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Staged Bilateral Total Knee Arthroplasty: Differing Results Comparing the First and Second Knees
Logan E Radtke1, Derek J Matheson1, Mia J Woychik1
1Department of Orthopaedic Surgery, University of Utah, Salt Lake City, Utah.
The Journal of Arthroplasty
|April 11, 2024
Summary
Patients undergoing staged bilateral total knee arthroplasty (BTKA) experience similar final outcomes, but the first knee shows greater early pain reduction and functional improvement. Preoperative knee condition influences these differences.
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Rehabilitation Medicine
Background:
- Staged bilateral total knee arthroplasty (BTKA) often results in patient preference for one knee.
- Understanding discrepancies in patient-reported outcomes (PROs) between knees is crucial for optimizing surgical strategies.
- Factors influencing differential recovery following BTKA require investigation.
Purpose of the Study:
- To compare patient-reported outcomes scores between knees in patients undergoing staged BTKA.
- To identify factors contributing to discrepancies in PROs following BTKA.
- To evaluate the impact of time interval between procedures on outcomes.
Main Methods:
- Retrospective analysis of 911 patients undergoing staged BTKA (July 2014 - August 2022).
- Collection of PROs (preoperative and at 2 weeks, 6 weeks, 1 year, 2 years), Kellgren-Lawrence Grade (KLG), range of motion (ROM), reoperation rates, and manipulations under anesthesia (MUAs).
- Comparison of outcomes between first and second knees using paired t-tests and McNemar tests, stratified by time between TKAs.
Main Results:
- No significant differences in ROM, patient satisfaction, MUAs, or reoperations between knees.
- The first knee demonstrated significantly greater early pain reduction and improvement in Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores compared to the second knee.
- 71% of patients had identical preoperative KLG for both knees; 21% had lower KLG in the first knee.
- Outcomes at 1 year and recovery curves were similar between knees regardless of the time interval between procedures.
Conclusions:
- The second knee in staged BTKA shows less delta improvement in KOOS JR and pain scores early postoperatively, potentially due to higher baseline scores.
- Similar final patient satisfaction and clinical outcomes are achieved despite early differential improvements.
- Lower preoperative KLG in the second TKA and a prior MUA on the first knee may predict MUA on the second knee.
