adjusting bolt is provided with a driving portion.

[0019] Furthermore, the lower clamp arm is provided with an auxiliary support rod located behind the connecting rod, the front end of the auxiliary support rod is hinged to the inner side of the lower clamp arm, the front part of the auxiliary support rod is used to push the middle part of the connecting rod, and the rear part of the auxiliary support rod is used as an operating part, which extends to the outer side of the rear end of the lower clamp arm.

[0020] Furthermore, a return spring is provided between the movable block and the upper clamp arm, one end of the return spring is fixed to the middle part of the rear end of the movable block, and the other end is fixed to the middle part of the upper clamp arm.

[0021] Furthermore, the front outer side surfaces of the upper jaw and the lower jaw are both designed with arc-shaped edges;

[0022] And / or, a sliding hammer is connected to the rear end of the adjusting bolt.

[0023] The utility model has the following beneficial effects:

[0024] The femoral stem removal pliers of the utility model adopt the form of pliers as the overall structure. After operating the upper pliers arm and the lower pliers arm, the opening angles of the upper jaw and the lower jaw can be adjusted. The upper groove of the upper jaw and the lower groove of the lower jaw can adapt to the cone heads of femoral stems of different specifications, so as to achieve the adaptation of the taper of the cone head of the femoral stem to be removed, and can effectively wrap the cone head of the femoral stem to be removed, so as to adapt to the cone heads of femoral stems of different lengths and different diameters, with good adaptation effect and simple operation. The front ends of the upper groove and the lower groove are respectively provided with a plurality of openings for the upper jaw and the lower jaw to clamp the cone head of the femoral stem. The upper and lower bosses of the femoral stem can be used to cooperate with the neck of the femoral stem to hook the upper and lower bosses of the femoral stem. In this way, when the upper and lower jaws clamp the cone head of the femoral stem, the upper groove and the lower groove effectively wrap the cone head of the femoral stem to be removed, and the upper and lower bosses hook the neck of the femoral stem, which better clamps the femoral stem to be removed, and can efficiently and securely remove the femoral stem. The femoral stem removal forceps also include an expansion locking device for keeping the upper and lower forceps arms in an expanded state to clamp the cone head of the femoral stem, which better clamps the femoral stem to be removed, frees both hands, and is convenient for use during surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the femoral stem removal forceps of the present invention;

[0026] Figure 2 for Figure 1 Schematic diagram of the decomposition structure;

[0027] Figure 3 for Figure 1 Schematic diagram of the structure of the middle upper jaw, where (a) is a bottom view and (b) is a side sectional view;

[0028] Figure 4 for Figure 1Schematic diagram of the combined structure of the middle and lower jaws and the movable block, wherein (a) is a side view, (b) is a left view of (a), and (c) is a back cross-sectional view of (a);

[0029] Figure 5 It is an enlarged structural schematic diagram of the upper and lower jaws of the femoral stem removal forceps in Example 2 of the utility model;

[0030] Figure 6 for Figure 5 Schematic diagram of the decomposition structure;

[0031] Figure 7 for Figure 1 Schematic diagram of the structure of the adjusting bolt. DETAILED DESCRIPTION

[0032] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0033] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0034] The utility model provides a femoral stem removal forceps, such as Figure 1-7 As shown, it includes an upper clamp arm 1, a lower clamp arm 2 and a movable block 3, wherein:

[0035] The front lower side of the upper clamp arm 1 is hinged to the rear upper side of the movable block 3, and the front end of the upper clamp arm 1 is fixed with an upper jaw 4. The front end of the lower clamp arm 2 is hinged to the rear lower side of the movable block 3, and the front end of the movable block 3 is provided with a lower jaw 5.

[0036] An upper groove 41 and a lower groove 51 are respectively provided on the opposite end surfaces of the upper jaw 4 and the lower jaw 5 for accommodating the femoral stem cone to be removed, and an upper boss 42 and a lower boss 52 are respectively provided at the front ends of the upper groove 41 and the lower groove 51, which can cooperate with the neck of the femoral stem to hook the femoral stem when the upper jaw 4 and the lower jaw 5 clamp the femoral stem cone.

[0037] The femoral stem extraction forceps further comprise a distraction locking device for keeping the upper forceps arm 1 and the lower forceps arm 2 in a distraction state so as to clamp the femoral stem cone head.

[0038] When in use, the upper forceps arm 1 and the lower forceps arm 2 are squeezed by hand to open the upper jaw 4 and the lower jaw 5, and then the upper groove 41 of the upper jaw 4 and the lower groove 51 of the lower jaw 5 are aligned with the cone head of the femoral stem to be removed, and then the upper forceps arm 1 and the lower forceps arm 2 are loosened and spread open, and the upper jaw 4 and the lower jaw 5 are closed, so that the upper groove 41 and the lower groove 51 both cover the cone head of the femoral stem to be removed, and the upper boss 42 and the lower boss 52 both hook the neck of the femoral stem to be removed, and finally the expansion locking device is used to keep the upper forceps arm 1 and the lower forceps arm 2 in the expanded state (that is, the upper jaw 4 and the lower jaw 5 are kept in the clamped state), and the cone head of the femoral stem to be removed is clamped to achieve final locking (see Figure 1 ).

[0039] The femoral stem removal pliers of the utility model adopt the form of pliers as the overall structure. After operating the upper pliers arm and the lower pliers arm, the opening angles of the upper and lower jaws (i.e. the taper of the jaws) can be adjusted. The upper groove of the upper jaw and the lower groove of the lower jaw can adapt to the cone heads of femoral stems of different specifications, so as to achieve adaptation to the taper of the cone head of the femoral stem to be removed, and can effectively wrap the cone head of the femoral stem to be removed, so as to adapt to the cone heads of femoral stems of different lengths and different diameters, with good adaptation effect and simple operation. The front ends of the upper groove and the lower groove are respectively provided with a plurality of openings for the upper and lower jaws to clamp the femoral stems. The stem cone head can cooperate with the neck of the femoral stem to hook the upper boss and the lower boss of the femoral stem, so that when the upper jaw and the lower jaw clamp the stem cone head, the upper groove and the lower groove effectively wrap the stem cone head to be removed, and the upper boss and the lower boss hook the neck of the femoral stem, so as to better clamp the stem to be removed, and the stem can be removed efficiently and reliably; the stem removal forceps also include a spreading locking device for keeping the upper forceps arm and the lower forceps arm in a spread state to clamp the stem cone head, so as to better clamp the stem to be removed, free the hands, and facilitate use during surgery. The utility model is suitable for hip joint revision surgery.

[0040] According to the different structures of the upper jaws 4, 4' and the lower jaws 5, 5', the utility model can have the following embodiments:

[0041] Example 1

[0042] like Figure 1-4 As shown, the lower front end of the movable block 3 may be provided with a lug 31, and the rear portion of the lower jaw 5 may be provided with a receiving groove 53, and the lug 31 is hinged in the receiving groove 53, so that when the upper clamp arm 1 and the lower clamp arm 2 are loosened, and the upper jaw 4 and the lower jaw 5 are closed to clamp the femoral stem cone head, the lower jaw 5 can rotate around the hinge axis 54 (fixing pin) to achieve adaptation to the taper of the femoral stem cone head to be removed, and better clamp the femoral stem to be removed.

[0043] Example 2

[0044] like Figure 5-6As shown, the upper front end of the movable block 3 can be fixedly connected to the lower jaw 5', an upper liner 6' is provided in the upper groove 41', a lower liner 7' is provided in the lower groove 51', and an upper accommodating groove 61' and a lower accommodating groove 71' are respectively provided on the opposite end surfaces of the upper liner 6' and the lower liner 7';

[0045] An upper elastic member 62' is provided between the upper lining 6' and the bottom wall of the upper groove 41', which enables the upper lining 6' to move up and down in the upper groove 41'; a lower elastic member 72' is provided between the lower lining 7' and the bottom wall of the lower groove 51', which enables the lower lining 7' to move up and down in the lower groove 51'.

[0046] In this way, when the upper and lower clamp arms are loosened and the upper jaw 4' and the lower jaw 5' are closed to hold the femoral stem cone head, the upper liner 6' moves up and down in the upper groove 41', and the lower liner 7' moves up and down in the lower groove 51'. The upper and lower liners are automatically adjusted to adapt to femoral stem cone heads of different sizes. When the femoral stem cone head has the largest diameter, the upper and lower elastic parts are in the maximum compression state. As the cone head diameter decreases, the upper and lower elastic parts gradually restore their original lengths, but still fit the femoral stem cone head, and rely on the upper and lower bosses to hook the femoral stem neck, so as to achieve adaptation to the taper of the femoral stem cone head to be removed, and better clamp the femoral stem to be removed.

[0047] To make the movement of the upper and lower linings smoother, Figure 6 As shown, the upper surface of the upper lining 6' may be provided with an upper guide column 63', the bottom wall of the upper groove 41' is provided with an upper guide hole 43' matching with the upper guide column 63', and the upper elastic member 62' is an upper spring sleeved on the upper guide column 63'; the lower surface of the lower lining 7' may be provided with a lower guide column 73', the bottom wall of the lower groove 51' is provided with a lower guide hole (not shown) matching with the lower guide column 73', and the lower elastic member 72' is a lower spring sleeved on the lower guide column 73'.

[0048] To prevent the upper and lower liners from falling out, the lower end surface of the upper jaw 4' may be provided with upper fixing strips 44' on both sides of the upper groove 41' for preventing the upper lining 6' from falling out, and the upper end surface of the lower jaw 5' may be provided with lower fixing strips 54' on both sides of the lower groove 51' for preventing the lower lining 7' from falling out.

[0049] In the above embodiments, the expansion and locking device can adopt various structural forms that can be easily thought of by those skilled in the art. For example, the expansion and locking device includes an arc-shaped rack located at the rear of the upper clamp arm and a positioning tooth located at the rear of the lower clamp arm and matched with the arc-shaped rack; however, for ease of use, the present utility model preferably adopts the following structural form:

[0050] like Figure 1-2As shown, the lower rear side of the upper clamp arm 1 may be provided with a connecting rod sliding groove (not shown) extending along the length direction thereof, and the spreading and locking device includes a connecting rod 8 located between the upper clamp arm 1 and the lower clamp arm 2, the lower end of the connecting rod 8 is hinged to the middle of the lower clamp arm 2, and the upper end of the connecting rod 8 is slidably connected in the connecting rod sliding groove, and the spreading and locking device also includes a locking member located on the upper clamp arm 1 and used to lock the upper end of the connecting rod 8 in the connecting rod sliding groove. At this time, the connecting rod 8 forms a secondary lever between the upper clamp arm 1 and the lower clamp arm 2, forming a lever pressurization design, pushing the connecting rod 8, so that the upper end of the connecting rod 8 moves forward in the connecting rod sliding groove, and the upper end of the connecting rod 8 is locked in the connecting rod sliding groove by using the locking member, so that the upper clamp arm 1 and the lower clamp arm 2 can be kept in the spread state.

[0051] The locking member can adopt various structural forms that can be easily thought of by those skilled in the art, for example, the locking member is a locking screw located on the rear side of the upper clamp arm and used to squeeze the upper end of the connecting rod; however, for ease of use, the utility model preferably adopts the following structural form:

[0052] like Figure 1-2 and Figure 7 As shown, the rear end of the upper clamp arm 1 may be provided with a threaded hole (not shown) connected to the connecting rod sliding groove, and the locking member is an adjusting bolt 9 threadedly connected in the threaded hole, and the front end of the adjusting bolt 9 is provided with a supporting portion 91 for abutting against the upper end of the connecting rod 8, and the rear part of the adjusting bolt 9 is provided with a driving portion 92. At this time, the driving portion 92 of the adjusting bolt 9 is driven to make the abutting portion 91 of the adjusting bolt 9 gradually approach and press forward the upper end of the connecting rod 8, so that the upper end of the connecting rod 8 moves forward in the connecting rod sliding groove, and the locking degree of the upper and lower jaws can be adjusted to achieve final locking and keep the upper jaws 4, 4' and the lower jaws 5, 5' in a clamped state.

[0053] like Figure 1-2 As shown, the lower clamp arm 2 may be provided with an auxiliary support rod 10 located behind the connecting rod 8, the front end of the auxiliary support rod 10 is hinged to the inner side of the lower clamp arm 2, the front part of the auxiliary support rod 10 is used to push the middle part of the connecting rod 8, and the rear part of the auxiliary support rod 10 is used as an operating part, which extends to the rear end outside of the lower clamp arm 2, so that the connecting rod 8 can be driven with one hand, so that the upper end of the connecting rod 8 can be quickly moved forward in the connecting rod sliding groove, which is convenient for use during surgery. At this time, the operating part of the auxiliary support rod 10 is driven to make the front part of the auxiliary support rod 10 push the middle part of the connecting rod 8, so that the upper end of the connecting rod 8 can be moved forward in the connecting rod sliding groove.

[0054] A return spring 32 may be provided between the movable block 3 and the upper clamp arm 1, one end of the return spring 32 being fixed to the middle of the rear end of the movable block 3, and the other end being fixed to the middle of the upper clamp arm 1, so as to facilitate the resetting of the upper and lower clamp arms and facilitate use during surgery.

[0055] The front outer side surfaces of the upper jaw 4 and the lower jaw 5 can be designed with arc-shaped edges to avoid irritation to the tissue during the operation. The rear end of the adjusting bolt 9 can be connected with a slide hammer (not shown), so that after the final locking is achieved, the femoral stem can be removed more easily and conveniently with the help of the slide hammer.

[0056] The above is a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A femoral stem removal forceps, characterized in that: It includes an upper clamp arm, a lower clamp arm and a movable block, wherein: The front lower side of the upper clamp arm is hinged to the rear upper side of the movable block, the front end of the upper clamp arm is fixed with an upper jaw, the front end of the lower clamp arm is hinged to the rear lower side of the movable block, and the front end of the movable block is provided with a lower jaw; An upper groove and a lower groove are respectively provided on the opposite end surfaces of the upper jaw and the lower jaw for accommodating the femoral stem cone to be removed, and an upper boss and a lower boss are respectively provided at the front ends of the upper groove and the lower groove for cooperating with the neck of the femoral stem to hook the femoral stem when the upper jaw and the lower jaw clamp the femoral stem cone. The femoral stem extraction forceps also include a distraction locking device for keeping the upper forceps arm and the lower forceps arm in a distraction state to clamp the femoral stem cone head.

2. The femoral stem removal forceps according to claim 1, characterized in that: A lug is provided at the lower part of the front end of the movable block, and a receiving groove is provided at the rear part of the lower jaw, and the lug is hinged in the receiving groove.

3. The femoral stem removal forceps according to claim 1, characterized in that: The upper front end of the movable block is fixedly connected to the lower jaw, an upper liner is arranged in the upper groove, a lower liner is arranged in the lower groove, and an upper accommodating groove and a lower accommodating groove are respectively arranged on opposite end surfaces of the upper liner and the lower liner; An upper elastic member capable of enabling the upper liner to move up and down in the upper groove is provided between the upper liner and the bottom wall of the upper groove, and a lower elastic member capable of enabling the lower liner to move up and down in the lower groove is provided between the lower liner and the bottom wall of the lower groove.

4. The femoral stem removal forceps according to claim 3, characterized in that: An upper guide column is provided on the upper surface of the upper liner, an upper guide hole matching with the upper guide column is provided on the bottom wall of the upper groove, and the upper elastic member is an upper spring sleeved on the upper guide column; And / or, a lower guide column is provided on the lower surface of the lower lining, a lower guide hole matching with the lower guide column is provided on the bottom wall of the lower groove, and the lower elastic member is a lower spring sleeved on the lower guide column.

5. The femoral stem removal forceps according to claim 3, characterized in that: The lower end surface of the upper jaw is provided with upper fixing strips on both sides of the upper groove for preventing the upper lining from falling out; And / or, the upper end surface of the lower jaw is provided with lower fixing strips on both sides of the lower groove for preventing the lower lining from falling out.

6. The femoral stem removal forceps according to any one of claims 1 to 5, characterized in that: A connecting rod sliding groove extending along the length direction of the upper clamp arm is provided on the lower rear side of the upper clamp arm, and the expansion and locking device includes a connecting rod located between the upper clamp arm and the lower clamp arm, the lower end of the connecting rod is hinged to the middle part of the lower clamp arm, and the upper end of the connecting rod is slidably connected in the connecting rod sliding groove. The expansion and locking device also includes a locking piece located on the upper clamp arm and used to lock the upper end of the connecting rod in the connecting rod sliding groove.

7. The femoral stem removal forceps according to claim 6, characterized in that: The rear end of the upper clamp arm is provided with a threaded hole connected to the connecting rod sliding groove, the locking piece is an adjusting bolt threadedly connected in the threaded hole, the front end of the adjusting bolt is provided with a supporting portion for abutting against the upper end of the connecting rod, and the rear part of the adjusting bolt is provided with a driving portion.

8. The femoral stem removal forceps according to claim 6, characterized in that: The lower clamp arm is provided with an auxiliary support rod located behind the connecting rod, the front end of the auxiliary support rod is hinged to the inner side of the lower clamp arm, the front part of the auxiliary support rod is used to push the middle part of the connecting rod, and the rear part of the auxiliary support rod is used as an operating part, which extends to the outer side of the rear end of the lower clamp arm.

9. The femoral stem removal forceps according to claim 6, characterized in that: A return spring is arranged between the movable block and the upper clamp arm, one end of the return spring is fixed to the middle part of the rear end of the movable block, and the other end is fixed to the middle part of the upper clamp arm.

10. The femoral stem removal forceps according to claim 7, characterized in that: The front outer sides of the upper jaw and the lower jaw are both designed with arc-shaped edges; And / or, a sliding hammer is connected to the rear end of the adjusting bolt.

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