However, the pegged all polythelene glenoid components outperform the keeled in terms of survivorship (see reference 1) and the metal backed glenoid components fail more often and by different modes compared to all polyethylene glenoid components (in print unpublished data).
Reference 1: http://www.ncbi.nlm.nih.gov/pubmed/24352774
On the modes of failure of the glenoid: http://www.ncbi.nlm.nih.gov/pubmed/18381328
Review on the evolution of the design of the glenoid component: http://reviews.jbjs.org/content/1/2/e2
We prefer to use the all polyethylene pegged cemented glenoid components which allow bone ingrowth at the fenestrations of the central peg. After drilling the hole for the central peg of the glenoid the bone removed is used as bone graft for the central peg.
The radiographs below demonstrate that at 4 months postop there is bony ingrowth at the fenestrations of the central peg and no radiolucent lines.
Radiographically at 10 years 50% of the glenoid components are loose. However the revision rate is low at that point and most of the glenoids "survive" to 10-15 years if the end point is considered to be revision for glenoid failure.