Ever looked at some part of a gadget and thought: I wonder what this little gizmo does? Remove it and find out! Maybe nothing happens at first. But wait a few years and the importance of that piece becomes all too clear. Such has been the case for removing knee cartilage, or the meniscus.
If you tore your meniscus 20 years ago, the surgeon would probably just take it out. But studies since then have shown the importance of the meniscus to the knee. Without it the space between the two leg bones that form the knee joint gets narrow. There is less cushioning for the joint. Eventually the joint starts to wear down.
Now, improved methods in surgery allow doctors to save as much of the cartilage as possible. New research has focused on the results of this type of surgery, called tissue-conserving therapy. As part of this ongoing research, researchers in Sweden rechecked a group of patients who had either partial or total removal of the cartilage, called a meniscectomy.
Fourteen years after surgery, patients had X-rays and physical exams. Knee function, range of motion, and muscle strength were measured. X-rays were used to look for flattening of the bones, narrowing of the joint space, and hardening of the tissues.
Physical exams showed that range of motion was less on the operated side when patients had the whole meniscus taken out (total meniscectomy). Range of motion was not changed when patients only had part of the meniscus removed (partial meniscectomy). Muscle strength was the same for both groups. Also, knee function was the same before and after surgery for both total and partial meniscectomies. There was a decrease in physical activity in both groups, but overall, there were no major problems in either group. X-rays showed that patients had much greater changes in the joint after total meniscectomy compared to the partial procedure.
How much of the meniscus is removed determines the final result. There are very few long-term changes with a partial meniscectomy, even years later. However, a total meniscectomy increases the risk of changes in the joint. Joint space narrowing seems to be the biggest change, though knee function appears to stay the same. With continued improved methods, doctors will be able to save more of the torn tissue. This will give patients a healthier knee years later.