Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two‐Thirds Glenoid Height Technique Compared to the “Best‐fit Circle”
Justin L. Makovicka, M. Lane Moore, Jordan R. Pollock, Marina Rodriguez, James S. Shaha, Jack M. Haglin, John M. Tokish
Abstract
PURPOSE: To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy. METHODS: The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, 2 reviewers independently estimated glenoid size using the two-thirds technique and the "best-fit circle" technique at 2 different times. A Student t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients. RESULTS: This study included 112 patients. Using the results of glenoid height and "best-fit circle" diameter, the diameter of the "best-fit circle" was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the 2 measures of glenoid diameter (27.6 vs 27.9, P = .456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The interclass and intraclass coefficients for the perfect circle methods were 0.84 and 0.73, respectively. CONCLUSIONS: We determined that the diameter of a circle placed on the inferior glenoid using the "best-fit circle" technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intraclass reliability. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.