Indications and Long-Term Outcomes of Intercalary Reconstruction Techniques for Diaphyseal Bone Tumors

Objective: Intercalary reconstruction after resection of diaphyseal bone tumors allows for adjacent-joint preservation; however, despite implant advancements they continue to experience high failure rates. Free fibular autograft (FFA), allograft interposition, and metallic endoprostheses are used, but there is no consensus on optimal construct. Methods: We conducted an IRB-approved retrospective review of patients who underwent intercalary reconstruction for oncologic indications at a single institution (1999 to 2022). Inclusion criteria included intercalary reconstruction with FFA, allograft, or endoprosthesis for oncologic indications and with minimum follow-up of 3 months. Primary outcome was implant survival. Secondary outcomes included complication type, rate, and timing, resection length, distance from articular surface, and failure modes. Results: Thirty-five patients met inclusion criteria, 23 men and 12 women. Reconstructive options included: FFA (N=8), endoprosthesis (N=16), and allograft (N=11). Average follow-up was 3.9 years. Average patient age was 41.8 years; FFA patients were younger than endoprosthesis patients (P=0.0002). FFAs were closer to the articular surface than endoprostheses (P=0.0003). Overall implant survival was 36.6% at 21 years; median survival was 2.04 years. Overall complication rate was 65.7%, with no difference between groups. Ten patients (28.5%) ultimately ended with a joint-sacrificing operation. Conclusions: This study supports the existing literature’s reported high rate of complication and implant failure of intercalary reconstructions. Salvage options are available, including those for secondary joint-sparing operations; however, they often result in a joint-sacrificing endoprosthesis limiting function and longevity. With patients having improved life expectancy for both metastatic and primary bone tumors, implant optimization is critical.