Related Experiment Video
Updated: Sep 19, 2025

The Transition to an Anterior-Based Muscle Sparing Approach Improves Early Postoperative Function but is Associated with a Learning Curve
Published on: September 7, 2022
Comparing 90-day morbidity and mortality after unilateral versus simultaneous bilateral total knee arthroplasty in a
Ali Al-Yami1,2,3, Raad M Althaqafi4, Al-Waleed Al-Yami2
1King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.
Purpose:
Patients presenting with bilateral knee disease could undergo unilateral total knee arthroplasty (UTKA) or simultaneous bilateral TKA (SBTKA); however, the safety profile between the two procedures remains controversial; furthermore, data from our population is scarce. So, the current study objective was to report the incidence of 90-day complications comparing UTKA to SBTKA in a Saudi population.
Methods:
In this retrospective cohort study, we reviewed the medical records from a single institution over ten years, where 1, 046 patients who underwent TKA were identified, of whom 904 fulfilled inclusion criteria, resulting in 514 UTKA and 390 SBTKA. Perioperative and 90-day postoperative morbidity and mortality data were collected.
Results:
There were no significant differences in basic demographic characteristics (age, sex, or BMI) or medical comorbidities (including ASA score) between groups. There were no differences between groups regarding length of hospital stay (LOS), p = 0.43. Patients in the SBTKA group had a higher blood transfusion rate, 25.9 vs. 15.8%, respectively, p = 0.001. The overall individual complication incidents were 8.6 and 10.8% for the UTKA and SBTKA groups, respectively. There was no significant difference regarding infection, 2.4 and 2.1% for UTKA and SBTKA groups, respectively, p = 0.52. However, patients in SBTKA had a significantly higher incidence of deep venous thrombosis compared to UTKA patients, 3.3 vs. 1.8%, respectively, p < 0.05. Furthermore, no differences were found regarding gastrointestinal bleeding, pulmonary embolism, cardiovascular, and central nervous system complications. The overall 90-day mortality incidence was 1% (nine patients), and there was no difference between groups, 0.8 vs. 1.3% for the UTKA and SBTKA, respectively, p = 0.56.
Conclusion:
Although patients who underwent SBTKA had a higher incidence of blood transfusion and DVT compared to those who underwent UTKA, other complications (including infection) and mortality rates within 90 days were not different. We considered the SBTKA procedure relatively safe in our population; however, longer follow-up is warranted.

