Medial collateral ligament protector during meniscectomy in knee replacement surgery

Abstract

A medial collateral ligament protector for meniscus resection during knee replacement surgery comprises a protector body that is elongated and has a flat cross-section. The rear end of the protector body is straightened and extended to form a handle, and the front end of the protector body is bent in an arc with an arc angle of 2π / 9 to form a shielding portion for shielding the medial collateral ligament. The total width of the front end of the shielding portion is 22-24 mm, and a trapezoidal opening groove is provided at the front end, biased toward the central axis of the protector body, for making way for the meniscus. The trapezoidal opening groove extends backward along the arc of the shielding portion. The groove depth of the trapezoidal opening groove is 20-24 mm, and the groove width of the trapezoidal opening groove is 6-8 mm, which is the large end of the opening. The angle between the oblique sides of the trapezoidal opening groove is 10°. The trapezoidal opening groove divides the shielding portion into a femoral isolation portion and a tibial isolation portion. The width of the femoral isolation portion is 9-12 mm, and the width of the tibial isolation portion is half of the femoral isolation portion.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a medial collateral ligament protector during meniscus resection in knee replacement surgery. Background Art

[0002] The medial collateral ligament (MCL) is a flat strip with a length of 96.40±4.49mm, a width of 12.53±2.22mm, and a thickness of 1.82±0.36mm. It originates from the medial epicondyle of the femur and inserts 7-10cm below the articular surface. It is divided into three layers from the bottom: 1. The superficial layer of the medial collateral ligament, also known as the anterior bundle of the medial collateral ligament, has an oval attachment point on the femur, usually 3.2mm above the medial epicondyle and 4.8mm behind the medial epicondyle of the femur. The superficial layer of the medial collateral ligament extends distally to two insertions on the tibia. The proximal insertion is mainly covered by a layer of soft tissue and is located in front of the semimembranosus tendon. It is located approximately 12.2mm below the tibial joint line. The distal insertion is wider and is directly attached to the tibia, approximately 61.2mm distal to the tibial joint line, just anterior to the posteromedial tibial crest. 2. The posterior oblique ligament, also known as the posterior bundle of the medial collateral ligament, has a femoral attachment point that differs considerably in its description. It is generally believed that the posterior oblique ligament originates posterior to the superficial fibers of the medial femoral condyle, fanning downward to insert on the posterior half of the medial tibial condyle below the joint line. 3. The deep medial collateral ligament extends vertically downward from the bony surface of the inferior periphery of the medial epicondyle of the femur (approximately 20.72 ± 2.52 mm from the horizontal line of the joint), attaches to the mid-periphery of the medial meniscus, and inserts on the bony surface below the articular surface at the midpoint of the medial margin of the tibial plateau (approximately 7.32 ± 3.23 mm). The medial meniscus is C-shaped, narrow at the anterior end and wide at the posterior end. The mid-lateral portion of the outer margin is connected to the fibrous layer of the joint capsule and the deep layer of the medial collateral ligament.

[0003] During knee replacement surgery, the medial collateral ligament (MCL) forms a 78° angle with the horizontal when the knee is in 90-degree flexion, increasing its contact area with the medial meniscus. This increases the risk of accidental injury to the ligament during meniscus removal. The MCL is the most critical structure for maintaining medial knee stability. Damage to the ligament can negatively impact the long-term survival of the prosthesis and lead to knee replacement failure. Currently, there are two common methods for protecting the medial collateral ligament during knee replacement surgery: one is to fully expose the tibial plateau, then use toothed forceps to grasp the medial meniscus, pull it away from the medial collateral ligament, and then remove the meniscus. However, because the medial collateral ligament is closely connected to the meniscus, the medial collateral ligament will inevitably be pulled along with it during the pulling of the medial meniscus, making the boundary between the medial meniscus and the medial collateral ligament more blurred, thereby causing damage to the medial collateral ligament during meniscus removal. The other method is to have an assistant use a retractor to pull the medial collateral ligament away from the joint surface during meniscus removal. However, the contact area between the medial collateral ligament and the medial collateral ligament with existing retractors is small, and they can only pull the surface of the medial collateral ligament, which will cause the deep layer of the medial collateral ligament to be closer to the meniscus. Therefore, it is difficult to clearly expose the contact point between the medial collateral ligament and the meniscus, which can easily cause medial collateral ligament damage during meniscus removal.

[0004] Because the gap between the medial meniscus, joint capsule and the deep layer of the medial collateral ligament is narrow, it is difficult for ordinary retractors to penetrate the gap between the meniscus and the medial collateral ligament. Therefore, it is necessary to design a tool that can not only penetrate the gap between the medial meniscus, joint capsule and the deep layer of the medial collateral ligament, but also fully expose the contact area to better protect the medial collateral ligament. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the existing technology and provide a medial collateral ligament protector for meniscus resection during knee replacement surgery. The protector can be inserted into the gap formed by the medial meniscus, the joint capsule and the deep layer of the medial collateral ligament, and the medial collateral ligament is blocked on the inner side of the arc of the shielding portion, so that the upper and lower edges of the contact between the meniscus and the medial collateral ligament are fully exposed, thereby protecting the medial collateral ligament when the meniscus is removed.

[0006] The technical solution of the present invention is: a medial collateral ligament protector during meniscus resection during knee replacement surgery, comprising a protector body that is long and has a flat cross-section, the rear end of the protector body is straightened and extended to form a handle, the front end of the protector body is bent in an arc with an arc angle of 2π / 9 to form a shielding part for shielding the medial collateral ligament, the total width of the front end of the shielding part is 22~24mm, and a trapezoidal opening groove is provided at the front end biased towards the central axis of the protector body to make way for the meniscus, the trapezoidal opening groove extends backward along the arc of the shielding part, the groove depth of the trapezoidal opening groove is 20~24mm, the groove width of the trapezoidal opening groove is 6~8mm, which is the large end of the opening, the angle between the oblique sides of the trapezoidal opening groove is 10°, the trapezoidal opening groove divides the shielding part into a femoral isolation part and a tibial isolation part, the width of the femoral isolation part is 9~12mm, and the width of the tibial isolation part is half of the femoral isolation part.

[0007] Furthermore, the shielding portion is in a shape with a wide front end and a gradually narrowing tail end, the tail end of the shielding portion is connected to the front end of the handle, and the angle between the oblique sides on both sides of the shielding portion is 10°.

[0008] Furthermore, the length of the handle is 200-210 mm, and the width gradually increases from the front end to the rear end for gripping.

[0009] Furthermore, a hanging hole is provided at the rear end of the handle.

[0010] Furthermore, two corners on the outer side of the front end of the shielding portion are chamfered with circular arcs, and two sides of the notch of the trapezoidal opening groove of the shielding portion are chamfered with circular arcs.

[0011] Furthermore, the thickness of the protector body is 1-2 mm.

[0012] The above-mentioned technical solution is adopted: it includes a protector body with a long strip shape and a flat cross-section, the rear end of the protector body is straightened and extended to form a handle, and the front end of the protector body is curved in an arc with an arc angle of 2π / 9 to form a shielding part for shielding the medial collateral ligament. The shielding part can be inserted into the gap formed by the medial meniscus, the joint capsule and the medial collateral ligament, and because the shielding part is curved in an arc shape, the shielding part can fit the medial collateral ligament after being inserted into the gap, so that the medial collateral ligament can be blocked by the inner side of the arc of the shielding part. The total width of the front end of the shielding part is 22~24mm, and a trapezoidal opening groove is set at the front end, biased towards the central axis of the protector body, for making way for the meniscus. The trapezoidal opening groove extends backward along the arc of the shielding part. The groove depth of the trapezoidal opening groove is 20~24mm, and the groove width of the trapezoidal opening groove is 6~8mm, which is the large end of the opening. The angle between the oblique sides of the trapezoidal opening groove is 10°, and the width of the trapezoidal opening groove gradually decreases, which can match the width of the connection between different types of medial meniscus and medial collateral ligament, so that the contact between the medial meniscus and the medial collateral ligament can be stuck in the trapezoidal opening groove. The trapezoidal opening groove divides the shielding part into a femoral isolation part and a tibial isolation part. The width of the femoral isolation part is 9~12mm, and the width of the tibial isolation part is half of the femoral isolation part. The femoral isolation part is used to be inserted into the gap between the femoral condyle and the medial collateral ligament, and the tibial isolation part is used to be inserted into the gap between the tibial plateau and the medial collateral ligament, which can increase the contact area between the shielding part and the deep layer of the medial collateral ligament. At this time, the medial collateral ligament is located on the inner side of the arc of the shielding part and fits into the concave surface of the arc-shaped shielding part. Then, the deep layer of the medial collateral ligament can be pulled away from the bone joint surface by applying force with the handle, thereby separating the contact between the medial collateral ligament and the medial meniscus, thereby fully exposing the upper and lower edges of the contact between the medial meniscus and the medial collateral ligament. Therefore, the surgeon will not damage the medial collateral ligament when removing the medial meniscus at this time, which facilitates the surgical operation, plays a role in protecting the medial collateral ligament, shortens the operation time, and reduces postoperative complications.

[0013] The shielding part is wide at the front end and gradually narrows at the tail end. The tail end of the shielding part is connected to the front end of the handle. The angle between the oblique sides on both sides of the shielding part is 10°, that is, the width of the front and rear ends of the femoral isolation part are consistent, and the width of the front and rear ends of the tibial isolation part are consistent, so that the rear ends of the two isolation parts can be smoothly inserted along the insertion path of the front end, and at the same time, it is convenient to observe whether the femoral isolation part and the tibial isolation part of the shielding part are inserted in place.

[0014] The length of the handle is 200-210 mm, and the width gradually increases from the front end to the rear end for gripping, which can not only reduce the handle's obstruction of the surgical field of view, but also make it easier for doctors to grip and apply force during surgery.

[0015] The two outer corners of the front end of the shielding part are chamfered with arcs, and the two sides of the notch of the trapezoidal opening groove of the shielding part are chamfered with arcs to avoid scratching ligaments or muscle tissues due to the sharp front end of the shielding part and the trapezoidal opening groove during insertion.

[0016] The thickness of the protector body is 1-2 mm, ensuring that the shielding part can be inserted into the narrow gap formed between the medial meniscus, the joint capsule and the deep layer of the MCL.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 for Figure 1 A-direction schematic diagram;

[0020] Figure 3 for Figure 2 Schematic diagram of direction B. DETAILED DESCRIPTION

[0021] See also Figures 1 to 3A medial collateral ligament protector for meniscus resection during knee replacement surgery includes a protector body that is long and flat in cross-section. The thickness of the protector body is 1-2 mm. The protector body of this embodiment is optimally 1 mm thick to ensure that the shielding portion 2 can be smoothly inserted into the narrow gap formed between the medial meniscus, the joint capsule, and the deep layer of the medial collateral ligament. The rear end of the protector body is straightened and extended to form a handle 1. The length of the handle 1 is 200-210 mm, and the width gradually increases from the front end to the rear end for gripping. This can reduce the obstruction of the surgical field by the handle 1 and facilitate the doctor's grip and force application during surgery. The handle 1 of this embodiment is optimally 200 mm long, which is suitable for the width of the palm of most doctors. The rear end of the handle 1 is provided with a hanging hole 6. The front end of the protector body is curved in an arc with an arc angle of 2π / 9 to form a shielding part 2 for shielding the medial collateral ligament. The shielding part 2 is used to be inserted into the gap formed by the medial meniscus, the joint capsule and the medial collateral ligament. Since the shielding part 2 is curved in an arc, the shielding part can fit the medial collateral ligament after being inserted into the gap, so that the medial collateral ligament can be isolated on the inner side of the arc of the shielding part. The medial collateral ligament is then fitted into the concave surface of the shielding part 2, making it convenient to apply force to pull the medial collateral ligament away from the medial meniscus. The total width of the front end of the shielding portion 2 is 22~24mm, and a trapezoidal opening groove 3 for making way for the meniscus is set at the front end, which is biased towards the central axis of the protector body. The trapezoidal opening groove 3 extends backward in an arc along the shielding portion 2, and the groove depth of the trapezoidal opening groove 3 is 20~24mm. In this embodiment, the groove depth of the trapezoidal opening groove 3 is 22mm, which is the best. The groove width of the trapezoidal opening groove 3 is 6~8mm, which is the largest end of the opening. In this embodiment, the groove width of the trapezoidal opening groove 3 is 8mm, which is the best. The angle between the oblique sides of the trapezoidal opening groove 3 is 10° The width of the trapezoidal opening groove 3 is greater than the width of the groove bottom. The width and depth of the trapezoidal opening groove 3 are designed according to the attachment point of the deep layer of the medial collateral ligament on the medial femoral condyle and the medial tibial condyle, as well as the thickness of the contact point with the medial meniscus. When inserted, it can adapt to the shape of the medial meniscus with a narrow front end and a wide rear end, so that the contact point between the medial meniscus and the medial collateral ligament can be stuck in the trapezoidal opening groove 3. The width of the trapezoidal opening groove 3 gradually decreases, which can match the width of the connection between different types of medial menisci and the medial collateral ligament. The two corners of the front outer side of the shielding part 2 are chamfered with arcs, and the two sides of the notch of the trapezoidal opening groove 3 of the shielding part 2 are chamfered with arcs to avoid scratching ligaments or muscle tissues due to the sharp edges of the front end of the shielding part 2 and the trapezoidal opening groove 3 during insertion.The trapezoidal opening groove 3 divides the shielding part 2 into a femoral isolation part 4 and a tibial isolation part 5. The width of the femoral isolation part 4 is 9~12mm. In this embodiment, the optimal width of the femoral isolation part 4 is 10mm. The width of the tibial isolation part 5 is half of the femoral isolation part 4. The femoral isolation part 4 is used to be inserted into the gap between the femoral condyle and the medial collateral ligament, and the tibial isolation part 5 is used to be inserted into the gap between the tibial plateau and the medial collateral ligament. Since the gap between the femoral condyle and the medial collateral ligament is larger than the gap between the tibia and the medial collateral ligament, the width of the femoral isolation part 4 is set to be larger than the width of the tibial isolation part 5. This can increase the contact area between the shielding part 2 and the deep layer of the medial collateral ligament, ensuring that the medial collateral ligament can be pulled away from the contact point of the medial meniscus during surgery.

[0022] The present protector is not limited to the above-mentioned embodiment. The shielding part 2 can also be in a shape with a wide front end and a gradually narrowing tail end. The tail end of the shielding part 2 is connected to the front end of the handle 1. The angle between the oblique sides on both sides of the shielding part 2 is 10°, that is, the width of the front and rear ends of the femoral isolation part 4 is consistent, and the width of the front and rear ends of the tibial isolation part 5 is consistent, so that the rear ends of the two isolation parts can be smoothly inserted along the insertion path of the front end, and it is convenient to observe whether the femoral isolation part 4 and the tibial isolation part 5 are inserted in place.

[0023] Attachment Figure 1-3 The figure shows a protector for right knee surgery. The positions of the femoral isolation part and the tibial isolation part of the protector for the left knee can be opposite to those of this embodiment. This embodiment takes the protector for the right knee as an example. When using this protector, first make the patient's knee joint flexed at 90 degrees, clean the joint cavity, remove excess bone spurs, and expose the gap between the medial meniscus and the medial collateral ligament, femur, and tibia; then hold the handle 1 of this protector with the arc-shaped concave surface of the shielding part 2 facing the medial collateral ligament, insert the femoral isolation part 4 into the gap between the medial collateral ligament and the medial condyle of the femur, and at the same time insert the tibial isolation part 5 into the gap between the medial collateral ligament and the tibial plateau. At this time, the contact point between the medial meniscus and the medial collateral ligament is stuck in the trapezoidal opening groove 3, and then Continue to extend the shielding part 2 until the contact position of the medial meniscus and the medial collateral ligament is completely stuck in the trapezoidal opening groove 3. At this time, the medial collateral ligament is blocked by the arc-shaped inner side of the shielding part 2 and fits into the concave surface of the arc-shaped shielding part 2; then apply force through the handle 1 to pull the deep layer of the medial collateral ligament away from the bone joint surface, thereby separating the contact point between the medial collateral ligament and the medial meniscus, thereby fully exposing the upper and lower edges of the contact point between the medial meniscus and the medial collateral ligament, and the surgeon removes the medial meniscus along the trapezoidal opening groove 3. After completing the medial meniscus removal, the protector can be removed.

[0024] In summary, the shielding plate 2 of the present protector is designed according to the size of the gap formed by the medial meniscus, the joint capsule and the deep layer of the medial collateral ligament, as well as the thickness of the meniscus, which can solve the problem that ordinary retractors cannot penetrate into the gap. The shielding plate 2 of the present protector has a large contact area with the deep layer of the medial collateral ligament and a high degree of fit, which can not only ensure that the upper and lower edges of the meniscus and the deep layer of the medial collateral ligament are fully exposed, but also isolate the medial collateral ligament outside the trapezoidal opening groove 3. Therefore, it can greatly improve the convenience of the surgeon in removing the medial meniscus, facilitate the surgical operation, avoid damage to the medial collateral ligament, play a role in protecting the medial collateral ligament, and reduce postoperative complications; and simplify the surgical operation process, shorten the operation time, and is easy to use, fast and convenient. In addition, the present protector has a simple structure, is easy to make, is safe and reliable to use, and is easy to implement and promote on a large scale.

Claims

1. A medial collateral ligament protector for meniscus resection during knee replacement surgery, characterized by: The invention comprises a protector body having a long strip shape and a flat cross-section, wherein the rear end of the protector body is straightened and extended to form a handle (1), and the front end of the protector body is curved in an arc with an arc angle of 2π / 9 to form a shielding portion (2) for shielding the medial collateral ligament, wherein the shielding portion (2) is wide at the front end and gradually narrows at the rear end, and the rear end of the shielding portion is connected to the front end of the handle (1), and the total width of the front end of the shielding portion (2) is 22-24 mm, and a trapezoidal opening groove (3) for making way for the meniscus is provided at the front end, which is biased toward the central axis of the protector body. The trapezoidal opening groove (3) is provided at the front end. ) extends backward along the shielding portion (2) in an arc shape, the groove depth of the trapezoidal opening groove (3) is 20~24mm, the groove width of the trapezoidal opening groove (3) is 6~8mm, which is the large end of the opening, the angle between the oblique sides of the trapezoidal opening groove (3) is 10°, and the angle between the oblique sides of the shielding portion (2) is 10°. The trapezoidal opening groove (3) divides the shielding portion (2) into a femoral isolation portion (4) and a tibial isolation portion (5), the width of the femoral isolation portion (4) is 9~12mm, and the width of the tibial isolation portion (5) is half of the femoral isolation portion (4).

2. The medial collateral ligament protector for meniscectomy during knee replacement surgery according to claim 1, characterized in that: The handle (1) has a length of 200-210 mm and a width that gradually increases from the front end to the rear end for gripping.

3. The medial collateral ligament protector for meniscectomy during knee replacement surgery according to claim 1, characterized in that: A hanging hole (6) is provided at the rear end of the handle (1).

4. The medial collateral ligament protector for meniscectomy during knee replacement surgery according to claim 1, characterized in that: The two outer corners of the front end of the shielding portion (2) are arc chamfered, and both sides of the notch of the trapezoidal opening groove (3) of the shielding portion (2) are arc chamfered.

5. The medial collateral ligament protector for meniscectomy during knee replacement surgery according to claim 1, characterized in that: The thickness of the protector body is 1-2 mm.

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