Related Experiment Videos
Quantifying potential leg axis alteration from extramedullary tibial guide malalignment in total knee arthroplasty: a
Stefan M Zimmermann1,2, Ken Bertschy3, Christoph Zindel4,3
1Balgrist University Hospital, Forchstrasse 340, Zurich, 8008, Switzerland. St.zimmermann@gmx.ch.
BMC Musculoskeletal Disorders
|July 17, 2026
Summary
Axial malrotation during tibial resection in total knee arthroplasty (TKA) significantly impacts coronal alignment but minimally affects the posterior tibial slope. Rotational errors are more critical in slope-sensitive alignment strategies.
Area of Science:
- Orthopedic surgery
- Biomechanical engineering
- Surgical navigation
Background:
- Conventional instrumentation is common in total knee arthroplasty (TKA), despite technological advances.
- Rotational errors in tibial resection can affect postoperative alignment.
- The relationship between axial rotation and posterior tibial slope needs further definition.
Purpose of the Study:
- To quantify the effect of axial malrotation during tibial resection on projected coronal alignment and effective posterior tibial slope.
- To analyze how malrotation interacts with different posterior tibial slope targets.
Main Methods:
- Generated 3D models from CT data of 20 lower extremities.
- Simulated tibial cuts with varying axial malrotation (±5° to ±40°) and posterior tibial slopes (3°, 5°, 7°).
- Recorded changes in projected coronal alignment and effective posterior tibial slope.
Main Results:
- Coronal deviation increased with axial rotation and planned slope.
- ±20° rotation at 7° slope caused 2.4° coronal deviation.
- Effective posterior tibial slope changed by ≤0.3° even with ±20° rotation.
Conclusions:
- Axial malrotation primarily impacts projected coronal alignment, not the effective posterior tibial slope.
- Coronal deviation magnifies with higher planned slope angles.
- Rotational errors are significant in slope-sensitive or individualized TKA alignment strategies.