MR imaging after hip and knee replacement.
BACKGROUND
Diffusion-weighted (DW) imaging abnormalities often develop in patients after invasive procedures associated with cerebral microembolism. Cerebral microembolism has recently been shown during orthopedic surgery. We here examine the effects of intraoperative microembolism on acute magnetic resonance(MR) imaging in patients undergoing hip and knee replacement.


METHODS
We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. MR with DW and axial fluid-attenuated inversion recovery (FLAIR) imaging was performed pre- and postoperatively. All patients were monitored intraoperatively for microemboli.


RESULTS
The mean age of patients was 74 years. All patients had intraoperative microemboli. The mean number of emboli detected was 9.9 +/- 18 per surgery. MR imaging was obtained a mean of 3.5 days postoperatively. No DW imaging abnormalities were found after surgery. One patient had new findings on postoperative FLAIR imaging.


CONCLUSIONS
Intraoperative microembolism occurred universally, but did not lead to acute DW imaging abnormalities following knee and hip replacement. Acute imaging abnormalities on FLAIR imaging are rare but may occasionally occur after joint surgery.
Koch
Sebastian
S
Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, USA. skoch@med.miami.edu
Forteza
Alejandro
A
Lavernia
Carlos
C
Romano
Jose G
JG
Campo
Nelly
N
Bhatia
Rita
R
Campo-Bustillo
Iszet
I
D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis; D018709:Statistics, Nonparametric