Progression of Femoral Osteolytic Metastases after Intramedullary Nailing and Subsequent Salvage Techniques

Simple Summary Intramedullary nailing spanning from the proximal to distal femur is a well-accepted orthopedic surgical technique for patients with metastatic cancer in the diaphysis of the femur. However, in the new era of precision cancer care and improved survival, there is a critical need to address cancer progression after reaming and insertion of a nail through the cancer-laden bone. We aim to characterize rates of cancer progression following long nailing and subsequent salvage techniques for patients with progression. We also present a novel rod-retaining percutaneous salvage using radiofrequency ablation and cementoplasty to delay or prevent open surgery which may not be favorable for advanced-stage cancer patients. We find that 14% of nailing patients experience progression. Percutaneous salvage showed promising improvements in pain and ambulatory scores and avoided the need for open surgery in most patients. Overall, cancer progression does occur following nailing and continued monitoring, and timely intervention is required to prevent nail or bone breakage.Abstract Intramedullary nailing insertion from the proximal-to-distal femur is frequently performed for impending and complete pathological femur fractures due to osteolytic metastases. After nailing through cancer-laden bone, residual chemotherapy- and/or radiation-resistant tumor may progress. Progression of osteolysis risks future nail failure or pathological fractures. This study assesses the incidence of cancer progression following intramedullary nailing in a femur-only cohort and describes a percutaneous rod-retaining salvage technique. A single-institution, retrospective study was conducted to identify adult patients who underwent intramedullary nailing for femoral osteolytic lesions for complete or impending nail failure from 2016 to 2023. Progression was defined as enlargement of the pre-existing lesion and/or appearance of new lesions on radiographs. Surgical outcomes were assessed with a combined pain and functional score. A total of 113 patients (median age 66.8 years (IQR = 16.4); median follow-up 6.0 months (IQR = 14.5)) underwent intramedullary nailing. Sixteen patients (14.2%) exhibited post-nailing cancer progression. Pre- and postoperative radiation and chemotherapy did not decrease the odds of cancer progression. Three patients underwent initial open surgical salvage consisting of proximal femur replacement arthroplasty, and six patients did not receive salvage due to poor surgical candidacy or patient choice. Seven patients (median follow-up 10.7 months (IQR = 12.9)) received percutaneous salvage. In this group, pain and functional scores improved by 4.0 points (p = 0.0078) at two-week postoperative follow-up and 2.0 points (p = 0.0312) at the most recent follow-up (mean follow-up 13.0 +/- 9.4 months). All three nonambulatory patients became ambulatory, and six patients were able to ambulate independently without walking aids. No major complications were reported 30 days postoperatively. Progression of femoral osteolytic metastases may occur following intramedullary nailing. Continued monitoring of the entire femur is needed to maintain improved functional status and to prevent catastrophic progression of pre-existing lesions or appearance of new lesions. In patients with more proximal metastases only, the customary practice of bringing a long nail from the proximal femur to distal metaphysis should be reconsidered. Furthermore, there is concern of mechanical transport of cancer cells during guide wire insertion, reaming, and rod insertion through cancer laden bone to cancer free distal bone.