Creatine supplementation in the pediatric and adolescent athlete-- A literature review.

Background: An increase in intra-muscular creatine through supplementation has been proposed as a strategy for improving muscle performance and recovery, with studies showing some benefit for adult athletes who rely on short, explosive movements. We reviewed and summarized the current literature on creatine supplementation in a pediatric and adolescent population. Methods: The databases PubMed and EMBASE were queried to identity articles related to the use of creatine supplementation in a healthy pediatric and adolescent population according to the guidelines established by PRISMA. The abstracts of all articles were reviewed to determine relevancy, with those meeting the pre-defined criteria included in the final review. Results: A combined total of 9393 articles were identified. Following application of filters and review of abstracts, 13 articles were found to meet criteria and were included in the final review. There was a total of 268 subjects across all studies, with mean age ranging from 11.5 to 18.2 years. More than 75% of the studies were randomized-controlled trials, and 85% involved either soccer players or swimmers. The overall quality of the studies was poor, and there were no consistent findings regarding creatine supplementation and improvements in athletic performance. No studies were designed to address the topic of safety. Conclusions: There is a gap in the study of the safety and efficacy of creatine supplementation in adolescents. Additional studies are needed to evaluate the effects of alterations in muscle composition on the growth, development, and performance of the developing athlete. Orthopedic providers should counsel their pediatric and adolescent patients on the current limitations in trying to assess the true risk and benefit of creatine supplementation for the aspiring athlete. Level of evidence: Review, III.

Modulation of Synthetic Tracheal Grafts with Extracellular Matrix Coatings.

Synthetic scaffolds for the repair of long-segment tracheal defects are hindered by insufficient biocompatibility and poor graft epithelialization. In this study, we determined if extracellular matrix (ECM) coatings improved the biocompatibility and epithelialization of synthetic tracheal grafts (syn-TG). Porcine and human ECM substrates (pECM and hECM) were created through the decellularization and lyophilization of lung tissue. Four concentrations of pECM and hECM coatings on syn-TG were characterized for their effects on scaffold morphologies and on in vitro cell viability and growth. Uncoated and ECM-coated syn-TG were subsequently evaluated in vivo through the orthotopic implantation of segmental grafts or patches. These studies demonstrated that ECM coatings were not cytotoxic and, enhanced the in vitro cell viability and growth on syn-TG in a dose-dependent manner. Mass spectrometry demonstrated that fibrillin, collagen, laminin, and nephronectin were the predominant ECM components transferred onto scaffolds. The in vivo results exhibited similar robust epithelialization of uncoated and coated syn-TG patches; however, the epithelialization remained poor with either uncoated or coated scaffolds in the segmental replacement models. Overall, these findings demonstrated that ECM coatings improve the seeded cell biocompatibility of synthetic scaffolds in vitro; however, they do not improve graft epithelialization in vivo.