Multicenter retrospective study of 319 primary osteoarthritis total shoulder arthroplasties (Aequalis prosthesis) examining whether the radial mismatch between humeral head and glenoid components — ranging 0 to 10 mm across 21 head-glenoid size combinations — influences glenoid radiolucent line scores at mean 4.5-year follow-up.
When selecting humeral head and glenoid component sizes in total shoulder arthroplasty, target a radial mismatch of 6–10 mm rather than anatomic congruence — the data show this nearly halves radiolucency scores without increasing instability risk.
The intuitive appeal of a perfectly matched articulation is biomechanically counterproductive: zero mismatch eliminates obligate translation and concentrates stress at the cement-bone interface.
Multicenter retrospective study of 319 primary osteoarthritis total shoulder arthroplasties (Aequalis prosthesis) examining whether the radial mismatch between humeral head and glenoid components — ranging 0 to 10 mm across 21 head-glenoid size combinations — influences glenoid radiolucent line scores at mean 4.5-year follow-up.
When selecting humeral head and glenoid component sizes in total shoulder arthroplasty, target a radial mismatch of 6–10 mm rather than anatomic congruence — the data show this nearly halves radiolucency scores without increasing instability risk.
The intuitive appeal of a perfectly matched articulation is biomechanically counterproductive: zero mismatch eliminates obligate translation and concentrates stress at the cement-bone interface.