Abstract

Cerebral fat embolism can complicate long bone fractures and orthopaedic surgery. We present two patients with this syndrome who developed coma following long bone fracture or hip replacement surgery.

Patient 1 was a 71 year old previously independent lady who was admitted following a fall and underwent total hip replacement surgery for a left neck of femur fracture. Immediately after cementing the shaft, she developed marked hypoxia, tachycardia, hypotension and pyrexia and remained intubated and sedated after surgery. Following withdrawal of sedation, she remained unconscious. Neurological examination revealed a GCS of 3/15, roving eye movements, intact brainstem reflexes, increased tone on the left side and up–going plantars. Over the next few days her GCS remained low at 5/15, with flexor motor response to pain. EEG was diffusely slow and compatible with an encephalopathic process. MRI showed innumerable small emboli on DWI (“star–field pattern”), and multiple, hyper–intense lesions on T2 and FLAIR. Bubble echo was positive and suggestive of a patent foramen ovale. Over the next four weeks, she made a dramatic recovery and one month after surgery was obeying commands, verbally communicating, oriented in time but disoriented in place.

Patient 2 was a 66 year old, previously independent lady who was admitted with a femoral shaft fracture. The day following her admission, her GCS dropped to 7/15 and she developed hypoxia, tachycardia and pyrexia. Neurological examination initially did not reveal a focal deficit. During a transient improvement in GCS to 14/15, she was noted to have a right sided face and arm weakness. MRI DWI again showed the characteristic “star–field pattern”. Clinically she deteriorated again with a drop in her GCS, development of thrombocytopaenia, pulmonary emboli and nephrogenic diabetes insipidus and remained on ITU at the time of writing this abstract.

Cerebral fat embolism syndrome may be under–diagnosed in clinical practice. It should be considered in the differential of coma following orthopaedic surgery and fractures. Neurological outcome has been reported to be generally good.