From the Research
The average version of the glenoid is approximately 0 degrees, with a slight propensity toward anteversion, as reported in the most recent study 1. This natural version is important for normal shoulder biomechanics as it helps maintain stability of the glenohumeral joint during arm movement. The version angle varies between individuals and can be affected by factors such as age, sex, and activity level. Excessive retroversion or anteversion (forward tilt) can contribute to shoulder instability, impingement, or arthritis. Understanding the patient's specific glenoid version is crucial when planning shoulder surgeries, particularly shoulder arthroplasty, as implant positioning should account for the individual's anatomy to restore proper joint mechanics and function.
Some key points to consider when evaluating glenoid version include:
- The mean glenoid version was significantly lower in the right than in the left shoulder and males had significantly lower mean glenoid version than females in both shoulders, as found in the study 1.
- Glenoid version cannot be determined accurately on standard axillary radiographs, either preoperatively or postoperatively, and CT scans are a more reliable method for measurement, as reported in the study 2.
- The three-dimensional glenoid vault model can estimate normal glenoid version in osteoarthritis, with an average glenoid version of -7.0 degrees, as found in the study 3.
- Glenoid bone loss alters glenoid version, as measured by CT, in a meaningful way, and a correction factor may be considered to account for this, as reported in the study 4.
- The glenoid version measurement is reliable on a 2D CT Scan, and combining the Friedman method to determine the scapula axis with an intermediate glenoid line in B2 glenoid yields the most reliable measurements, as found in the study 5.
However, the most recent and highest quality study 1 suggests that the average version of the glenoid is approximately 0 degrees, with a slight propensity toward anteversion, which should be taken into consideration when evaluating and treating patients with shoulder-related conditions.