First of all: Don’t get hurt. Once you injure your knee — if the meniscus cartilage, articular cartilage or ligaments do not heal normally, or are not repaired, reconstructed or replaced quickly — the knee is doomed to develop arthritis. That’s because loss of function of any of these key tissues means an increase in concentrated force on the joint surface, and early wear.
An analogy to a car tire comes pretty close: If your car is out of alignment, the tires wear very rapidly. So does your knee.
If you do get hurt, insist on accurate surgery and restoration of full function. Don’t accept less. The following cases will illustrate some of your potential hurdles, and solutions:
The most common patient story we hear is: “I injured my meniscus cartilage, and they took out part of it. Now I have arthritis. Isn’t there just a shock absorber you can put in my knee?”
The answer is yes. It is called the meniscus. It is available as a collagen scaffold (to regrow part of the meniscus) or as a full allograft (human tissue) to actually replace the meniscus.
The second most common story is: “I tore my ACL, and it was reconstructed. Now I have arthritis.”
Data shows that 50 percent of people with an ACL injury will get arthritis. This is partly due to the force of the original injury, but also due to the inaccuracies of ACL reconstruction techniques. The surgery either fails to restore normal biomechanics, or the harvesting of the patient’s hamstrings or patella tendon (to rebuild the ACL) weakens the knee — leading to abnormal motion and early wear.
The answer here is anatomic ACL reconstruction, which restores the original knee anatomy as closely as possible. This includes the use of off-the-shelf ACL replacement devices. In the United States, this will be an allograft; in Europe, either an allograft or the newly available Z-Lig animal-derived tissue. Long-term data is needed to determine if these alternatives diminish the arthritis. In any case, you are not injuring one part of the knee to restore another part.
The third most common story is: “I damaged my articular cartilage, and the doctor shaved it away.”
Cartilage restoration procedures have advanced to the point where damaged cartilage can now often be repaired rather than removed. At Stone Clinic, we often use a paste graft technique. We have more than 20 years of data demonstrating that this leads to effective cartilage repair. Other orthopedic centers have other techniques, which also have promising long-term data.
The days of hearing, “Cartilage cannot be repaired” are in the past.
The fourth most-heard story is: “I have arthritis and have been told I need a total knee replacement.”
This scenario has four possible outcomes. One is that the joint spaces are still open. In this case, the patient can be treated with lubrication, growth factors and physical therapy, diminishing many of the symptoms but not curing the problem. Two is that the joint spaces are open, and the cartilage can be restored with a biologic knee replacement. Three, the X-ray shows only one part of the knee is bone-on-bone. Here, a partial knee replacement using a MAKO robot can be performed, saving the rest of the knee. Four is that the arthritis has progressed to severe deformity in multiple parts of the knee, in which case a total knee replacement really is the best option.
The reason this is the last option is that 50 percent of people with a total knee replacement have pain at 10 years, and there is a high revision rate in the first two years. The replacement knees are not normal, and there is no going back to a biologic solution once the knee is completely replaced.
So while a total knee replacement is a great solution if and when the knee is completely worn out, we advocate exhausting the other options first. The best advice is if you get hurt, fix the damage immediately … and avoid arthritis.
Dr. Kevin R. Stone is an orthopedic surgeon at The Stone Clinic and chairman of the Stone Research Foundation in San Francisco.