Currently many surgeons are using augmented glenoid components or reverse total shoulder arthroplasty to manage arthritic shoulders with type B2 and B3 glenoid pathoanatomy.
These authors sought to evaluate the ability of shoulder arthroplasty using a standard glenoid component to improve patient self-assessed comfort and function and to correct preoperative humeral-head decentering on the face of the glenoid in patients with primary glenohumeral arthritis and type-B2 or B3 glenoids. They identified 66 shoulders with type-B2 glenoids (n = 40) or type-B3 glenoids (n = 26) undergoing total shoulder arthroplasties with a non-augmented glenoid component inserted without attempting to normalize glenoid version and with clinical and radiographic follow-up at a minimum of 2 years.
The Simple Shoulder Test (SST) score improved from 3.2 ± 2.1 points preoperatively to 9.9 ± 2.4 points postoperatively (p < 0.001) at a mean time of 2.8 ± 1.2 years for type-B2 glenoids and from 3.0 ± 2.5 points preoperatively to 9.4 ± 2.1 points postoperatively (p < 0.001) at a mean time of 2.9 ± 1.5 years for type-B3 glenoids. These patient reported outcomes were as good as those achieved with other glenoid types.
These outcomes were achieved without changing glenoid version: postoperative glenoid version was not significantly different from preoperative glenoid version.
The rates of bone integration into the central peg for type-B2 glenoids (83%) and type-B3 glenoids (81%) were not inferior to those for other glenoid types (A1 67%, A2 85%, B1 74%, D 75%).
Anterior penetration of the glenoid neck by the central peg of the glenoid component was observed in 2 (11%) of 19 of the type-B1 glenoids, in 6 (15%) of 40 of the type-B2 glenoids, and in 6 (23%) of 26 of the type-B3 glenoids. Perforation of the glenoid by the central peg was not associated with inferior clinical or radiographic outcomes. Twelve of the 14 shoulders with glenoid neck penetration had ingrowth of bone between the flanges of the central peg with no radiographic evidence of component loosening. The final mean SST score for the 14 shoulders with central peg penetration was 9.4 ± 2.3 points, a value not significantly different (p = 0.649) from that for all of the type-B2 and B3 glenoids (9.7 ± 2.2 points).
This study demonstrates that good two year clinical outcomes can be achieved for B2 and B3 glenoid components using a standard (non-augmented) glenoid component inserted without changing glenoid version. Further glenoid research with longer followup will be required to compare these outcomes to those achieved using other techniques.
