Skip to main content

Total Shoulder Arthroplasty: Landmarks & Measurements Guidelines

This document defines the anatomical landmarks and measurements used during preoperative planning and postoperative surgical planning for total shoulder procedures.

This reference is for surgeons and clinical teams reviewing shoulder arthroplasty plans in CustoMED. It defines each landmark and measurement used in preoperative planning and in the surgical plan.

Shoulder: Total Shoulder Arthroplasty (Anatomic / Reverse)

All landmarks and measurements are derived from patient imaging and are intended to support planning, verification, and communication. They do not replace clinical judgment.

Note: In CustoMED, preoperative measurements appear in the Landmarks step and postoperative (surgical plan) measurements appear in the Surgery Planning step. Labels in the app can be shorter than the names in this guide.

Note: For Shoulder Hemi Arthroplasty cases, only the humerus landmarks and measurements apply.


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.

Did this answer your question?