Mechanical comparison of iliosacral reconstruction techniques after sarcoma resection.

•Plate-and-screw constructs performed better than spinal instrumentation constructs.•A single point-of-fixation in each segment predisposes to rotational displacement.•Increased motion through the defect resulted in failure at the pubic symphysis.•Implant-bone interface, not implant strength, chiefly defines construct stability.•Reconstructive techniques should prioritize quality sacral and iliac fixation.