Traumatic Sacral Fracture with Neurological Impairment

History

The patient is a 55-year-old woman with a history of osteoporosis, schizophrenia, and Hepatitis C. She presents with ongoing and severe buttock pain, severe burning leg pain, and indicates increased incontinence (over 2/52).

Prior to presenting to the emergency department, the patient fell backwards at home and immediately complained of back and buttock pain. She underwent lumbar spine and pelvic x-rays, which ruled out hip fracture and obvious lumbar spinal fractures. Hence, the patient was discharged with an analgesic.

Over the next 2 weeks, she continued to have mechanical pain and gradually developed increasing perineal numbness and incontinence.

Examination

• Normal power in both legs
• Sensory deficit in the perineum
• Saddle anesthesia
• Loss of rectal tone

Pre-treatment Imaging

Figures 1A and 1B: AP and lateral lumbosacral x-rays
show the difficulty of making the diagnosis on plain radiographs.

Figure 2. Sagittal lumbosacral CT

Figure 3. Coronal sacral CT scan shows the complexity of the fracture

Figure 4. Sagittal MRI

Figure 5. Sagittal MRI with STIR sequence

Figure 6. Axial sacral MRI

Diagnosis

S1-S2 fracture; Denis Type 3 and Roy-Camille Type 2 fractures

Selected Treatment

The patient underwent posterior spine surgery with decompression of the sacrum followed by L5 to ileum fixation because of her history of osteoporosis.

Surgeons' Treatment Rationale
The patient had an unstable fracture with neurological dysfunction.  She needed stabilization and fixation. Because of the patient's history of osteoporosis, more fixation points would be preferable; and, it was decided to use 2 iliac fixation screws, as well as extend the fixation to L5.

Post-operative Imaging

Figure 7. Post-operative PA x-ray

Figure 8. Coronal CT shows double iliac screws

Outcome

The patient's pre-operative buttock and leg pain has completely resolved, and she mobilizing well. In followup, the patient reports reduced perineal numbness and improved bladder control.

Figure 9. PA x-ray at 8-months post-op

Figure 10. Lateral x-ray at 8-months post-op

Case Discussion

Joshua M. Ammerman, MD

Neurosurgeon

Washington Neurosurgical Associates

Drs. Fehlings and Ibrahim present a fascinating case of a delayed onset cauda equina syndrome following a sacral fracture. The fracture pattern is quite complex; likely, as a byproduct of the patient’s osteoporosis, which in turn can complicate surgical fixation.

The authors have chosen a thoughtful and creative internal fixation strategy, utilizing dual bilateral iliac screws that provide multiple points of fixation in this patient with poor bone quality. The authors’ approach is supported by existing biomechanical data that demonstrates that dual iliac screws provide much higher construct stability than single iliac screws when sacral stability is compromised (Yu B, Zhuang X, Zheng Z, Li Z, Wang T, Lu, W. Biomechanical advantages of dual over single iliac screws in lumbo-iliac fixation construct. Eur Spine J. 2010;19(7):1121-1128).

It seems this strategy was warranted as the patient improved neurologically and notably, the hardware did not fail.