24 osteoarthritic patients were randomised to undergo either computer-assisted navigated unilateral total knee arthroplasty or a conventional standard surgical method using intramedullary alignment guides. The primary outcome was the presence and number of micro-emboli which was evaluated using a non-invasive transcranial Doppler device. The results indicated that there was a significantly lower presence of systemic emboli with the computer-navigated group. However, no significant differences were seen in the secondary outcome measures between the two groups.