Microplastics in Musculoskeletal Disorders: An Emerging Threat.

Introduction: Microplastics (MPs), defined as plastic particles smaller than 5 mm, are emerging environmental contaminants that pose potential health risks. Although their systemic toxicity is increasingly recognized, the impact of MPs on the musculoskeletal system is underexplored. Materials and methods: A narrative literature review was conducted using PubMed, Scopus, and Web of Science. Studies published from 2010 to 2024 were selected using the keywords 'microplastics,' 'nanoplastics,' 'bone,' 'cartilage,' 'muscle,' and 'musculoskeletal system.' Inclusion criteria encompassed original experimental studies, animal models, and clinical data where available. Results: MPs can enter the body via ingestion, inhalation, and dermal absorption. Once inside, they trigger oxidative stress, inflammation, apoptosis, and cellular dysfunction in musculoskeletal tissues. MPs have been associated with disrupted osteoblast and chondrocyte function, increased osteoclastogenesis, and impaired muscle regeneration. Preclinical models indicate reduced bone density and muscle atrophy following chronic exposure. Nanoplastics may have distinct toxicokinetics with deeper tissue penetration and higher bioavailability. Conclusion: Current evidence suggests that MPs adversely affect musculoskeletal health through inflammation, oxidative damage, and cellular dysfunction. The findings, although predominantly preclinical, raise concerns about long-term skeletal and muscular degeneration. Further clinical studies are urgently needed.