Meniscal lesions represent one of the most common orthopedic injuries, and the standard of care, partial meniscectomy, often leads to long-term joint deterioration. The current meniscal replacement devices fail to recreate the native meniscus biomechanics that may explain the uncertainty of their clinical efficacy. A biomechanically functional, collagen-hyaluronan infused, three-dimensional printed polymeric scaffold was implanted into 18 sheep for up to 24 weeks to assess the scaffold's fixation, cellular response, tissue generation, integration to the host tissue, and effect on the surrounding articular cartilage. The scaffolds were assessed via gross inspection, histology, immunofluorescence, and biochemical analysis and the articular cartilage was assessed via gross inspection and histology. Scaffolds were ingrown with cells that generated a dense fibrocartilage-like tissue with significant collagen and glycosaminoglycan deposition. The stability of the surgical fixation was variable, however, with three partially displaced and five completely displaced implants at 12 weeks and three anatomic, four partially displaced, and two completely displaced implants at 24 weeks. Those implants remaining in the anatomic position displayed markedly improved outcomes. There was no significant degeneration observed in the surrounding articular cartilage for any condition. This study demonstrated the scaffold induces fibrochondrocytic tissue ingrowth, integrates robustly, and continues to mature as late as 24 weeks, and the articular cartilage is not adversely changed. The surgical model and fixation method must be improved and longer time points need to be investigated to further determine the scaffold's efficacy and chondroprotective abilities. The only FDA-approved partial meniscus scaffold, the Collagen Meniscus Implant (CMI), is not approved for reimbursement by government and only reimbursable by certain private insurers. Scaffolds with improved mechanical properties and greater efficacy are needed. A previous study (Ghodbane, et al. DOI: 10.1002/jbm.b.34331) demonstrated the ability of our novel acellular, off-the shelf scaffold to restore knee biomechanics following partial meniscectomy, which could potentially decrease the risk of osteoarthritis following partial meniscectomy, providing the motivation for this study. This article presents a first-in-animal feasibility study.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering
- ovine model
- tissue engineering