Meta-analysis finds high mortality associated with simultaneous bilateral TKA

Rates of deep venous thrombosis tended to be lower after bilateral vs. unilateral and staged TKA, but the difference was not statistically significant.

Patients who undergo simultaneous bilateral total knee arthroplasty have a higher risk of life-threatening complications compared to patients who receive unilateral or staged bilateral knee replacements, according to a meta-analysis of published studies.

Camilo Restrepo, MD, and colleagues at Thomas Jefferson University Hospital, Philadelphia, and at Boston University Medical Center, Boston, reviewed all randomized and nonrandomized trials comparing simultaneous vs. staged bilateral total knee arthroplasty (TKA) that could be identified via searches of MEDLINE and other literature databases. The researchers sought to evaluate the safety of simultaneous bilateral TKE compared with staged bilateral and unilateral TKA.

They published their findings in the American edition of Journal of Bone & Joint Surgery on the 18 articles included in the meta-analysis. These studies provided data for 27,807 patients treated with 44,684 TKA procedures, including 10,930 unilateral TKAs, 16,419 simultaneous bilateral TKAs and 458 staged bilateral TKAs, according to the study.

The researchers focused their comparison on the prevalence of deep venous thrombosis, pulmonary embolism, cardiac events and mortality.

"The analysis showed that, although a large number of studies on this topic have been published, the overall conclusions are inconsistent. There is also a marked variation in the reporting of the results, specifically the final odds ratio, among the different articles," the authors wrote.

"The meta-analysis ... revealed that the prevalence of major complications such as pulmonary embolus, cardiac events and death was higher following simultaneous [TKA]. The prevalence of deep venous thrombosis seemed to be slightly lower after bilateral [TKA] than it was after unilateral and staged [TKA], but was not significantly different. This complication was not consistently reported in the studies included in this meta-analysis," they wrote.

Simultaneous bilateral TKA patients had a higher probability for pulmonary embolism compared to unilateral TKA, with an overall odds ratio of 1.82 and ranging from 0.14 to 7.22.

The probability for cardiac complications also showed little variation between groups, the authors wrote.

"Almost all of the articles analyzed showed an increase in the prevalence of cardiac events in patients who had undergone simultaneous [TKA]. The overall odds ratio was 2.49, which was the highest for all of the complications analyzed," they wrote.

In addition, simultaneous bilateral TKA patients showed significantly higher mortality, again with little variation between studies. Only one study showed a negative odds ratio for the probability of mortality. "All other studies showed a significant increase in mortality following simultaneous bilateral [TKA]," they wrote.

Mortality had an overall odds ratio of 2.24, ranging from 0.99 to 10.15, according o the study.

"The higher rates of cardiopulmonary complications and mortality call for caution in the selection of patients for simultaneous bilateral [TKA]. Although it was not a direct finding of this study, one may deduce that patients with concomitant cardiopulmonary conditions may not be good candidates for simultaneous bilateral [TKA] even with the improvements in surgical and anesthesia techniques that have occurred over the last few years," the authors noted.

Simultaneous bilateral TKA had overall pooled odds ratio of 0.99 for the probability of experiencing deep venous thrombosis, but the odds ratio ranged from 0.37 to 3.53, according to the study.

For more information:
Restrepo C, Parvizi J, Dietrich T, Einhorn TA. Safety of simultaneous bilateral total knee arthroplasty. J Bone Joint Surg Am. 2007;89-A:1220-1226.