Reverse total shoulder arthroplasty - adverse radiographic changes

 Radiographic changes around the glenoid component in primary reverse shoulder arthroplasty at mid-term follow-up

These authors analyzed the radiographic changes around the glenoid component and determined the risk factors associated with the presence of these radiographic changes in 105 primary Grammont-style reverse total shoulders with 5 years of radiographic follow-up. 

Standardized digital radiographs obtained immediately postoperatively and at a minimum follow-up time of 5 years were analyzed to determine 

(1) glenoid component position (inclination and height) and 

(2) minor radiographic changes (Sirveaux grade 1 or 2 scapular notching; nondisplaced acromial

fracture; radiolucent lines around 1 or 2 screws; Brooker grade 1a, 1b, or 2 heterotopic calcifications; or single screw rupture), and

(3) major radiographic changes (Sirveaux grade 3 or 4 scapular notching; radiolucent lines around 3 screws or central peg; Brooker grade 1c or 3 heterotopic calcifications; prosthetic dislocation; loosening or migration; or disassembly).

Major radiologic changes were identified in 14.3% of the cases. Bivariate analysis showed that more changes were associated with the arthroplasties implanted in the first years of the study.

Multivariate analysis revealed an increased risk of severe scapular notching mainly associated with superior tilt of the baseplate and a high glenosphere position.

They also noted an increased risk of loosening with superior tilt.

Superior tilt of baseplate

Superior position of glenosphere

Comment: This is an informative case series. It demonstrates some of the challenges associated with designs of reverse total shoulder in which a glenoid hemisphere is placed directly on the glenoid bone. This results in medialization of the proximal humerus with the associated risk of scapular notching. This risk is further increased by superior positioning of the glenosphere and superior inclination of the baseplate.

These issues can be addressed by positioning the glenosphere flush with the lower edge of the glenoid bone, by avoiding superior inclination and by using an offset glenosphere, which can be accomplished with a bone graft as shown in yellow below right

or by using a glenosphere offset by a neck as shown below.

Our technique for reverse total shoulder arthroplasty is shown in this link.

How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link).

How to x-ray the shoulder (see this link).

The total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).