Evaluation of Meniscal Regeneration in a Mini Pig Model Treated With a Novel Polyglycolic Acid Meniscal Scaffold

Abstract

Background: Meniscal injury is a severe impediment to movement and results in accelerated deterioration of the knee joint. Purpose: To evaluate the effect of a novel meniscal scaffold prepared from polyglycolic acid coated with polylactic acid/caprolactone on the treatment of meniscal injury in a mini pig model. Study Design: Controlled laboratory study. Methods: The model was established with a 10-mm resection at the anterior medial meniscus on both knee joints. A scaffold was implanted in the right knee joint. The meniscal scaffold was inserted and sutured next to the native meniscus. The histological analysis was performed to determine meniscal regeneration with safranin O staining, cell proliferation with PCNA, inflammation with TNF, and collagen structure and production with picrosirius red and immunofluorescence. Cartilage degeneration was evaluated with Safranin O. Meniscal regeneration and joint fluid were evaluated with magnetic resonance imaging. Results: Although compressive stress and elastic modulus were significantly lower in the scaffold than in the native porcine menisci, ultimate tensile stress was similar. Implanted scaffolds were covered with tissue beginning at 4 weeks, with increased migration of proliferating cells to the implant area at 4 and 8 weeks. Scaffolds were absorbed with freshly produced collagen at 24 weeks. Cartilage degeneration was significantly lower in the meniscus-implanted group than in the meniscectomy group. Magnetic resonance imaging results did not show severe accumulation of joint fluids, suggesting negligible inflammation. Density of the implanted menisci was comparable with that of the native menisci. Conclusion: Meniscal scaffold prepared from polyglycolic acid has therapeutic potential for meniscal regeneration. Clinical Relevance: This meniscal scaffold can improve biological knee reconstruction and prevent the increase of total knee arthroplasty.