The Analyses Of Reasons For Revision After The Tumor-type Knee Prosthesis Replacement

Objective To analyze the reasons for revision after the tumor-type knee prosthesis replacement, and to evaluate the influence of different reason on revision.Methods The clinical data of 167 patients who has had tumor-type keen prosthesis replacement between June 2008 and June 2013 were reviewed. There were 106 males and 61 females with an average age of 25.27 years(range, 8-72 years).The involved locations were distal femur in 95 cases, proximal tibia in 72 cases. The pathological diagnosis included 113 osteosarcomas, 41 giant cell tumor of bone, 6 Ewing’s sarcoma, 5 chondrosarcoma, 2 malignant fibrous histiocytoma. According to Enneking staging classification, there were 5 cases in ⅠB, 27 cases in ⅡA, and 88 cases in ⅡA. 121 cases of sarcoma patients underwent chemotherapy, included Lobaplatin, Doxorubicin, Cisplatin, Ifosfamide, and Methotrexate. The prosthesis used included 44 new axial tumor-type knee prosthesis, 58 custom rotating-hinged knee prosthesis, 63 modular hinged knee prosthesis. The average interval between the first-time prosthetic replacement and revision was 32.7 months(range, 4-40 months).The average operative time of the first-time prosthetic replacement was178.58minutes(range, 80-275minutes). The averageblood loss in the first-time prosthetic replacement was 681.67ml(range, 450-1,000ml). The drainage in the first day after the first-time prosthetic replacement was 175.75ml(range, 90-270ml).Results 34 patients(20.36%) have had revision after the tumor-type keen prosthesis replacement. The reason for revision included periprosthetic infection in 16 cases(9.58%), tumor recurrence in 8 cases(4.79%), aseptic loosening in 7 cases(4.19%), and prosthetic fracture in 3 cases(1.80%). Among 121 cases that had undergone chemotherapy, 15 cases had periprosthetic infection(12.40%). Among 45 cases that haven’t undergone chemotherapy, 1 cases had periprosthetic infection(1.80%). Among 72 proximal tibia cases, 57 cases have had gastrocnemius muscle flap transposition(periprosthetic infection 2 cases, 3.51%), 15 cases haven’t(periprosthetic infection 6 cases, 40.00%). The difference between chemotherapy and non-chemotherapy cases has statistical significance in the incidence of infection via χ2 test(p=0.045). The difference between gastrocnemius muscle flap transposition and no transposition cases has statistical significance in the incidence of infection via logistic regression test(p2=0.003).The difference between infection cases and non-infected cases in operative time, blood loss and drainage in the first day after the first-time prosthetic replacement has no statistical significance(p=0.457、p=0.339、p=0.385).Conclusion Periprosthetic infection is on the main position of reasons for revision after the tumor-type knee prosthesis replacement. Chemotherapy and lack of soft tissue are the main reasons for periprosthetic infection.