Short-Term Outcomes of Inactivated Reimplantation Versus Prosthetic Replacement of Periarticular Osteosarcoma of the Knee in Children

Song Ning; Zhang Qiang; Du Junwei; Wu Junshen; Dai Zhibing; Jiang Renbing

Abstract：Objective To investigate the difference in short-term clinical efficacy between inactivation and replantation of tumor segments of periarticular osteosarcoma of the knee joint and total knee tumor prosthesis replacement in children.Methods A retrospective analysis was conducted on clinical data from 26 patients with knee joint osteosarcoma treated in the Bone and Soft Tissue Tumors and Melanoma Department of Xinjiang Medical University Affiliated Tumor Hospital from January 2019 to January 2022.The cohort comprised 13 males and 13 females,ranging in age from 8 to 16 years,with a mean age of(11.88±2.42)years.Eight patients underwent tumor segment inactivation and replantation(5 femur,3 tibia),forming the inactivation-replantation group,while 18 patients underwent total knee tumor prosthesis replacement surgery(9 femur,9 tibia),constituting the prosthesis replacement group.Comparisons were made between the two groups in terms of general clinical data,functional assessment using the musculoskeletal tumor society(MSTS)score,knee joint range of motion(ROM)evaluation,regular postoperative X-ray examination,limb length discrepancy evaluation,oncologic assessment,and complication analysis.Results The follow-up period for the 26 patients with osteosarcoma around the knee joint ranged from 20 to 56 months,averaging(29.50±6.46)months.In the inactivation and replantation group,the limb length discrepancy ranged from 0.63 to 1.75 cm,averaging(1.03±0.37)cm,while in the prosthesis replacement group,the discrepancy ranged from 0.73 to 4.00 cm,averaging(1.96±0.88)cm.The comparison between the two groups revealed a statistically significant difference in limb length discrepancy(t=2.86,P=0.009).The average MSTS score for the inactivation and replantation group was(26.63±1.51),whereas the prosthesis replacement group scored(24.50±1.89)points on average.This comparison also showed a statistically significant difference in MSTS scores(t=2.81,P=0.01).At the final follow-up,the average knee flexion angle in the inactivation and replantation group was(62.13±13.78)％of the healthy side,while the total knee tumor prosthesis replacement group exhibited an average knee flexion angle of(65.68±10.40)％of the healthy side.However,the comparison of knee flexion angles between the two groups did not reveal a statistically significant difference(x2=1.25,P=0.26).Conclusion In children,the inactivation and reimplantation of periarticular osteosarcoma tumor segments,aimed at preserving the epiphysis,can effectively maintain the growth and development potential of the affected limb.This approach also significantly enhances the joint function of the patient,demonstrating superior implant fusion,fewer complications,and overall,a better clinical outcome during short-term follow-up.