Surgeons often strive to correct glenoid retroversion in performing reverse total shoulder arthroplasty. Some have suggested that glenoid version should be corrected so that glenoid component is within 10 degrees of neutral glenoid version as measured on axillary lateral radiographs relative to the plane of the scapula. A computer model suggested that an optimal range of motion would be achieved with neutral to 5° of retroversion.
Version correction techniques may be associated with increased complication rates. In one series, bone grafting had an increased risk of baseplate loosening.
In another series, the use of augmented base plates had an increased risk of acromial stress fractures.
Other surgeons have accepted deviations from "normal" glenoid version to optimize baseplate fixation, using, for example, the alternative center line.
The authors of Baseplate version in reverse shoulder arthroplasty: does excessive retroversion or anteversion affect functional activities of daily living? sought to determine whether patients with reverse total shoulders inserted with high degrees of baseplate anteversion or retroversion demonstrated poorer clinical outcomes than those inserted in more neutral glenoid version.
All patients underwent RSA with a monoblock baseplate with a 6.5 mm central screw and four peripheral locking screws.
The goal of glenoid reaming was to achieve at least 80% backside contact of the baseplate with glenoid bone while minimizing bone removal. There was no specific attempt to change glenoid version to neutral. The humeral implant was an “inlay” design with a 135 degree neck shaft angle.
Because CT scans are impractical for assessing postoperative version in patients having RSA, version was assessed using standardized axillary "truth" views
Patients were grouped into four categories: those with baseplates in ≥ 10 degrees (moderate to severe anteversion; n = 14), 10 to -10 degrees (neutral; n = 69), -10 to -20 (moderate retroversion; n = 25), and ≤ -20 degrees (severe retroversion; n = 7).
They found no differences in final Simple Shoulder Test (SST), final American Shoulder and Elbow Surgeons score (ASES) or change in SST from pre- to post-operative across the four version groups. There was no linear correlation between baseplate version and final SST. There were no statistically significant differences in difficulty performing tasks related to internal rotation, external rotation, and cross-body adduction among the four baseplate version groups; however, patients with moderate to severe anteversion had a greater frequency of difficulty putting on a coat (86%) compared to patients with neutral version (42%), moderate retroversion (45%) and severe retroversion.
There were no differences in rates of complications and revisions across the four groups.
These results are consistent with other studies, such as
Mid-term outcomes of reverse shoulder arthroplasty using the alternative center line for glenoid baseplate fixation: a case-controlled study,
Baseplate retroversion does not affect postoperative outcomes after reverse shoulder arthroplasty. and
Do preoperative and postoperative glenoid retroversion influence outcomes after reverse total shoulder arthroplasty?
Comment: This study suggests that baseplate version is not a major derminant of patient outcome for RSA component designs similar to those used in this study.
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 ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).