Effectiveness and safety of intra-articular hyaluronic acid SEMICAL GEL-B CROSS therapy in knee osteoarthritis (SEM-ART1): Study protocol for a randomized, placebo controlled, double-blind, cross-over clinical trial - Meral Bilgilisoy Filiz; Hanife Hale Hekim; Ahmet Bal; Aslıhan Kara (PLoS ONE, 2026)