Medium-term outcomes in single anaesthetic bilateral total knee replacement surgery: a single surgeon series.

BACKGROUND The lifetime risk of developing symptomatic knee osteoarthritis (OA) is estimated to be 45%, with up to two thirds of patients presenting with bilateral knee symptoms. Patients presenting with end stage bilateral knee OA may benefit from single anaesthetic bilateral total knee replacement (SABTKR). Our study aim was to compare the outcomes of SABTKR with unilateral total knee arthroplasty (TKA) in a single surgeon series over a 20 year period. METHODS We performed a retrospective review of a single surgeon's data from the New Zealand Joint Registry (NZJR) over a 20-year period from January 1999 to December 2018. This review reports on patient demographics, functional outcomes, revision rates and mortality rates. RESULTS 1225 total knee replacements were performed by the senior author (995 TKAs and 115 patients underwent SABTKRs) over the 20 year period reviewed. The mean ages of the TKA and SABTKR groups were 67.7 and 66.7 years, respectively. There was 16.9% mortality rate for the TKA group versus 7.8% in SABTKR group. There were no revisions in the SABTKR group versus 17 revisions in the TKA group representing a revision rate of 0.23/100 component years which can be viewed against a 20 year revision rate of 0.48/100 component years (p < 0.05) for all comers in the NZJR. CONCLUSION This NZJR study demonstrates excellent medium term survival outcomes for selected patients having simultaneous bilateral total knee replacements.