Minimally invasive sacroiliac fixation in oncologic patients with sacral insufficiency fractures using a fluoroscopy-based navigation system.

STUDY

DESIGN

Surgical technique article with retrospective case series.

SUMMARY OF BACKGROUND DATA: Sacral insufficiency fractures are commonly encountered in oncologic patients and constitute a cause for persistent lower back and pelvic pain.

OBJECTIVE

The aim of this study is to describe the modified technique of navigated percutaneous sacroiliac (SI) fixation using multiple long screws per level that cross both SI joints and engage bilateral iliac bones; furthermore to evaluate its safety and efficacy in oncologic patients with sacral insufficiency fractures.

METHODS

Six oncologic patients (3 male, 3 female, mean age: 58.8 y) with sacral insufficiency fractures who had undergone additional radiation therapy were operated with navigated percutaneous fixation. Two patients had failed preoperative sacroplasty and 1 had failed SI pinning. Eighteen SI screws were placed (15 at S1 level and 3 at S2). In the majority of cases the screws were long enough to engage bilateral ilium and sacrum. Additionally, 1 patient underwent percutaneous iliolumbar instrumentation and in 4 patients we performed concomitant sacroplasty or polymethylmethacrylate screw augmentation. The patients were followed for 18.8 months in average (range: 12-30 mo). Outcome was assessed using the Karnofsky Performance Status score (KPS), pain scale (0-10) and detailed neurologic examination.

RESULTS

In 1 case, a revision of a screw was required due to radiculopathy. There was no perioperative morbidity or mortality. No hardware failure was encountered. There was significant improvement in KPS (P=0.04) and pain levels (P=0.02).

CONCLUSIONS

These preliminary data suggest that navigated percutaneous SI screw fixation is a safe and effective intervention in terms of pain control and performance status improvement in oncologic patients with sacral insufficiency fractures. For optimal fixation, multiple long screws that engage both iliac bones may be inserted through the S1 level in a safe manner. The technique may be combined with sacroplasty or closed posterior instrumentation to augment the screw fixation. Further investigation is needed to compare this technique with other treatment modalities.