The pelvis is the preferred site for primary malignant bone tumors and metastatic carcinoma. The pelvic tumors are large in size, extensive in invasion, complex in anatomy, and closely related to the surrounding organs, nerves and blood vessels, so the surgical techniques are demanding, difficult to resect, difficult to reconstruct, and have many postoperative complications. In this paper, we retrospectively analyzed the clinical data and treatment results of 12 cases of pelvic tumor patients, which are reported as follows. 1. Data and methods 1.1 General data From May 2006 to July 2009, 12 patients with pelvic malignant bone tumors were admitted, 5 males and 7 females; age ranged from 16 to 52 years old, with an average of 36 years old. Postoperative pathology: 4 cases of chondrosarcoma, 2 cases of osteosarcoma, 2 cases of giant cell tumor of bone, 2 cases of metastasis, 1 case of malignant fibrous histiocytoma, and 1 case of synovial sarcoma. According to the classification of pelvic tumor sites by Enneking et al [3]: 4 cases in Zone I, 4 cases in Zone II, 2 cases in Zone III, and 2 cases in Zone IV. According to the bone tumor stage of Enneking et al [3]: 2 cases of stage IB, 5 cases of stage IIA, 3 cases of stage IIB, and 2 cases of metastases. 1.2 Preoperative preparation All patients underwent CT 3D reconstruction and MRI scan of the lesion site to determine the tumor site and scope. X-rays and ECT examinations were taken to exclude lung and other distant metastases. For chordoma, giant cell tumor of bone and metastasis, CTA angiography was performed before surgery to determine the blood supply of the tumor, and interventional embolization of the blood supply of the tumor was performed one day before surgery. Preoperative puncture or biopsy was performed to obtain pathological diagnosis. The gastrointestinal tract was prepared according to abdominal surgery with clean enema before surgery. 1.3. Surgical method: The patient was placed in a prone position, and an enlarged Smith-Petersen incision was made with an additional oblique incision along the inguinal ligament, which was combined into a “human” incision. During the operation, the pelvis could be pushed anteriorly and posteriorly to reveal the anterior and posterior pelvis, and an extraperitoneal approach was made to reveal the anatomical separation of the abdominal aorta and to preposition the blocked rubber tube. For 4 cases in zone I, 2 cases in zone III and 2 cases in zone IV, the pelvic weight-bearing ring could not be preserved, and the tumor was surgically enlarged and fixed with autologous or allogeneic bone graft and reconstruction plate. Four patients in Zone II had surgical enlargement of the tumor and adjustable artificial hemipelvic replacement. Postoperatively, the tumor was treated according to its sensitivity to radiotherapy or chemotherapy. 2. Results The postoperative follow-up ranged from 12 months to 36 months. Intraoperative bleeding ranged from 1200 to 4400 ml with an average of 2400 ml without hemorrhagic shock, no other organ damage or intraoperative death. There were 3 cases of postoperative complications, 2 cases of poor healing of wound effusion, 1 case of sciatic nerve injury, and the poor healing of wound effusion healed after partial incision drainage was removed. One case of lower extremity nerve injury was basically recovered 1 year after surgery. All patients were followed up for a minimum of 1 year and a maximum of 3 years, with a mean of 2.4 years. Two cases recurred 1.2-2 years after surgery, one case of local recurrence of the primary tumor, one case of pulmonary metastasis, and two cases of metastasis with other sites of metastasis after surgery, and there was no case of death. Bone graft healing was evident in 4-6 months after surgery. All patients were able to walk on the ground, and there was no significant limb shortening. According to the postoperative functional criteria of pelvic tumor proposed by Fan Qingyu et al: 4 cases were excellent, 7 cases were good, and 1 case was acceptable. Because of the early symptoms are not obvious, pelvic malignant tumor is already in the middle and late stage when it is found, and the tumor is large and the boundary with surrounding tissues is not clear. Hemipelvic resection was the common method to treat pelvic malignant tumor in the past. However, because of the loss of half of the pelvis and ipsilateral lower limbs after surgery, it causes great trauma and disability to the patient, which is often difficult for the patient to accept. In the past 20 years, with the development of imaging and the advancement of surgical techniques, the limb preservation treatment of pelvic malignant tumors has been greatly improved. 3.1 Pelvic tumors should be surgically resected and reconstructed according to the anatomical region according to the site of tumor occurrence. At present, the zoning standard of Enneking pelvic tumor is mostly adopted, that is, the pelvic ring is divided into 4 regions according to the anatomical site of tumor invasion and resection: iliac bone as Ⅰ region; acetabulum as Ⅱ region; sciatic bone and pubic bone (around the closed ring) as Ⅲ region; and sacral wing as Ⅳ region. According to the patient’s preoperative CT 3D reconstruction and MRI film, the site and scope of the tumor were judged in detail, and the scope of intraoperative tumor resection was prepared before surgery. For zone Ⅰ, Ⅲ and Ⅳ tumors, if the pelvic weight-bearing ring could not be preserved, the tumor was directly surgically enlarged and fixed with autologous bone plus allogeneic bone graft and reconstruction plate. For zone II tumors, the tumor will be surgically enlarged and the adjustable artificial half pelvis will be replaced. 3.2 Problems encountered in the process of tumor resection. The surgical resection of pelvic tumor is more complicated because of the adjacent important blood vessels and nerves. In order to avoid organ damage and to preserve the iliofemoral vessels, femoral nerve and sciatic nerve, the tumor can often be resected only by marginal resection or intra-focal resection. Hemorrhage is a common complication of pelvic tumor surgery. In order to prevent massive intraoperative blood loss, intraoperative ligation of the internal skeletal artery, temporary blockage of the abdominal aorta, and preoperative selective embolization of the internal iliac artery and the tumor supply artery were reported by Bading et al. We chose preoperative tumor donor artery embolization and intraoperative temporary blockade of the abdominal aorta according to the bleeding situation to control bleeding by an average of 2400 ml. Primary surgical creation of the bladder, ureter and rectum is not common in injury, but often prone to occur in secondary surgery due to tissue adhesions. The sciatic nerve and lumbosacral plexus are easily injured during sacroiliac resection, the femoral nerve is easily injured during situs and pubis resection, and the foramen occulta nerve may also be injured due to direct injury, pulling, compression or encapsulated jamming, and ischemia. Pant et al. reported 2 patients with permanent foot drop due to tumor resection at the sacroiliac joint with attempt to achieve a tumor-free margin and pulling the l4-5 nerve roots, which was later treated with bracing; it is believed that intentional or unintentional injury to the nerve roots to achieve a tumor-free margin is not contradictory to limb-preserving surgery. In this group, one case of unintentional injury to the sciatic nerve, and the nerve injury was basically recovered 1 year after surgery. 3.3 Wound healing problems after pelvic tumor resection. The main problems include skin flap necrosis, hematoma and infection, especially after radiotherapy and chemotherapy. Pre-operative radiotherapy causes local skin soft tissue paralysis contracture and muscle fibrosis, while poor blood transport and reduced ability to absorb reactive substances, which may lead to delayed healing of incision or infection, so radiotherapy should be carried out after surgery. Pre-operative chemotherapy can cause immunosuppression and low resistance of the body. Another reason is that the surgical stripping and excision is extensive, even with bone graft plate fixation and artificial half pelvis reimplantation fixation, there will still be a large cavity, resulting in a large amount of blood accumulation, and if the postoperative drainage is poor, it is more likely to produce hematoma, which is very easy to cause infection. If the graft is exposed or even forced to be removed, it takes a long time to change the medication after surgery to heal. Our treatment experience is to closely observe the postoperative drainage flow, if the drainage flow is less than 200ml, and after 72 hours after extubation to two weeks during the removal of the stitches, should be at least two times to try to penetrate the fluid, if there is stubborn exudate, we should promptly choose to open the incision to fully drain, supplemented by local pressure to reduce and gradually eliminate the dead space. Wound complications should be regarded as an important step in the success or failure of resection and reconstructive limb preservation surgery for pelvic malignancies.