Retrospective cohort study of 46 RSA patients introducing two plain radiograph angles — the lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) — to estimate implant positioning geometry and determine which angular ranges correlate with the best functional outcomes after RSA for cuff tear arthropathy.
When reviewing postoperative RSA radiographs, calculate the LSA and DSA: if LSA falls outside 75°–95° or DSA outside 40°–65°, expect compromised external rotation or elevation respectively — and use these targets prospectively when planning implant selection and positioning.
A DSA >70° is a red flag for over-distalization and predicts poor elevation regardless of implant type.
Retrospective cohort study of 46 RSA patients introducing two plain radiograph angles — the lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) — to estimate implant positioning geometry and determine which angular ranges correlate with the best functional outcomes after RSA for cuff tear arthropathy.
When reviewing postoperative RSA radiographs, calculate the LSA and DSA: if LSA falls outside 75°–95° or DSA outside 40°–65°, expect compromised external rotation or elevation respectively — and use these targets prospectively when planning implant selection and positioning.
A DSA >70° is a red flag for over-distalization and predicts poor elevation regardless of implant type.