Meniscal scaffold for partial meniscal defect: clinical and and laboratory results

Abstract

Introduction The menisci are fundamental structures for knee homeostasis and to the present day there is a consensus deriving from several publications that have increasingly highlighted the importance of these fibrocartilaginous structures. When repair of a damaged meniscus is not viable, meniscal replacement (partial or total) seems to be the most adequate method, whenever possible. Currently two are those currently used: MAT (meniscal allograft transplantation) - indicated when it is necessary to restore entirely or almost entirely the meniscus - and meniscal scaffold implantation. The latter is the subject of this doctoral thesis. The rationale about the use of a meniscal scaffold is twofold: 1) increase the meniscal surface thus improving patient symptoms resulting from post-meniscectomy syndrome and 2) regenerate the meniscus to preserve joint integrity. Scientific justification Artificial meniscal scaffolds has become popular in the last decades due to promising clinical results. One of the most studied scaffold is the a biodegradable and synthetic acellular scaffold composed of aliphatic polyurethane (Actifit®; Orteq Ltd., London, UK). Although our studies showed results in line with the literature regarding improvement in symptomatology, the meniscal regeneration part gave exactly opposite results. Subsequent studies have focused precisely on evaluate whether possible meniscal remnant extrusion can improve outcome and, the second part demonstrating how by enhancing a scaffold with mesenchymal cells and using appropriate laboratory techniques can be obtained, in vitro, the repopulation of meniscal tissue. Assumptions and objectives This thesis is structured as a compendium of 3 papers (two already published and one submitted). The goal is to answer the following questions: 1. What is clinical and MRI results of the meniscal scaffold for partial meniscal defect? 2. Does Preoperative Remnant Meniscal Extrusion have an influence on postoperative extrusion and knee function? 3. Laboratory techniques could increase biocompatibility of the scaffold? 4. What's the difference between the regenerated meniscal tissue of a scaffold loaded with mesenchymal stromal cell in comparison with a cell-free scaffold Materials and methods The I° paper (Magnetic Resonance Imaging and Functional Outcomes After a Polyurethane Meniscal Scaffold Implantation: Minimum 5-Year Follow-up. Monllau JC, Poggioli F, Erquicia J, Ramírez E, Pelfort X, Gelber P, Torres-Claramunt R. Arthroscopy. 2018 May) is a retrospective study that included all consecutive patients who were operated on from September 2008 to February 2011 for either persistent medial or lateral joint line compartmental pain receiving a polyurethane meniscal scaffold due to a previous partial meniscus resection. The II° (Polyurethane Meniscal Scaffold: Does Preoperative Remnant Meniscal Extrusion Have an Influence on Postoperative Extrusion and Knee Function? Gelber PE, Torres-Claramunt R, Poggioli F, Pérez-Prieto D, Monllau JC. J Knee Surg. 2020 May 25) is a retrospective study that was conducted to assess all the patients who had had a medial polyurethane scaffold implanted for a postmeniscectomy syndrome. The study evaluates, with a 2-year follow-up after the implantation if there is a correlation between polyurethane scaffold and preoperative MRE (major or minor extrusion). The III° article - accepted - (Fibronectin-coating enhances attachment and proliferation of mesenchymal stem cells on a polyurethane meniscal scaffold. Raquel Arredondo, Francesco Poggioli, Santos Martínez, María Piera, Raúl Torres, Laura Tío, JC Monllau) is a laboratory study with the aim of evaluate if use of FN-coated scaffold allows MSCs to attach to Actifit® in vitro and finally leads to MSC differentiation into new cells producing ECM similar to the ones produced by chondrocytes. Results Polyurethane meniscal scaffold in patients with symptomatic meniscus deficit leads to a good functional outcome at 5-years after surgery. However, the MR-imaging aspect of the new meniscal tissue is far from a native meniscal tissue and the volume of the new tissue is far less than expected. The SE observed at the 2-year follow-up after the implantation of a polyurethane scaffold did not depend on the pre-operative MRE (major or minor extrusion). The WOMET score, which was the only meniscal-specific functional scored used, detected some inferior results in those most extruded meniscal scaffolds