In vivo characterization of glenoid with use of computed tomography.

Improvement in the treatment of the shoulder could be achieved by accurately describing the pathologic characteristics of the joint. The goal of this study was to characterize, in vivo, glenoids with 3 different diagnoses by using computed tomography (CT): rotator cuff pathology with a limited rupture and without bony changes (group A, n = 15), primary osteoarthritis (group B, n = 13), and rheumatoid arthritis (group C, n = 4). The bone density distribution was assessed by means of the CT value expressed in Hounsfield units. The version angle was also measured. The examination of the CT value showed different distributions according to the pathology. In group A, the cancellous bone presented a central area with a relatively homogeneous and low density. In group B, the reinforcement of the density along with the posterior region seemed to be correlated with the retroversion angle. In the rheumatoid arthritis group, the main characteristic was the loss of the subchondral bone margin. The cartography of the CT value was not reproducible among the 4 cases examined. These in vivo descriptions provide guidelines for the surgeon before total shoulder arthroplasty, helping preoperative planning as well as simulation of implantation.