Effect and prognosis of tumor-type artificial knee prosthesis replacement for treatment of malignant bone tumors around the knee / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the effects, complications and survival of patients tumor-type artificial knee prosthesis replacement for treatment of malignant bone tumors around the knee.Methods:The data of 47 patients undergoing tumor-type knee prosthesis replacement in Shanxi Medical University from January 2010 to April 2018 was retrospectively analyzed. There were 21 males and 26 females, with a median age of 21 years (7-70 years). There were 39 cases of osteosarcomas, 3 cases of chondrosarcomas, 2 cases of malignant fibrous histiocytomas, 2 cases of giant cell bone tumors, and 1 case of fibrosarcoma. The involved locations were the distal femur in 35 cases and proximal tibia in 12 cases. Patients with osteosarcoma and malignant fibrous histiocytomas received chemotherapy for 2 courses before operation and 4-6 courses after operation. The data included the survival time, prosthesis survival time, complications, limb function, tumor recurrence and lung metastasis of patients.Results:Patients were followed up for a median time of 25 months (5-102 months). The 1-year, 3-year and 5-year overall survival rates were 95.74%, 71.29% and 58.06%, respectively. The 1-year, 3-year and 5-year disease-free survival rates were 86.42%, 55.49% and 50.86%, respectively. Local tumor recurrence occurred in 10 patients (21.28%) within 3 years after operation. Of the 10 patients, 8 cases had a recurrence of the soft tissue tumor and then they received the resection surgery; the other 2 patients underwent amputation of the diseased limb. The pulmonary metastasis occurred in 15 patients (31.91%). The 5-year survival rate of prosthesis was 82.33%, and the 5-year survival rate of prosthesis in patients with tumor in the distal femur was higher than that in patients with tumor in the proximal tibia [86.96% vs. 75.00%, P = 0.338]. The periprosthetic infection occurred in 3 patients (6.38%), and 1 case (2.13%) received revision after prosthesis loosening, 1 case (2.13%) received revision after prosthesis breakage. At the patient's last follow-up, the Musculoskeletal Tumor Society (MSTS) score was 21 points (15 points, 24 points), and the excellent rate was 61.70% (29/47). The incidence of extensor lag in patients with tumor in the proximal tibia was higher than that in patients with tumor in the distal femur, and the difference was statistically significant [33.33% (4/12) vs. 2.86% (1/35), P = 0.016]. Conclusions:Tumor-type artificial knee prosthesis replacement can effectively treat malignant bone tumors around the knee and maintain satisfactory limb function and patients' survival rate. However, the postoperative complications may lead to limb salvage failure. It is necessary to reduce the occurrence of complications through standardized chemoradiotherapy, extensive and strict tumor resection and proper rehabilitation exercises.