Femur landmarking defines the anatomical reference framework used for alignment, measurements, and PSI design.
Landmarks are generated automatically and must be reviewed and confirmed before planning can proceed.
This step ensures that all downstream planning logic is aligned with the patient’s anatomy.
When This Step Is Available
Femur landmarking is performed:
After segmentation approval
Before or during the planning stage
The case cannot progress until landmarking is confirmed.
Interface Elements
During femur landmarking, the interface includes:
A 3D femur model in the main canvas
Landmark points placed on key anatomical features
Reference axes derived from landmark positions
Alignment angles displayed numerically and visually
Interactive rotate and zoom controls
All displayed angles update automatically when landmarks are adjusted.
Femur Landmarks
Common femur landmarks include:
Femoral head center
Femoral shaft (anatomical axis)
Medial and lateral condyles
Distal femoral reference points
These landmarks define femoral orientation in 3D space.
Alignment Angles
The following angles are calculated from the femur landmarks:
Mechanical Axis (Coronal Plane)
Indicates varus or valgus alignment using the femoral head and distal reference points.Anatomical vs Mechanical Axis
Represents the angular relationship between the shaft axis and mechanical axis.Distal Femoral Varus / Valgus
Describes distal femur orientation relative to the mechanical axis.Femoral Flexion / Extension (Sagittal Plane)
Defines anterior–posterior tilt of the femur.Femoral Rotation (Axial Plane)
Defines internal or external rotation based on condylar landmarks.
These angles are reference values used for planning logic and PSI positioning.
Reviewing and Adjusting Landmarks
To review landmarks:
Rotate and zoom the femur to inspect placement.
Confirm each landmark aligns with the correct anatomical feature.
Check that axes and angles appear anatomically reasonable.
To adjust a landmark:
Select the landmark and reposition it directly on the anatomy.
All dependent axes and angles update automatically.
Angles are not edited directly only landmarks are adjusted.
Confirming Landmarking
Once review is complete:
Confirm the landmarking step to lock references.
The system records the confirmation with user and timestamp.
Planning and PSI generation proceed using the finalized landmarks.
Why Accuracy Matters
Accurate landmarking ensures:
Correct alignment of planning tools
Reliable measurements
Proper PSI positioning and fit
Consistency between digital planning and physical guides
Incorrect landmarks may affect downstream planning outcomes.
Troubleshooting Tips
If angles appear incorrect:
Recheck femoral head and condylar landmarks
Inspect placement from multiple orientations
Adjust landmarks rather than interpreting angles in isolation
For unresolved issues, contact CustoMED support.