Supplement Use in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Systematic Review

To assess whether a standardized dietary supplementation can help to decrease postoperative muscle atrophy and/or improve rehabilitation outcomes in patients who underwent anterior cruciate ligament reconstruction (ACLR). A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). MEDLINE, Scopus, and Cochrane Library databases were searched, and articles that examined protein or amino acid, vitamin, or any other type of supplementation in ACLR were reviewed. Two independent reviewers conducted the search using pertinent Boolean operations. A total of 1818 articles were found after our database search. Ten studies fulfilled our inclusion criteria and only assessed patients undergoing ACLR. Four studies assessed protein-based supplementation. One study assessed creatine as a supplement. Four studies assessed vitamin-based supplementation. One study assessed testosterone supplementation. Protein and amino acid supplementation showed potential benefits; multiple authors demonstrated a combination of improved achievement of rehabilitation benchmarks, graft maturation, muscular hypertrophic response, and peak dynamic muscle strength. When we examined creatine, vitamin, or hormone-based protocols, none demonstrated results, suggesting these factors may attenuate muscle atrophy after surgery. Vitamin C and E demonstrated potentially increased local inflammation in skeletal muscle, which runs contrary to the belief that antioxidant vitamin-based supplementation may decrease the inflammatory response that plays a role in the post injury/operative period. Protein-based supplementation may play a role in mitigating muscle atrophy associated with ACLR, as multiple authors demonstrated a combination of improved achievement of rehabilitation benchmarks, thigh hypertrophic response, and peak dynamic muscle strength. However, based on current literature, it is not possible to recommend a specific protein-based supplementation protocol at this time for patients undergoing ACLR. Limited evidence suggests no benefit for creatine, vitamin, or hormone-based protocols. II, a systematic review of level I-II studies.