Treatment And Influencing Factors Of Infection After Resection And Prosthetic Replacementof Malignant Bone Tumor Around The Knee

PartⅠ Influencing factors of infection after resection and prosthetic replacement of malignant bone tumor around the kneeObjectiveThis study aimed to analyze the characteristics of infection and the clinical factors influencing treatment outcomes of infections associated with resection and prosthetic replacement of malignant bone tumor around the knee,through the mid-term follow-up(≥5 years)study,in order to reduce the recurrence of postoperative infection and improve the success rate of infection control.Materials and methodsWe analyzed clinical data of 61 patients with infections involving resection and prosthetic replacement of malignant bone tumor around the knee,record the recurrence of infection and survival rate.The factors of age,sex,duration of operation,bone resection length,tumor grade,extra compartmental tumor extension,time from surgery until infection,the classification of infection,soft tissue condition,C-reactive protein and postoperative chemotherapy were analyzed.The univariate multivariate analysis of infection control status was performed by COX regression model and the Kaplan-Meier survival curve was also performed with SAS9.3 software.ResultsAll the 61 patients with infections involving resection and prosthetic replacement of malignant bone tumor around the knee were followed for 60-99 months(mean,75.3 months).Infections were controlled in 53 cases(86.9%).The period between infection diagnosis and infection control ranged from 1 to 25 months(mean,19.1 months).The COX regression model single factor analysis showed that the extra compartmental tumor extension,the classification of infection,soft tissue condition were associated with infection control periods(P<0.05).The COX regression model multi-factor analysis showed that time from surgery until infection,the classification of infection,soft tissue condition were independent factors(P<0.05).Relative to the late-onset infection,early-onset infection were easier to control,the HR was 2.547(1.242-5.223);Relative to the severe degree of infection,mild degree of infection were easier to control,the HR was 2.121(1.021-4.408);Relative to the poor soft tissue condition,the infection of patients with good soft tissue condition were easier to control,the HR was 3.343(1.433-7.799).ConclusionsThe independent factors influencing treatment outcomes of infections associated with resection and prosthetic replacement of malignant bone tumor around the knee were the time from surgery until infection,the classification of infection,soft tissue condition.Early diagnosis of infection,assess the severity of the infection and the condition of soft tissue is conducive to improving the success rate of infection control.Part Ⅱ Comparison of the efficacy of different therapies for the treatment of infection after resection and prosthetic replacement of malignant bone tumor around the kneeObjectiveThe aim of this study was to compare the treatment efficacy of different surgical methods of infections associated with resection and prosthetic replacement of malignant bone tumor around the knee.Materials and methodsSixty one patients with infections associated with resection and prosthetic replacement of malignant bone tumor around the knee were included in this retrospective study and treated with debridement,one-stage arthroplasty exchange,two-stage arthroplasty exchange,Ilizarov technique and amputation.The time to determine the diagnosis of infection after surgical resection of artificial joint replacement as a starting point,at least follow-up for more than 5 years to determine whether the mid-term successful treatment of infection.The treatment efficacy of different surgical methods were compared.ResultsAll the success rates of 61 patients with infections involving resection and prosthetic replacement of malignant bone tumor around the knee were 86.9%,in which the success rates of debridement was 22.2%,the success rates of one-stage arthroplasty exchange was 66.7%,the success rates of two-stage arthroplasty exchange was 64.9%,the success rates of Ilizarov technique and amputation were both 100%.According to the result of Fisher test,it showed significant differences of the success rates between debridement and two-stage arthroplasty exchange(P=0.0260),debridement and Ilizarov technique(P=0.0032),debridement and amputation(P=0.0210).Conclusions1.Early infections(occurring within 10 days)involving tumor endoprostheses patients with stable endoprostheses and good soft tissue condition are most appropriate for debridement;2.Early infections(occurring within 1 month)involving tumor endoprostheses patients with good soft tissue condition are most appropriate for one-stage arthroplasty exchange;3.Late infections(occurring after 1 month)involving tumor endoprostheses patients with poor soft tissue condition and refractory mixed pathogen are most appropriate for two-stage arthroplasty exchange;4.Ilizarov technique is typically reserved as a salvage strategy to avoid amputation after prior failed treatment attempts or for patients who are not candidates for debridement or one-stage arthroplasty exchange and cannot or do not want to undergo multiple surgeries.