Abstract
PURPOSE: The purpose of this study was to investigate the clinical outcomes of joint-preserving endoprosthesis reconstruction for primary sarcomas about the knee. METHODS: A retrospective cohort study was conducted on 45 patients (21 males, 24 females) who underwent joint-preserving endoprosthesis reconstruction (JPER) for bone tumours about the knee between January 2009 and January 2023. The average age was 23.9 ± 15.1 years (range, 7-66 years) and the most common pathological type was osteosarcoma (34), followed by Ewing's sarcoma (5), adamantinoma (3), spindle cell sarcoma (2), and undifferentiated pleomorphic sarcoma (UPS, 1). There were 35 cases of tumors located in the femur and 10 cases located in the tibia. The oncological outcomes included local control, metastasis, progression-free survival, and overall survival. The functional outcomes were evaluated by the Musculoskeletal Tumour Society Score (MSTS-93). RESULTS: 45 patients were included in this retrospective study, and no patient were lost in the follow-up. The mean follow-up time was 105.3 ± 44.6 months (range, 15-183 months). Five patients (11.1%) died in the last follow-up. Four patients had local recurrences, and the mean interval between the index procedure to local recurrence was 25.5 months (range, 4-36 months). The 5-year and 10-year overall survival rate was 91.2% (95% CI 82.5%-99.9%) and 86.2% (95% CI 74.3%-98.1%), respectively. The 5-year and 10-year progression-free survival rate was 85.5% (95% CI 74.9%-96.1%) and 81.5% (95% CI 69.3%-93.7%), respectively. The average MSTS-93 score was 93% (range, 70-100%). The overall survivorship of the JPER was 84.4% (38/45) at an average of 8.7 years follow-up. Failure mechanisms included 4 infections (57%), 2 local tumour progression (29%), and one structural failure (14%) according to Henderson classification. CONCLUSIONS: The joint-preserving endoprosthesis reconstruction (JPER) is a reliable technique to reconstruct massive bone defects after primary sarcoma resection about the knee with acceptable oncological outcomes, function, and satisfaction. LEVEL OF EVIDENCE: Level IV therapeutic study.