What type of screws are required for the securement of trunnions in the Univers II and Apex stems?

The securement of trunnions in the Univers II and Apex stems specifically requires inferior and superior screws. This design is crucial for ensuring that the trunnion, which is a pivotal part of the shoulder implant, is held firmly in place within the stem to provide stability and maintain proper alignment during shoulder movements.

Using inferior and superior screws allows for a two-point fixation, enhancing the stability of the trunnion and preventing potential micromotion that could lead to loosening of the implant. This fixation pattern effectively addresses biomechanical forces acting on the shoulder, ultimately contributing to a successful total shoulder arthroplasty outcome.

Other types of screws mentioned, such as locking screws or self-tapping screws, do not specifically fulfill the same purpose and function for trunnion securement in these particular stems. While they may have their own applications in other contexts, they do not provide the optimized stability that the inferior and superior screws offer in this scenario.