Study enrollment rate was far slower than anticipated. Study was stopped for business purposes.

The Kensey Nash Corp. Cartilage Repair Device is a bioresorbable scaffold designed to promote repair of knee cartilage and subchondral bone. Subjects with knee cartilage damage meeting eligibility criteria will be randomly assigned to receive treatment with the Cartilage Repair Device or a standard surgical technique called microfracture. The purpose of the study is to evaluate the initial safety and effectiveness of the Cartilage Repair Device compared to microfracture.

Damage to articular cartilage in the knee by acute or chronic injury causes pain and limits knee function. If left untreated, damage to the articular cartilage can lead to painful osteoarthritis. The human body has a limited ability to regenerate or adequately repair damage to articular cartilage. There are several surgical techniques available to assist the repair of articular cartilage and improve pain and function. Microfracture is the most commonly used technique for cartilage repair. Microfracture involves the creation of numerous small fractures in the bone with a pick. These small fractures cause the release of multipotential stem cells from the bone marrow creating a clot on the surface. Over time, this clot causes reparative fibrocartilage to form. However, fibrocartilage is less durable and lacks the mechanical properties of normal articular cartilage. The majority of patients treated with microfracture has good results within the first 2 years after microfracture. However, beyond 2 years, functional deterioration is seen in over 50% of patients. Therefore, there is a clinical need for a product that improves surgical outcomes in patients with cartilage damage.

The Kensey Nash Corp. Cartilage Repair Device is a two layer, bioresorbable implant. The top layer consists of collagen fibers like those found in normal cartilage. The collagen layer is about as thick as the cartilage in human knees. The bottom layer of the Cartilage Repair Device mainly consists of a calcium mineral naturally found in human bones. The mineral is held within a biodegradable polymer material. The device has a highly porous structure that allows the blood, stem cells and joint fluid to infiltrate the device during the healing process. Over time, the top layer is designed to be replaced by cartilage and the bottom layer is designed to be replaced by bone.

Both microfracture and the Cartilage Repair Device are expected to reduce knee pain and increase knee function in a majority of patients during the first 2 years post-operative. However, if the Cartilage Repair Device produces better and more durable cartilage than the microfracture technique, those patients treated with the Cartilage Repair Device may have a better long term outcome.

Inclusion Criteria:

• 21 years old and skeletally mature
• KOOS Pain subscale score is less than 65 (i.e. moderate pain)
• KOOS Activities of Daily Living score is less than 70 (i.e. moderate functional limitations)
• ICRS grade 3 or 4 cartilage lesion on the medial femoral condyle, lateral femoral condyle or trochlea measuring less than or equal to 15mm in diameter
• Stable meniscus with greater than 50% remaining bilaterally
• Mental capacity and willingness to comply with the post-operative rehabilitation plan and follow-up evaluations
• Written informed consent

Exclusion Criteria:

• Body mass index greater than 35
• Contraindication for MRI
• Previous microfracture, autograft implantation, allograft implantation or autologous chondrocyte implantation procedure on the damaged cartilage surface
• Knee ligament surgery within the past 6 months
• Clinically significant knee malalignment
• Osteoarthritis in the knee
• Multiple cartilage lesions
• Inflammatory arthropathy (i.e. rheumatoid arthritis, systemic lupus or active gout)
• Active infection in either lower limb
• Hyaluronic acid or cortisone injections within the past 3 months
• History of substance abuse
• Current participation in a study of an investigational product for a similar purpose
• Active litigation for the knee injury