Optimizing lateralization and distalization shoulder angles in shoulder arthroplasty: A systematic review of functional outcomes and complication.

Background: The lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) are critical factors in predicting postoperative complications in shoulder surgeries. This study investigates the impact of LSA and DSA variations on functional outcomes and complications in shoulder surgery.

Methods: A systematic literature search was conducted in PubMed, Scopus, Web of Science, and the Cochrane Library up to December 2024. The primary outcomes evaluated included the impact of LSA and DSA on postoperative functional outcomes, complication rates, optimal angular parameters, and biomechanical implications.

Results: We included 14 high-quality studies encompassing 8372 patients. The synthesis demonstrated that maintaining an LSA within the optimal range of 75° to 95° is consistently linked to improved functional scores and enhanced active external rotation. Similarly, a DSA range of 40° to 65° is associated with superior anterior active elevation and abduction. The interplay between LSA and DSA is crucial, as balanced adjustments of these angles optimize deltoid tension and shoulder biomechanics, reducing the risk of different complications.

Discussion: Maintaining the LSA between 75° and 95° and the DSA between 40° and 65° significantly enhances functional outcomes and shoulder mobility following arthroplasty. Future research should aim to validate these optimal ranges.