Ilizarov Femoral Lengthening

Ilizarov femoral extension can be used to extend the limbs of children. During the Second World War, the former Soviet Union, according to the experience of treating a large number of wounded, Ilizarov (1951) reported a method of extending the limb with a new external fixator. And introduced to Italy (1981), and then extended to Europe and the United States, has become the best bone extension method for correcting limb shortening deformity and widely used. The Ilizarov device is a complex annular stent system that is connected to the stent by a multi-planar horizontal Kirschner wire that penetrates the bones and limbs. It contains many components that can be corrected for angular and rotational deformities while prolonged; The function of pressing, extending and lateral shifting. Since the bone extension has a tension-stress effect, it can stimulate the growth and regeneration of the tissue, thereby forming a so-called "bone growth zone" in the center of the bone extension to promote the regeneration of bone and soft tissue. In the case of bone extension and deformity correction, bone grafting is not required, so it can be widely applied. Composition of the femur Ilizarov frame: Ilizarov stands for Ijs, for the extension of the femur by two proximal curved plates (90° and 120°, ie small and large), the middle of the empty ring and the distal 2 A complete ring composition, if the child is too small, subject to space constraints, the proximal end can use a curved plate, the distal end uses a complete ring. If the distal ring affects knee flexion, it can also be replaced with a 5/8 ring. The proximal curved plates are connected by a six-sided column, and the distal curved plate and the empty ring are connected by two oblique columns and two straight columns; the empty ring and the distal ring are connected by a lead screw; It is also connected by a six-sided column. The proximal curved plate is fixed with the femur by two radii needles, and the distal end is passed through the 1-2 radius needles; the distal distal complete ring is fixed by two Kirschner wires from the two planes and the femur, and the proximal complete ring is The stability of the stent is fixed with the femur by 1 or 2 Kirschner wires; the empty ring in the middle is not connected to the femur. Limb lengthening is only a common method for correcting unequal length of limbs, while contralateral shortening and osteophyte blockade are also effective ways to achieve limb balance, but the latter is not easily accepted. Therefore, this chapter focuses on limb lengthening. Children for various reasons, such as congenital sacral pseudoarthrosis, congenital limb shortening, and limb shortening due to infection and trauma (Figure 12.44.3-0-1 to 12.44.3-0-3), Both limb extension methods can be used to resolve limb shortening deformities. Codivilla (1905) proposed a method of oblique osteotomy of the femur. Putti (1992) extended the extension of a Kirschner wire at the upper and lower ends of the osteotomy. Abbott (1928) improved the method of traction of Putti's bone, ie, at the upper and lower ends of the fracture. Each of the two Kirschner wires was inserted for fixed traction, which enhanced the pulling force of the traction, prevented the steel needle from slipping, and improved the effect of bone lengthening. The author also proposed the humerus extension in 1927. Bost (1956) was treated with a slanted osteotomy and an intramedullary nail. In the osteotomy defect area, Westin (1967) used the periosteum wrapping method to achieve the purpose of prolongation. At present, Abbott has developed a number of improved methods based on the extension of the humerus, such as percutaneous transection of the upper and lower ends of the humerus, percutaneous bone drilling, closure of the humerus, humeral osteotomy and ankle joint fusion to prevent sputum. Articular valgus deformity and so on. Anderson (1952) believes that this method has the advantages of light soft tissue damage, retention of periosteum, and promotion of local bone tissue growth. Limb lengthening involves the elongation and regeneration of tissues such as bones, muscles, nerves, and blood vessels. There are many problems involved in the limb extension process, and the problem of bone lengthening of the lower limbs is emphasized here. 1. According to the reasons that affect limb shortening and bone growth and development, choose the best time for bone extension. Normal children in the growth and development stage, the lower limb bone growth and development stop time, the boy is 16 years old, the girl is 14 years old. Colemen (1967) believes that children aged 8 to 12 are the best time to extend bone. After the age of 20, due to the slow healing of the bone, careful consideration should be given to the bone extension. 2. According to the growth rate of the long bones of the lower limbs, the site of bone extension is selected. Normal children from 4 years old to growth and development, the lower extremity femur increased by 2cm per year, the tibia increased by an average of 1.6cm per year. Dighy observation showed that 70% of the femur growth comes from the lower end of the femur, 30% from the proximal femur; 65% of the tibia growth From the proximal end of the humerus, 35% came from the distal radius. Therefore, the femoral lengthening is mainly performed in the lower middle part of the femur, while the tibia is mainly selected in the upper middle part of the tibia. Although the extension of the femur or the extension of the tibia can correct the unequal length of the limb, in principle, the femoral extension should be performed in the case of thigh shortening. Conversely, if the calf is shortened, the humerus extension is selected. 3. Calculation method of length of bone extension In order to achieve the expected effect of bone lengthening, it is necessary to comprehensively consider the growth and development of children. Age is a major factor in the extension of bone. X-ray films of the wrist must be taken to determine the bone age of the child. . Bone extension = [tibia shortening length + (male 15.5/female 14.5 - age at surgery) x 0.1] cm. 15.5 and 14.5 are the average ages at which the lower limbs of boys and girls stop growing. 4. At present, the commonly used limb extension method can be divided into a single extension of the femur and a daily extension according to the extension speed. The former is limited in length and has many complications, such as vascular nerve injury, long bone healing time, and even non-healing. At present, there are many methods of daily extension and daily extension. The main difference is that the osteotomy site is different from the external fixation device (extension device) used. For example, Wagner adopts a bone osteotomy extension and a cantilever extender. When the required length is reached, autologous bone implantation and internal fixation are required. DeBastiani selects the metaphyseal osteotomy and is fixed with a single arm external fixator. It is extended day by day; Ilizarov uses a ring-extension-pressure system for tarsal extension and metaphyseal osteotomy, as well as bone grafting and internal fixation. Treatment of diseases: femoral skull and tibial rickets Indication Ilizarov femoral extension is suitable for: 1. Congenital or acquired constipation of short limb deformity, limb shortening >3cm. 2. The appropriate age for surgery is 10 to 12 years old. If the extension of the tarsal plate is used, it should be carried out when the development is mature, that is, the bone age is about 14 years old. 3. The hip joints and knee joints of the lower limbs function well, and the muscle strength is above grade IV or the lower limbs are prolonged, and the muscle balance is conditionally adjusted. Contraindications 1. Age <8 years old. 2. The limb is shortened below 3cm or greater than 15cm. 3. Lower extremity muscle strength, postoperative bone extension, no adjacent normal muscle replacement. 4. The hips, knees, and ankles are unstable or have obvious deformities. Preoperative preparation 1. Measurement of body height and lower limb length. 2. True length measurement of femur and tibia X-ray films. 3. Determine the total length of the unequal length of the lower limbs. 4. Take a X-ray of the wrist and determine the bone age. 5. Raise the affected limb to adjust the pelvic tilt, balance the trunk and other comprehensive factors to determine the length required for bone extension, and increase the total length of the bone extension by 0.5 ~ 0.6cm, as a compensation for bone shortening deformity. Surgical procedure 1. Placement of the proximal radius needle After the femoral external fixator is assembled, the first radius needle is placed first. According to the age of the sick child, a 4mm or 5mm diameter radius needle is selected from the outside of the lower edge of the large trochanter, perpendicular to the lower limb bio-dynamic line (rather than perpendicular to the femoral axis), and connected to the nearest side curved plate The top. Adjust the outer fixing bracket so that the thigh is evenly located in the middle of the shelf, and the second radius needle is placed. It should be perpendicular to the first needle and placed from the lower side of the nearest side curved plate, and then fixed with the curved plate. The third needle should be placed at an angle of 45° to the above two needles and fixed to the distal curved plate. If necessary (older children) put a fourth needle on the distal curved plate. 2. Insertion of the distal Kirschner wire First, the first Kirschner wire is drilled from the outside to the inside on the most distal ring. The center of the needle should be olive with the outer side and should be parallel to the knee joint (a). The knee joint should be kept before drilling. Flexion position (to prevent the quadriceps from passing through in the extension position and affecting the knee flexion after surgery); the second root is also an olive needle, which is drilled from the inside to the outside and fixed on the distal proximal ring ( e); drill two other K-wires, one of which is to be drilled from the front outer side (f) and the other one from the front inner side (g). 3. Osteotomy So far the external fixator has been mounted on the thigh, and the lead screw between the middle ring and the distal ring is removed and the osteotomy is started. For the principle and technical operation of osteotomy, see Ilizarov's tibia extension; the 1cm plane on the proximal ring should be selected and the lateral incision should be used to complete the osteotomy. To verify that the osteotomy is complete, the distal and proximal I-frames can be held and rotated while observing the osteotomy end. Another method is to attach an extender, and adjust the extender to visually observe whether the osteotomy ends are separated, if necessary, by fluoroscopy. After the osteotomy is completed, the cut periosteum is sutured and closed, and the incision is closed.