# Partial sacrectomy with en bloc tumor resection without instrumentation. What level is safe?

## TL;DR

This paper investigates the safety of performing partial sacrectomy without surgical instrumentation, finding that it can be stable in most patients, especially those with lower activity levels.

## Contribution

The study demonstrates that non-instrumented high en bloc sacrectomy can provide sufficient stability for proton therapy in selected cases.

## Key findings

- Non-instrumented high en bloc sacrectomy can retain the cranial sacrum and allow for proton therapy.
- Instrumentation is mainly needed for younger, more active patients.
- Lower bone mineral density does not always require instrumentation for stability.

## Abstract

En bloc sacrectomy is an extensive surgical procedure which is often the only option which provides cure. Our experience shows that, in selected cases, instrumentation is not necessary even in case of a high en bloc sacrectomy retaining the cranial part of the sacrum in situ. This creates suitable conditions for subsequent proton therapy.

What level of resection is safe without reconstruction?

Between 2014 and 2023 we performed a total of 29 sacral resections for various etiologies. Patients following reconstruction of the lumbosacral region by internal fixator (3) and patient after hemicorporectomy (1) were excluded from the study. The study group comprised 25 patients, 15 men and 10 women with a mean age of 45.1 years (range, 1.7–72.2 years). The most frequent indication for surgery was chordoma (8), followed by MPNST (4), yolk sac tumor (2) and undifferentiated sarcoma (2).

Stress fractures of the sacral stump occur in elderly patients with lower bone mineral density, or in younger patients with a higher bone mineral density who are more active when resuming their daily routine after the operation.

Instrumentation is, in our view, primarily indicated in younger and more active patients, whereas in most cases, even with lower bone mineral density, non-instrumented procedure results in sufficient stability in all levels of partial resection.

•En bloc sacrectomy is an extensive surgical procedure which is often the only option which provides cure.•In selected cases, instrumentation is not necessary in case of a high en bloc sacrectomy retaining the cranial part of the sacrum, because it creates suitable conditions for subsequent proton therapy.•Instrumentation is primarily indicated in younger and active patients, whereas in a majority of patients, even with lower bone mineral density, non-instrumented procedure results in sufficient stability.

En bloc sacrectomy is an extensive surgical procedure which is often the only option which provides cure.

In selected cases, instrumentation is not necessary in case of a high en bloc sacrectomy retaining the cranial part of the sacrum, because it creates suitable conditions for subsequent proton therapy.

Instrumentation is primarily indicated in younger and active patients, whereas in a majority of patients, even with lower bone mineral density, non-instrumented procedure results in sufficient stability.