Cartilage is a durable yet flexible substance that lines our joints, allowing bones to move against each other without experiencing discomfort. Even though cartilage protects our bones, it can deteriorate over the years through wear and tear.
Knee cartilage injuries are common in sports that involve jumping, pivoting, cutting, rapid acceleration, and deceleration. Damaged cartilage doesn't usually heal because it's an avascular tissue, meaning that oxygenated blood cells can't repair injuries.
When knee cartilage damage occurs, the first step is usually conservative treatment, especially when the symptoms are minor and don't require surgical interventions. These include:
- RICE protocol (Rest, Ice, Compress, Elevate)
- Physical therapy
- Losing excess weight
- Using a knee brace
- Prescribed painkillers
- Injections to reduce joint inflammation
When conservative treatments don't alleviate the symptoms, surgery may be required to address the underlying issue. The main approaches to this type of intervention focus on cartilage repair and regrowth.
Available Surgical Options
- Chondroplasty – Using a thin instrument known as an arthroscope that is inserted through a minute incision in the knee, the surgeon mechanically removes damaged cartilage and smooths the tissue to prevent further damage. Debridement may be required to remove residual irritants from the knee.
- Microfracture – With the help of arthroscopic instruments, surgeons scrape the damaged area and expose blood and marrow from the bone to fill the injury. As the cartilage absorbs the marrow, it gradually scars and becomes part of the tissue reinforcing it.
- Autologous Chondrocyte Implantation – In this two-step procedure, surgeons first obtain a small knee cartilage sample and culture it in a lab to develop 8 to 12 times its initial size. After a few weeks, the cultured tissue is implanted into the injury and progressively fills the defect.
- Osteochondral Autograft Transfer – Surgeons harvest a plug from the patient's own cartilage, usually from a part of the knee that isn't involved in weight-bearing. The harvested plug is implanted in the injured knee, providing long-term durability by using the patient's own hyaline cartilage.
- Osteochondral Allograft Transplant – The procedure is similar to Autograft Transfer, except that the plug is harvested from a donor who has passed away. Likewise, surgeons have the opportunity to use more tissue as needed compared to the limited sample they can obtain from a patient's own cartilage.