Related Experiment Video
Updated: Jul 4, 2026
10:10
Reverse Total Shoulder Arthroplasty
Published on: July 5, 2011
Optimizing glenosphere position and fixation in reverse shoulder arthroplasty, Part Two: The three-column concept
C Scott Humphrey1, James D Kelly, Tom R Norris
1Boise Shoulder Clinic, Boise, ID 83704, USA. humphrey@boiseshoulderclinic.net
Journal of Shoulder and Elbow Surgery
|June 11, 2008
Summary
This study presents an optimal screw placement technique for the Aequalis Reversed Shoulder Prosthesis to improve glenoid component fixation. Understanding scapular bone anatomy and using variable-angle locking screws are key for secure initial glenosphere fixation.
Area of Science:
- Orthopedic surgery
- Biomechanical engineering
- Anatomical studies
Background:
- Scapular geometry presents challenges for optimal screw placement in reverse shoulder arthroplasty.
- A standardized technique for maximizing glenoid component fixation with the Aequalis Reversed Shoulder Prosthesis is lacking.
Purpose of the Study:
- To describe an optimized screw placement technique for the Aequalis Reversed Shoulder Prosthesis.
- To identify screw trajectories that maximize fixation in cadaveric scapulae.
Main Methods:
- Ten cadaveric human scapulae were used.
- Two types of reverse arthroplasty baseplates were implanted: fixed-angle and multidirectional locking screws.
- Anterior cruciate ligament drill guides were employed to determine optimal screw trajectories for length, cortical fixation, and bone stock.
Main Results:
- Screw trajectory angles relative to the baseplate face were determined for optimal fixation.
- The study identified key anatomical landmarks (coracoid base, spine, pillar) crucial for screw purchase.
Conclusions:
- Optimal initial fixation of the glenosphere is achievable through awareness of scapular bone columns.
- Utilizing a baseplate with variable-angle locking screws is recommended for enhanced glenoid component fixation.
