internal fixation

There are few reports on the treatment of intertrochanteric fractures with multi-needle internal fixation. In the past 10 years, multi-needle internal fixation in foreign countries has been mainly used for femoral neck fractures. Only Ender needles for intertrochanteric fractures have been used. Outside the Ender needle, there are mainly four internal fixations by a rectangular needle, three screw internal fixations and a double-needle crane internal fixation. Den-Harton's experiment emphasizes the center position of the femoral neck and head for a single needle such as a compression screw to maintain stress balance during loading, while multi-needle fixation is easier to overcome the balance of the fixation at the center of the neck. used the Singh index test to save the corpse femur, made Evans III a type intertrochanteric fracture, fixed by 4 moments of the Sterling needle, Knowles 4 needles, 140° steel plate and goose nail (nail plate) Test the load bearing and fatigue test on the mechanical test machine. As a result, the bearing capacity, tensile strength and fatigue resistance of the four-dimensional Needle were the best. Followed by the Knowles 4 needles, both superior to the angled steel plate and single nail-plate. Observation of the upper femur bone section showed. In 4 cases of the sigma-like needle, the trabecular bone of the femoral neck near the femoral moment is severely compressed compared with the lateral femoral cortex, suggesting that the femoral head and the internal fixation needle move simultaneously in the neck at the time of hip load, and the femoral moment is dense. The fulcrum is formed at the beam, the pin load arm is shortened, and the bearing capacity is strong. The horn-shaped plate and the goose nail are severely damaged by the trabecular bone at the lateral femoral cortex, indicating that the force point is outside and the load-bearing arm is long. Therefore, although the nail-plate type internal fixation structure itself has more needles Strong, but its biomechanical load performance is not good, the internal fixation nail together with the femoral head and neck, repeated load activity, the force point on the outer cortical corner of the inner stem of the internal fixation, prone to fatigue fracture. The lower two needles of the four teeth of the Sterling needle are moved along the upper trabecular bone of the femur, close to the femoral moment. When the hip is loaded, the lower needle can be the fulcrum of the femoral moment, which shortens the load arm. The Knowles needle inserted parallel to the long axis of the femoral neck is also 4 pieces. Because it is not close to the femoral moment, it can not form a short force arm, and its fulcrum is at the lateral cortex of the femur, so the biomechanical performance is worse than that of the Needles. Compared with the single nails, the internal friction of the four-dimensional Sterling needle has three characteristics in biomechanical properties: 1. A stable fixation system is formed through the femoral lateral cortical bone, the femoral moment and the solid part of the upper end of the femur at the pressure bone beam. 2. The lower needle is nearly parallel to the hip negative gravity line. The normal hip joint negative gravity line projection is 25° to the femoral shaft axis, and the lower needle is about 30° to the femoral shaft axis. When the weight is loaded, the shearing force of the fracture end is small, and the axial force is large, which is beneficial to the insertion of the fracture end, and enhances the stability and promotes the fracture healing. 3, the needle crosses each other in the femoral head, increases the anti-rotation ability, strengthens the stability, 3 screws, highly inclined fixed intertrochanteric fractures, also has the above biomechanical characteristics, 4 needles increase the insurance coefficient. If one needle is withdrawn, the other 3 needles will retain their biomechanical characteristics. Yan Shaoting et al (1992) reported four internal fixations of the needle, also known as the internal fixation of the needle. Treatment of diseases: intertrochanteric fractures Indication 1. For humeral intertrochanteric fractures, according to Evans classification, this procedure is applicable to type II, type IIIa, type IIIb, and type IV. 2, for type I fractures, although traction therapy generally does not occur hip varus, but there may still be some, so in order to reduce the patient's bed complications and prevent hip varus, this surgery can also be used. Contraindications In the case of retrograde intertrochanteric fracture, the fracture line is obliquely descended from the small trochanter to the lateral femoral cortex. Because the fracture line is consistent with the direction of the pin, it is difficult to fix, so it is a contraindication for this method. As for indications and contraindications for general conditions, this procedure can be applied to most elderly patients with intertrochanteric fractures. There are severe heart, lung, liver and kidney dysfunction, which is a contraindication for surgery. Because the operation is performed under local anesthesia, there is no need for surgical incision, and there is very little blood loss. Therefore, those with mild or moderate heart, lung, liver and kidney dysfunction can generally be tolerated. Preoperative preparation 1, systemic preparation, blood, heart, lung, liver, kidney function tests after admission, high blood pressure and diabetes cases can be controlled after several days of medication. 2, local preparation, after the admission, the affected limbs were treated with tibial tuberosity or skin traction, and the affected limbs were kept in the middle rotation position and slightly outside the booth. After the whole body examination, the operation was performed within 3 to 7 days after the injury. 3, routine preparation of skin 1d before surgery. Surgical procedure 1, reset It is best to have a C-arm TV X-ray machine to perform a reset under fluoroscopy. First traction, after recovery under fluoroscopy, observe the normal neck angle, after the fracture line is completely reset, the lower extremity is rotated to the largest trochanter, the outer edge of the tibia is upward, the internal rotation of the foot is about 40°50°, the femur The anteversion angle is nearly disappearing and the limb is fixed. 2, needle position design The lowest position is the first needle, and the needle insertion point is 12 to 14 cm below the large trochanter. Thereby, the bone beam is pressed upwards and inward through the femoral moment to the center of the femoral head, 0.5 cm below the cartilage. The second needle enters forward 2 cm proximal to the first needle, and the femoral moment pressures the bone beam into the femoral head. In the lower inner side of the first needle, the lateral phase is on the posterior side of the femoral head, that is, the two needles cross in the head. . The third needle is about 1 cm above the second needle, and is directed upward and outward in the head, and is on the front side. The fourth needle is placed 5 to 6 cm below the trochanteric tip through the tension skeletal to the inside of the third needle in the head, and the two intersect. 3, the needle method Choose a 3.5mm diameter Sterling needle and place it on the bone drill. The needle insertion point of the first needle is 12 to 14 cm below the tip of the large trochanter. After local anesthesia, a small hole is pierced with a sharp knife, and the needle is inserted into the cortical bone of the femur, in the middle of the outer side. While drilling, the needle tail is tilted to the far side, and the direction of the needle is controlled by the X-ray television to reach the inner cortical femoral moment of the small trochanter. In order to reduce the use of X-ray TV, a single Sterling needle can be placed in front of the strand along this line to enter in the direction. Because the lateral femur of the femur is about 0.5 to 1 cm thick, it is difficult to drill, and once it is drilled, it is difficult to change the direction. Therefore, it is best to use an electric drill to drill the first moment into the femoral moment under the TV. After the femoral moment From the inside of the femoral head to the center, 1.5 cm below the cartilage surface. Look at the side TV, the needle is in the center of the head as well. However, it can be either front or backward. If the needle is biased forward, the other 3 needles and 2 needles are behind and 1 needle is forward. The second needle enters 2 cm above the first needle, and after the third needle is on the second needle, the fourth needle is at the top, and the entry point is slightly rhomboid. Each time a needle is inserted, the positive side position is in the head position, and each needle is 1.5 cm below the cartilage surface. 4, fixed Press the skin tightly, cut the outer needle tail, cut 1 needle each time, use the driver to hold the needle tail inward and then inject about 1cm, so that the needle tip reaches about 0.5cm under the cartilage. If it is cut and scored 4 needles After that, insert the towel or forceps into the needle hole and lift the fascia, so that the needle tail is buried under the fascia. 5, the incision does not need to be sutured, covered with sterile dressing, loose traction. complication 1. Needle withdrawal. Among the 80 patients with intertrochanteric fractures in China, 4 of them were arrested, and 28 of them (35%) had a needle withdrawal. The other 3 needles were still in place and did not affect the fracture. Heal. 2, infection, may occur pinhole infection, after the change of medicine, no adverse consequences. 3, the occurrence of hip varus, a group of 80 cases in China all fractures healed, 13 cases (16%) had hip varus, and no other complications. Mainly for type IIIb and IV fractures. Since the needle may be withdrawn, it has been fixed by hollow nails according to this principle since 2000.

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