Minimum two-year follow-up of a reverse total shoulder arthroplasty using a wedged baseplate.

Background: Avoiding inclination of the glenoid baseplate in reverse shoulder arthroplasty often requires considerable glenoid reaming. It is proposed that the use of a metal wedged baseplate in all patients can achieve neutral inclination with reduced glenoid reaming.

Materials and methods: A prospective clinical single-centre study with minimum two-year follow-up was carried out. Glenoid deformity was classified on CT and surgery planned using BluePrint^TM. The Tornier Perform^® Reversed Wedged Augmented Glenoid was used in all cases. Clinical outcome scores and radiographs were assessed.

Results: Seventy-three patients, mean age 76.6 years. Twenty-eight demonstrated no glenoid deformity and 19 demonstrated marked retroversion. Seventy completed two-year follow-up. Mean pain scores fell from 6 to 0.7. All Patient Reported Outcome Meaures (PROMS) were significantly improved. Active elevation increased by 62° and external rotation by 28.7° (p < 0.001). In patients with no glenoid wear (E0/A1), correction of inferior inclination was achievable with a 15° full-wedge baseplate in all cases, reducing the reaming depth by 4.4 mm (p < 0.001). In patients with severe glenoid wear, a 35° half wedge baseplate was often necessary to correct the deformity. The most common complications were stress reactions/fractures.

Conclusion: A metal wedged baseplate can achieve neutral inclination in all patients, minimising bone reaming and preserving lateralisation with good two-year outcomes.

Level of evidence: IV (case series with no comparison group).