[New reconstructive technique for massive zone 2+1 pelvic defects after oncological resection]

Introduction: Reconstruction after internal hemipelvectomy of the acetabular dome is complex, especially in young patients. At our institution, we have developed a technique that uses a proximal tibial allograft to recreate the acetabulum without compromising the proximal femur. Materials and Methods: Three patients with primary bone sarcoma of the pelvis in Zone 2+1 underwent limb-sparing surgery and reconstruction with proximal tibial allograft. Results: All patients were minors, with a follow-up of 42 months. Two patients were discharged in the second week and one in the fourth week, achieving satisfactory reconstruction allowing assisted ambulation and full weight bearing in two cases. There were two acute and one chronic infection-related complications. Discussion: Pelvic sarcomas have a worse prognosis than long bone sarcomas and require massive resections. The tibial allograft reconstruction technique improves function and satisfaction without compromising the proximal femur. This technique is feasible in low-income countries and allows for future primary arthroplasty. Conclusion: We present a successful pelvic reconstruction technique that does not affect growth in young patients, avoiding the use of prostheses and preserving the proximal femur.