Percutaneous Screw Stabilization of Non-Periacetabular Pelvic Lesions Caused by Metastatic Cancer and Multiple Myeloma.

BACKGROUND: The pelvis is one of the most common locations for metastatic bone disease. While many of the publications that describe surgical treatments focus on periacetabular lesions (Enneking zone II), there is a lack of investigation into lesions in the non-periacetabular areas (zones I, III, and IV). We recently described a minimally invasive percutaneous screw application for metastatic zone-II lesions with excellent results. In the present study, we aimed to extend this approach to the other pelvic areas. METHODS: Twenty-two consecutive patients with painful non-periacetabular pelvic metastatic cancer were included based on retrospective chart review. There were 16 women and 6 men with an average age of 60 years (range, 36 to 81 years). The most common primary cancers were multiple myeloma (7 cases) and breast (5 cases). The most common locations were the sacrum and the ilium. A pathologic fracture was identified in 15 patients. Most of the lesions were treated with multiple large-diameter screws, except for the isolated zone-III lesions. All of the procedures were completed in a standard operating room without the need for special instruments. Radiation therapy was given to 19 patients; the average dose was 15 Gy. The studied outcomes were pain and functionality as assessed by a visual analog scale (VAS) score and the Eastern Cooperative Oncology Group score (ECOG), respectively. RESULTS: There were no surgical complications and no need for blood transfusion. The average follow-up time was 7 months (range, 0.3 to 34.0 months). Two patients died within 4 weeks of surgery due to COVID-19 infection. There was significant improvement in the postoperative VAS pain score (p < 0.0001) and the ECOG score (p < 0.05) when compared with the preoperative scores. There was no implant failure or revision surgery. Local bone-healing was observed in 12 of 14 patients (86%) who survived for >3 months after surgery. CONCLUSIONS: Percutaneous screw application is safe and effective in the treatment of metastatic non-periacetabular pelvic lesions. Given the simplicity of the technique and the instrumentation and the tolerance for concomitant treatments, this approach is worthy of broader consideration. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.