Management of Focal Cartilage Lesions of the Knee: The Benefits of an Autograft Procedure

Cartilage is a tissue whose primary function is to transmit and distribute loads when joints are under stress. It acts as a buffer between bones at the joints. Over time, or due to diseases and/or trauma, this surface can disappear, leading to pain and limited movement. Cartilage lesions are particularly difficult to treat because cartilage has a limited capacity for regeneration. When cartilage lesions are characterized by a localized defect, several surgical techniques are available to restore cartilage tissue to the affected area. The most frequently used surgical technique is bone marrow stimulation, also known as microfracture. The cartilage lesion is debrided, the subchondral bone exposed, and then a punch is used to perforate the subchondral bone, allowing a clot to form within the defect. This clot will proliferate and differentiate into scar tissue. However, this cellular differentiation results in fibrocartilaginous tissue rather than hyaline cartilage, sometimes with disappointing clinical outcomes. Other techniques for cartilage restoration exist and are used routinely, including more biological techniques such as Minced Cartilage Implantation (MCI). Autologous cartilage is first harvested from around the defect, chopped into very small fragments, and then reimplanted. Cartilage fragmentation activates cell proliferation and migration, followed by the synthesis of an extracellular, cartilaginous matrix. The effectiveness of this fragmentation is increased with fine fragments (\<0.3 mm). Cell proliferation and activity appear to be stimulated by the systematic addition of PRP (Platelet-Rich Plasma) during the MCI procedure. The expected benefit of an MCI approach lies in clinical improvement and better cartilage regeneration (observed on imaging) compared to microfracture. The objective is to conduct a controlled, randomized, blinded study (blinded to both the patient and the MRI assessor of the bone graft) to determine the benefit of an MCI approach