Bilateral knee replacements: simultaneous or staged?

Approximately one-third of primary knee replacements are performed on patients with bilateral symptomatic disease. This retrospective study compared the complication rate, functional outcome and cost implications of performing bilateral total knee replacements under a single anaesthetic or as staged procedures with a control group of unilateral cases. There was no significant difference in the complications or outcome. There was a significant reduction in the mean hospital admission time of 7 days per knee replacement (P < 0.001, Student's t test) by performing bilateral knee replacements for osteoarthritis under the same anaesthetic. However, a survey of practising knee surgeons in three health regions in the United Kingdom shows that only 24% would regularly perform bilateral knee replacements under one anaesthetic.