Small soft tissue tension changes do not affect patient-reported outcomes one year after primary TKA
Ethan Krell1, Amethia Joseph1, Joseph Nguyen2
1Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY, 10021, USA.
International Orthopaedics
|October 11, 2020
Summary
A 1-mm increase in total knee arthroplasty (TKA) liner thickness, slightly increasing ligament tension, showed transient benefits in early patient-reported outcomes. However, these differences in TKA outcomes were not noticeable at 12 months.
Area of Science:
- Orthopedic Surgery
- Biomechanical Engineering
- Arthroplasty Research
Background:
- Achieving optimal soft tissue tension and balance is crucial for successful total knee arthroplasty (TKA) outcomes.
- Implant manufacturers provide 1-mm liner increments for precise ligament tension adjustment during TKA.
- This study investigates the impact of subtle soft tissue tension alterations on early patient-reported outcomes in TKA.
Purpose of the Study:
- To evaluate the effect of a 1-mm increase in TKA liner thickness on early patient-reported outcomes.
- To determine if minor changes in ligament tension influence functional scores and range of motion post-TKA.
- To assess the clinical relevance of transient outcome differences observed at four months post-TKA.
Main Methods:
- Ninety-nine primary TKA procedures were analyzed, with 50 knees in the control group (standard liner) and 49 in the study group (1-mm thicker liner).
- Ligament balance was established, and compartmental loads were recorded using sensor technology.
- Patient-reported outcomes including Knee Society Score (KSS), KOOS Jr., range of motion (ROM), and Forgotten Joint Score (FJS) were collected pre-operatively and at 6 weeks, 4 months, and 12 months post-operatively.
Main Results:
- No significant demographic or pre-operative differences were found between the control and study groups.
- At four months post-TKA, the control group showed statistically significant improvements in KOOS Jr. and FJS compared to the study group.
- No statistically significant differences in any outcome variables were observed between the groups at 12 months post-TKA.
Conclusions:
- A 1-mm increase in TKA liner thickness, leading to slightly higher soft tissue tension, resulted in transiently better patient-reported outcomes at four months.
- These early outcome differences favored the group with lower ligament tension (control group).
- No clinically significant differences in TKA outcomes were apparent at the 12-month follow-up, suggesting transient effects of minor tension changes.
