Radiation-Associated Femoral Nonunion and Fixation Failure Following Limb-Salvage Surgery for Thigh Soft-tissue Sarcoma: Two Case Reports and a Review of the Literature.

INTRODUCTION: Femoral fractures following combined surgery and radiotherapy for soft-tissue sarcomas of the anterior thigh are uncommon but clinically challenging complications. Reported outcomes vary widely, with internal fixation frequently complicated by delayed union, non-union, or mechanical failure, particularly in the setting of irradiated bone and additional patient- or treatment-related risk factors.

CASE REPORT: In this report, we describe two patients with high-grade anterior thigh soft-tissue sarcomas treated with limb-sparing surgery and radiotherapy who subsequently developed femoral fractures within the irradiated field. Both patients underwent intramedullary nail fixation and progressed to non-union with fixation failure, necessitating salvage with distal femur endoprosthetic reconstruction. One patient achieved durable limb salvage following reconstruction, whereas the second developed progressive soft-tissue compromise and periprosthetic infection, ultimately requiring above-knee amputation.

CONCLUSION: These cases highlight the complexity of managing femoral fractures in irradiated bone and underscore the limitations of fixation strategies reliant on biologic healing in high-risk patients. Persistent, unexplained thigh pain may represent an early warning sign of impending mechanical failure. Early risk stratification and timely consideration of reconstructive strategies that provide immediate mechanical stability may help mitigate morbidity in select patients following limb-salvage treatment for soft-tissue sarcoma.