lower femur resection

Tumors of the long bones are more common, with the vicinity of the knee joint being a good site, or at the lower end of the femur, or at the upper end of the humerus. When the entire end of the bone is extensively damaged, or if there is a malignant tumor, the entire end of the bone should be removed. Treatment of diseases: bone tumors Indication Tumors with long bone ends are more common. Preoperative preparation 1. The operation time is longer, the bleeding is more, and the blood should be used before surgery. 2. Take x-ray film, ct scan when needed, and initially determine the extent of the tumor and the need to be removed. 3. Prepare sufficient and sufficient length of storage bone for bone grafting. 4. Tumor cases should be prepared for frozen sections. Surgical procedure 1. Position: supine position, under the knee bolster. 2. Incision, exposure: Place the tourniquet at the upper part of the femur, take the anterior medial approach of the knee joint (see the knee joint exposure), and make a long anterior medial incision from the middle of the femur to the upper end of the femur. Entering from the rectus femoris and medial femoral muscles, the lower part of the femur is exposed under the periosteum. The aponeurosis and joint capsule of the medial aspect of the humerus were dissected, and the tibia was pulled open. The lower part of the femur and the anterior part of the knee joint cavity were all exposed [Fig. 1 (1)]. If the tumor has worn the periosteum, a partial enlargement should be performed. 3. Separation and excision of the lower femur: flexion of the knee joint, cutting of the knee, lateral collateral ligament and cruciate ligament, ready for the removal of the lower femur [Fig. 1 (2)]. However, when performing semi-articular resection on the side of the tumor, it is best to cut the bone at the backbone and then remove it. The plane height of the femoral shaft cut should be initially set at 1 cm above the upper pole of the tumor seen on the x-ray film, but the final resection range must be based on the pathological examination. The proximal medullary cavity tissue was taken for frozen section to identify the tumor surface with or without tumor residual. If tumor cells are found, they should continue to be removed upward until a minimum of 1 cm of normal tissue above the tumor cell plane is found (minimum 5 cm for malignant tumors). When cutting, the wire saw can be used to cover the femur, and the surrounding soft tissue can be properly protected and sawn off. Clamp the broken end with a rongeur, peel the lower part of the femur downward under the periosteum, cut off the origin of the diaphragm, diaphragm and gastrocnemius muscle and the joint capsule at the back of the knee joint. At this time, the lower part of the femur can be completely removed. Figure 1 (3)]. In the subperiosteal peeling and separation of the joint capsule should be close to the bone surface; in the lower part of the lower femur, there are spurs, veins and nerves, should pay attention to avoid damage. For example, in some parts of the bone tumor, the cortex becomes thinner, so be careful not to wear it when peeling off, so as not to implant the tumor tissue into the soft tissue. If the cortex is very thin and has a small defect, indicating that the tumor tissue has invaded the soft tissue, it should be separated outside the periosteum and the infiltrated soft tissue should be removed together with the tumor. Then, the meniscus is removed, the cartilage surface of the humerus is removed, and the upper end of the humerus is excised 3 to 4 cm to prepare the bone graft; if the lower femur is inactivated or replanted or the allogeneic joint is transplanted, the above tissue need not be removed and retained. The humeral cartilage surface is placed close to the femoral condyle to cut the cruciate ligament for repair. 4. Repair and reconstruction: According to the condition and combined with patient requirements, the following methods are used: Bone grafting: bone grafting can be performed with a double-bone bone graft with an allogeneic cortical bone plate; or the upper part of the humerus can be opened longitudinally, and the inner half is inverted to be a transplant in the defect area. The two ends of the bone graft are overlapped with the femoral and tibia by 3 to 4 cm, and fixed by screws (the defect area between the femur and the tibia can be shortened by 2 cm, which does not affect the function of the lower limb). The total length of the graft plate should be the length of the final defect zone plus 6-8 cm, and the width should be more than 3 cm. The remaining bone defect area was filled with cancellous bone removed from the humerus and the upper end of the tibia [Fig. 1 (4)]. The position after bone grafting should be equivalent to the knee joint function position, taking care to avoid rotation or internal and external valgus deformity. Autologous tumor segment inactivation and replantation: all the tumor tissue of the removed tumor segment is scraped, placed in 75% alcohol for half an hour, or boiled for half an hour, taken out in situ, and pressed into the plate. Fixation, the tumor cavity is filled with autologous humerus and humerus segments, and most holes or windows are drilled on the bone shell to facilitate the growth of peripheral blood vessels and promote healing. Repair the cruciate ligament. Allogeneic half-joint transplantation: The lower part of the femur stored in the bone bank is shaped opposite to the upper part of the patient's femur. The arm length is about 3 cm, and then the position is fixed by three screws (Fig. 1 (5)). Other treatments with inactivation and replantation. Artificial half joint transplantation: If it meets the conditions, it can be applied. 5. Suture, loosen the tourniquet, completely stop bleeding, flush the wound, and place the negative pressure drainage tube and suture layer by layer. complication infection.