CN201253254Y - Instrument for anterior approach operation of thoracolumbar - Google Patents

Abstract

The utility model provides a set of instruments for thoracolumbar anterior surgery, which is composed of a long-handled retractor I, a long-handled periosteum stripper II, a long-handled bone knife III, a long-handled curette IV and a long-handled endplate curette V. Handle retractor I is composed of retractor tip 1, head 2, body 3, and round hole 4 at the tail end; long-handled periosteal stripper II is composed of round blunt head 5, body 6, and handle 7; the long-handle osteotome III consists of a flat cutter head 8, a body 9, and a tail 10; a long-handled curette IV consists of a blunt curette head 11 with a curved hook, a body 12, and a tapered handle 13; the long-handled endplate The curette V is composed of a curette head 14 , a body 15 and a handle 16 in a hollow oval structure. The utility model has reasonable design, simple and convenient manufacturing process and low cost. Using the instrument of the utility model can reduce the surgical incision, improve the surgical field of view, optimize the surgical steps, reduce the difficulty of the operation, reduce the bleeding in the operation, and shorten the operation time.

Description

A set of instruments for anterior thoracolumbar surgery

technical field

The utility model belongs to a surgical instrument, which relates to a surgical instrument for the spine, and mainly relates to a set of instruments for thoracolumbar anterior surgery.

Background technique

Accidents such as traffic, work injury, and falling from heights are likely to cause spinal fractures, 90% of which are thoracolumbar fractures. For such fractures, especially severe blowout fractures, conservative treatment is ineffective and surgical treatment is often required.

Currently, surgical treatment includes anterior surgery and posterior surgery. Due to the advantages of simple approach, few complications, and significant short-term curative effect, the posterior approach has become the most commonly used surgical method for the treatment of thoracolumbar fractures. It achieves reduction and decompression of vertebral fractures by opening the intervertebral space and tightening the anterior and posterior ligament complexes. However, in cases of severe vertebral body compression (more than 50%), severe trabecular bone fractures exist inside the vertebral body, and at the same time, the accompanying instantaneous axial force causes the intervertebral disc tissue to protrude into the vertebral body through the ruptured endplate. Although the posterior approach can significantly improve the appearance of the vertebral body, the internal intervertebral disc tissue and trabecular bone structure cannot be well restored, so the result is similar to the "soft tissue embedding" of the broken end of a limb, which seriously affects the interior of the vertebral body The fracture healed, leading to long-term "eggshell changes" in the vertebral body. In addition, in the process of distracting the intervertebral space through the posterior approach, peripheral endplate fractures can be reduced with the tension of the fibrous annulus, but for central endplate fractures, due to the lack of attachment of the fibrous annulus, satisfactory reduction cannot be obtained . The change in the shape of the endplate will eventually lead to pathological changes in the three-dimensional structure of the intervertebral space. In order to adapt to the change in the shape of the intervertebral disc, the intervertebral disc will creep, making it gradually lose the role of buffering and absorbing loads, resulting in increased stress on the vertebral body. , causing loss of height of the injured vertebrae, long-term progressive kyphosis and low back pain. Furthermore, for some cases of spinal canal occupying, the posterior approach may achieve the goal of indirect decompression by resecting the laminae and expanding the space of the spinal canal. However, if the spinal canal seriously occupies space or the bone in the spinal canal turns over, this indirect decompression effect is not ideal, and the surgical method of removing the laminae will not only lead to the formation of epidural scars, but will further damage the structure of the posterior column. Integrity, weakening the stability of the spine. The anterior and central column bears about 70% of the spinal load. In severe thoracolumbar fractures, the anterior and central column is often injured, and the center of rotation of the spine located in the posterior half of the intervertebral disc often shifts along with the fracture. If the stability of the anterior and central column and the center of rotation cannot be restored after fracture surgery, the load on the posterior internal fixation will increase abnormally, causing complications such as broken nails and rods.

The anterior spinal technique removes the compression objects under direct vision, the decompression range is thorough and wide, the spinal canal is expanded reliably, and does not interfere with the stability of the posterior column structure; the spinal cord does not need to be stretched during the decompression process, and the risk of nerve injury is small; at the same time , Through subtotal resection of the injured vertebrae, the problems caused by non-reduction of trabecular bone and endplate fractures, intervertebral disc tissue embedded in the vertebral body, etc. were eliminated; with the use of structural bone grafting and anterior internal fixation instruments, the anterior and central column was restored Center of stability and rotation of the spine. Therefore, severe thoracolumbar vertebral body bursts such as severe compression of some vertebral bodies (over 75% of the anterior height compression), obvious space occupation of the spinal canal (more than 50%), severe kyphosis (greater than 30 degrees) or fracture time of more than 2 weeks For fracture cases, the anterior technique has obvious advantages in terms of surgical decompression, fracture healing, biomechanical stability, and long-term efficacy.

Although the anterior approach has the above advantages, the traditional anterior approach also has some obvious defects, such as: large surgical trauma, difficulty in exposing the diseased vertebra, excessive bleeding during the operation, long operation time, and difficult revision, etc. These technical bottlenecks are serious This restricts its wide clinical application, especially in some grassroots hospitals, which often regard posterior surgery as the final treatment plan for all thoracolumbar fractures.

Contents of the invention

The purpose of the utility model is to design and provide a set of instruments for thoracolumbar anterior surgery on the premise of satisfying the ideal goal of anterior surgery. A set of instruments provided by the utility model is composed of a long-handled retractor, a long-handled periosteum stripper, a long-handled bone knife, a long-handled curette and a long-handled endplate curette. The long-handled retractor is composed of a retractor tip, a head, a body and The tail end is composed of a round hole; the long-handled periosteal stripper is composed of a head, body and handle; the long-handled bone knife is composed of a flat head, body and tail; the long-handled curette is composed of a blunt curved hook The curette head, body and tapered handle; the long-handled endplate curette is composed of a hollow oval curette head, body and handle with a wavy surface design.

The tip of the long-handled retractor is used to fix the upper and lower vertebral bodies of the diseased vertebrae. Its head is wider in a trapezoidal shape with a narrow bottom and a wide top, which can push away soft tissues. The body is longer and is suitable for deep exposure in anterior surgery. Features, the round hole at the end can be used to bind the sterile bandage to the chest support handle, so as to achieve the purpose of retracting the lung lobe to expose the surgical field of the diseased vertebra.

The head of the long-handled periosteal stripper is round and blunt, which is used to compress blood vessels. The connection between the handle and the body is in a tapered structure, which is suitable for human beings to hold objects with both hands. The body is long and suitable for deep anterior surgery. features.

The head of the long-handled bone knife is flat and has no curvature. When in use, the direction is always perpendicular to the trunk of the specimen to avoid entering the spinal canal. The body is longer, which is in line with the characteristics of deep anterior thoracolumbar surgery. The cross-section of the tail is larger than the body. , to ensure a more stable hammer strike.

The head of the long-handled curette is a blunt hook, which is used to separate bone fragments from dura mater, bone fragments and intervertebral disc tissue. The junction of the parts is a tapered structure, which is in line with the anatomical characteristics of the human hand holding the fist.

The inner edge of the endplate curette with long handle is sharp, and it is used to remove the endplate and intervertebral disc tissue.

The method for using the set of instruments provided by the utility model in corpse specimens:

The surgical incision starts from the posterior axillary line of the cadaver specimen, obliquely forward and downward to the vicinity of the anterior axillary line, about 13-18 cm. For patients with lumbar ₁ lesion, choose the _12th rib approach, cut the left diaphragmatic crus, and peel off the _12th thoracic vertebral body The front parietal pleura, and make full use of the waist bridge to expand the exposure space, so as not to enter the chest;

Surgical area exposure: Use the lumbar bridge to bend the thoracolumbar spine to the left, expand the left intercostal space, increase the distance between the costal arch and the iliac crest, and expand the exposure space. The tip of the long-handled retractor is fixed to the vertebral body, and the tail is fixed to the thoracic spreader, which makes the exposure tool a whole and improves the exposure effect;

Segmental arterial treatment: the long-handled periosteum stripper is used to compress both ends of the blood vessel to treat the segmental blood vessel, the proximal end is fully freed and given double ligation or suturing, and the distal end is ligated or electrocoagulated to stop bleeding. During the operation, only the corresponding unilateral segmental artery of the diseased vertebra was ligated;

Spinal canal decompression: first use a sharp knife to cut off the first half of the upper and lower intervertebral discs of the diseased vertebra, and then directly use a bone knife to chisel out the anterior middle part of the vertebral body. The direction of the bone knife is always perpendicular to the patient's trunk to avoid entering the spinal canal by mistake, and a sharp circular chisel is used instead Carefully chisel off the back wall of the diseased vertebra, and enter the spinal canal from the back wall for decompression. For those with old fractures, a breakthrough point can be found between the posterior wall of the bone and the spinal canal with a drill, and then a small curette with a long handle or a meningeal hook can be used to carefully separate the bone fragments of the canal wall from the dura mater, and remove the fracture fragments protruding into the spinal canal. Complete decompression of the anterior wall of the spinal canal;

Bone graft preparation: decompress to the spinal canal, prepare the bone graft bed and titanium surgical mesh bone graft components in advance, once the decompression is satisfactory, the bone graft can be completed quickly.

The beneficial part of the utility model is:

1. The utility model has reasonable design, simple manufacturing process, low cost and convenient use.

2. The surgical incision is greatly reduced. The traditional thoracolumbar anterior surgery incision is as long as 30cm, but the method of the utility model is used, and the incision length is only about 15cm;

3. The surgical field of view is greatly improved, and the distance between the iliac crest and the costal arch is enlarged by using the lumbar bridge of the operating bed. At the same time, the special long-handled retractor is used together with the thoracic spreader to ensure a stable and clear surgical field of view;

4. Optimizing the operation steps and reducing the difficulty of the operation. It is one of the difficulties in the operation to deal with the segmental arteries during the anterior thoracolumbar surgery. The application of the method and instrument for dealing with the segmental arteries of the utility model reduces the risk of rupture and bleeding of the segmental arteries. At the same time, the simplified spinal canal decompression technique is used to reduce the difficulty of decompression;

5. Reduce intraoperative bleeding, reduce surgical complications, and reduce spinal venous plexus bleeding through the above-mentioned optimized spinal canal decompression and bone graft internal fixation process;

6. Shorten the operation time. By using the technology and special instruments of the present utility model, the operation process is simplified, the operation difficulty is reduced, the operation time is obviously shortened, the hospitalization time is shortened, and the hospitalization fee is reduced.

7. To provide a set of simple and fast teaching methods for thoracolumbar anterior surgery for the training of medical students.

Description of drawings

Fig. 1 is a schematic diagram of a long-handled drag hook of the present invention.

Fig. 2 is a schematic diagram of the long handle periosteal stripper of the present invention.

Fig. 3 is a schematic diagram of the long handle bone knife of the present invention.

Fig. 4 is a schematic diagram of a long-handled curette of the present invention.

Fig. 5 is a schematic diagram of the long-handled endplate curette of the present invention.

Detailed ways

The utility model is further described in conjunction with the accompanying drawings and embodiments.

Example 1

A set of instruments provided by the utility model is composed of a long-handled retractor I, a long-handled periosteum stripper II, a long-handled bone knife III, a long-handled curette IV and a long-handled endplate curette V. The long-handled retractor I is composed of a retractor tip 1 , a head 2, a body 3 and a round hole 4 at the tail end; the long-handled periosteal stripper II is made of a head 5, a body 6 and a handle 7; the long-handled osteotome III is made of a flat cutter head 8, a body The long-handled curette IV is composed of a blunt curette head 11 with a curved hook, a body 12 and a tapered handle 13; the long-handled endplate curette V is composed of a hollow oval curette. The spoon head 14, the body 15 and the handle 16 with a corrugated surface design are formed.

The hook tip 1 of the long-handle drag hook 1 is used to fix the upper and lower vertebral bodies of the diseased vertebra. The head 2 is wider and has a trapezoidal shape with a narrow bottom and a wide top, which can push away soft tissues. The body 3 is longer and suitable for the anterior path Due to the deep surgical exposure position, the round hole 4 at the tail end can be used to bind the sterile bandage to the chest support handle, so as to achieve the purpose of retracting the lung lobe to expose the surgical field of the diseased vertebra.

The head 5 of the long-handle periosteal stripper II is round and blunt, and is used to compress blood vessels. The connection between the handle 7 and the body 6 is in a tapered structure, which is suitable for holding objects with both hands. The body 6 is longer and suitable for front The characteristics of deep operation position.

The head 8 of the long-handled bone knife III is flat and has no radian. When in use, the direction is always perpendicular to the trunk of the specimen to avoid entering the spinal canal. The section is larger than the body portion 9 to ensure that the hammer strikes more stably.

The head 11 of the long-handled curette IV is a round and blunt hook, which is used to separate the bone fragment from the dura mater, bone fragment and intervertebral disc tissue. The connection between the handle 13 and the body 12 is in a tapered structure, which conforms to the anatomical characteristics of a human hand holding an object in a fist.

The inner edge of the curette head 14 of the long-handled endplate curette V is sharp, and is used to remove the endplate and intervertebral disc tissue. The body 15 is longer, which is in line with the characteristics of deep anterior thoracolumbar surgery.

Embodiment 2 The method of use in fresh frozen corpse specimens

1. Fresh frozen cadaver specimens are taken in lateral position. Renal support is placed on both sides of the pelvis and upper chest, and the operating bed restraint belt is used to keep the trunk in the positive lateral position, which is very important for the direction of screw entry during spinal canal decompression and fixation. During the key steps of the operation, such as decompression of the spinal canal and screw fixation, it is best to ensure that the specimen is in the lateral decubitus position, so as to prevent the bone knife and screw from entering the spinal canal or damaging the paravertebral blood vessels.

2. The surgical incision starts from the posterior axillary line, obliquely forward and downward to near the anterior axillary line, about 13-18cm. For the lumbar ₁ surgical specimen, choose the _12th thoracic rib approach, incise the left diaphragmatic crus, peel off the parietal pleura in front of the _12th thoracic vertebra, and make full use of the lumbar bridge to expand the exposure space to achieve the purpose of not entering the chest;

Surgical area exposure: Use the lumbar bridge to bend the thoracolumbar spine to the left, expand the left intercostal space, increase the distance between the costal arch and the iliac crest, and expand the exposure space. The tip of the long-handled retractor is fixed to the vertebral body, and the tail is fixed to the thoracic spreader, which makes the exposure tool a whole and improves the exposure effect;

Segmental arterial treatment: the long-handled periosteum stripper is used to compress both ends of the blood vessel to treat the segmental blood vessel, the proximal end is fully freed and given double ligation or suturing, and the distal end is ligated or electrocoagulated to stop bleeding. During the operation, only the corresponding unilateral segmental artery of the diseased vertebra was ligated;

Spinal canal decompression: first use a sharp knife to cut off the first half of the upper and lower intervertebral discs of the diseased vertebrae, and then directly use a bone knife to chisel out the anterior middle part of the vertebral body. The bone knife carefully cuts off the back wall of the diseased vertebra, and enters the spinal canal from the back wall for decompression. For those with old fractures, a breakthrough point can be found between the posterior wall of the bone and the spinal canal with a drill, and then a small curette with a long handle or a meningeal hook can be used to carefully separate the bone fragments of the canal wall from the dura mater, and remove the fracture fragments protruding into the spinal canal. Complete decompression of the anterior wall of the spinal canal;

Bone graft preparation: decompress to the spinal canal, prepare the bone graft bed and titanium surgical mesh bone graft components in advance, once the decompression is satisfactory, the bone graft can be completed quickly.

3. Specimen surgical approach and incision selection

Compared with the posterior approach, the anterior approach to the thoracolumbar spine is more risky, most of which are vascular complications. Most of the complications are related to the surgical approach, so choosing an appropriate approach is critical to reduce surgical complications. In cadaveric specimens, we routinely choose the left approach. However, clinically, some factors need to be considered: the right exposure has liver interference, and the wall of the vena cava on the same side is thin and brittle, so it is easily damaged by stretching, and it is difficult to stop bleeding after injury; while the organs on the left side of the vertebral body are easily retracted, and the main The arterial pulsation is obviously easy to identify and the wall thickness is resistant to stretching and other factors. Therefore, the right decubitus position and the left approach can be chosen. However, the left approach should be carefully considered in the following situations: (1) the lesion is located on the right side and it is difficult to remove it on the left side; (2) the left side has a previous operation history and serious tissue adhesion, and the difficulty and risk of secondary surgery are higher (3) For patients who are old and have severe aortic calcification, intraoperative traction may lead to accidental rupture of the arterial wall; (4) Patients who need a thoracic approach and have lesions or injuries in the right lung while the left lung function is normal . For segmental lesions above the thoracic _12th vertebra, the extrapleural approach (or thoracic approach) is used; below the thoracic _12th vertebra, the retroperitoneal approach is used.

For lumbar ₁ surgery, traditional surgery uses a combined thoracoabdominal incision, which requires incision of the diaphragm and access to the chest cavity, which greatly interferes with physiological functions and is not conducive to postoperative recovery. We chose the _12th thoracic rib approach, incised the left diaphragmatic crus, stripped the parietal pleura in front of the _12th thoracic vertebra, and made full use of the lumbar bridge to expand the exposure space to achieve the purpose of not entering the chest.

4. Exposure of the surgical area and the use of the long-handled retractor I

After the specimen was lying on its side, a lumbar bridge was erected to bend the thoracolumbar spine to the left, expand the left intercostal space, increase the distance between the costal arch and the iliac crest, and create conditions for surgical exposure. Regardless of the thoracic or extraperitoneal approach, different from traditional incisions, they all start obliquely from the posterior axillary line to the vicinity of the anterior axillary line. The length of the incision varies from person to person, about 13-18 cm. The main knife is located on the ventral side of the cadaver specimen, which is conducive to confirming the position of the spinal canal during spinal canal decompression and internal fixation. The thoracic approach does not usually remove the ribs, and enters from the intercostal space of the two segments near the diseased vertebra, and the upper and lower intercostal spaces are opened by the chest brace. During the operation, a thoracic spreader and two long-handled retractors I (see Fig. 1) are used in conjunction, and the tip I of the retractors is fixed to the upper and lower two vertebral bodies of the diseased vertebra; the head 2 is wide enough to push away soft tissues; the body 3 It is longer and is suitable for the deep exposure position of anterior surgery; through the round hole 4 at the tail end, it is bound to the chest handle with a sterile bandage to achieve the purpose of retracting the lung lobe to expose the surgical field of the diseased vertebra.

5. Segmental artery treatment and the use of long-handled periosteal dissector II

Due to the relatively dense surrounding tissue, the process of separating and ligation of segmental arteries may cause damage and lead to bleeding. Therefore, the treatment of segmental arteries is one of the difficulties in thoracolumbar anterior surgery. Traditional anterior surgical methods often require ligation of blood vessels in three segments including the upper and lower vertebral bodies of the diseased vertebra, which is time-consuming and laborious. When summarizing the experience of previous operations, we found that anterior decompression, bone grafting and internal fixation can be completed only by ligation of the diseased vertebral segmental arteries. In the specimen, two special long-handled periosteal dissectors II (see Figure 2) were used. The head 5 is relatively blunt and used to compress blood vessels; the body 6 is long and suitable for the deep anterior surgical position; the tail It is the handle 7, and its connection with the body 6 is a tapered structure, which is suitable for the anatomical characteristics of human beings to hold objects with both hands. After compressing segmental blood vessels, the proximal end was fully freed and given double ligation or suturing, while the distal end was electrocoagulated to stop bleeding.

6. Spinal canal decompression and the use of long-handled osteotome III, long-handled endplate curette IV, and long-handled curette V

See Figure 3. Spinal canal decompression is not only difficult and risky, but also causes a lot of bleeding, which is a key link in anterior spinal surgery. After confirming that the cadaver specimen was in the upright and lateral position, we first cut off the anterior half of the upper and lower intervertebral discs of the diseased vertebra with a sharp knife, and then directly chiseled out the anterior middle part of the vertebral body with a long-handled osteotome III, whose blade 8 is flat, There is no radian, and the direction is always perpendicular to the trunk of the specimen to avoid mistaken entry into the spinal canal when used. The body 9 is longer, which is in line with the characteristics of deep anterior thoracolumbar surgery; the tail 10 is larger than the cross section of the body to ensure more stable hammering. . When decompressing to the front wall of the spinal canal during surgery, do not enter the spinal canal in a hurry, because once the spinal canal is opened, it may cause more bleeding in the venous plexus that is difficult to stop. Patiently remove the upper and lower disc tissue and cartilage endplates at this time. Referring to Fig. 5, a long-handled endplate curette IV is used for the treatment of intervertebral disc tissue and cartilage endplate. The head 11 of the curette is a hollow oval structure with sharp inner edges for removing endplate and intervertebral disc tissue. The body 12 is relatively Long, in line with the characteristics of the deep position of the anterior thoracolumbar surgery, the surface of the handle 13 is designed in a wavy shape to prevent slipping during use. After the endplate was prepared, the bone graft gap was pre-stretched with a spreader, and the length of the bone graft was measured. While the assistant started to prepare the appropriate iliac bone block or titanium surgical mesh/bone graft component (TSM/bone graft component), the posterior wall of the diseased vertebra was carefully chiseled away with a special long-handled osteotome III. See Figure 4. For those with old fractures, you can use a drill to find a breakthrough point between the posterior wall of the bone and the spinal canal, and then use a long-handled curette V to carefully separate the bone fragments of the canal wall from the dura mater. The curette head 14 is a The blunt hook is used to separate bone fragments from dura mater, bone fragments and intervertebral disc tissue. The body 15 is longer, in line with the deep anterior position of the thoracolumbar spine. The tail is a conical structure connected to the body 15 The handle 16 is more in line with the anatomical characteristics of the human hand holding a fist. After the bone fragment and dura mater were separated, the fracture fragment protruding into the spinal canal was removed, and the anterior wall of the spinal canal was thoroughly decompressed. In the actual operation of using the long-handled curette V, it is found that entering the spinal canal decompression from the posterior wall of the vertebral body has two advantages: 1. No need to expose and remove the pedicle; The soft tissue of the ligament and the dura mater are easy to distinguish, so it is easy and relatively safe to find the breakthrough of the spinal canal here. Then, after thorough decompression, take the pre-prepared TSM/bone graft component body, and gently knock it into the bone graft bed under the premise of expanding the gap (note that the TSM/bone graft component body should not be too long, so as not to be placed Difficult to damage the bony endplate or scoliosis on the approach side), after confirming that the TSM/bone graft component is in a satisfactory position on the bone graft bed, perform internal fixation and pressurize the TSM/bone graft component.

In short, through the application of a set of instruments provided by the utility model including long-handled retractor I, periosteal stripper II, long-handled osteotome III, long-handled curette IV and endplate curette V; the change of segmental blood vessel treatment concept And the innovation of the sequence and method of decompression of the spinal canal reduces the requirement for the incision in the conventional anterior thoracolumbar surgery, shortens the operation time, and makes it possible for the anterior thoracolumbar surgery to be as popular as the posterior surgery.

The utility model is described in conjunction with the best embodiment, but after reading the above content of the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the rights of the utility model within the scope of the requirements.

Claims (5)

1. a cover is used for the apparatus of breast lumbar vertebra anterior approach, it is characterized in that: by long handle drag hook (I), long handle periosteal elevator (II), long handle osteotome (III), long handle curet (IV) and long handle soleplate curet (V) are formed, long handle drag hook (I) is by drag hook tip (1), head (2), body (3) and tail end circular hole (4) constitute, long handle periosteal elevator (II) is by circle obtuse head (5), body (6) and handgrip (7) constitute, long handle osteotome (III) is by the cutter head (8) of flat, body (9) and afterbody (10) constitute, long handle curet (IV) is by the curet head (11) of the blunt band crotch of circle, body (12) and taper handle (13) constitute, and long handle soleplate curet (V) is by the oval-shaped curet head (14) of hollow, body (15) and handle (16) constitute.

2. a cover according to claim 1 is used for the apparatus of breast lumbar vertebra anterior approach, it is characterized in that: the head (2) of long handle drag hook (I) is the narrow down wide trapezoidal shape of.

3. a cover according to claim 1 is used for the apparatus of breast lumbar vertebra anterior approach, it is characterized in that: the handgrip (7) of long handle periosteal elevator (II) is tapered with body (6) junction.

4. a cover according to claim 1 is used for the apparatus of breast lumbar vertebra anterior approach, and it is characterized in that: the cutter head 8 of long handle osteotome (III) does not have radian, and afterbody (10) cross section is greater than body (9).

5. a cover according to claim 1 is used for the apparatus of breast lumbar vertebra anterior approach, it is characterized in that: the inside edge of the curet head (14) of long handle curet (IV) is sharp keen, handle (13) is tapered with body (12) junction, the design of handle (16) surface wave shape.

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