Laser morphometric analysis of the glenoid fossa of the scapula

We have assessed the topography of the articular surface of the glenoid fossa using a laser morphometric technique. Eighteen cadaveric scapulae from individuals aged 66 to 90 years were scanned and the degree of version of five lines constructed in the horizontal plane was determined. The lines comprised a transverse reference line (equatorial midline) located midway between the superior and inferior tubercles of the fossa, lines at 45% of the height of the glenoid fossa above and below the equatorial line, and further lines midway between these pairs. The cartilage-covered glenoid articular surface displayed differences in version between its superior and inferior aspects; the mean difference in version between the superior and inferior lines was 11.2 degrees, with the most superior line being retroverted 8.2 degrees with respect to the equatorial midline and the most inferior line anteverted 3.2 degrees. These data may be of importance in understanding the kinematics of the glenohumeral joint and in translating this knowledge to joint replacement surgery.