Mid-to long-term outcomes and CT-assessed radiolucency with cemented single-peg glenoid component for anatomic total...

Evidence on postoperative outcomes and computed tomography (CT) assessment of glenoid radiolucency after anatomic total shoulder arthroplasty (aTSA) with a cemented single-peg component remains limited. This study evaluated mid-to long-term clinical outcomes and their association with CT-assessed radiolucency.

We retrospectively reviewed 26 shoulders in 23 patients who underwent aTSA with a cemented single-peg polyethylene glenoid component between 2006 and 2015. Clinical outcomes and radiographic parameters were evaluated, including the critical shoulder angle (CSA), proximal humeral superior subluxation, glenoid inclination, and retroversion. Radiolucency was assessed on coronal and axial CT images (0-30), with a radiolucent line total score ≥9 defined as radiolucency-positive. Outcomes were compared by radiolucency, and coronal-axial discordance was analyzed.

The mean follow-up was 132 months. Implant survival was 100 %. At the final follow-up, mean range of motion and clinical scores were favorable (forward elevation 110.6°, abduction 104.4°, external rotation 39.2°, internal rotation 5.2 (Flurin score; L3-L1); American Shoulder and Elbow Surgeons score 70.9, Oxford Shoulder Score 37.2, University of California, Los Angeles Shoulder Score 24.8). Radiolucency was observed in 8 shoulders (30.8 %). Although clinical outcomes did not differ significantly by radiolucency, the positive group had a larger CSA (36.9° vs 31.2°, P = 0.008) and more frequent superior subluxation (50.0 % vs 5.6 %, P = 0.020). Coronal-axial discordance occurred in 8 shoulders (30.8 %), with 6 (75 %) radiolucency-positive.

The cemented single-peg glenoid component for aTSA showed 100 % implant survival at mid-to long-term follow-up. Radiolucency was associated with larger CSA and superior humeral head subluxation but was not associated with worse clinical outcomes. CT assessment using both axial and coronal planes was a useful method for providing a more accurate evaluation of radiolucency.