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In Vitro Application of a Wireless Sensor in Flexion-Extension Gap Balance of Unicompartmental Knee Arthroplasty
Published on: May 5, 2023
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Mechanical alignment changes during flexion in total knee arthroplasty without affecting clinical outcomes
Andrea Giorgini1, Francesco Zambianchi1, Martina Lombardi1
1Policlinico di Modena, Department of Orthopaedic and Traumatology, Via del Pozzo 71, Modena, Italy.
Clinical Biomechanics (Bristol, Avon)
|December 16, 2019
Summary
The Hip-Knee-Ankle angle changes with knee flexion after total knee arthroplasty. However, maintaining a neutral angle throughout flexion does not guarantee better clinical outcomes in patients.
Area of Science:
- Orthopedic Surgery
- Biomechanics
- Arthroplasty Research
Background:
- Total knee arthroplasty (TKA) aims to restore knee function.
- Limb alignment is crucial for TKA success.
- The Hip-Knee-Ankle (HKA) angle's behavior during flexion is not fully understood.
Purpose of the Study:
- To investigate changes in the Hip-Knee-Ankle (HKA) angle during knee flexion post-total knee arthroplasty.
- To assess the correlation between the HKA angle during flexion and mid-term clinical outcomes.
Main Methods:
- Retrospective analysis of 334 computer-assisted TKAs.
- Intraoperative measurement of HKA angle at various knee flexion degrees.
- Clinical outcome assessment at a mean 35-month follow-up for 233 patients.
Main Results:
- The HKA angle demonstrated changes with increasing knee flexion across all preoperative alignment groups (varus, neutral, valgus).
- A significant proportion of knees maintained neutral alignment at 20°, 45°, and 90° flexion.
- No correlation was found between neutral HKA angle during flexion and poor clinical outcomes.
Conclusions:
- Intraoperative HKA angle is dynamic and changes with knee flexion after TKA.
- Achieving a neutral HKA angle throughout the range of motion does not predict superior clinical outcomes.
