20 questions regarding meniscus injuries.

1) What is a meniscus?
To explain this, we will use some anatomy. The knee consists of three bones. These are the thighbone (os femur), the shinbone (os tibia) and the patella. In this section we will not discuss the patella. Then, in each knee, there are two menisci. These are cartilage disks that ensure that everything fits snugly. The femur and the tibia should not be disconnected, but should be aligned when the leg is straight or bent. On both outer ends of the knee are ligaments that ensure this alignment. These ligaments also ensure stability during sideways motions. On the inner side of the knee are two cruciate ligaments that ensure that the tibia cannot be dislocated towards the front or backside.

2) Are both menisci equally vulnerable?
No. The menisci are connected to the surrounding tissue, so they are not just floating around. The inner meniscus (medial meniscus) is slightly stronger bonded, and can therefore get stuck and damaged more easily. This however does not change anything in the remaining information or treatment.

3) What is the function of the menisci?
During walking and jumping strong forces are exerted on the knee joint. The menisci moderate the effects of these shocks and forces, such that they do not drone through to the back and head. In addition they ensure that the upper and lower legs join better at the knee, which makes motions smoother.

4) What can go wrong?
When one gets older the elasticity of the menisci reduces and they become brittle. Slowly a small tear or rupture can occur due to injury through heavy burdening of the knee. This injury can for instance occur during strength and jump training or when you twist your leg (cartilage trouble).

5) What do you notice?
Possibilities are: You cannot move the knee. It is ‘locked’ and cannot be straightened. This is very painful. The knee feels unstable and you can collapse through the knee. You feel pain when you touch or put little pressure on the cartilage. You can see local swelling on the outside of the cartilage area. This is called a meniscus cyst. There might be fluid buildup in the knee during or after playing sports. Bending the knee becomes limited and painful. The body resists the motion to form a corset of protection. Finally the thigh muscles can become weak and thin.

6) What should you do when you have any of these problems?
First and foremost ice the knee with a cold pack or ice and take pressure off of it. In case of immediate injury or long-term complaints one should go to a physician or to a hospital.

7) What can they do about it?
In the hospital they will use X-Ray, MRI or an arthroscopic exploratory surgery to evaluate the knee.

8) How does the arthroscopic exam go?
Initially they will give a local or complete anesthetic. Then through a small incision they will place a tube inside the knee. The tube (arthroscopy) contains light guiding fibers and lenses. The tube is connected to a camera, which in turn is connected to a monitor, so that they can get a clear picture of the knee.

9) Clear picture?
But aren’t there blood and fluids in the knee? Indeed there are fluids and, depending on the injury, possibly blood in the knee. That is why they can, if needed, add clear fluids through a second incision and rinse the knee. They can even place a pressure band around the thigh to keep the whole knee blood-free for a moment, if necessary.

10) Alright, so they checked and know what is going on. Then what?
Sometimes they will insert tiny tools directly to stitch everything back together, clear out the rough edges and clean up the mess. It is also seen that they still need to do a second arthroscopy exam or do a ‘regular’ surgical procedure and open up the joint.

11) Do I have to be admitted into the hospital to have the arthroscopy exam done?
That depends on the circumstances. An arthroscopy exam can be done with or without being admitted into the hospital.

12) I hear that for some people the entire meniscus is removed.
That is a possibility. When the damage is severe enough, it might be necessary. Obviously they try to avoid this as much as possible, because we cannot function well without the reduction of the impact on the knee joint.

13) Is an arthroscopy exam dangerous?
Every operation has risk factors such as chance of infection. The joint mucous membrane could become irritated. This can cause the knee to remain swollen for weeks. When a cut is made into the skin, skin nerves can become damaged, which might become numb. In general the risks are limited and any complaints that arise fade away in time.

14) Can you play sports right afterwards?
Often pressure on the knee has to be avoided for a short period of time. After the arthroscopy exam you will need crutches and the physician will give additional advice and send you to a physiotherapist.

15) What kind of exercises will I have to do with the therapist?
Usually muscle building training will be needed for the thighs on both the front and backsides. All training that requires you to tense up your legs will help. But the knee itself should not be bent or straightened. For instance: sitting on a chair and lifting your leg with sand-weights is effective. Especially when you do this several times a day in series of 3 with 15 repetitions. Shortly after other training can be added, such as aqua jogging and riding a bike. Proper guidance is a must.

16) When can I run again?
In general the assumption can be made that running is allowed when the knee is not swollen and the muscle strength has regained its original status. If the knee swells up again after running then you have started too soon and you will have to show more patience. The physician or physiotherapist will give you advice with this.

17) Can anything be done to avoid meniscus injuries?
Yes, aside from normal prevention, like a proper warm-up, cool-down, proper training setup and proper technique, muscle building training on the anterior side of the thigh can be useful. You do this by standing on one leg and slowly bending and straightening your knee. After 15 repetitions do the other leg. Also shock reduction through shoes, surface and weight (perhaps try to lose weight after all?) have great impact on the menisci. The less shocks that need to be reduced, the less impact they will have. A flat surface reduces the risk of twisting the knee. Prevention should happen, but to completely exclude an injury is impossible.

18) Playing Sports remains a risk factor.
Not playing sports is far worse. Besides, not every twist of the knee is an immediate knee injury. In 90% of the cases the knee is sprained. The complaints formed from that injury should disappear on their own within weeks to months.

19) Do you have anything positive to say?
Yes, in earlier days people thought that the menisci were not in the bloodstream and were impossible to regenerate themselves. Nowadays they know that there is some part in the bloodstream and limited regeneration is possible.

20) Any final advice?
Yes, listen to your body, it gives you the best advice.

Live Long and Prosper!