Silva-Diaz, Yshoner AntonioYshoner AntonioSilva-DiazOdar-Rojas, CintyaCintyaOdar-RojasPasten-Hidalgo, WilsonWilsonPasten-HidalgoGallegos-Chavez, EduardoEduardoGallegos-ChavezBarros-Osorio, CristianCristianBarros-OsorioSepulveda-Loyola, WalterWalterSepulveda-Loyola2026-07-072026-07-072026PEERJ, 14, e20527 (2026). https://doi.org/10.7717/peerj.205272167-8359https://hdl.handle.net/20.500.12740/24761Purpose This review aims to map the existing literature on the prevalence, diagnostic criteria, and impact of osteosarcopenia on postoperative clinical outcomes in older adults. Methods The search for this scoping review followed the PRISMA extension guidelines across five databases (Medline, Scopus, Web of Science, Scielo, and PEDro) from their inception until August 2025. Eligible studies included older adults with osteosarcopenia who underwent major surgeries and reported clinical outcomes. Additionally, data extraction covered three themes: study and population characteristics; prevalence and impact of osteosarcopenia on post-major surgery clinical outcomes; and diagnostic criteria for osteosarcopenia. Results A total of 164 studies were identified, of which 18 met the inclusion criteria, involving 3,235 participants aged between 60.7 and 83 years. The impact of osteosarcopenia varies depending on the type of procedure: (1) in oncological surgeries, the prevalence ranged from 12% to 44%, with reported complications including prolonged surgical time and reduced survival; (2) in orthopedic surgeries, prevalence ranged from 28% to 100%, with issues such as delayed recovery and increased mortality;" and (3) in cardiovascular and gastrointestinal surgeries, the prevalence of osteosarcopenia ranged from 6.5% to 38.5%, associated with delayed wound healing and higher infection rates. Diagnostic approaches to osteosarcopenia showed substantial heterogeneity, most frequently relying on skeletal muscle mass index and bone mineral density, but applying different cutoff values. Conclusions The prevalence of osteosarcopenia differs across populations and surgical contexts. This syndrome represents an important risk factor for adverse postoperative outcomes in older adults undergoing major surgery. Furthermore, considerable variability persists in the diagnostic criteria employed, underscoring the need for standardized definitions to improve clinical applicability and comparability across studies."info:eu-repo/semantics/openAccessSarcopeniaSurgeryOsteopeniaAgedReviewhttps://doi.org/10.7717/peerj.20527