This retrospective case series examined anatomic total shoulder arthroplasty for primary osteoarthritis with a biconcave (Walch B2) glenoid. The B2 pattern combines posterior glenoid erosion with static posterior humeral head subluxation. The authors asked which preoperative CT arthrogram measurements predict glenoid loosening and dislocation.
When you see a biconcave (Walch B2) glenoid on preoperative CT, understand that anatomic TSA here is a durability problem, not an early-function problem. Function improved and two-thirds of patients were satisfied, but the 16.3% revision and 20.6% loosening rates at 6 years are unacceptable for a degenerative procedure.
The mechanism to remember: static posterior subluxation and posterior erosion generate eccentric, rocking-horse loads on the glenoid, and this recurs even after retroversion is corrected. Measure the neoglenoid retroversion. At 27° or more the complication risk is 44%, and it is the single parameter that predicts both loosening and dislocation.
Do not reach for posterior bone grafting as a rescue: only 2 of 7 grafts survived and grafted shoulders did worse across every clinical domain. This is the evidence base underlying the shift toward reverse shoulder arthroplasty or augmented glenoid components for severe B2 morphology.
This retrospective case series examined anatomic total shoulder arthroplasty for primary osteoarthritis with a biconcave (Walch B2) glenoid. The B2 pattern combines posterior glenoid erosion with static posterior humeral head subluxation. The authors asked which preoperative CT arthrogram measurements predict glenoid loosening and dislocation.
When you see a biconcave (Walch B2) glenoid on preoperative CT, understand that anatomic TSA here is a durability problem, not an early-function problem. Function improved and two-thirds of patients were satisfied, but the 16.3% revision and 20.6% loosening rates at 6 years are unacceptable for a degenerative procedure.
The mechanism to remember: static posterior subluxation and posterior erosion generate eccentric, rocking-horse loads on the glenoid, and this recurs even after retroversion is corrected. Measure the neoglenoid retroversion. At 27° or more the complication risk is 44%, and it is the single parameter that predicts both loosening and dislocation.
Do not reach for posterior bone grafting as a rescue: only 2 of 7 grafts survived and grafted shoulders did worse across every clinical domain. This is the evidence base underlying the shift toward reverse shoulder arthroplasty or augmented glenoid components for severe B2 morphology.