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Design and Implementation of a Bespoke Robotic Manipulator for Extra-corporeal Ultrasound
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True Confessions of Neutral Mechanical Disciple-How I Learned to Love a Patient-Specific Target
Nathalie Willems1, Kevin B Marchand2, Christina Esposito1
1Stryker Corporation, Mahwah, New Jersey.
Surgical Technology International
|March 28, 2024
Summary
Robotic-assisted total knee arthroplasty (TKA) using 3D CT planning shifted a surgeon
Area of Science:
- Orthopedic Surgery
- Biomechanical Engineering
- Medical Robotics
Background:
- Total knee arthroplasty (TKA) traditionally relies on neutral mechanical alignment.
- Alternative alignment strategies like kinematic, individualized, and functional are emerging.
- The impact of advanced planning tools on surgical alignment choices requires investigation.
Purpose of the Study:
- To evaluate the influence of 3D CT-based robotic surgical planning on TKA component positioning and alignment targets.
- To analyze changes in alignment strategies over time in a high-volume TKA practice.
Main Methods:
- Analysis of 1,394 robotically-assisted TKAs performed by a single surgeon (2016-2020).
- Collection of pre- and post-balancing planned implant positions and CT-derived constitutional alignment.
- Categorization of alignment strategies into true mechanical alignment (tMA), adjusted mechanical alignment (aMA), and no mechanical alignment (noMA).
Main Results:
- A progressive shift towards varus component positioning was observed over the study period.
- Increased variability in joint line obliquity and coronal alignment angles (tibial and femoral) was noted.
- The surgeon's alignment strategy evolved from tMA towards predominantly non-mechanically aligned philosophies.
Conclusions:
- Three-dimensional CT-based robotic planning significantly altered TKA component positioning and alignment targets.
- Patient-specific anatomy assessment via 3D CT planning was the primary driver for this shift.
- Further research is necessary to correlate these alignment changes with patient outcomes.
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