Meniscus repair via collagen matrix wrapping and bone marrow injection: clinical and biomolecular study.

Purpose: The functional outcomes of arthroscopic matrix-based meniscus repair (AMMR) in patients two and five years after the treatment clearly show that the use of the collagen matrix and bone marrow aspirate creates favorable biological conditions for meniscus healing. This study not only provides ten follow-up results but also investigates biomolecular mechanisms governing the regenerative process.

Methods: Case series was based on data collected from patients who underwent AMMR procedure, starting with preoperatively through two-year and five-year till ten-year follow-up. The outcomes are presented as IKDC and the Lysholm subjective scores as well as the imaging results. Biomolecular investigation of the membranes utilized in the AMMR procedure include DNA content analysis, cell viability and proliferation study of bone marrow and bone marrow concentrate-derived cells, and cytokine array performed on monocytes cultured on the membranes.

Conclusion: Data collected from patients who underwent AMMR procedure, starting with pre-operatively through two year and five year till ten year follow-up, indicate the possibility for long-term, stable meniscus preservation. Outcomes are manifested with a visible improvement of the IKDC and the Lysholm subjective scores as well as in the imaging results. The type of the meniscal tear or complexity of the knee injury (isolated AMMR vs. AMMR + ACL) did not affect the clinical outcomes. The study highlighted the role of the membrane in facilitating cell adhesion and proliferation. Additionally, several cytokines were selected as potentially crucial products of the membrane vs. monocyte interactions, driving the tissue regeneration and remodeling. Interestingly, thresholds of what constitutes a safe and well-decellularized membrane according to relevant literature have been significantly breached, but ultimately did not elicit detrimental side effects.