What is a Meniscus Injury?
The Meniscus is a cartilage which sits within your knee joint. There is two menisci within the knee, including the medial (the one which sits on the inside of your knee) and the lateral (which sits on the outer part of your knee). The primary role of the meniscus is to act as a shock absorber of the knee and protect the underlying cartilage from loading.
Whilst injury to the meniscus often occurs with a specific mechanism, this isn't always the case and can occur as a byproduct of degenerative changes in the knee or poor patterning throughout the knee.
Not all meniscus injuries are the same, and can differ in location and severity. Types of meniscus injuries include bucket handle, horizontal flap, radial, parrot beak, posterior horn, complex and vertical longitudinal tears.
How do I know if I have a Meniscus Injury?
Due to the differences in both how Menisci can be injured and the location of the injury, symptoms can be variable. Possible symptoms include;
Catching or locking of knee: Often significant locking or catching of the knee is an indication of a more severe injury, particularly if you're unable to fully straighten your knee.
Pain when bending and twisting: Compressive and rotation loading to the knee is a common complaint following meniscus injury.
Swelling: This is not consistent however, as only one-third of the meniscus has a rich blood supply.
Gold standard in diagnosis of Meniscus injury is MRI, both an X-Ray or Ultrasound does not provide information regarding this structure. That being said, referral for an MRI is not always necessary if symptoms are low grade as the result will often not change management.
What are my management options?
In general, preserving the meniscus is preferred due to its role in protecting the underlying cartilage. There is research that demonstrates cleaning up and removing parts of the meniscus following a tear accelerates osteoarthritis to the knee. Many tears do not require surgical management in order to return to full function.
Protection / Improve Symptoms: During the phase, the priority is to allow the knee to settle following the development of symptoms. Basic injury management principles including icing, compression and elevation can be useful at this stage. Rehabilitation is often conservative with minimal weigh-bearing loading through the knee. That being said, there is often work which can be done for the calf the glute to preserve strength whilst the knee is settling from the acute injury.
Load Introduction: This is a key phase to re-introduce key movement patterns which are loaded in later stages and also relate to athletic movement. A concept which is vital in rehabilitation is preventing knee valgus (which is the position which the knee buckles in) or foot turn out (see here). Hence reintroducing squatting, lunging and similar single leg exercise is important with a particular emphasis on control. The glute and foot intrinsic muscles also have a role to play here in preventing the knee from collapsing into this position.
Strength Development: A byproduct of this injury is residual weakness that occurs from the injury. Restoring this is an important component to fully rehabilitate the knee and restore full function for squatting, climbing stairs or running. For those returning to sport, we also want to build capacity into the knee so it does not collapse into valgus when under fatigue.
Speed & Power: As always, returning to sport means the requirement to accelerate, change direction and sprint. Poor control of the foot or hip can result in additional rotation loads to the knee which can provoke meniscus injuries. Hence this phase often includes a range of running technique and change of direction drills to develop control in these positions. We also want to restore lower limb power and explosive capacity as this relates highly to sports performance.
Unfortunately not all meniscus injuries can restore to full function with non-surgical management. Injuries with significant pain, instability, catching or locking symptoms can result in the need for a surgical opinion. The type, location and extent of tear all are taken into consideration into surgical management.