Morphological and mechanical analysis of the glenoid by 3D geometric reconstruction using computed tomography

Objective. To provide a morphological and mechanical analysis of the glenoi d by 3D geometric reconstruction using computed tomography. Design. For patients with different pathologies (Group A = control group, G roup B = primary osteoarthritis, Group C = rheumatoid arthritis), the varia tion in shape of the scapula was characterized by measuring the glenoid ver sion (P). Methods. Mapping the computed tomography number and its 3D variation in the bone as a finite element structure. Results. In Group A, the mean value of version was 17 degrees (range 12-22 degrees). In Groups B and C the mean value of version were 27 degrees (rang e 4-48 degrees) and 31 degrees (range 25-31 degrees) of retroversion. At th e center of the glenoid there was a homogeneous area of bony tissue with lo w computed tomography values and the subchondral bone could be clearly iden tified. For Group B patients, the computed tomography values were increased at the posterior margin of the glenoid, with a thickening of the posterior area acting as a strengthening column. For the Group C patients, the anato mical modifications were not reproducible between two cases examined. Conclusion. Results reveal a great difference between a healthy and a patho logical glenoid.