This Level I randomized trial compared two methods of glenoid lateralization in reverse shoulder arthroplasty. It pitted bony increased-offset RSA (autograft under the baseplate) against a porous metal wedge-augmented baseplate. The primary question was whether one technique migrates more than the other, measured by model-based radiostereometric analysis over 2 years.
When you choose between bone graft and a metal wedge augment to lateralize the glenoid in RSA, migration data says either is safe: both settle within 3 months and stay stable at 2 years.
The core teaching point is the migration principle borrowed from hip and knee arthroplasty. Implants that migrate early tend to loosen late. Here, both constructs stopped moving after 3 months, which predicts durable fixation.
The one clinical edge for BIO-RSA was external rotation, likely because the autograft is shaped to the patient's specific defect while the metal wedge came in one fixed 15-degree geometry. Treat this cautiously since ROM was a secondary outcome.
Remember the notching lesson: combining lateralization with a 145-degree neck-shaft angle drove notching down to 7%, versus 40% in older BIO-RSA series. Notching is not just about lateralization, it is also about inlay angle.
This Level I randomized trial compared two methods of glenoid lateralization in reverse shoulder arthroplasty. It pitted bony increased-offset RSA (autograft under the baseplate) against a porous metal wedge-augmented baseplate. The primary question was whether one technique migrates more than the other, measured by model-based radiostereometric analysis over 2 years.
When you choose between bone graft and a metal wedge augment to lateralize the glenoid in RSA, migration data says either is safe: both settle within 3 months and stay stable at 2 years.
The core teaching point is the migration principle borrowed from hip and knee arthroplasty. Implants that migrate early tend to loosen late. Here, both constructs stopped moving after 3 months, which predicts durable fixation.
The one clinical edge for BIO-RSA was external rotation, likely because the autograft is shaped to the patient's specific defect while the metal wedge came in one fixed 15-degree geometry. Treat this cautiously since ROM was a secondary outcome.
Remember the notching lesson: combining lateralization with a 145-degree neck-shaft angle drove notching down to 7%, versus 40% in older BIO-RSA series. Notching is not just about lateralization, it is also about inlay angle.