Cemented Fixation Method of Glenoid Prosthesis in Total Shoulder Arthroplasty in a Pig Model

Chun, Jae Myeung; Kim, Soung Yon; An, Sung Chan; Shin, Jae Myoung

Abstract

PURPOSE: To observe the amount and distribution of overflown cement on the backsurface of the glenoid prosthesis and to determine the amount of cement required for ideal fixation of the glenoid prosthesis.
MATERIALS AND METHODS
48 keeled type glenoid prostheses (Global total shoulder, Depuy Co., U.S.A.) were fixed with four different volumes of cement (fully filled in the slots, and cement removed to depths of 4, 7 and 10 mm) to the scapulae of mature pigs, in which 46 scapulae that could be freed from the prostheses were investigated in terms of the amount and distribution of the leaked cement by gross inspection and evaluation using Arc view GIS 8.1.
RESULTS
The cement overflowed in an irregular fashion. The average ratio of the area covered by leaked cement to glenoid surface was 30.7% (12.9-52.2) in 27 cases, in which the slots were completely filled by cement; 19% (13.4-29.9) in 6 cases in which a 4 mm depth of cement was removed from the slots; 1.8% (-7.5~16.8) in 8 cases in which a 7 mm depth of cement was removed from the slots; -10.2% (-15.8~-5.2) in 5 cases in which a 10 mm depth of cement was removed from the slots.
CONCLUSION
It is impossible to prevent leakage of cement behind the backsurface of the glenoid prosthesis with the conventional cemented fixation method. This can be prevented by removing the equivalent amount of cement before inserting the prosthesis.