The risk of pathological fractures after intralesional curettage in Atypical Cartilaginous Tumours: A retrospective cohort study

Purpose: Atypical cartilaginous tumors (ACT) are locally aggressive, cartilage-producing neoplasms, traditionally classified as chondrosarcoma grade 1. They exist within the spectrum of cartilaginous tumors, between enchondroma and high-grade chondrosarcoma. The diagnosis of ACT remains challenging, with limited consensus on optimal treatment. Despite ongoing debate, intralesional curettage is commonly performed, though the risk of pathological fractures post-treatment remains a significant complication. This study aims to investigate the impact of cortical window design on fracture risk following curettage for ACT in the distal femur. Methods: We compared two types of cortical windows: smooth oval (low stress riser) and windows with sharp or predrilled rounded corners (high stress riser). A retrospective cohort of 153 patients treated between 2000 and 2020 was included. Fracture occurrence was recorded, and logistic regression models were used to assess the relationship between surgical technique and fracture risk. We corrected for void filling and tumour size. Results: Our findings revealed no significant difference in fracture risk between the two types of cortical windows (OR = 1.62, 95 % CI:0.66–3.96). However, the use of cement as a void filler significantly increased fracture risk, with odds ratio (OR) approximately five times higher than those using bone chips (OR = 5.00, 95 % CI:1.81–13.88). Tumor size (cm) was also associated with fracture risk (OR 1.31, 95 % CI:1.04–1.63). Conclusion: The study highlights the importance of choosing appropriate void filling material, with bone chips offering a lower fracture risk compared to cement. These results suggest that optimizing surgical techniques, particularly the choice of filling material, may reduce post-curettage fracture risk in ACT treatment.