MedWire News:
Unilateral total knee arthroplasty (TKA) appears to be associated with better peri-operative morbidity and mortality than bilateral procedures, say researchers.
They also found that staging bilateral TKA procedures during the same hospitalization offers no mortality benefit and may even increase morbidity compared with carrying out bilateral TKA on the same day.
“The performance of bilateral TKA during one hospitalization (staged or simultaneous) cannot be recommended based on our findings,” say Stavros Memtsoudis and colleagues from Cornell University in New York, USA.
“If performed, however, careful patient selection for bilateral TKA and in-depth discussion about risks and alternatives with the patient cannot be overemphasized.”
The researchers analyzed Nationwide Inpatient Sample data from 1998 to 2006 and identified a total of 670,305 admissions for TKA procedures. Of these, 6.52% were bilaterally performed procedures.
Patients undergoing bilateral TKA procedures tended to be younger at an average age of 66 years compared with 67 years for those receiving unilateral procedures, and had a lower co-morbidity burden.
Despite this, there were higher rates of procedure-related complications and in-hospital mortality after bilateral TKA than unilateral TKA, at 9.45% versus 7.07% and 0.30% versus 0.26%, respectively.
The most common complications were acute posthemorrhagic anemia, venous thrombosis, and pulmonary embolism.
Among the patients undergoing bilateral TKA, 74.8% were performed simultaneously, whereas the remainder procedures were performed on separate days of the same hospital admission (staged), within an average 3.59 days of each other.
The researchers report in the journal Anesthesiology that the risk for complications was higher among patients receiving staged bilateral TKA than among those receiving simultaneous bilateral TKA, at 10.30% versus 9.15%.However, there was no difference in mortality between the two groups (0.29% and 0.26%, respectively).
Bilateral TKA was an independent risk factor for in-hospital mortality, at odds ratios (ORs) of 2.23 and 2.01 for simultaneous and staged procedures, respectively, compared with unilateral TKA.
Other independent risk factors included male gender (OR=2.02), age older than 75 years (OR=3.96) and the presence of a number of comorbidites and complications, including peri-operative shock (OR=15.10), complications affecting the nervous system (OR=22.77) and pulmonary embolism (OR=17.54).
Memtsoudis and team conclude: “In view of the increasing use of TKA, and in particular of bilateral TKA among the US population, these findings are of importance to the peri-operative physician for better assessment of the chance of morbidity and mortality and better identification of patients at risk.”
They add: “These data can help to inform patients adequately of related risks before embarking on this by and large elective procedure.”
