The MERCuRE (MEniscus, REstoration, Conservation, and Repair) group is embarking on a 20-year follow-up study to evaluate the clinical outcomes, graft longevity, and chondral protection following primary or revision Meniscal Allograft Transplantation surgery This clinical investigation is a prospective, primary observational, open-label, non-randomized, multi-center study. It is designed to collect clinical follow-up data on patients

Inclusion Criteria:

Subjects enrolled in this study must meet all of the following inclusion criteria:

• Males and females aged 10-65 years
• MRI or arthroscopic images confirming the suitability for meniscus transplantation.
• Patients undergoing an isolated primary/revision MAT (meniscal allograft transplant) procedure, or concomitant MAT with other knee procedures such as ligament reconstruction, realignment osteotomy, or cartilage resurfacing.
• Medically suitable for meniscus transplantation.
• Appropriate understanding of the language of the surgical center in terms of communication and reading.
• Ability of the Patient or parent/guardian to provide informed consent.

Exclusion Criteria:

• Inability to comply with rehabilitation programs.
• Patient aged less than 10 years and more than 65.
• Presence of diffuse full thickness cartilage loss (widespread ICRS Grade III-IV chondral damage) and/or architectural remodeling of bone (i.e. flattening of condyle) in the knee of interest.
• Significant medical comorbidities that limit patients from undergoing surgery.
• Presence of confounding neuromuscular, genetic/congenital, or post-traumatic conditions.

Patients with meniscal deficiency