This invention comprises base plate and glenosphere designs, as well as
cutting guides and holder instruments, developed to provide stronger fixation with a more minimally invasive approach to the shoulder in patients undergoing
reverse shoulder arthroplasty for any reason. This newly developed technique allows for
surgical operation in a more
confined space, particularly in challenging cases such as tight shoulders. In addition, it offers advantages such as being
usable as an alternative technique in osteoporotic patients with high cortical fixation and in
revision surgeries or in cases with reduced
bone stock due to various reasons. In standard base plate designs, it is known that fixation is predominantly achieved in the
trabecular bone by screws inserted from the reamed
peripheral bone surface surrounding the
implant. However, in osteoporotic patients,
trabecular bone becomes weakened and the
bone stock may not provide sufficient support. Furthermore, version differences related to anatomical variations of the glenoid seen among patients may cause problems in
component placement and screw
insertion if proper preoperative assessment is not performed. Moreover, in classical component design, in order to send the guidewire in the correct direction corresponding to the surface where the central peg will be applied,
soft tissue dissection exposing the entire glenoid must be performed. Performing this
dissection may
pose challenges for the surgeon in tight shoulders, increase the duration of
surgery, and carry risks of complications such as
instability or injury to neurovascular structures. In addition, in classical component design, the acceptable threshold of contact between the glenoid and base plate is considered to be 80%. If this is not achieved,
implant failure may occur after
prosthesis application. When the contact surface between the glenoid and base plate falls below 50%, graft application becomes indicated. Although it is a successful method, it is technically demanding, and in cases of graft non-union, alternative options are limited. Another method is the use of augment components for the defective area. This application not only presents high technical difficulty but also requires well-prepared three-dimensional
preoperative planning. Custom-made implants are another option and are technically the most laborious and expensive to manufacture. With this invention, compared to previous techniques, the management of glenoid defect and excessive version problems can be achieved by providing higher cortical fixation with anterior-weighted support.