A study, published in The Journal of Bone & Joint Surgery, evaluated whether patients undergoing simultaneous bilateral total knee arthroplasty had a higher or lower risk of developing stiffness requiring postoperative manipulation while under anesthesia.
John Meehan, MD, of UC Davis, and colleagues utilized the California Discharge Database and master death file database. They estimated the number of patients who failed to undergo the second stage of a staged bilateral TKA procedure between 2005 and 2013, and they selected replacement cases from among patients who had unilateral TKA by matching them on eight clinical characteristics of the patients who had staged bilateral TKA.
Here's what they found:
1. The cumulative incidence of manipulation within 90 days was 2.14 percent for unilateral TKA, 2.11 percent for staged bilateral TKA and 1.62 percent for simultaneous bilateral TKA.
2. At 180 days, the cumulative manipulation incidence rate was 3.07 percent after unilateral TKA, 2.89 percent after staged bilateral TKA and 2.29 percent after simultaneous bilateral TKA.
3. Researchers used multivariate analysis to adjust for risk factors, and in that instance the 90-day odds ratio of needing manipulation after a simultaneous bilateral TKA was lower than that for an unilateral TKA or a staged bilateral TKA.
That trend stayed true at 180 days.
Researchers concluded, "Although the odds ratios were small, simultaneous bilateral TKA had a significantly decreased rate of stiffness requiring manipulation under anesthesia at 90 days and 180 days after knee replacement compared with that after staged bilateral TKA and unilateral TKA."