This prospective study introduces BIO-RSA, a technique that places a disc of autologous cancellous bone from the resected humeral head between the reamed glenoid and a specially designed long-peg baseplate. The central question: can bony lateralization reduce scapular notching and improve rotation without the glenoid loosening risk associated with metallic offset designs? 42 rotator-cuff-deficient patients were followed for a minimum of 2 years with clinical, radiographic, and CT assessment.
Scapular notching plagued early RSA — reported in up to 96% of medialized Grammont cases. And attempts to fix it with metallic lateral offset traded one problem for another, with 12% glenoid loosening rates at under 2 years.
BIO-RSA resolves this tradeoff: harvest a 29-mm cancellous disc from the humeral head (10 mm thick for a 36-mm glenosphere, 7 mm for a 42-mm glenosphere), thread it onto the lengthened 25-mm central peg, and impact the assembly onto the reamed glenoid.
Once healed, the center of rotation sits at the bone-prosthesis interface. Same as Grammont. So no lever arm is created and glenoid torque stays low, even though the construct is lateralized.
In practice: restrict heavy lifting until 12 weeks to protect the graft during the consolidation phase, and use inferior tilt plus inferior glenosphere positioning alongside lateralization for maximum notching protection.
This prospective study introduces BIO-RSA, a technique that places a disc of autologous cancellous bone from the resected humeral head between the reamed glenoid and a specially designed long-peg baseplate. The central question: can bony lateralization reduce scapular notching and improve rotation without the glenoid loosening risk associated with metallic offset designs? 42 rotator-cuff-deficient patients were followed for a minimum of 2 years with clinical, radiographic, and CT assessment.
Scapular notching plagued early RSA — reported in up to 96% of medialized Grammont cases. And attempts to fix it with metallic lateral offset traded one problem for another, with 12% glenoid loosening rates at under 2 years.
BIO-RSA resolves this tradeoff: harvest a 29-mm cancellous disc from the humeral head (10 mm thick for a 36-mm glenosphere, 7 mm for a 42-mm glenosphere), thread it onto the lengthened 25-mm central peg, and impact the assembly onto the reamed glenoid.
Once healed, the center of rotation sits at the bone-prosthesis interface. Same as Grammont. So no lever arm is created and glenoid torque stays low, even though the construct is lateralized.
In practice: restrict heavy lifting until 12 weeks to protect the graft during the consolidation phase, and use inferior tilt plus inferior glenosphere positioning alongside lateralization for maximum notching protection.