The three-dimensional glenoid vault model can estimate normal glenoid version in osteoarthritis

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Radiology

Background:

• Glenohumeral arthroplasty requires accurate correction of glenoid version.
• Predicting normal glenoid version in individuals is clinically difficult.
• Existing methods for assessing glenoid version lack precision.

Purpose of the Study:

• To evaluate a 3D glenoid vault model for predicting normal glenoid version.
• To assess the accuracy and reliability of the vault model in estimating glenoid version.
• To determine the utility of the model in correcting pathologic glenoid version.

Main Methods:

• Computed tomography (CT) scans of 14 subjects with unilateral osteoarthritis were analyzed.
• A validated 3D glenoid vault model was used as a template in custom graphic software.
• Three observers independently placed the vault model into glenoid vaults, blinded to the contralateral side.
• Interobserver and intraobserver reliability were assessed using statistical analysis.

Main Results:

• The mean healthy glenoid version was -7.0 degrees, while the arthritic glenoid version averaged -15.6 degrees.
• The vault model consistently estimated a normal version of -7.1 degrees on the healthy side and -7.2 degrees on the arthritic side.
• No significant differences were found between observer measurements (P = .98).
• High interobserver (0.79) and intraobserver (0.80) reliability was demonstrated.

Conclusions:

• The 3D glenoid vault model accurately and reproducibly estimates normal glenoid version.
• This novel technique shows promise for guiding glenohumeral arthroplasty and correcting pathologic glenoid version.
• The vault model provides a reliable method for pre-operative planning in shoulder surgery.