Chordoma is a rare low and moderate-grade malignant tumor originated in the embryonic period residual notochord tissue.Due to its critical location, local aggressive nature, and high recurrence, chordoma is not sensitive to radiotherapy and chemo-therapy with poor prognosis .Surgery is the main treatment method .Here we present a review focusing on basic and clinical research progress of chordoma .

Objective The periacetabular tumor has a low rate of incidence, but its special location poses a challenge to clinical treatment.The aim of this study was to discuss the methods, effects, and complications of surgical treatment of periacetabular tumors. Methods We retrospectively analyzed the clinical data of 36 cases of periacetabular tumor surgically treated in our depart-ment, including 21 males and 15 females, aged 15 to 64 (45.2 ±6.3) years.Among them, there were 8 cases of benign tumor (4 ca-ses of simple bone cyst, 1 case of desmoplastic fibromas, 1 case of osteofibrous dysplasia, and 2 cases of hemangioma) and 28 cases of malignant tumor (5 cases of osteosarcomas, 12 cases of chondrosarcomas, 2 cases of giant cell tumor of the bone, 1 case of malignant chondroblastoma, 2 cases of malignant fibrohistiocytoma, and 5 cases of metastatic tumor of the bone).The benign cases received sim-ple tumor resection plus bone graft and steel plate system internal fixation, while malignant cases underwent reconstruction by combined pedicle screw fixation system with bone cement. Results No patients died perioperatively and controllable complications occurred in 5 cases after operation.All the patients were followed up for 5 to 96 months except for 1 case of benign tumor.None of the benign cases experienced recurrence, and all of them achieved normal hip function.Lung metastases occurred in 10 malignant cases (4 cases of os-teosarcomas and 6 cases of chondrosarcomas) , who died of respiratory failure, and the other 18 remained tumor-free after surgery.Of the 2 patients with malignant fibrohistiocytoma, 1 died 2 years postoperatively and the other survived with tumor.Neither local recur-rence nor lung metastasis was found in the patients with chordoma and malignant chondroblastoma till the end of follow-up.The 5 pa-tients with metastases died within 3 years after operation.At 3 months after surgery, the Harris scores after total hip replacement were >90 in the 7 benign cases, 70-79 in 9 malignant cases, and <70 in the other 19 malignant cases. Conclusion For the treatment of malig-nant tumors, reconstruction by combined pedicle screw fixation system with bone cement does not affect the general daily activities of the pa-tients.Preoperative embolization of the internal iliac artery can reduce bleeding and improve operation safety, and measures should be taken to minimize postoperative complications.

Objective The incidence rate of sacrococcygeal tumor is low , however , due to its special position , clinical symptoms are inclined to be more severe .The aim of the article was to explore the methods and therapeutic effects of operative treat-ment for sacrococcygeal tumors . Methods A retrospective analysis was made on 44 cases of sacrococcygeal tumors treated in our hospital from January 2008 to December2012 .Of all the cases , there were 11 chordomas , 9 neurinoma , 4 malignant fibrous histioto-ma, 4 giant cell tumor, 7 metastases tumors and 9 others.All the patients had definite pathological diagnosis after operation .Operative treatments involved simple resection of rumors , simple resection of lesions and resection of lesions plus screw-rod system internal fixa-tion. Res ults No patients died in perioperative period .Follow-up was made in all patients for the average time of 3.3 years(4 months to 59 months).Except for 4 patients'delayed healing of incision operation and 1 patient′s healing of operation incision after de-bridement , all the other patients healed after enhancing the wound dressing , among which there are 3 cases of chordoma recurrence , 1 case of giant cell tumor recurrence , 3 death cases of malignant fibrous histiotoma in 2 years and 1 case alive with tumor .All patients with metastases tumor died in 3 years.Except 1 patients with osteosarcoma alive with tumor , all patients′symptoms had been alleviated after operation. Conclusion Chordoma and giant cell tumor still have a high recurrence rate after operation . The extent of rumor resection and nerve preservation are determined by the range of tumors.Preoperative embolization of the internal iliac artery can clearly reduce bleeding and improve the operation safety .