Ma. Wirth et al., Radiologic, mechanical, and histologic evaluation of 2 glenoid prosthesis designs in a canine model, J SHOUL ELB, 10(2), 2001, pp. 140-148
Aseptic loosening of glenoid components is a common problem associated with
total shoulder arthroplasty. A new glenoid design aimed at improving fixat
ion outcomes was compared with conventional keeled glenoids in weight-beari
ng canine shoulders. Radiographic, histologic, and mechanical tests were pe
rformed at 3 postoperative intervals (0, 3, and 6 months). The uncemented p
egged glenoid achieved bone ingrowth around the peg flanges in each case. T
his result was confirmed histologically and radiographically. Mechanical re
sults indicated that mean fixation strength increases significantly between
0 and 3 months after surgery and remains strong through 6 months. In contr
ast, conventional keeled glenoids were found to have partial or complete ra
diolucent lines around the keel in each instance, and mechanical testing de
monstrated that mean fixation strength weakens significantly between 0 and
3 months after surgery and remains weak through 6 months. These results sho
w that stem design changes can improve implant fixation. A cementless flute
d peg stem was superior to a conventional cemented keel design in achieving
osseous integration and fixation in a weight-bearing animal model.