MRI detection of spontaneous rupture of a well differentiated pineal teratoma

A Rare Case of Complex Pelvic Injury and Associated Intrathecal Fat Embolism due to Spinopelvic Dislocation with Sacral Burst Fracture

Introduction

Pelvic and lumbar spine injuries are very common especially in multiple trauma patients. The usual mechanism in young patients leading to pelvic fractures is a high-energy trauma such as traffic accidents. In elderly patients, low energy traumas are causal for such injuries. Compared to the high number of patients with pelvic or lumbar spine injuries, cerebral fat embolism is a quite rare finding but it needs to be considered to not misinterpret the radiological findings.

Case

We present the case of a 41-year-old patient, who got hit and trapped in the lumbar region by a hydraulic arm in a car repair shop. The patient was primarily admitted to a level II trauma center. The radiological and clinical examinations revealed an open pelvic type C injury in terms of a spinopelvic dissociation, dislocation of the left hip joint, rupture of the mesentery of the rectum and colon sigmoideum, and a complex injury to the left ureter. Additionally, CT scan showed fluid with higher density than cerebro spinal fluid (CSF) in the lateral ventricles indicating an intracranial bleeding. After an immediate surgery to stabilize the patient, he was admitted to a level I trauma center. The reanalysis of the existing CT datasets combined with a new head CT leads to the conclusion that the high density fluid in the lateral ventricles is not a intracranial bleeding but rather fat deriving from the complex pelvic and lumbar spine fracture into the CSF system. Therefore, an immediate operation was performed to stabilize the spinopelvic dissociation and to close the injured dural sheath. Additionally, a ventricle drainage has been placed, which confirmed the diagnosis of intrathecal fat embolism. Afterwards, complex plastic surgery was necessary to restore the soft tissue damage.

Conclusions

Intrathecal fat embolism in muliple trauma patients is a rare condition, which should be considered in patients with complex spine or pelvic injuries. It is important to distinguish this rare condition from intracranial bleedings, which are much more common because the consequent therapeutic strategy is quite different. In case of intrathecal fat embolism, a ventricle drainage system should be placed immediately, and the underlying spine or pelvic injuries need to be stabilized combined with closure of the dural sheath to prevent continuous fat embolism and meningeal infection.

Intracranial transthecal subarachnoid fat emboli and subarachnoid haemorrhage arising from a sacral fracture and dural tear

We present the case of a 28-year-old man with an unusual aetiology of lipid-dense material in the subarachnoid space. CT of the head at presentation was normal. MRI of the spine revealed a defect in the dura at L5/S1, with avulsed left L5 and S1 nerve roots. Haematoma and marrow fat were observed in close relation to the dural tear adjacent to the sacral fracture. Head CT and MRI subsequently demonstrated new lipid-dense material and haemorrhage in the subarachnoid space after sacral instrumentation, presumably owing to transthecal displacement of fatty marrow.