A 3D finite element model of the shoulder was used to quantify how increasing glenoid retroversion (0°–20°) affects the biomechanical forces driving glenoid component loosening after total shoulder arthroplasty — specifically cement stress, bone stress, and bone-cement interface micromotion during internal and external rotation.
When planning total shoulder arthroplasty in a patient with posterior glenoid wear, measure retroversion on preoperative CT: if it exceeds 10°, correct it (eccentric reaming, bone graft, or osteotomy) — because above that threshold cement stress exceeds fatigue limits and micromotion rises exponentially, both driving early loosening.
If correction is not achievable, consider hemiarthroplasty rather than risking a glenoid component destined to fail.
A 3D finite element model of the shoulder was used to quantify how increasing glenoid retroversion (0°–20°) affects the biomechanical forces driving glenoid component loosening after total shoulder arthroplasty — specifically cement stress, bone stress, and bone-cement interface micromotion during internal and external rotation.
When planning total shoulder arthroplasty in a patient with posterior glenoid wear, measure retroversion on preoperative CT: if it exceeds 10°, correct it (eccentric reaming, bone graft, or osteotomy) — because above that threshold cement stress exceeds fatigue limits and micromotion rises exponentially, both driving early loosening.
If correction is not achievable, consider hemiarthroplasty rather than risking a glenoid component destined to fail.