Safety and cost benefits of bilateral total knee replacement in an acute hospital

Background: Total knee arthroplasty of both knees under the one anaesthetic has become a common procedure. Benefits reported include a shorter overall hospital stay and reduced costs. The published studies come from university associated tertiary referral hospitals with well-established research establishments and a vast experience of joint replacement. This study examines the experience of a small hospital to see if similar benefits can be achieved. Methods: A retrospective medical record review was performed of the synchronous bilateral knee replacements against a match group of bilateral staged knee replacements. Both groups were compared with a control group of unilateral knee replacements. A prospectively conducted review of the synchronous and staged bilateral knee replacement groups was then carried out to assess the clinical outcome in these two groups. Results: The incidence of surgical and medical complications was not statistically different in any group. The bed stay for bilateral surgery was increased by 2 days compared to unilateral surgery with a net saving of 6 days hospital stay for the patient group having both knees replaced at separate operations within 1 year. At an average of 2.5 years post surgery there was no statistically significant difference in outcome between those patients who had both knees replaced either synchronously or at staged intervals. Conclusions: Bilateral knee replacement is a good choice for patient and hospital. Bilateral surgery does not increase the risk of perioperative complications to the patient and reduces the overall cost to the hospital. There is no difference in short to medium term clinical outcome between patients who have had both knees replaced synchronously or at staged intervals. Results comparable in safety, as judged by complication rates and efficiency, as judged by length of stay can be achieved in a smaller metropolitan level 2 hospital environment.