meniscus injury anatomy
The meniscus is a “C” shaped “shock absorber” which lies between the thigh bone (femur) and the shin bone (tibia). There is a meniscus on the inner (medial) side of the knee and one on the outer (lateral) side of the knee. Meniscal Injury to either the medial meniscus or the lateral meniscus are common and are often referred to as a “torn cartilage”.
Articular cartilage covers the ends of the bones that make up the joint. The articular cartilage surface is a tough, slick material that allows the surfaces to slide against one another without damaging either surface. The ability of the meniscus to spread out the force on the joint surfaces as we walk and run is important because it protects the articular cartilage from excessive forces occurring in any one area on the joint surface. Without the meniscus, the concentration of force into a small area on the articular cartilage would damage the surface, leading to meniscus injury and degeneration over time. chronic injury of the meniscus will lead to knee arthritis.
The meniscus also helps with stability of the knee joint, since it converts the tibial surface into a shallow socket. A socket configuration is more stable than a flat surface, as shown below.
Without the meniscus, the round femur would slide freely on top of the flat tibial surface.
Meniscus injury will often result in pain and swelling in the knee. If the torn piece of meniscus is large, it may cause the knee to catch, lock, or give way.
Catching occurs when the torn fragment briefly lodges between the bones then works its way out. If the fragment does not work its way out the knee will remain “locked”, meaning the knee cannot fully bend or straighten. Locking can be brief (lasting seconds or minutes) or persistent (lasting weeks). Giving way occurs when the torn piece of meniscus slips out of place which causes pain and reflex relaxation of the thigh muscles. When the muscles relax the knee “gives way” or “gives out.”
Remember that virtually all meniscus injury problems happen at the contact phase of gait (when the foot hits the ground) due to increased biomechanical stress at this point.
Golden rule- Don’t ignore the problem, it won’t go away
The way we function biomechanically is predominantly controlled by genetics, its hereditary (runs in the family). The way you function is set and cannot be cured. What you can do however is control lower limb biomechanics by altering foot position during the contact phase of gait. This can be achieved by wearing a good shoe (see our shoe guide) with orthotics (foot beds), knee strengthening and knee support.
1. Check your footwear
Are your running shoes worn and in need of replacing? If so change them. The chances of meniscus injury is greatly increased with higher impact forces so a good shock absorbing shoe is a must. For more advice on running trainers our running shoe advice page is worth reading. Read more->
Below are a selection of trainers that are ideal for athletes.
Trainers for a neutral or under pronating foot type
Trainers for over pronators
2. rectify Poor biomechanics with orthotics
The way your foot strikes the ground and the forces that are placed on it can have a direct effect on biomechanics causing meniscus injury and can also delaying healing times. Check our biomechanics page for detailed information. Read more->
3. Knee strengthening
The single best exercise to improve the strength of the muscles around the knee is eccentric loading. This is usually done none weight bearing, however the use of a wobbleboard is an excellent way to strengthen muscles around the knee, foot and ankle in a controlled gentle manner. Whilst our clinicians have found it a brilliant way to strengthen muscles around the knee, traditionally a wobbleboard was used to help balance (proprioception). Proprioception is the nerve connection from the brain to the foot. This is often damaged/ disrupted after injury and can increase the chances of injury from recurring. It can also significantly delay recovery.
Use of a wobbleboard therefore has a dual benefit in the treatment of meniscus injury.
4. Knee support
Consider purchasing a knee brace . This device provides extra stability to the knee when playing sports. The material also causes localised vasodilation (opening of the blood vessels) increasing circulation to the area. This is vital as the knee structures have a notoriously poor blood supply. Increasing circulation to the ligaments can reduce the chance of injury. Extra stability will reduce the chances of irritation and damage to the meniscus.
Meniscus injury prevention checklist summary
- Rectify Biomechanics if necessary
- Check Running shoes
- Knee strengthening
- Knee support
Returning to Activity
The goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your meniscus injury, which could lead to permanent damage. Everyone recovers from meniscal injury at a different rate. Returning to your activity is determined by how soon your meniscus recovers, not by how many days or weeks it has been since your meniscus injury occurred
You may safely return to your sport or activity when, starting from the top of the list and progressing to the end, each of the following is true:
You have full range of motion in the injured leg compared to the uninjured leg.
You have full strength of the injured leg compared to the uninjured leg.
You can jog straight ahead without meniscus injury pain.
You can sprint straight ahead without meniscal injury pain.
You can do 45-degree cuts, first at half-speed, then at full-speed.
You can do 20-yard figures-of-eight, first at half-speed, then at full-speed.
You can do 90-degree cuts, first at half-speed, then at full-speed.
You can do 10-yard figures-of-eight, first at half-speed, then at full-speed.
You can jump on both legs without pain and you can jump on the injured leg without pain.
If a torn meniscus does not heal, and pain, swelling or intermittent catching persists, arthroscopic (keyhole) surgery may be necessary.
Video below of meniscus surgery