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

Purpose: To investigate the up-to-date clinical outcomes of tissue-engineered meniscus implants for meniscus defects.

Methods: 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.

Results: 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.

Conclusions: 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 Of Evidence: Level IV, systematic review of Level I to IV studies.