Short-Term but Not Long-Term Knee Symptoms and Functional Improvements of Tissue Engineering Strategy for Meniscus Defects: A Systematic Review of Clinical Studies

To investigate the up-to-date clinical outcomes of tissue-engineered meniscus implants for meniscus defects. A search was performed by 3 independent reviewers on PubMed, MEDLINE, EMBASE, and Cochrane from 2016 to June 18, 2023, with the term “meniscus” with all the following terms: “scaffolds,” “constructs,” “implant,” and “tissue engineering.” Inclusion criteria included “Clinical trials” and “English language articles” that involved isolated meniscus tissue engineering strategies for meniscus injuries. Only Level I to IV clinical studies were considered. The modified Coleman Methodology score was used for quality analysis of included clinical trials. The Methodological Index for Non-Randomized Studies was employed for analysis of the risk of study bias and methodological quality. The search identified 2,280 articles, and finally 19 original clinical trials meeting the inclusion criteria were included. Three types of tissue-engineered meniscus implants (CMI-Menaflex, Actifit, and NUsurface) have been clinically evaluated for meniscus reconstruction. Lack of standardized outcome measures and imaging protocols limits comparison between studies. Tissue-engineered meniscus implants can provide short-term knee symptom and function improvements, but no implants have been shown to propose significant long-term benefits for meniscus defects. Level IV, systematic review of Level I to IV studies.