Does glenoid baseplate geometry affect its fixation in reverse shoulder arthroplasty?

The effect of glenoid bone loss on reverse shoulder arthroplasty baseplate fixation

“…In addition, surgical techniques designed to avoid impingement, such as implanting the baseplate with inferior tilt and alteration of glenoid version, may result in further uncoverage of the baseplate. Because the ultimate goal is to achieve osseous integration of the glenoid component to the native glenoid, 9,23 it is important to understand the consequences of implanting the baseplate with incomplete support of the native glenoid bone. Results of this study suggest that when a central screw-based baseplate with 4 peripheral locked screws is used, glenoid bone coverage of 50% or more results in stable fixation within the acceptable limits of micromotion for bone-implant ingrowth to occur.…”

“…Management of glenoid bone loss with use of RSA has evolved, with a variety of surgical techniques and advancements in prosthetic designs being introduced during the past 15 years. 7,9,17 Because RSA designs universally use a metal baseplate with peripheral screw fixation, obtaining secure fixation together with opportunities for bone graft fixation is enhanced. Eccentric reaming is often required during glenoid preparation, as the glenoid baseplate requires a matched surface for optimal fixation and ultimate osseous integration.…”

“…Eccentric reaming is often required during glenoid preparation, as the glenoid baseplate requires a matched surface for optimal fixation and ultimate osseous integration. 9 However, eccentric reaming has limitations, as available glenoid bone diminishes when the glenoid is medialized. Recently, the introduction of augmented baseplates has been proposed for cases in which incomplete corrections of deformities are encountered.…”

“…In addition, initial fixation of the baseplate may be compromised as the peripheral baseplate screws have less bone remaining for purchase. 9 Walch et al 24,25 have reported on subsidence and radiographic loosening of the glenoid component in total shoulder arthroplasty with aggressively reamed glenoids that violate the subchondral bone. This has the potential to occur with RSA as well with extreme amounts of reaming.…”

“…However, with further medial reaming of the glenoid, the bone volume continues to decrease and may compromise the ability to achieve stable implant fixation. 9,21 In addition, medialization has the potential to lose the stabilizing effects of lateralization and to increase the risk of instability. Bone grafting of the defect has become an attractive option to aid in correction of the glenoid morphology without the need for excessive reaming and medialization of the component.…”