A biomechanical study of posterior glenoid bone loss and humeral head translation.

Background: Results of shoulder arthroplasty have been reported to be inferior with posterior glenoid wear and accompanying subluxation of the humeral head. The purpose of this study was to examine the effect of posterior glenoid wear on posterior subluxation of the humeral head.

Material And Methods: A custom loading device was used to simulate physiologic loading conditions in 8 cadaver shoulders with the humerus positioned at neutral, forward flexion, and extension.

Location of the optimized centerline of the glenoid vault: a comparison of two operative techniques with use of three-dimensional computer modeling.

Background: The three-dimensional vault geometry beneath the glenoid face reduces to a narrow width in many individuals, creating a risk of perforation of the glenoid component pegs or keel in total shoulder arthroplasty. The purpose of this study was to introduce the concept of a centerline of the glenoid vault determined by computed optimization and to compare this centerline geometry against two existing surgical methods for orienting the glenoid component.

Methods: Thirty-four subject-specific computer models of three-dimensional scapular geometry were created from computed tomography scans.

Two-dimensional glenoid version measurements vary with coronal and sagittal scapular rotation.

Background: Accurate analysis of osseous glenoid morphology is important in treating glenohumeral arthritis and instability. Two-dimensional computed tomography scans are used to evaluate glenoid alignment. Accuracy of this method is dependent on the angle of axial reconstruction in relation to the position of the scapula.