Shoulder – Total Shoulder Arthroplasty (Anatomic / Reverse)
All landmarks and measurements are derived from patient imaging and are intended to support planning, verification, and communication, not automated clinical decision-making.
Preoperative Landmarks – Scapula
Scapular Axis
Stage: Pre
Type: Landmark
Bone: Scapula
Description:
A line defined from the center of the glenoid surface to the trigonum scapulae.
This axis serves as the primary anatomical reference for glenoid orientation measurements.
Glenoid Plane
Stage: Pre
Type: Landmark
Bone: Scapula
Description:
A plane parallel to the native glenoid rim, explicitly excluding osteophytes, representing the true articular surface of the glenoid.
Inferior Angle of the Scapula
Stage: Pre
Type: Landmark
Bone: Scapula
Description:
The most inferior anatomical point of the scapula, used to support consistent definition of the scapular anatomical orientation.
Preoperative Measurements – Scapula
Glenoid Inclination
Stage: Pre
Type: Measurement
Bone: Scapula
Description:
The angle between the scapular anatomical axis and the glenoid surface measured in the coronal scapular plane.
Glenoid Version
Stage: Pre
Type: Measurement
Bone: Scapula
Description:
The angle between the scapular anatomical axis and the glenoid surface measured in the axial scapular plane.
Postoperative / Surgical Plan Measurements – Scapula
Planned Inclination
Stage: Post
Type: Measurement
Bone: Scapula
Description:
The angle between the scapular anatomical axis and the central K-wire axis measured in the coronal scapular plane, reflecting the planned implant orientation.
Planned Version
Stage: Post
Type: Measurement
Bone: Scapula
Description:
The angle between the scapular anatomical axis and the central K-wire axis measured in the axial scapular plane.
Screw Length – Central
Stage: Post
Type: Measurement
Bone: Scapula
Description:
The maximum potential depth of the central screw based on planned implant trajectory and available bone stock.
Baseplate Entry Points
Stage: Post
Type: Measurement
Bone: Scapula
Description:
Defined anterior and inferior baseplate entry points, positioned at 90° from the baseplate center, used for planning fixation screw trajectories.
Screw Length (Bone Contact)
Stage: Post
Type: Measurement
Bone: Scapula
Description:
The portion of the screw length that remains in direct contact with bone, excluding non-engaged sections.
Preoperative Landmarks – Humerus
Humeral Anatomical Axis
Stage: Pre
Type: Landmark
Bone: Humerus
Description:
A line passing through the center of the humeral shaft, extending from distal to proximal, representing the humeral anatomical reference axis.
Humeral Neck Plane
Stage: Pre
Type: Landmark
Bone: Humerus
Description:
The native head–neck plane of the humerus, representing the patient’s current humeral version.
Preoperative Measurements – Humerus
Neck–Shaft Angle
Stage: Pre
Type: Measurement
Bone: Humerus
Description:
The angle between the humeral neck plane and the humeral anatomical axis.
Postoperative / Surgical Plan Measurements – Humerus
Planned Neck–Shaft Angle
Stage: Post
Type: Measurement
Bone: Humerus
Description:
The angle between the humeral anatomical axis and the planned cutting plane.
Planned Humeral Version
Stage: Post
Type: Measurement
Bone: Humerus
Description:
The angular difference between the native humeral neck plane and the planned cutting plane.
Humeral Cut Height (Perpendicular)
Stage: Post
Type: Measurement
Bone: Humerus
Description:
The distance from the cutting plane to the humeral head, measured perpendicular to the cutting plane.
Humeral Cut Height (Axial)
Stage: Post
Type: Measurement
Bone: Humerus
Description:
The distance from the cutting plane to the humeral head, measured parallel to the humeral anatomical axis.
Postoperative Landmarks – Humerus
Cutting Plane
Stage: Post
Type: Landmark
Bone: Humerus
Description:
A plane coincident with the humeral stem axis, defining the final humeral resection level for implant placement.
Notes & Best Practices
All landmarks must be reviewed and approved by the clinician prior to final plan approval.
Osteophytes should be excluded when defining native anatomical reference planes.
Measurements are provided for planning and verification purposes only and must be clinically validated by the surgeon.