Williams Intramedullary Rod Insertion and Bone Grafting

Williams intramedullary rod insertion and bone grafting are used for the surgical treatment of congenital sacral pseudoarthrosis. Congenital sacral pseudoarthrosis is a special type of nonunion that has existed at birth or started at birth. The cause of the disease is unclear, but congenitality occurs in patients with neurofibromatosis or related features. The chance of patellofemoral joints is significantly increased, suggesting that neurofibromatosis is not closely related to congenital sacral pseudoarthrosis, even if it is not the cause of congenital sacral pseudoarthrosis. The congenital sacral pseudoarticular joint most often involves the distal end of the tibia 1/2. Congenital patellofemoral joints are rare, with an incidence of about 1 in 25,000, of which 50% to 90% are associated with neurofibromatosis, including skin and bone damage. Boyd has divided congenital sacral pseudoarthrosis into 6 types: Type I pseudoarticular joints present with tibia forward flexion and humeral defects at birth, as well as other congenital malformations that can affect the treatment of pseudoarthrosis. Type II pseudoarthrosis often occurs spontaneously or after a minor trauma before the age of 2 years. This is the so-called high-risk humerus, the humerus becomes thin and round and hardened, and the tibia is bent forward with the stenosis of the medullary cavity. This type is the most common, usually with neurofibromatosis, and has the worst prognosis. Fractures often occur repeatedly during growth, but as the age increases, the frequency of fractures decreases. In general, fractures do not occur after the bones mature. Type III pseudoarticular joints usually have congenital bone cysts at the lower third of the tibia. The anterior curvature of the tibia can occur before or after the fracture. The recurrence of fractures after treatment is less common than type II, and the results are satisfactory only through one operation and can be maintained until adulthood. The type IV pseudoarticular joint occurs in the hardened segment of the typical site, the tibia is not thinned, and the medullary cavity partially or completely disappears. After the "incomplete" fracture or "stress" fracture of the humeral cortical bone, and gradually extended to the hardened bone. If a complete fracture occurs and the fracture line widens, it becomes a pseudo joint. In general, this type of prognosis is good, especially before the "incomplete" fracture develops to a complete fracture. V-shaped patellofemoral joints with tibiofibular dysplasia can occur in the patellofemoral or sacral pseudoarthrosis, or both. If the lesion is limited to the tibia, the prognosis is good. If the pseudoarthrosis involves the tibia, the prognosis is similar to that of the type II sacral pseudoarticular. Type VI pseudoarticular is a rare type of intraosseous neurofibroma or progenitor cell tumor, and its prognosis depends on the degree of invasion and treatment of intraosseous lesions. The treatment of congenital sacral pseudoarthrosis depends on the age of the sick child and the type of pseudoarthrosis. For a true congenital sacral joint, it is impossible to cure with a simple plaster fixation. For the sacral pseudoarthrosis (type III) with cyst in the medullary cavity, it is recommended to use prophylactic cyst scraping and autologous iliac bone grafting, and postoperative plaster fixation until the bone graft is healed. Then use a short leg brace to protect until the bones mature. A patellofemoral joint (type II or high-risk tibia) with a tibia forward flexion and a narrowed, hardened medullary cavity usually fractures within the first 2 years after birth. Before the fracture occurs, it is very beneficial to use a brace to fix it. It is contraindicated to try to correct it. Once a fracture has occurred, surgery is performed. Congenital tibial pseudoarthrosis, which has been clearly diagnosed, has been treated with bone grafting or amputation surgery in the past. The bone healing of this disease is more difficult than other diseases. Boyd and Sage reviewed the English literature in 1958 and found 23 different operations. Of the 91 patients treated, approximately 56% had initial bone healing; Morrissy, Risebororgh, and Hall reported less than 50% of the 40 patients treated with 172 bone grafts; Marray and Lovell reported 36 For example, a total of 85 bone grafts were performed with a bone graft. The success rate was only 31%. Crossett et al found that in 25 long-term follow-up studies, 25 patients received 96 surgical procedures, and 52% were good and the results were good. McElvenny first noticed the existence of sleeve tissue around the pseudoarticular area, and concluded that the presence of this tissue, whether for the congenital or post-fracture pseudo-articles, will reduce bone formation and healing, regardless of which surgery is chosen to treat congenital False joints should include complete removal of this tissue. In recent years, the treatment of congenital sacral pseudoarthrosis, representative surgical methods are intramedullary rod fixation, anastomosed free iliac bone grafting technology, Ilizarov technology and electrical stimulator technology, data reported, the first three bone healing rate >90% . The most common method is the intramedullary rod fixation technique described by Anderson, Schoenecker, Sheridan, and Rich. They report that 9 of the 10 confirmed congenital sacral pseudoarteries healed, and 1 required additional bone grafts and bones. Heal. Baker, Cain, and Tullos reported the results of a clinical study of 18 patients with congenital sacral pseudoarticular joints. The best results (7 of 8 patients healed) were intramedullary rod fixation and bone grafting. Transplantation of a free iliac or iliac crest with an anastomosis requires microvascular techniques and experience, but nonunion still occurs after surgery. It has been reported in the literature that the treatment of the patellofemoral joint with Ilizarov technique has obtained satisfactory initial results, but the problems include difficulty in the proximal humerus, poor docking malalignment and poor quality of the regenerated bone, which ultimately leads to re fracture. For most of the diagnosed pseudoarthres, intramedullary rods and bone grafts should be selected for initial treatment. For those with more than 3 cm of pseudoarticular joint clearance and multiple surgical failures, there are surgical indications for free iliac bone grafts with anastomosed vessels, while Boyd bilateral Surface bone grafting is only suitable for type IV pseudo joints. The Williams device consists of an intramedullary rod and an insertion rod. The surface of the intramedullary rod is smooth, cylindrical, and of different diameters. The proximal end is processed into a diamond-like cone, and the blunt distal end has a circumference. 15mm long internal thread to temporarily connect the insertion rod with the same outer diameter to it. The proximal end of the insertion rod is machined into an external thread that can be screwed into the internal thread at the distal end of the intramedullary rod, and the distal end of the insertion rod is also machined into a diamond-like cone. To determine the length of the desired rod, a lateral radiograph was taken to estimate the length of the calf after the affected bone and soft tissue resection and angular deformity correction. Treatment of diseases: congenital sacral pseudoarthrosis Indication Williams intramedullary rod insertion and bone grafting are suitable for congenital sacral pseudoarthrosis. Preoperative preparation Regular preoperative examination. Equipped with blood 200ml. Surgical procedure Tibial bone The ipsilateral iliac crest was exposed along the incision, and the bone tissue was excised from the outer plate of the humerus, and the cancellous bone was cut as much as possible. 2. Excision A skin incision is made from the anterior side of the humerus. The incision is centered on the pseudoarticular joint and is located outside the humeral condyle. At this level, the deep fascia of the anterior fascia is opened, and the proximal and distal ends of the pseudoarticular joint are exposed under the periosteum. Normal humeral shaft, remove the bone tissue and fibrous tissue of the pseudoarticular joint until the normal medullary cavity is exposed at both ends of the tibia. Usually, removal of the pseudo joint can cause the tibia to shrink by 1 to 3 cm. Use a drill bit or a small spatula to enlarge the medullary cavity at both ends of the tibia. 3. Insert the Williams intramedullary rod The two rods joined together are distally driven from the distal end of the humerus at the osteotomy, and the skin is passed through the ankle joint, the subtalar joint, and the heel pad. When the stick is inserted into the ankle joint, it is very important to pay attention to correcting the valgus of the ankle joint and the deformity of the foot and back. These two deformities are the inevitable result of the weight bearing when the anterior and lateral tibia are bent. The intramedullary rod can be smoothly inserted by means of fluoroscopy. When approaching the ends of the tibia, the rod is retrogradely driven into the metaphysis of the proximal humerus, close to the tarsal plate but avoiding damage to the tarsal plate. Loosen the insertion rod one turn, take the lateral X-ray film to confirm that it has been loosened, then fully loosen the insertion rod and take it out, and the distal end of the medullary rod remains in the calcaneus. 4. Bone graft fusion The autologous cortical cancellous bone fragments cut from the tendon were placed around the osteotomy and sutured with absorbable sutures. The subcutaneous tissue and skin were sutured, and the single hip herringbone plaster was fixed after operation. complication 1. Ankle joint and hind foot stiffness The ankle joint stiffness will follow the longitudinal growth of the distal radius, and the distal end of the internal fixation rod will be displaced to the proximal end of the ankle joint, and the joint stiffness may disappear. Minimizes the function of the ankle and foot. 2. Fracture The intramedullary rod can be removed and placed into the intramedullary rod for additional bone grafting. Even if the pseudo joint has healed, it is recommended to remove the internal fixation rod after the bone is mature. 3. valgus deformity The distal end of the humerus must be fixed, so the ankle valgus deformity should be corrected when the intramedullary rod is placed. In order to minimize progressive valgus valgus, braces should be used for long periods of time during growth. 4. Tibial shortening It should be expected that almost all of these children will have a shortened tibia, and the contralateral sacral block can be used to shorten the contralateral humerus or to extend the ipsilateral proximal humerus.