Outcomes of surgical treatments for sacral metastases

Sacral metastases can cause severe pain, neurologic deficits, and sacroiliac instability, leading to substantial functional impairment. Although surgery is used for symptom palliation, patient-reported outcomes (PROs) following minimally invasive spinopelvic fixation remain poorly characterized.

We retrospectively reviewed 10 patients (median age, 63 years) who underwent surgery for sacral metastases between 2015 and 2022. Procedures included posterior decompression alone or posterior decompression with minimally invasive spinopelvic fixation for sacroiliac instability. Eastern Cooperative Oncology Group (ECOG) performance status and PRO measurement information system (PROMIS) pain interference (PI), physical function (PF), and Depression scores were collected preoperatively and at 3 months postoperatively. Overall survival was estimated using Kaplan-Meier analysis.

Four patients underwent posterior decompression alone, and six underwent decompression with minimally invasive spinopelvic fixation. Mean ECOG improved from 2.5 preoperatively to 1.6 at 3 months (P = 0.06). PROMIS PI improved by a mean of -8.7 (P < 0.01), exceeding the minimum clinically important difference, while PF improved by 4.5 (P = 0.03). Depression scores improved by -3.5 but were not statistically significant (P = 0.20). In the instrumented subgroup, PROMIS PI improved by -8.5 (P = 0.028), with trends toward improved ECOG and PF. Three surgery-related complications occurred, with no instrumentation failures. Median survival was 9 months, with 6-, 12-, and 24-month survival rates of 80%, 70%, and 35%, respectively.

Surgery for sacral metastases provides clinically meaningful pain relief and short-term functional improvement. Minimally invasive spinopelvic fixation is a feasible option for patients with sacroiliac instability and supports durable symptom palliation.