Van Nes Rotationplasty

Van Nes rotational angioplasty is used for the surgical treatment of congenital femoral defects (localized defects of the proximal femur). Congenital femoral defects are rare malformations, with complete defects and partial defects. The latter is more common than the former, and is most common in the proximal femur, called proximal femoral focal deficiency (PFFD). . Aitken's four-category method is often used. Type I hip joint has formed, early X-ray film shows femoral neck defect, femoral shortening; type II femoral head is incompletely developed, proximal femoral defect is more obvious, pseudoarticular formation between femur and femoral head; type III femoral head defect The acetabulum becomes shallow and the proximal femur is small; the IV femoral head and acetabulum are absent, and the femoral shaft defect is more obvious. The treatment of this disease should be determined according to the different types and specific conditions of the deformity. Most patients do not have indications for reconstructive surgery. Most scholars believe that it is best not to perform surgery on patients with bilateral PFFD, because these patients can walk better without prosthetic limbs. Most patients have no indications for limb lengthening and are only considered for certain selected cases. In 1981, Herring and Coleman proposed that in patients with congenital malformation, the maximum length of a single long bone is 10 to 12 cm. Combined with the contralateral limb shortening, the maximum correction of limb length is 17 cm. They believe that limb lengthening can only be performed if the affected femur is expected to reach more than 60% of the normal femur length or less than 17 cm in length. At the same time, it should have a stable hip joint and a stable ankle foot. Regardless of the method used to extend the limbs, there are great difficulties, and there is often a risk of subluxation of the knee and hip joints. If the limbs are not equal in length 12 to 14 cm, they can be extended in the second phase of 8 to 9 years old and 12 to 13 years old. According to the prediction, the contralateral epiphyseal fusion is performed at the right time. It is important to consider stabilizing the hip joint when deciding on treatment. Both Type I and Type II have a femoral head and an acetabulum. Many scholars advocate surgery to establish the continuity of the femoral head and femur. Because the proximal femur is short and technically difficult, the operation should be postponed until the tibiofibular end of the femoral head and femur near the femoral head is intact. In some patients, the femur is too short and knee fusion is performed at the same time to create a "one-bone leg" that gives better bone leverage. The severely deformed type III and IV did not form the femoral head and acetabulum, and many did not advocate hip reconstruction. However, King advocates patellofemoral fusion, while Chiari pelvic internal osteotomy is performed to provide a bone bed that accommodates a short femoral stump. After the tibiofemoral fusion, the knee joint assumes the "hip joint" function. When the knee joint is fully extended, it is equivalent to the "hip joint" flexing 90° to meet the sitting position; when the knee joint is flexed 90°, it is equivalent to the "hip joint" straightening position. walk. Although this method can eliminate the instability of the hip joint, it can seriously limit the mobility of the limb. The knee joint can only perform the extension and flexion activities, but the hip joint rotation and abduction movement are lost after the patellofemoral fusion. In order to improve the limb function of PFFD, which can not be used for limb lengthening, the unilateral limb is severely shortened. Van Nes rotational angioplasty, also known as lower extremity rotational angioplasty, can be used. The operation rotates the lower extremity 180° outward, and at the same time, the knee joint is performed. The ankle joint is placed on the same plane of the temporal knee joint, and the ankle joint is used as the "knee joint" in the prosthetic limb to perform its function. Ankle joint flexion is equal to "knee joint" straightening, while ankle joint dorsiflexion is "knee joint" flexion. Treatment of diseases: traumatic femoral head necrosis Indication Van Nes Rotational Angioplasty is suitable for: 1. Patients with severe femoral defects on one side cannot undergo femoral extension. 2. It has proper hip joint stability and good ankle joint activity, and the ankle joint activity is at least 90°. 3. The age of surgery can be 2 years old. Early surgery can preserve better mobility of the ankle and foot, and the osteotomy is easy to heal. In order to avoid losing the corrected degree of rotation with growth, some authors advocate that the operation is not performed until the age of 12. Contraindications 1. Bilateral PFFD or unilateral femur defect is not serious. 2. Those with severe deformity of the ankle and ankle and ankle joint activity disorder. Preoperative preparation Two problems must be explained to the patient and his parents before surgery: one is the meaning and effect of the toe of the affected side after the rotation, so as not to cause psychological burden and misunderstanding; the second is that the rotation angle may be increased with age after surgery. There is a tendency to decrease, and it is possible to do a rotary osteotomy again. Surgical procedure Incision Starting from the proximal outer side of the knee joint, the knee joint is crossed distally and extends distally along the humerus. 2. Expose free knee joints, nerves, blood vessels The inward and lateral separate flaps were used to expose the knee joint capsule and the patellofemoral ligament, and the patellofemoral ligament and the knee joint capsule were cut transversely to fully expose the knee joint. Cut the collateral ligament, cruciate ligament and anterior, medial and lateral joint capsules. The adductor muscle is severed to rotate the femoral artery forward, and the femoral artery is released posteriorly to the temporal artery plane. Cut off the medial hamstring muscle stop point. Carefully dissociate and protect the common peroneal nerve on the outside (if there is a tibial defect, the relationship between the common peroneal nerve and the upper end of the humerus varies). Cut the attachment points of the posterior joint capsule and the triceps of the calf. At this point, only the continuity of the skin, subcutaneous tissue and neurovascular bundle is preserved between the femur and the tibia. 3. Lower limb rotation forming Remove the articular cartilage from the plane of the proximal humerus with a bone knife or an airsaw. Be careful not to damage the tarsal plate. If you need to shorten the limb, use the same method to remove the distal femoral epiphysis and tarsal plate. An intramedullary needle is inserted from the distal end of the femur, and the tibia is inserted from the proximal end and then reversed. During this process, the external rotation of the humerus relaxes the common peroneal nerve, and the femoral, iliac, and vein are removed from the adductor muscle. The hole is displaced forward. If the rotation of the limb is not satisfactory, the osteotomy can be performed in the middle part of the humerus and the humerus can be cut off. If you need to shorten your limbs further, you can do this when you have a tibia. Externally rotate the distal end of the humerus, so that the limbs rotate 180° outward and the toes are facing backwards. The humeral osteotomy is still fixed with this intramedullary needle. 4. Stitching Rinse the wound, completely stop bleeding, layer suture, and put negative pressure on the wound. complication 1. Nerve and vascular damage. 2. This operation is performed in young children. After surgery, the degree of rotation correction may decrease with age, and if necessary, the rotation osteotomy may be performed again.