Meniscal lesions represent the most frequently encountered joint pathology in the adult population and can cause pain symptoms, mechanical blockages, and recurrent effusions. The treatment of these lesions has progressively evolved from meniscectomy (removal of the damaged meniscal tissue) to the use of meniscal sutures (where possible) to preserve as much meniscus as possible. Numerous studies have demonstrated a correlation between the amount of meniscus removed and the future onset of osteoarthritis.

However, in some cases, especially in the presence of complex and/or chronic lesions, meniscectomy remains the only viable surgical option. Over time, months or years later, a subgroup of patients may develop symptoms such as pain, joint swelling, and mechanical overload of the compartment that underwent meniscectomy, a condition known as post-meniscectomy syndrome..A portion of these patients will later develop knee osteoarthritis and require invasive procedures such as partial or total knee replacement.

In an attempt to treat this condition, scaffolds-collagen implants-have been developed and are arthroscopically implanted in the knee with the aim of functionally replacing the tissue removed during surgery. The goal is to reduce the incidence of long-term osteoarthritis and, consequently, the need for more invasive procedures. To date, no study has definitively demonstrated the real efficacy of these scaffolds (CMI), particularly regarding chondroprotection and the long-term onset of osteoarthritis.

Inclusion Criteria:

• Patients aged between 18 and 65 years at the time of surgery
• Both male and female patients
• Patients who underwent meniscectomy and/or CMI implantation from January 1, 1998 to December 31, 2010 at the Rizzoli Orthopedic Institute.

Exclusion Criteria:

• Patients who are no longer reachable;
• Patients who do not consent to be included in the study;
• Presence of infection or hematological, rheumatic, or hemostatic disorders at the time of evaluation.

Patients, upon signing the informed consent, will be clinically evaluated during the follow-up visit by specialized medical personnel. A clinical examination will be performed, including the administration of subjective assessment questionnaires, and weight-bearing radiographs of the lower limbs will be conducted.