In vivo characterization of glenoid with use of computed tomography

Improvement in the treatment of the shoulder could be achieved by accuratel y 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 ruptu re and without bony changes (group A, n = 15), primary osteoarthritis (grou p B, n = 13), and rheumatoid arthritis (group C, n = 4). The bone density d istribution was assessed by means of the CT value expressed in Hounsfield u nits. 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 po sterior region seemed to be correlated with the retroversion angle. In the rheumatoid arthritis group, the main characteristic was the loss of the sub chondral bone margin. The cartography of the CT value was not reproducible among the 4 cases examined. These in vivo descriptions provide guidelines f or the surgeon before total shoulder arthroplasty, helping preoperative pla nning as well as simulation of implantation.