Partial meniscectomy is one of the most common surgical strategy for a meniscal injury, but sometimes, patients complain of knee pain due to an overload in the ablated compartment. In these cases, implantation of tissue engineering scaffold could be indicated. Currently, two commercial scaffolds, based on collagen or polycaprolactone-polyurethane (PCL-PU), are available for meniscus scaffolding. In short term follow-up assessments, both showed clinical improvement and tissue formation. However, long-term studies carried out in PCL-PU showed that the new tissue decreased in volume and assumed an irregular shape. Moreover, in some cases, the scaffold was totally reabsorbed, without new tissue formation. Mesenchymal stem cells (MSCs) combined with scaffolds could represents a promising approach for treating meniscal defects because of their multipotency and self-renewal. In this work, we aimed to compare the behaviour of MSCs and chondrocytes on a PCL-PU scaffold in vitro. MSCs express integrins that binds to fibronectin (FN), so we also investigate the effect of a FN coating on the bioactivity of the scaffold. We isolated rabbit bone marrow MSCs (rBM-MSCs) from two skeletally mature New Zealand white rabbits and stablished the optimum culture condition to expand them. Then, they were seeded over non-coated and FN-coated scaffolds and cultured in chondrogenic conditions. To evaluate cell functionality, we performed an MTS assay to compare cell proliferation between both conditions. Finally, a histologic study was performed to assess extracellular matrix (ECM) production in both samples, and to compare them with the ones obtained with rabbit chondrocytes (rCHs) seeded in a non-coated scaffold. A culture protocol based on low FBS concentration was set as the best for rBM-MSCs expansion. The MTS assay revealed that rBM-MSCs seeded on FN-coated scaffolds have more cells on proliferation (145%; 95% CI: 107%–182%) compared with rBM-MSCs seeded on non-coated scaffolds. Finally, the histologic study demonstrated that rCHs seeded on non-coated scaffolds displayed the highest production of ECM, followed by rBM-MSCs seeded on FN-coated scaffolds. Furthermore, both cell types produced a comparable ECM pattern. These results suggest that MSCs have low capacity attachment to PCL-PU scaffolds, but the presence of integrin alpha5beta1 (FN-receptor) in MSCs allows them to interact with the FN-coated scaffolds. These results could be applied in the design of scaffolds, and might have important clinical implications in orthopaedic surgery of meniscal injuries.

Background/Objectives: The purpose of this study was to evaluate the outcomes of meniscal suture repair in patients over 50 years of age with a minimum follow-up of 6 months, following failure of at least 6 months of conservative treatment. Methods: We retrospectively reviewed patients older than 50 years treated between 1 January 2017 and 30 June 2023 at the Orthopaedics and Traumatology Division of ASST Papa Giovanni XXIII (Bergamo, Italy) who underwent meniscal repair after failed conservative management. Patients underwent clinical, radiological and functional assessments. Meniscal healing was evaluated by MRI at 6 months postoperatively. Patient-reported outcome measures (PROMs), including KOOS, IKDC, Lysholm and Tegner Activity Scale, were collected preoperatively and at final follow-up. Results: Eleven patients were included, with a mean age of 53.4 ± 4.1 years (range, 50–64). Nine patients had lateral meniscus tears, and two had medial meniscus tears. At a mean follow-up of 22.0 ± 16.8 months (range, 6–66), significant improvements were observed in KOOS, IKDC and Lysholm scores (p < 0.05), with mean postoperative values of 95.4 ± 5.1, 87.5 ± 8.3 and 97.1 ± 3.5, respectively. All patients returned to their pre-injury activity level according to the Tegner scale. One complete failure and one partial failure were observed, both in patients with medial meniscus tears. Conclusions: In this small cohort, arthroscopic meniscal repair in patients over 50 years of age was associated with significant improvements in clinical and functional outcomes, with a failure rate of 18.2%. These findings suggest that meniscal repair may be a viable joint-preserving option in carefully selected middle-aged patients, particularly in lateral meniscus lesions. However, results should be interpreted cautiously given the limited sample size and retrospective design.