This study is testing a new way to treat large chondral lesions (areas of damaged cartilage) in the knee using a product called Chondro-Gide®. This product is used along with a procedure called microfracture, which involves making small holes in the bone to encourage cartilage growth. The study will compare this new treatment to just using microfracture for smaller lesions. Patients will report their outcomes and any side effects they experience.

To participate, you need to be 18 to 55 years old, have a knee cartilage problem confirmed by MRI or arthroscopy, and be able to attend all study appointments and follow the rehab plan. You can't join if you have certain other knee or health problems, are pregnant, or are in another study.

• The study is double-blind, meaning neither you nor the person assessing your results will know which treatment you received.
• You must attend all study visits and follow rehabilitation instructions.
• Participants will be monitored for side effects and report how the treatment affects them.