Long-term Functional Difference between the First and Second Knees in Simultaneous Bilateral Total Knee Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Rehabilitation Medicine

Background:

• Simultaneous bilateral total knee arthroplasty (SBTKA) is a common procedure for treating severe osteoarthritis in both knees.
• Assessing the long-term functional symmetry between the first and second operated knees is crucial for patient outcomes.
• Limited data exists on the comparative long-term functional results of knees operated simultaneously in bilateral total knee arthroplasty.

Purpose of the Study:

• To compare the long-term functional outcomes of the first and second knees following simultaneous bilateral total knee arthroplasty (SBTKA).
• To evaluate patient-reported outcome measures and range of motion between the operated knees.
• To investigate potential correlations between patient age and functional results after SBTKA.

Main Methods:

• A descriptive study was conducted with 47 patients who underwent SBTKA between January 2003 and December 2010.
• Functional outcomes including range of motion, Forgotten Joint Score (FJS), Oxford Knee Score (OKS), and Western Ontario McMaster University Osteoarthritis Index (WOMAC) were assessed.
• Statistical analysis included the Dependent t-test, Wilcoxon Sign test, Spearman's correlation test, and Bonferroni correction for significance.

Main Results:

• No significant differences were observed in WOMAC total scores (p=0.755), OKS (p=0.239), or FJS (p=0.321) between the first and second operated knees.
• A decrease in range of motion was observed with increasing patient age.
• WOMAC pain scores showed a decreasing trend with increasing patient age.

Conclusions:

• The functional results of the first and second knees are comparable in the long term after simultaneous bilateral total knee arthroplasty.
• While no direct correlation was found between age and overall functional scores, age-related trends in range of motion and pain were noted.
• These findings support the efficacy of SBTKA in achieving symmetrical long-term functional recovery.