LAUSR

Resection of malignant bone tumors in the posterior ilium may result in pelvic ring disruption. Preserving the pelvic ring and keeping an adequate surgical margin is ideal, but is challenging, especially when the tumor extends to the sacroiliac joint. The current report proposes a line from the lateral point of the second sacral dorsal foramen to the anterior surface of sacral ala (S2‐sacral ala line), and cutting from the line to the ilium over the sciatic notch and to the sacral wing using thread saws. This preserves the cortex at the sciatic notch and the distal sacroiliac joint. Two posterior iliac tumors extending to the sacroiliac joint, a metastatic melanoma in a 75‐year‐old male, and an osteosarcoma in a 56‐year‐old male were resected. The resections were performed along the S2‐sacral ala line, and consequently lumbo‐sacro‐pelvic fusions were performed. Both patients were able to walk with one crutch. Indications for the method using the S2‐sacral ala line for iliac tumors may be limited. However, the method can increase pelvic ring preservation in cases with posterior iliac malignant bone tumors.