Articular cartilage is the smooth, low friction surface that covers the ends of bones where they form joints. This cartilage allows us to have smooth, pain free range of motion within the joint.
The meniscus is a piece of cartilage that is positioned between the femur (thigh bone) and tibia (lower leg bone) in the knee. There are two menisci in each knee, one on the inside and one on the outside. These serve as shock absorbers with activity and thereby decrease the pressure on the articular cartilage.
Damage to these cartilage structures in the knee may be due to trauma or normal wear and tear over time. Injury may present as pain in the affected joint, swelling, or a sense of locking or catching. Unfortunately, damaged cartilage does not have the ability to repair itself. When non-operative treatments fail to improve a patient's symptoms due to a cartilage injury, surgery is typically recommended. Several surgical techniques have been created to either stimulate the body to create new cartilage, or transplant normal cartilage to the injured area. These surgeries attempt to restore the normal anatomy of the knee and therefore relieve pain, improve function and potentially delay the onset of arthritis.
Most candidates for cartilage restoration surgeries are young adults with a single area of cartilage damage. Older patients with damage to several parts of the knee are less likely to have a successful outcome from cartilage restoration.
Microfracture: A sharp instrument called an awl is used to create holes in the damaged joint surface. The blood clot that forms in the area of the holes then matures into a cartilage-like substance.
Autologous Chondrocyte Implantation (ACI): This is a two-staged procedure. In the first surgery, normal healthy cartilage is harvested arthroscopically from a non-weight bearing portion of the joint. The cartilage is then sent to a lab where it is cultured and grown for 6 weeks. The second surgery involves making an incision to prepare the area of damaged cartilage. A patch is sewn over the area and the cultured cells are injected under the sealed patch where they will grow into mature cartilage.
- ACI Preparation
- Before ACI
- After ACI
Osteochondral Autograft Transplantation: In this procedure, plugs of healthy bone and cartilage are transferred from one part of the body to the area of damaged cartilage. This procedure may be done arthroscopically or through a small incision.
Osteochondral Allograft Transplantation: This procedure is generally reserved for large defects or those that have failed to improve with previous surgeries. This techniques transplants bone and cartilage plugs from a freshly frozen cadaveric graft into the area of damaged cartilage. The cadaver graft is size matched to your anatomy in order to accurately restore the geometry of the joint.
- Before Osteochondral Allograft
- After Osteochondral Allograft
Meniscal Transplantation: Patients with significant loss of their meniscal cartilage due to trauma or multiple arthroscopic trimmings of the meniscus may experience symptoms due to the loss of this tissue. A meniscal transplant uses a size-matched cadaver meniscus to replace the damaged meniscus in an effort to alleviate pain, improve function and preserve the joint.