Use of custom glenoid components for reverse total shoulder arthroplasty

Abstract

Background: Our purpose was to evaluate a custom reverse total shoulder arthroplasty glenoid baseplate for severe glenoid deficiency, emphasizing the challenges with this approach, including short-term clinical and radiographic outcomes and complications.

Methods: This was a single-institution, retrospective series of 29 patients between January 2017 and December 2022 for whom a custom glenoid component was created for extensive glenoid bone loss. Patients were evaluated preoperatively and at intervals for up to 5 years. All received preoperative physical examinations, plain radiographs, and computed tomography (CT). Intra- and postoperative complications are reported.

Results: Of 29 patients, delays resulted in only undergoing surgery, and in three of those, the implant did not match the glenoid. For those three, the time from CT scan to implantation averaged 7.6 months (range, 6.1-10.7 months), compared with 5.5 months (range, 2-8.6 months) for those whose implants fit. In patients with at least 2-year follow-up (n=9), no failures occurred. Significant improvements were observed in all patient-reported outcome measures in those nine patients (American Shoulder and Elbow Score, P<0.01; Simple Shoulder Test, P=0.02; Single Assessment Numeric Evaluation, P<0.01; Western Ontario Osteoarthritis of the Shoulder Index, P<0.01). Range of motion improved for forward flexion and abduction (P=0.03 for both) and internal rotation up the back (P=0.02). Pain and satisfaction also improved (P<0.01 for both).

Conclusions: Prolonged time (>6 months) from CT scan to device implantation resulted in bone loss that rendered the implants unusable. Satisfactory short-term radiographic and clinical follow-up can be achieved with a well-fitting device. Level of evidence: III.

Keywords: Glenoid bone loss; Reverse; Shoulder; Treatment outcomes; Arthroplasty.

Fig. 1.

Example patient who previously sustained an anatomic total shoulder arthroplasty and underwent antibiotic spacer placement for prosthetic joint infection. Preoperative radiographs (A-C) show the antibiotic spacer and severe glenoid bone loss. Computed tomography scan images (D-F) highlight the severity of bone loss due to osteolysis and previous glenoid screws.

Fig. 2.

Flow diagram for the 29 cases of custom glenoid replacement for significant glenoid bone loss.

Fig. 3.

(A-D) Three-dimensional modeling demonstrating the planned position for the custom glenoid component and the central screw (green) and peripheral locking screw (blue) trajectories.