Vacuum assist glenoid fixation: does this technique lead to a more durable glenoid component?

INTRODUCTION

This was a prospective random study to determine if suction applied to the glenoid vault through the coracoid process would facilitate deeper penetration of cement into the vault, and if deeper penetration would lead to a more durable glenoid component.

MATERIALS AND

METHODS

A group of 96 patients were randomly assigned to 1 of 2 pathways for glenoid fixation. One was cemented using modern "third generation" cementing techniques, while the second group utilizes these same steps as well as a vacuum assist (weep-hole) technique. We measured the "amount" of cement that penetrated the vault around either a pegged or keeled component as a function of the area of the cement noted on the fluoroscopic AP film that was taken 35.1 months postoperatively. We were able to determine the area of this irregular shape by using a program that was specifically written for the study. The films were evaluated by the senior author, as well as 2 musculoskeletal trained radiologists blind to the technique.

RESULTS

The area of the cement mantle was found to be significantly larger (P < .005) in the group with the vacuum assist technique. There was a positive relationship between the durability of the cement mantle as determined by the presence and the extent of radiolucent lines and the size of the cement mantle (P < .001).

CONCLUSION

If a cement technique is chosen to implant a glenoid component, the vacuum assist weep-hole technique is the most effective cementing technique to achieve durable fixation.