Why I Would Rather Repair Cartilage Than Replace A Knee

Patients come in all the time asking if I can replace or repair the damaged cartilage in their knee. I wish I could answer yes every time, but this isn’t always the case.
When we think of cartilage lesions we sometimes use the term “pothole” to describe the types that are presumed to be fixable. Patients develop defects or these “potholes” in their cartilage due to varying reasons;

  1. Trauma- from an occurrence such as a car accident, a ligament tear, a patellar dislocation, or a fracture.
  2. Avascular necrosis– a condition where the blood supply to bone is compromised due to oral steroid use, alcohol consumption, and often for no known cause. If this occurs under the cartilage in the knee, it can loosen and peel off.
  3. Osteochondritis Dissecans– a condition where an area of bone and cartilage can become loose or unstable in the knee. It affects growing kids and can become symptomatic in young adults.
  4. Degeneration- due to arthritis either inflammatory or degenerative osteoarthritis.
  5. Idiopathic causes– which means for reasons we don’t understand.

In the first four described conditions, we can often use either donor cartilage (particulated or osteochondral allograft,) or tissue engineered cartilage (MACI) to fill the hole. In cases where the damage is arthritis and affects both sides of a joint, then we start talking about a joint replacement, partial or total.
In summary, in patients with cartilage loss in just one area of their knee, I can often repair or replace the cartilage, but once a joint degenerates to the point where the cartilage is lost on both sides (femur and tibia,) it’s usually too late. At that point, the patient and I consider a partial or total joint replacement.