Knee-Sparing Resection and Reconstruction Surgery for Bone Sarcoma Using 3D-Surgical Approach: Average of 5-Year Follow-Up.

: To date, the gold standard of care for bone sarcomas is limb salvage surgical resection. In cases where the tumor arises in the distal femur or proximal tibia near the joint line, knee-sacrificing surgery is typically performed, followed by reconstruction with oncological megaprostheses. This study aims to evaluate the effectiveness of a precise 3D-based surgical approach for knee-sparing tumor resections, assessing its feasibility and its impact on surgical, oncological, and functional outcomes. : This single-center retrospective study presents the surgical and oncological outcomes of knee-sparing surgeries following bone sarcoma resections. All patients underwent either intercalary or geographic resection, and reconstruction was tailored to each patient, using either an allograft or a titanium alloy Ti64 implant, depending on the specific requirements of the case. : A total of 23 patients (average age 21.04 years, 14 males) were included, with an average postoperative follow-up of 58 months (range: 12-102 months). Clear surgical margins were achieved in all patients, with 16 patients (69.5%) showing wide negative margins (R0) and the rest showing close negative margins (R1). Resections were primarily intercalary (17 patients, 73.9%), with 6 patients (26.1%) undergoing geographic resections. Reconstruction methods included allografts (9 patients, 39.3%), vascularized fibula and allograft (8 patients, 34.7%), and printed Ti64 cage reconstructions (6 patients, 26.0%). At the last follow-up, 19 patients (82.6%) were disease-free, 3 patients (13.4%) were alive with evidence of disease, and 1 patient (4%) was dead of disease. Complications included four cases of non-union that required revision surgery, as well as two local recurrences, which necessitated revision surgery to a modular endoprosthesis and above-knee amputation. The average MSTS at the final follow-up was 23.16 ± 5.91. : The use of 3D-printed PSIs for knee-sparing bone tumor resections has emerged as the gold standard, enhancing both surgical and oncological outcomes. A future challenge lies in improving reconstruction techniques, shifting from traditional allografts to customized Ti64 printed lattice implants. As personalized healthcare and additive manufacturing continue to advance, the future of orthopedic oncology will likely see more precise, durable, and biologically integrated implants, further improving patient outcomes.