Knee pain can affect a large range of age groups, ranging from ‘growing’ pains experienced by young people to ‘arthritic’ pain in older persons, and everything in-between. In this Blog we will examine knee meniscus injuries, what causes them and how to treat these injuries.
What is the Meniscus of the Knee?
The meniscus are C-shaped structures in your knee joint which sit between your femur (or thigh bone) and your tibia (or shin bone). They are made of a type of cartilage called fibrocartilage, which is a little bit different to other form of cartilage in your knee called articular cartilage. Articular cartilage is often more affected with arthritis. Your knee has two menisci, the medial meniscus and lateral meniscus. The medial meniscus is located on the inside while the lateral meniscus is on the outside of your knee.
The menisci have a limited blood supply which rely on movement of the knee to keep it strong and healthy. The best thing you can do to prevent your meniscus from injury, is to keep active and keep the knee moving.
What does the Meniscus do?
The main role of the menisci is to help with absorbing and distributing forces through the knee joint. They work together with knee and hip muscles to act as a shock absorber when the knee is active. The menisci also increases the surface area of the knee joint, so it adds some extra stability to the knee.
How do you injure your meniscus?
The majority of meniscus injuries occur as people age (over 50 years). As you get older the limited blood supply to the meniscus becomes further reduced. As people age they develop wrinkles and grey hair. The aging process also occurs in the knee, the menisci begin to degenerate, lose some of their strength and become more prone to injury.
As the menisci become more susceptible to injury with age, the range and types of movements which can damage it become more prevalent. The majority of meniscus injuries occur when you twist your knee over a planted foot. – Sometimes it can be as simple, as turning to look over your shoulder or stepping off a ladder and putting weight on your foot and twisting your knee. You might notice the knee to slowly swell up.
Meniscus injuries in the younger ager group (under 30) are not as prevalent. Simple twisting movements to the knee are unlikely to cause menisci injury in younger persons. You are more likely to see menisci injuries occur with other knee injuries such as ligament damage caused through sport.
What should I do if I damage my meniscus?
So you have injured your knee and you are thinking, what to do next? Alternatively, you have had a scan on your knee and been diagnosed with a meniscus tear and wanting to know what is the best way to treat it?
A 2002 study involving people who had ‘degenerative’ menisci tears, compared the rehabilitation recovery rates of three groups. The first group had meniscus removal surgery (i.e. arthroscopic meniscectomy), the second experienced joint ‘wash-out’ (lavage) and third underwent ‘placebo’ surgery where the surgeon made skin incisions only. All groups undertook the same rehabilitation program. Amazingly they found no difference in between the 3 groups. All groups had the same levels of pain and function, and all improved at the same rate.
Since the initial 2002 study, further published studies have compared meniscus surgery with placebo surgery and physiotherapy treatment. These studies continue to confirm the same result, that is, there is no differences between all of the groups in terms of rehabilitation other than the surgery group having a higher cost of treatment!
The treatment for meniscus tears in the active, younger population (under 30) is more complex with some individuals needing surgery as soon as possible, while others can manage with physiotherapy and exercise.
What does this all mean?
Degenerative meniscus tears are more common as people age. In some cases people who not have any knee pain may have degenerative menisci and not be in any pain. In other words having a degenerative meniscus correlates poorly pain. The good news is, you might not need to have surgery at all if you are able to undertake a comprehensive physiotherapy rehabilitation program.
Will surgery provide you any benefits? Yes it will in the short term. However, arthroscopic meniscus surgery is associated with a ten-fold increase the risk of knee osteoarthritis.
Although most degenerative meniscus tears don’t need surgery, there are always some cases where surgery is going to be more effective than physiotherapy. Some menisci tears can either ‘stick-up’ into the joint or ‘break-off.’ In cases like these the tear can cause the knee to lock when trying to bend or straighten, and surgery is recommended to remove the tear.
What will my physiotherapist work on during my rehabilitation?
The first thing your physiotherapist will undertake is a full assessment of not only your knee, but your legs and even your back to see if you pain is coming from your meniscus or from somewhere else.
If you have hurt your meniscus recently your physiotherapist will start treatment aiming to reduce the swelling and begin to return it to its full range of movement.
If you have full range of movement and no swelling in your knee joint your physiotherapist will begin an exercise program focused on strengthening the muscles around your knee, and from around your hip. Weak quadriceps muscle has been found to place a greater load on your knee joint and your meniscus. Strengthening these muscle groups can reduce the pressure on the meniscus during movement. Weakness in your bottom (gluteal) muscles can also affect your knee function. Weakness in the gluteal muscles is known to place more load through the inside of the knee, which is where the majority of medial injuries occur. Strengthening the quadriceps and gluteal muscles will contribute to reducing the pressure on the knee.
Degenerative meniscus tears areas common as wrinkles and grey hair as you grow older. Although surgery is sometimes required for some knee injuries it often is not the only or best option in most cases. For most knee injuries involving the menisci the best anti-aging medicine is physical activity and exercise.