Computed tomography morphological analysis of the scapula and its implications in shoulder arthroplasty

Abstract

Background

Healthy shoulder morphology is still unclear. Since bone morphology influences prosthetic features, this is relevant for glenohumeral joint reconstruction. The objective of this study was to assess the normal values of glenoid version, maximum width, base width and vault depth on computed tomography scans.

Methods

Axial cut CT scans of 1072 healthy glenoids were retrospectively reviewed. Values of glenoid version, maximum glenoid width, glenoid base width and glenoid vault depth were measured by two different observers. Differences were determined between genders, and reproducibility and interrater reliability assessed.

Results

Glenoid version was 37.71° ± 10.75°, range −6.20° to 71.30°; maximum glenoid width was 26.06 ± 3.27 mm, range 15.40–36.90 mm; glenoid base width was 16.59 ± 2.61 mm, range 8.90–25.40 mm; glenoid vault depth was 9.72 ± 1.62 mm, range 4.70–15.90 mm. All measurements except for glenoid version were significantly higher in males than in females. Reproducibility was good for every measurement, except glenoid vault depth.

Conclusion

We found differences in maximum glenoid width, base width and vault depth by gender in a large sample. Glenoid components’ maximum width was defined, as was reaming extension and orientation, the space available for implantation of the glenoid component, placement of pegs or keels in anatomic prostheses and the target for glenoid screws in inverted prostheses.

Level of evidence

II.