What is cartilage?

Cartilage is a strong, flexible and fibrous tissue that can be found throughout the body performing a variety of different tasks. One of the most common types of cartilage is articular cartilage. It is found in the joints of the body—most notably the knees, along with the menisci—and is a smooth and shiny tissue that covers the surfaces of the bones that connect at a joint. Articular cartilage is designed to:

  • Allow bones to glide easily over one another as the body moves
  • Act as a shock absorber to keep the bones from crushing one another during activities such as jogging
  • Store synovial fluid, a thick and sticky substance that circulates nutrients through the joints and lubricates them

How does articular cartilage in the knee become injured?

Despite the tough jobs articular cartilage performs, it can still become damaged due to:

  • Certain diseases, such as rheumatoid arthritis
  • Gradual wear over time (which can result in osteoarthritis)
  • Injury

When the cartilage becomes damaged, the bones can rub against one another, producing friction. It may also create bone spurs, a protrusion of extra bone from the end of a joint.

What are the symptoms of damage?

When the bones of the joint grind against one another, the friction can cause symptoms including:

  • A grinding sensation or clicking
  • Pain in the knee that can worsen when resting or putting pressure on it
  • Swelling
  • The knee giving way or locking

How is articular knee cartilage repaired?

Because cartilage can’t really heal on its own, surgery is required to repair the damage and restore the functionality of the cartilage. There are a number of surgical options available (many of which can be done arthroscopically, a minimally invasive surgical procedure), including:

Microfracture

The goal of microfracture is to promote new articular cartilage growth. This is done by using tools to drill tiny holes in the bone underneath the cartilage known as the subchondral bone. The holes stimulate a healing response and allow a new blood supply—full of new cells—to reach the cartilage and help it grow.

Drilling

Drilling, like microfracture, is designed to help new tissue grow by creating holes in the subchondral bone. However, it is less precise than microfracture and may cause injury to surrounding tissues.

Abrasion Arthroplasty

This technique is similar to microfracture and drilling, but a different tool is used—called a burr—to create the holes while simultaneously removing damaged cartilage.

Autologous Chondrocyte Implantation (ACI)

This procedure is performed in two steps. First, healthy cartilage from a non-weightbearing section of the joint is removed and sent to a lab to grow new cells. The cells are then implanted underneath a surgically-inserted bone-lining tissue—known as the periosteum—to promote the growth of new cartilage.

Osteochondral Autograft Transplantation

Designed for small areas of cartilage damage, this procedure takes healthy tissue—known as a graft—from a non-weightbearing section of the joint and places it in the damaged space using a special tool. The impact of setting the graft in place leaves behind a smooth cartilage surface.

Osteochondral Allograft Transplantation

If the injured space is too big to repair with an osteochondral autograft transplantation, this technique is used to place a prepared (i.e., sterilized and tested) cadaver graft in the damaged area.

Recovery following surgery is dependent on a number of factors, including the procedure, age and personal healing ability.

Come to the Knee Specialists

At IGEA, our orthopaedic surgeon specializes in treating injuries, including cartilage injury, using advanced treatment options. These and other specialties are part of our practice’s full continuum of care for patients living with brain, spine, neuroendovascular and orthopaedic conditions.

For more information about the superior care and services we provide or to schedule an appointment with one of our experts, contact us today.