Five-year outcomes of anatomic total shoulder arthroplasty with Aequalis Perform+ posterior augmented glenoid implants in Walch B2 and B3 glenoids

Posterior glenoid wear and persistent static posterior subluxation of the humeral head (SPSH) are associated with early failure of anatomic total shoulder arthroplasty (aTSA). In patients with Walch B2 or B3 glenoid types, posterior augmented glenoid (PAG) implants have been reported to successfully correct SPSH on short-term follow-up. However, the medium-term and long-term clinical and radiological outcomes of PAG remain unclear.

We prospectively followed 10 consecutive patients (mean age, 67.9 ± 8.9 years; 5 females) with primary glenohumeral osteoarthritis and B2 or B3 glenoid types, who underwent aTSA with cemented keeled PAG implants (posterior augments of 15°, 25°, or 35°, Aequalis Perform+ shoulder system). Clinical outcomes were assessed using Constant and quick disabilities of arm, shoulder, and hand scores (QuickDASH). All patients underwent preoperative shoulder computed tomography (CT) scans with 3-dimensional surgical planning combined with patient-specific instrumentation at the time of surgery. Follow-up shoulder CT scans were performed at 3 months and 5 years postoperatively. Glenoid version (GV), glenoid inclination, and static humeral subluxation index (SHSI) were measured in 3-dimensional, on both preoperative and postoperative CT scans, using the same reliable quantitative method. At 5-year follow-up, we estimated the polyethylene wear of the glenoid component. The glenoid implant loosening was defined as the presence of a radiolucent line (thickness > 1.5 mm) at the glenoid bone-cement interface and/or migration (>5 mm) and/or tilt (>5°) of the glenoid component.

Five-year clinical outcomes revealed a Constant score of 78.2 ± 8.9 and a quick disabilities of arm, shoulder, and hand score of 8.4 ± 8.2. GV and SHSI significantly decreased from -17.1 ± 8.9° and 70.3 ± 5.9% preoperatively to -4.2 ± 7.7° and 55.5 ± 8.1%, respectively, at 3 months postoperatively (P < .001). At 5-year follow-up, GV and SHSI only varied by 0.9 ± 3.4° and -1.1 ± 5.5% compared to 3-month postoperative values, while glenoid inclination increased by 3.6 ± 3.0°. Five patients (50%) had CT signs of aseptic glenoid loosening. Only the preoperative Constant score differed significantly (P = .016) between patients with and without glenoid loosening.

Our 5-year evaluation revealed excellent clinical outcomes. PAG successfully corrected glenoid retroversion and SPSH over time, but there was a high rate of radiological glenoid implant loosening. Long-term comparative studies between aTSA and reverse shoulder arthroplasty are awaited to determine the optimal implant in patients with B2 and B3 glenoids.